WorldWideScience

Sample records for deg delta wings

  1. Surface-Pressure and Flow-Visualization Data at Mach Number of 1.60 for Three 65 deg Delta Wings Varying in Leading-Edge Radius and Camber

    Science.gov (United States)

    McMIllin, S. Naomi; Byrd, James E.; Parmar, Devendra S.; Bezos-O'Connor, Gaudy M.; Forrest, Dana K.; Bowen, Susan

    1996-01-01

    An experimental investigation of the effect of leading-edge radius, camber, Reynolds number, and boundary-layer state on the incipient separation of a delta wing at supersonic speeds was conducted at the Langley Unitary Plan Wind Tunnel at Mach number of 1.60 over a free-stream Reynolds number range of 1 x 106 to 5 x 106 ft-1. The three delta wing models examined had a 65 deg swept leading edge and varied in cross-sectional shape: a sharp wedge, a 20:1 ellipse, and a 20:1 ellipse with a -9.750 circular camber imposed across the span. The wings were tested with and without transition grit applied. Surface-pressure coefficient data and flow-visualization data are electronically stored on the CD-ROM. The data indicated that by rounding the wing leading edge or cambering the wing in the spanwise direction, the onset of leading-edge separation on a delta wing can be raised to a higher angle of attack than that observed on a sharp-edged delta wing. The data also showed that the onset of leading-edge separation can be raised to a higher angle of attack by forcing boundary-layer transition to occur closer to the wing leading edge by the application of grit or the increase in free-stream Reynolds number.

  2. Effect of leading- and trailing-edge flaps on clipped delta wings with and without wing camber at supersonic speeds

    Science.gov (United States)

    Hernandez, Gloria; Wood, Richard M.; Covell, Peter F.

    1994-01-01

    An experimental investigation of the aerodynamic characteristics of thin, moderately swept fighter wings has been conducted to evaluate the effect of camber and twist on the effectiveness of leading- and trailing-edge flaps at supersonic speeds in the Langley Unitary Plan Wind Tunnel. The study geometry consisted of a generic fuselage with camber typical of advanced fighter designs without inlets, canopy, or vertical tail. The model was tested with two wing configurations an uncambered (flat) wing and a cambered and twisted wing. Each wing had an identical clipped delta planform with an inboard leading edge swept back 65 deg and an outboard leading edge swept back 50 deg. The trailing edge was swept forward 25 deg. The leading-edge flaps were deflected 4 deg to 15 deg, and the trailing-edge flaps were deflected from -30 deg to 10 deg. Longitudinal force and moment data were obtained at Mach numbers of 1.60, 1.80, 2.00, and 2.16 for an angle-of-attack range 4 deg to 20 deg at a Reynolds number of 2.16 x 10(exp 6) per foot and for an angle-of-attack range 4 deg to 20 deg at a Reynolds number of 2.0 x 10(exp 6) per foot. Vapor screen, tuft, and oil flow visualization data are also included.

  3. Survey of research on unsteady aerodynamic loading of delta wings

    Science.gov (United States)

    Ashley, H.; Vaneck, T.; Katz, J.; Jarrah, M. A.

    1991-01-01

    For aeronautical applications, there has been recent interest in accurately determining the aerodynamic forces and moments experienced by low-aspect-ratio wings performing transient maneuvers which go to angles of attack as high as 90 deg. Focusing on the delta planform with sharp leading edges, the paper surveys experimental and theoretical investigations dealing with the associated unsteady flow phenomena. For maximum angles above a value between 30 and 40 deg, flow details and airloads are dominated by hysteresis in the 'bursting' instability of intense vortices which emanate from the leading edge. As examples of relevant test results, force and moment histories are presented for a model series with aspect ratios 1, 1.5 and 2. Influences of key parameters are discussed, notably those which measure unsteadiness. Comparisons are given with two theories: a paneling approximation that cannot capture bursting but clarifies other unsteady influences, and a simplified estimation scheme which uses measured bursting data.

  4. Survey of research on unsteady aerodynamic loading of delta wings

    Science.gov (United States)

    Ashley, H.; Vaneck, T.; Katz, J.; Jarrah, M. A.

    1991-01-01

    For aeronautical applications, there has been recent interest in accurately determining the aerodynamic forces and moments experienced by low-aspect-ratio wings performing transient maneuvers which go to angles of attack as high as 90 deg. Focusing on the delta planform with sharp leading edges, the paper surveys experimental and theoretical investigations dealing with the associated unsteady flow phenomena. For maximum angles above a value between 30 and 40 deg, flow details and airloads are dominated by hysteresis in the 'bursting' instability of intense vortices which emanate from the leading edge. As examples of relevant test results, force and moment histories are presented for a model series with aspect ratios 1, 1.5 and 2. Influences of key parameters are discussed, notably those which measure unsteadiness. Comparisons are given with two theories: a paneling approximation that cannot capture bursting but clarifies other unsteady influences, and a simplified estimation scheme which uses measured bursting data.

  5. Nonlinear, unsteady aerodynamic loads on rectangular and delta wings

    Science.gov (United States)

    Atta, E. H.; Kandil, O. A.; Mook, D. T.; Nayfeh, A. H.

    1977-01-01

    Nonlinear unsteady aerodynamic loads on rectangular and delta wings in an incompressible flow are calculated by using an unsteady vortex-lattice model. Examples include flows past fixed wings in unsteady uniform streams and flows past wings undergoing unsteady motions. The unsteadiness may be due to gusty winds or pitching oscillations. The present technique establishes a reliable approach which can be utilized in the analysis of problems associated with the dynamics and aeroelasticity of wings within a wide range of angles of attack.

  6. Feedback Linearization Controller Of The Delta WingRock Phenomena

    Directory of Open Access Journals (Sweden)

    Mohammed Alkandari

    2015-05-01

    Full Text Available This project deals with the control of the wing rock phenomena of a delta wing aircraft. a control schemeis proposed to stabilize the system. The controlleris a feedback linearization controller. It is shown that the proposed control scheme guarantee the asymptotic convergence to zero of all the states of the system. To illustrate the performance of the proposed controller, simulation results are presented and discussed. It is found that the proposed control scheme work well for the wing rock phenomena of a delta wing aircraft.

  7. Radio identification of decameter-wave sources. II: The 30deg<40deg declination interval

    CERN Document Server

    Verkhodanov, O V; Andernach, H; 10.1134/S1990341309010052

    2009-01-01

    This paper is dedicated to the identification of decameter-wave sources of the UTR catalog within declination interval 30deg<40deg. UTR sources are cross-identified with CATS database catalogs within 40'x40' error boxes. The sources are deblended using the data on the coordinates of the objects and the behavior of their continuum radio spectra. The spectra of 876 sources are derived and fitted by standard analytical functions. Of these sources, 221 objects have straight-line spectra with spectral indices alpha<-1.0. All objects are catalogued and stored in the CATS database.

  8. The leading-edge vortex of swift wing-shaped delta wings.

    Science.gov (United States)

    Muir, Rowan Eveline; Arredondo-Galeana, Abel; Viola, Ignazio Maria

    2017-08-01

    Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the leading-edge vortex (LEV) for lift generation in a variety of flight conditions. A well-documented example of an LEV is that generated by aircraft with highly swept, delta-shaped wings. While the wing aerodynamics of a manoeuvring aircraft, a bird gliding and a bird in flapping flight vary significantly, it is believed that this existing knowledge can serve to add understanding to the complex aerodynamics of natural fliers. In this investigation, a model non-slender delta-shaped wing with a sharp leading edge is tested at low Reynolds number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus. The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the unmodified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift wing-shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta-shaped wing.

  9. Vortex lift augmentation by suction on a 60 deg swept Gothic wing

    Science.gov (United States)

    Taylor, A. H.; Jackson, L. R.; Huffman, J. K.

    1982-01-01

    An experimental investigation was conducted in the Langley high-speed 7- by 10-foot wind tunnel to determine the aerodynamic performance of suction applied near the wing tips above the trailing edge of a 60 deg swept Gothic wing. Moveable suction inlets were symmetrically mounted in the proximity of the trailing edge, and the amount of suction was varied to maximize wing lift. Tests were conducted at Mach 0.15, 0.30, and 0.45, and the angle of attack was varied from -4 to 50 deg. The suction augmentation increases the lift coefficient over the entire range of angle of attack. The lift improvement exceeds the unaugmented wing lift by over 20%. Moreover, the augmented lift exceeds the lift predicted by vortex lattice theory to 30 deg angle of attack. Suction augmentation is postulated to strengthen the vortex system by increasing its velocity and making it more concentrated. This causes the vortex breakdown to be delayed to a higher angle of attack

  10. Geology of the Delta, Escalante, Price, Richfield and Salina 1 deg x 2 deg NTMS quadrangles, Utah

    Science.gov (United States)

    Thayer, P. A.

    1981-11-01

    The National Uranium Resource Evaluation (NURE) program was established to evaluate domestic uranium resources in the continental United States and to identify areas favorable for uranium exploration. The Grand Junction Office of the Department of Energy is responsible for administering the program. The Savannah River Laboratory (SRL) is responsible for hydrogeochemical and stream-sediment reconnaissance (HSSR) of 3.9 million sq km (1,500,000 mi(2)) in 37 eastern and western states. This document provides geologic and mineral resources reports for the Delta, Escalante, Price, Richfield, and Salina 1 deg x 2 deg National Topographic Map Series quadrangles, Utah. The purpose of these reports is to provide background geologic and mineral resources information to aid in the interpretation of NURE geochemical reconnaissance data. Except for the Escalante Quadrangle, each report is accompanied by a geologic map and a mineral locality map (Plates 1-8, in pocket).

  11. Effect of leading edge roundness on a delta wing in wing-rock motion

    Science.gov (United States)

    Ng, T. Terry; Malcolm, Gerald N.

    1990-01-01

    The effect of wing leading-edge roundness on wing rock was investigated using flow visualization in a water tunnel. Eighty degree delta wing models were tested on free-to-roll and forced oscillation rigs. The onset of wing rock was delayed by increasing the roundness of the leading edges. The wing rock amplitude and frequency results suggested that damping was increased at lower angles of attack but reduced at higher angles of attack. Vortex lift-off and vortex breakdown, especially during dynamic situations, were strongly affected by the leading edge roundness. Different forms of wing rock motion could be sustained by combinations of vortex breakdown and vortex lift-off. Behaviors of the wing and vortex motions were explained by the influence of leading edge roundness on the separation location, vortex trajectory, and vortex breakdown.

  12. A high sensitivity HI survey of the sky at delta < -25 deg Final data release

    CERN Document Server

    Bajaja, E; Larrarte, J J; Morras, R; Poppel, W G L; Kalberla, P M W

    2005-01-01

    We present the final data release of the high sensitivity lambda 21-cm neutral hydrogen survey of the sky south of delta < -25 degr. A total of 50980 positions lying on a galactic coordinate grid with points spaced by (Delta l, Delta b) = ((0.5 deg)/cos b, 0.5 deg) were observed with the 30-m dish of the Instituto Argentino de Radioastronomia (IAR). The angular resolution of the survey is HPBW = 0.5 deg and the velocity coverage spans the interval -450 km/s to +400 km/s (LSR). The velocity resolution is 1.27 km/s and the final rms noise of the entire database is 0.07 K. The data are corrected for stray radiation and converted to brightness temperatures.

  13. Static measurements of slender delta wing rolling moment hysteresis

    Science.gov (United States)

    Katz, Joseph; Levin, Daniel

    1991-01-01

    Slender delta wing planforms are susceptible to self-induced roll oscillations due to aerodynamic hysteresis during the limit cycle roll oscillation. Test results are presented which clearly establish that the static rolling moment hysteresis has a damping character; hysteresis tends to be greater when, due to either wing roll or side slip, the vortex burst moves back and forth over the wing trailing edge. These data are an indirect indication of the damping role of the vortex burst during limit cycle roll oscillations.

  14. The Mechanism of Aerodynamic Hysteresis for Sinusoidally Oscillating Delta Wings

    Institute of Scientific and Technical Information of China (English)

    黄国创; 王玉明; 曹桂兴

    1994-01-01

    An unsteady model of vortex system is developed to simulate the phenomena of aerodynamic hysteresis of sinusoidally oscillating delta wings.The dynamic behavior of leading-edge separation vortices simulated by the present method is in qualitative agreement with that of flow visualization by Gad-el-Hak and Ho.The calculated lift hysteresis loops are in quantitative agreement with the force measurements in the tunnel.The aerodynamic mechanism of the hysteresis phenomena is further investigated by the present method.

  15. A flow visualization and aerodynamic force data evaluation of spanwise blowing on full and half span delta wings

    Science.gov (United States)

    Visser, K. D.; Nelson, R. C.; Ng, T. T.

    1989-01-01

    A wind-tunnel investigation has been performed to quantify the effects of a jet on the leading-edge vortices generated by a 70-deg-sweep sharp-edged delta wing at low Reynolds numbers. Efforts were made ot optimize the jet nozzle position with respect to maximum lift increments. Both half-span force-balance testing and half- and full-span flow visualization tests were conducted. Two angles of attack were investigated, 30 and 35 deg, at Reynolds numbers of 150,000 and 200,000. Aerodynamic enhancement, including lift and drag gains of about 20 and 17 percent respectively, were measured. Results indicate an optimum jet nozzle location to be close to the leading edge, tangent to the upper wing surface, and in a direction aligned parallel to the leading edge. Nozzle interference effects, especially near the apex, were not negligible.

  16. A three-dimensional boundary-layer method for flow over delta wings with leading-edge separation

    Science.gov (United States)

    Woodson, S. H.; Dejarnette, F. R.

    1985-01-01

    A three-dimensional, laminar boundary-layer method is applied to the incompressible flow over a slender delta wing at incidence. The predictor-corrector finite-difference scheme of Matsuno is used to difference the governing equations. The method has the advantages that no iterations are required to advance the solution and the cross-flow derivatives are formed independent of the cross-field direction. The difference scheme is demonstrated to yield accurate numerical results when compared to the exact solution of the three-dimensional boundary-layer equations for parabolic flow over a moving flat plate. The method is applied to delta wings of various sweep angles at angles of attack up to 20 deg., with the inviscid solution determined using a higher-order, three-dimensional panel method.

  17. Thin-Layer Navier-Stokes Solutions for a Cranked Delta Wing

    Science.gov (United States)

    1988-12-01

    and Purcell C., "Numerical Experiment with Inviscid Vortex- Streched Flow Around a Cranked Delta Wing: Supersonic Speed", Engineering Cns. Vol 3: pp...230-234, (1986). 8_! 16. Rizzi A. and Purcell C., "Numerical Experiment with Inviscid Vortex- Streched Flow Around a Cranked Delta Wing: Subsonic Speed

  18. 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.

  19. A 20 GHz Bright Sample for Delta > 72 deg - II. Multi-frequency Follow-up

    CERN Document Server

    Ricci, R; Verma, R; Prandoni, I; Carretti, E; Mack, K -H; Massardi, M; Procopio, P; Zanichelli, A; Gregorini, L; Mantovani, F; Gawronski, M P; Peel, M W

    2013-01-01

    We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz Bright Sample, performed with the 32-m Medicina Radio Telescope and the 32-m Torun Radio Telescope. The KNoWS sources were selected in the Northern Polar Cap (Delta > 72 deg) and have a flux density limit S(20GHz) = 115 mJy. We include NVSS 1.4 GHz measurements to derive the source radio spectra between 1.4 and 30 GHz. Based on optical identifications, 68 per cent of the sources are QSOs, and 27 per cent are radio galaxies. A redshift measurement is available for 58 per cent of the sources. The radio spectral properties of the different source populations are found to be in agreement with those of other high-frequency selected samples.

  20. Development of Delta Wing Aerodynamics Research in Universiti Teknologi Malaysia Low Speed Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Shabudin Mat

    2014-07-01

    Full Text Available This paper presents wind tunnel experiment on two delta wing configurations which are differentiated by their leading edge profiles: sharp and round-edged wings. The experiments were performed as a part of the delta wing aerodynamics research development in Universiti Teknologi Malaysia, low speed tunnel (UTM-LST. Steady load balance and flow visualization tests were conducted at Reynolds numbers of 0.5, 1, and 1.5 × 106, respectively. The flow measurement at low Reynolds number was also performed at as low as speed of 5 m/s. During the experiments, laser with smoke flow visualizations test was performed on both wings. The study has identified interesting features of the interrelationship between the conventional leading edge primary vortex and the occurrence and development of the vortex breakdown above the delta wings. The results conclude the vortex characteristics are largely dependent on the Reynolds number, angle of attack, and leading-edge radii of the wing.

  1. Effects of flexibility on aerodynamic performance of delta wings with different sweep angles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Force measurement and surface oil flow visualization experiments were conducted in a wind tunnel to investigate the effects of flexibility on aerodynamic performance of delta wings with different sweep angles.The experimental results indicate that the maximum lift coefficient is increased and the stall angle is delayed as the sweep angle increases for both rigid and flexible wings.It is also found that the maximum lift coefficients of the flexible wings with a sweep angle from 35° to 50° are higher than those of the rigid ones.The increment of the maximum lift coefficient in particular achieves 32.9% compared with the case without lift enhancement for the 40° flexible delta wing.Moreover,the surface oil flow visualization experiments show that the stall of the flexible wing of the moderate low sweep angle is accompanied by helical flow structure,while the vortex bursting appears on the corresponding rigid wing.

  2. A 20 GHz bright sample for {\\delta} > +72{\\deg}: I. Catalogue

    CERN Document Server

    Righini, S; Ricci, R; Zanichelli, A; Mack, K -H; Massardi, M; Prandoni, I; Procopio, P; Verma, R; López-Caniego, M; Gregorini, L; Mantovani, F

    2012-01-01

    During 2010-2011, the Medicina 32-m dish hosted the 7-feed 18-26.5 GHz receiver built for the Sardinia Radio Telescope, with the goal to perform its commissioning. This opportunity was exploited to carry out a pilot survey at 20 GHz over the area for {\\delta} > + 72.3{\\deg}. This paper describes all the phases of the observations, as they were performed using new hardware and software facilities. The map-making and source extraction procedures are illustrated. A customised data reduction tool was used during the follow-up phase, which produced a list of 73 confirmed sources down to a flux density of 115 mJy. The resulting catalogue, here presented, is complete above 200 mJy. Source counts are in agreement with those provided by the AT20G survey. This pilot activity paves the way to a larger project, the K-band Northern Wide Survey (KNoWS), whose final aim is to survey the whole Northern Hemisphere down to a flux limit of 50 mJy (5{\\sigma}).

  3. Vortex Breakdown over Slender Delta Wings (Eclatement tourbillonnaire sur les ailes delta effil es)

    Science.gov (United States)

    2009-11-01

    Velocity Component VB 21-33 A.4 Tangential Velocity Component WB 21-34 A.5 Axial Velocity Induced on the Centreline 21-34 A.6 Numerical...Three Dimensional Vortex Sheet Structure on Delta Wings,” AGARD-CP-438, October 1988. [59] Brandon, J.M. and Shah , G.H., “Effect of Large Amplitude...TR-AVT-080 5 - 25 403020100-10-20-30-40 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 dynamic Static ( σ=30°, ∆φ=33°, =0.14 )k φ° x VB 15c15c 403020100-10

  4. Numerical simulations of leading-edge vortex core axial velocity for flow over delta wings

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Numerical simulations have been performed to investigate the characteristics of leading-edge vortex core axial velocity over two delta wings with leading edge swept angles Λ =50°and 76°, respectively. It is obtained that Reynolds number has the most important effect on the axial velocity of the primary leading-edge vortex core. At Reynolds numbers larger than 105, the jet-like flow of the vortex core is the most common type for both the large and the moderate swept delta wings. While if Reynolds number decreases to 103―104, the core axial velocity distributions for these two delta wings present the wake-like profile for all angles of attack considered in the present investigation.

  5. Reactive Flow Control of Delta Wing Vortex (Postprint)

    Science.gov (United States)

    2006-08-01

    Passive vortex control devices such as vortex generators and winglets attach to the wing and require no energy input. Passive vortex control...width. The dynamic test parameters are summarized in Table 2. The composite duty cycle input signal is denoted ( ) ( )ou t u u tδ= + in which ou

  6. Flow over 50º Delta Wings with Different Leading-Edge Radii

    NARCIS (Netherlands)

    Verhaagen, N.G.

    2011-01-01

    The experimental study focuses on the effects of the leading-edge radius on the flow over 50º swept delta wing models. Three models were tested, one model has a sharp leading edge and two other have a semi-circular leading edge of different radius. The vortical flow on and off the surface of the mod

  7. Effects of Leading-Edge Radius on Aerodynamic Characteristics of 50º Delta Wings

    NARCIS (Netherlands)

    Verhaagen, N.G.

    2010-01-01

    The study focuses on the effects of the leading-edge radius on the flow over 50º swept delta wing models. Three models were tested, one model having a sharp leading edge and the other two having a semi-circular leading edge of different radius. The vortical flow on and off the surface of the models

  8. Experimental investigation of high-incidence delta-wing flow control

    Science.gov (United States)

    Buzica, Andrei; Bartasevicius, Julius; Breitsamter, Christian

    2017-09-01

    The possibility of extending the flight envelope for configurations with slender delta-shaped wings is investigated in this study by means of active flow control through pulsating jets from slot pairs distributed along the leading edge. The experiments comprise stereoscopic particle image velocimetry as well as force and moment measurements on a half-delta wing model. The analysis focuses on three high-incidence regimes: pre-stall, stall, and post-stall. This study also compares different perturbation methods: blowing with spatially constant and variable parameters, frequency and phase. At an incidence of 45^circ, the unison pulsed blowing facilitates the most significant flow transformation. Here, the separated shear layer reattaches on the wing's suction side, thus increasing the lift. Phase-averaged flow field measurements describe, in this particular case, the underlying physics of the flow-disturbance interaction.

  9. A Study On Recent Trends In High Subsonic Flow Over Delta Wings .

    Directory of Open Access Journals (Sweden)

    Vishnu G Nair,

    2014-01-01

    Full Text Available An understanding of the vortical structures and vortex breakdown is essential for the development of highly maneuverable and high angle of attack flight. This is primarily due to the physical limits these phenomena impose on aircraft and missiles at extreme flight conditions. In today’s competitive world, demands for more maneuverable and stealthy air vehicles have encouraged the development of new control concepts for separated flows and vortex flow.An overview is given about investigations on a 65◦ delta wing using the Pressure Sensitive Paint (PSP and Particle Image Velocimetry (PIV techniques, carried out in the framework of Vortex flow experiment. For the delta wing with rounded leading edges and subsonic flow, the occurrence of a flat vortical structure as well as the onset of the primary vortex and the development of a vortex system consisting of an inner and outer vortex is described in dependency of the angle of attack and the Reynolds number. The Q - criterion is applied to the measured velocity data to estimate the circulation strength of individual vortices allowing for a quantitative description of the vortex developments and interactions. Furthermore, a case at transonic flow speeds (M = 0.8 is described, showing a sudden occurrence of vortex breakdown above the delta wing, most probably induced by a shock wave.Vortex Flow Experiment provided a variety of experimental data for a 65◦ swept delta wing sharp and blunt leading edges. Flow details including forces and moments, surface pressures,Pressure Sensitive Paint measurements, and off-surface flow variables from Particle Image Velocimetry were made available for comparisons with computational simulations. This paper concentrates on some typical problems of delta wings with rounded leading edges at subsonic speed: the prediction of the main leading edge separation, the generation of the second inner vortex, the effect of transition, and Reynolds number effects.

  10. Analytical and Experimental Investigations of Delta Wings in Incompressible Flow

    Science.gov (United States)

    1976-08-01

    redi’otions and to indicate aspects requtring special 3 tterti-;r, thec-eticalLy :r experientally . Tie available experi-ental evidence leads one to believe... Communicated by Dr. J.P. Jones", A.R.C. 24, 118, 1963. 40. Randall, D.G., "Oscillating Slender Wings in the Presence of Leading Edge Separation", R.A.E

  11. Monostatic radar cross section of flying wing delta planforms

    Directory of Open Access Journals (Sweden)

    Sevoor Meenakshisundaram Vaitheeswaran

    2017-04-01

    Full Text Available The design of the flying wing and its variants shapes continues to have a profound influence in the design of the current and future use of military aircraft. There is very little in the open literature available to the understanding and by way of comparison of the radar cross section of the different wing planforms, for obvious reasons of security and sensitivity. This paper aims to provide an insight about the radar cross section of the various flying wing planforms that would aid the need and amount of radar cross section suppression to escape detection from surveillance radars. Towards this, the shooting and bouncing ray method is used for analysis. In this, the geometric optics theory is first used for launching and tracing the electromagnetic rays to calculate the electromagnetic field values as the waves bounce around the target. The physical optics theory is next used to calculate the final scattered electric field using the far field integration along the observation direction. For the purpose of comparison, all the planform shapes are assumed to be having the same area, and only the aspect ratio and taper ratio are varied to feature representative airplanes.

  12. Experimental study of flow field distribution over a generic cranked double delta wing

    Directory of Open Access Journals (Sweden)

    Mojtaba Dehghan Manshadi

    2016-10-01

    Full Text Available The flow fields over a generic cranked double delta wing were investigated. Pressure and velocity distributions were obtained using a Pitot tube and a hot wire anemometer. Two different leading edge shapes, namely “sharp” and “round”, were applied to the wing. The wing had two sweep angles of 55° and 30°. The experiments were conducted in a closed circuit wind tunnel at velocity 20 m/s and angles of attack of 5°–20° with the step of 5°. The Reynolds number of the model was about 2 × 105 according to the root chord. A dual vortex structure was formed above the wing surface. A pressure drop occurred at the vortex core and the root mean square of the measured velocity increased at the core of the vortices, reflecting the instability of the flow in that region. The magnitude of power spectral density increased strongly in spanwise direction and had the maximum value at the vortex core. By increasing the angle of attack, the pressure drop increased and the vortices became wider; the vortices moved inboard along the wing, and away from the surface; the flow separation was initiated from the outer portion of the wing and developed to its inner part. The vortices of the wing of the sharp leading edge were stronger than those of the round one.

  13. Unsteady surface pressure measurements on a slender delta wing undergoing limit cycle wing rock

    Science.gov (United States)

    Arena, Andrew S., Jr.; Nelson, Robert C.

    1991-01-01

    An experimental investigation of slender wing limit cycle motion known as wing rock was investigated using two unique experimental systems. Dynamic roll moment measurements and visualization data on the leading edge vortices were obtained using a free to roll apparatus that incorporates an airbearing spindle. In addition, both static and unsteady surface pressure data was measured on the top and bottom surfaces of the model. To obtain the unsteady surface pressure data a new computer controller drive system was developed to accurately reproduce the free to roll time history motions. The data from these experiments include, roll angle time histories, vortex trajectory data on the position of the vortices relative to the model's surface, and surface pressure measurements as a function of roll angle when the model is stationary or undergoing a wing rock motion. The roll time history data was numerically differentiated to determine the dynamic roll moment coefficient. An analysis of these data revealed that the primary mechanism for the limit cycle behavior was a time lag in the position of the vortices normal to the wing surface.

  14. Effects of leading-edge flap oscillation on unsteady delta wing flow and rock control

    Science.gov (United States)

    Kandil, Osama A.; Salman, Ahmed A.

    1991-01-01

    The isolated and interdisciplinary problems of unsteady fluid dynamics and rigid-body dynamics and control of delta wings with and without leading-edge flap oscillation are considered. For the fluid dynamics problem, the unsteady, compressible, thin-layer Navier-Stokes (NS) equations, which are written relative to a moving frame of reference, are solved along with the unsteady, linearized, Navier-displacement (ND) equations. The NS equations are solved for the flowfield using an implicit finite-volume scheme. The ND equations are solved for the grid deformation, if the leading-edge flaps oscillate, using an ADI scheme. For the dynamics and control problem, the Euler equation of rigid-body rolling motion for a wing and its flaps are solved interactively with the fluid dynamics equations for the wing-rock motion and subsequently for its control. A four-stage Runge-Kutta scheme is used to explicitly integrate the dynamics equation.

  15. Review of delta wing space shuttle vehicle dynamics

    Science.gov (United States)

    Reding, J. P.; Ericsson, L. E.

    1972-01-01

    The unsteady aerodynamics of the delta planform, high cross range, shuttle orbiter were investigated. It has been found that these vehicles are subject to five unsteady flow phenomena that could compromise the flight dynamics. They are: (1) leeside shock induced separation, (2) sudden leading edge stall, (3) vortex burst, (4) bow shock-flap shock interaction, (5) forebody vorticity. Trajectory shaping is seen as the most powerful means of avoiding the detrimental effects of the stall phenomena. However, stall must be fixed or controlled when traversing the stall region. The other phenomena may be controlled by carefully programmed control deflections and some configuration modification. Ways to alter the occurrence of the various flow conditions are explored.

  16. Transonic Aerodynamic Characteristics of a 45 deg Swept Wing Fuselage Model with a Finned and Unfinned Body Pylon Mounted Beneath the Fuselage or Wing, Including Measurements of Body Loads

    Science.gov (United States)

    Wornom, Dewey E.

    1959-01-01

    An investigation of a model of a standard size body in combination with a representative 45 deg swept-wing-fuselage model has been conducted in the Langley 8-foot transonic pressure tunnel over a Mach number range from 0.80 to 1.43. The body, with a fineness ratio of 8.5, was tested with and without fins, and was pylon-mounted beneath the fuselage or wing. Force measurements were obtained on the wing-fuselage model with and without the body, for an angle-of-attack range from -2 deg to approximately 12 deg and an angle-of-sideslip range from -8 deg to 8 deg. In addition, body loads were measured over the same angle-of-attack and angle-of-sideslip range. The Reynolds number for the investigation, based on the wing mean aerodynamic chord, varied from 1.85 x 10(exp 6) to 2.85 x 10(exp 6). The addition of the body beneath the fuselage or the wing increased the drag coefficient of the complete model over the Mach number range tested. On the basis of the drag increase per body, the under-fuselage position was the more favorable. Furthermore, the bodies tended to increase the lateral stability of the complete model. The variation of body loads with angle of attack for the unfinned bodies was generally small and linear over the Mach number range tested with the addition of fins causing large increases in the rates of change of normal-force coefficient and nose-down pitching-moment coefficient. The variation of body side-force coefficient with sideslip for the unfinned body beneath the fuselage was at least twice as large as the variation of this load for the unfinned body beneath the wing. The addition of fins to the body beneath either the fuselage or the wing approximately doubled the rate of change of body side-force coefficient with sideslip. Furthermore, the variation of body side-force coefficient with sideslip for the body beneath the wing was at least twice as large as the variation of this load with angle of attack.

  17. 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.

  18. Design and Analysis of Delta Wing Tilt Rotor UAV

    Directory of Open Access Journals (Sweden)

    S.Ravikanth

    2015-07-01

    Full Text Available A tilt rotor is an aircraft of a special kind, which possesses the characteristics of a helicopter and a fixed-wing airplane. However, there are a great number of important technical problems waiting for settlements. Of them, the flight control system might be a critical one. A tiltrotor aircraft comprising a pair of contra-rotating co-axial tiltable rotors on the longitudinal center line of the aircraft. The rotors may be tiltable sequentially and independently. They may be moveable between a lift position and a flight position in front of or behind the fuselage.In this paper we present a project aimed for the designing of a small scale Unmanned Aerial Vehicle (UAV with Tiltrotor configuration (that uses two rotating rotors. he current paper describes the adopted design methodology, the mathematical and computational models created to represent the UAV, the physical components that constitute the UAV, and the results obtained so far. An unmanned aerial vehicle (UAV, also known as a remotely piloted aircraft (RPA or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously. A UAV is defined as a powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry payload.India‘s requirement of these unmanned aerial vehicles (UAV has become prior need for fighting in the northeast, against threat of terrorism, tension along the Pakistan border and its emerging role as a regional naval power and subsequent need for surveillance. The military wants to acquire at least 1,500 unmanned systems in the next 3-4 years, ranging from man-portable drones to high-altitude, long-endurance (HALE vehicles.Indian military is using Israeli-built UAVs such as the Heron, Searcher Mk II and Harop from Israel Aerospace Industries (IAI. Till date India has mostly deployed

  19. Wind Tunnel Application of a Pressure-Sensitive Paint Technique to a Double Delta Wing Model at Subsonic and Transonic Speeds

    Science.gov (United States)

    Erickson, Gary E.; Gonzalez, Hugo A.

    2006-01-01

    A pressure-sensitive paint (PSP) technique was applied in a wind tunnel experiment in the NASA Langley Research Center 8-Foot Transonic Pressure Tunnel to study the effect of wing fillets on the global vortex induced surface static pressure field about a sharp leading-edge 76 deg./40 deg. double delta wing, or strake-wing, model at subsonic and transonic speeds. Global calibrations of the PSP were obtained at M(sub infinity) = 0.50, 0.70, 0.85, 0.95, and 1.20, a Reynolds number per unit length of 2.0 million, and angles of attack from 10 degrees to 20 degrees using an insitu method featuring the simultaneous acquisition of electronically scanned pressures (ESP) at discrete locations on the model. The mean error in the PSP measurements relative to the ESP data was approximately 2 percent or less at M(sub infinity) = 0.50 to 0.85 but increased to several percent at M(sub infinity) =0.95 and 1.20. The PSP pressure distributions and pseudo-colored, planform-view pressure maps clearly revealed the vortex-induced pressure signatures at all Mach numbers and angles of attack. Small fillets having parabolic or diamond planforms situated at the strake-wing intersection were respectively designed to manipulate the vortical flows by removing the leading-edge discontinuity or introducing additional discontinuities. The fillets caused global changes in the vortex-dominated surface pressure field that were effectively captured in the PSP measurements. The vortex surface pressure signatures were compared to available off-surface vortex cross-flow structures obtained using a laser vapor screen (LVS) flow visualization technique. The fillet effects on the PSP pressure distributions and the observed leading-edge vortex flow characteristics were consistent with the trends in the measured lift, drag, and pitching moment coefficients.

  20. Sonic boom focusing prediction and delta wing shape optimization for boom mitigation studies

    Science.gov (United States)

    Khasdeo, Nitin

    Supersonic travel over land would be a reality if new aircraft are designed such that they produce quieter ground sonic booms, no louder than 0.3 psf according to the FAA requirement. An attempt is made to address the challenging goal of predicting the sonic boom focusing effects and mitigate the sonic boom ground overpressure for delta wing geometry. Sonic boom focusing is fundamentally a nonlinear phenomenon and can be predicted by numerically solving the nonlinear Tricomi equation. The conservative time domain scheme is developed to carry out the sonic boom focusing or super boom studies. The computational scheme is a type differencing scheme and is solved using a time-domain scheme, which is called a conservative type difference solution. The finite volume method is used on a structured grid topology. A number of input signals Concorde wave, symmetric and ax symmetric ramp, flat top and typical N wave type are simulated for sonic boom focusing prediction. A parametric study is launched in order to investigate the effects of several key parameters that affect the magnitude of shock wave amplification and location of surface of amplification or "caustics surface." A parametric studies includes the effects of longitudinal and lateral boundaries, footprint and initial shock strength of incoming wave and type of input signal on sonic boom focusing. Another very important aspect to be looked at is the mitigation strategies of sonic boom ground signature. It has been decided that aerodynamic reshaping and geometrical optimization are the main goals for mitigating the ground signal up to the acceptance level of FAA. Biconvex delta wing geometry with a chord length of 60 ft and maximum thickness ratio of 5% of the chord is used as a base line model to carry out the fundamental research focus. The wing is flying at an altitude 40,000 ft with a Mach number of 2.0. Boom mitigation work is focused on investigating the effects of wing thickness ratio, wing camber ratio, wing

  1. Analytical observations on the aerodynamics of a delta wing with leading edge flaps

    Science.gov (United States)

    Oh, S.; Tavella, D.

    1986-01-01

    The effect of a leading edge flap on the aerodynamics of a low aspect ratio delta wing is studied analytically. The separated flow field about the wing is represented by a simple vortex model composed of a conical straight vortex sheet and a concentrated vortex. The analysis is carried out in the cross flow plane by mapping the wing trace, by means of the Schwarz-Christoffel transformation into the real axis of the transformed plane. Particular attention is given to the influence of the angle of attack and flap deflection angle on lift and drag forces. Both lift and drag decrease with flap deflection, while the lift-to-drag ratioe increases. A simple coordinate transformation is used to obtain a closed form expression for the lift-to-drag ratio as a function of flap deflection. The main effect of leading edge flap deflection is a partial suppression of the separated flow on the leeside of the wing. Qualitative comparison with experiments is presented, showing agreement in the general trends.

  2. Flow structures in end-view plane of slender delta wing

    Directory of Open Access Journals (Sweden)

    Sahin Besir

    2017-01-01

    Full Text Available Present investigation focuses on unsteady flow structures in end-view planes at the trailing edge of delta wing, X/C=1.0, where consequences of vortex bursting and stall phenomena vary according to angles of attack over the range of 25° ≤ α ≤ 35° and yaw angles, β over the range of 0° ≤ β ≤ 20°. Basic features of counter rotating vortices in end-view planes of delta win with 70° sweep angle, Λ are examined both qualitatively and quantitatively using Rhodamine dye and the PIV system. In the light of present experiments it is seen that with increasing yaw angle, β symmetrical flow structure is disrupted continuously. Dispersed wind-ward side leading edge vortices cover a large part of flow domain, on the other hand, lee-ward side leading edge vortices cover only a small portion of flow domain.

  3. Stability Derivatives of a Delta Wing with Straight Leading Edge in the Newtonian Limit

    Directory of Open Access Journals (Sweden)

    Asha Crasta

    2014-03-01

    Full Text Available This paper presents an analytical method to predict the aerodynamic stability derivatives of oscillating delta wings with straight leading edge. It uses the Ghosh similitude and the strip theory to obtain the expressions for stability derivatives in pitch and roll in the Newtonian limit. The present theory gives a quick and approximate method to estimate the stability derivatives which is very essential at the design stage. They are applicable for wings of arbitrary plan form shape at high angles of attack provided the shock wave is attached to the leading edge of the wing. The expressions derived for stability derivatives become exact in the Newtonian limit. The stiffness derivative and damping derivative in pitch and roll are dependent on the geometric parameter of the wing. It is found that stiffness derivative linearly varies with the pivot position. In the case of damping derivative since expressions for these derivatives are non-linear and the same is reflected in the results. Roll damping derivative also varies linearly with respect to the angle of attack. When the variation of roll damping derivative was considered, it is found it also, varies linearly with angle of attack for given sweep angle, but with increase in sweep angle there is continuous decrease in the magnitude of the roll damping derivative however, the values differ for different values in sweep angle and the same is reflected in the result when it was studied with respect to sweep angle. From the results it is found that one can arrive at the optimum value of the angle of attack sweep angle which will give the best performance.

  4. Control of Flow Structure on Non-Slender Delta Wing: Bio-inspired Edge Modifications, Passive Bleeding, and Pulsed Blowing

    Science.gov (United States)

    Yavuz, Mehmet Metin; Celik, Alper; Cetin, Cenk

    2016-11-01

    In the present study, different flow control approaches including bio-inspired edge modifications, passive bleeding, and pulsed blowing are introduced and applied for the flow over non-slender delta wing. Experiments are conducted in a low speed wind tunnel for a 45 degree swept delta wing using qualitative and quantitative measurement techniques including laser illuminated smoke visualization, particle image velocimety (PIV), and surface pressure measurements. For the bio-inspired edge modifications, the edges of the wing are modified to dolphin fluke geometry. In addition, the concept of flexion ratio, a ratio depending on the flexible length of animal propulsors such as wings, is introduced. For passive bleeding, directing the free stream air from the pressure side of the planform to the suction side of the wing is applied. For pulsed blowing, periodic air injection through the leading edge of the wing is performed in a square waveform with 25% duty cycle at different excitation frequencies and compared with the steady and no blowing cases. The results indicate that each control approach is quite effective in terms of altering the overall flow structure on the planform. However, the success level, considering the elimination of stall or delaying the vortex breakdown, depends on the parameters in each method.

  5. The lateral-directional characteristics of a 74-degree Delta wing employing gothic planform vortex flaps

    Science.gov (United States)

    Grantz, A. C.

    1984-01-01

    The low speed lateral/directional characteristics of a generic 74 degree delta wing body configuration employing the latest generation, gothic planform vortex flaps was determined. Longitudinal effects are also presented. The data are compared with theoretical estimates from VORSTAB, an extension of the Quasi vortex lattice Method of Lan which empirically accounts for vortex breakdown effects in the calculation of longitudinal and lateral/directional aerodynamic characteristics. It is indicated that leading edge deflections of 30 and 40 degrees reduce the magnitude of the wing effective dihedral relative to the baseline for a specified angle of attack or lift coefficient. For angles of attack greater than 15 degrees, these flap deflections reduce the configuration directional stability despite improved vertical tail effectiveness. It is shown that asymmetric leading edge deflections are inferior to conventional ailerons in generating rolling moments. VORSTAB calculations provide coarse lateral/directional estimates at low to moderate angles of attack. The theory does not account for vortex flow induced, vertical tail effects.

  6. DSMC calculations for the delta wing. [Direct Simulation Monte Carlo method

    Science.gov (United States)

    Celenligil, M. Cevdet; Moss, James N.

    1990-01-01

    Results are reported from three-dimensional direct simulation Monte Carlo (DSMC) computations, using a variable-hard-sphere molecular model, of hypersonic flow on a delta wing. The body-fitted grid is made up of deformed hexahedral cells divided into six tetrahedral subcells with well defined triangular faces; the simulation is carried out for 9000 time steps using 150,000 molecules. The uniform freestream conditions include M = 20.2, T = 13.32 K, rho = 0.00001729 kg/cu m, and T(wall) = 620 K, corresponding to lambda = 0.00153 m and Re = 14,000. The results are presented in graphs and briefly discussed. It is found that, as the flow expands supersonically around the leading edge, an attached leeside flow develops around the wing, and the near-surface density distribution has a maximum downstream from the stagnation point. Coefficients calculated include C(H) = 0.067, C(DP) = 0.178, C(DF) = 0.110, C(L) = 0.714, and C(D) = 1.089. The calculations required 56 h of CPU time on the NASA Langley Voyager CRAY-2 supercomputer.

  7. Low-Speed Investigation of a Full-Span Internal-Flow Jet-Augmented Flap on a High-Wing Model with a 35 deg Swept Wing of Aspect Ratio 7.0

    Science.gov (United States)

    Turner, Thomas R.

    1960-01-01

    An investigation of a full-span 17-percent-chord internal-flow jet-augmented flap on an aspect-ratio-7.0 wing with 35 deg of sweepback has been made in the Langley 300-MPH 7- by 10-foot tunnel. Blowing over the conventional elevator and blowing down from a nose jet were investigated as a means of trimming the large diving moments at the high momentum and high lift coefficients. The results of the investigation showed that the model with the horizontal tail 0.928 mean aerodynamic chord above the wing-chord plane was stable to the maximum lift coefficient. The large diving-moment coefficients could be trimmed either with a downward blowing nose jet or by blowing over the elevator. Neither the downward blowing nose jet nor blowing over the elevator greatly affected the static longitudinal stability of the model. Trimmed lift coefficients up to 8.8 with blowing over the elevator and up to 11.4 with blowing down at the nose were obtained when the flap was deflected 70 deg and the total momentum coefficients were 3.26 and 4.69.

  8. 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.

  9. A low-speed wind tunnel study of vortex interaction control techniques on a chine-forebody/delta-wing configuration

    Science.gov (United States)

    Rao, Dhanvada M.; Bhat, M. K.

    1992-01-01

    A low speed wind tunnel evaluation was conducted of passive and active techniques proposed as a means to impede the interaction of forebody chine and delta wing vortices, when such interaction leads to undesirable aerodynamic characteristics particularly in the post stall regime. The passive method was based on physically disconnecting the chine/wing junction; the active technique employed deflection of inboard leading edge flaps. In either case, the intent was to forcibly shed the chine vortices before they encountered the downwash of wing vortices. Flow visualizations, wing pressures, and six component force/moment measurements confirmed the benefits of forced vortex de-coupling at post stall angles of attack and in sideslip, viz., alleviation of post stall zero beta asymmetry, lateral instability and twin tail buffet, with insignificant loss of maximum lift.

  10. Water tunnel results of leading-edge vortex flap tests on a delta wing vehicle

    Science.gov (United States)

    Delfrate, J. H.

    1986-01-01

    A water tunnel flow visualization test on leading edge vortex flaps was conducted at the flow visualization facility of the NASA Ames Research Center's Dryden Flight Research Facility. The purpose of the test was to visually examine the vortex structures caused by various leading edge vortex flaps on the delta wing of an F-106 model. The vortex flaps tested were designed analytically and empirically at the NASA Langley Research Center. The three flap designs were designated as full-span gothic flap, full-span untapered flap, and part-span flap. The test was conducted at a Reynolds number of 76,000/m (25,000/ft). This low Reynolds number was used because of the 0.076-m/s (0.25-ft/s) test section flow speed necessary for high quality flow visualization. However, this low Reynolds number may have influenced the results. Of the three vortex flaps tested, the part-span flap produced what appeared to be the strongest vortex structure over the flap area. The full-span gothic flap provided the next best performance.

  11. Longitudinal aerodynamic characteristics at Mach numbers from 1.60 to 2.86 for a fixed-span missile with three wing planforms. [conducted in the Langley Unitary Plan wind tunnel

    Science.gov (United States)

    Spearman, M. L.; Sawyer, W. W.

    1977-01-01

    Effects of wing planform modifications on the longitudinal aerodynamic characteristics of a fixed span, maneuverable cruciform missile configuration were determined. A basic delta planform and two alternate trapezoidal planforms having progressively increasing tip chords were included. Data were obtained for angles of attack up to approximately -32 deg, model roll angles of 0 deg to 45 deg, and tail control deflections of 0 deg and -20 deg. The experimental drag due to lift was compared with linear values.

  12. The Influence of the Punched Delta Wings on Flow Pattern and Heat Transfer Characteristic in a Fin-and-Oval-Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Amnart Boonloi

    2015-01-01

    Full Text Available 3D numerical investigations are performed to study the heat transfer, friction factor, and thermal performance of a fin-and-oval heat exchanger with punched delta wings for a range of 500 ≤ Re ≤ 2500 (based on the hydraulic diameter. The influences of the punched angles, 20°, 30°, and 45°, flow directions, wing tips pointing downstream and upstream, and pitch ratios, 2, 3, 4, 5, and 6, are investigated. The results show that the use of the punched delta wings in the fin-and-oval-tube heat exchanger leads to an enhancement in the heat transfer and friction loss as compared to the plain fin for all cases (Nu/Nu0 and f/f0 higher than 1. The enhancements of the heat transfer and friction factor are around 1.01–1.22 and 1.37–2.65 times higher than the base case, respectively. The punched delta wings create the vortex flows through the test section that helps enhance the strength of the impinging flow on the tube walls. The impingement of the fluid flow is an important key to augment the heat transfer rate and thermal performance in the heat exchanger.

  13. Study on Forms of Vortex Breakdown over Delta Wing%三角翼涡破裂形态研究

    Institute of Scientific and Technical Information of China (English)

    吕志咏; 祝立国

    2004-01-01

    通过对三角翼上漩涡破裂形态及涡破裂过程的流态变化的分析,可以得到以下结论.在三角翼上,除了通常知道的螺旋破裂核泡状破裂之外,还有双螺旋、涡丝以及蛙跳另外3种破裂形态.涡破裂是一个非定常过程,在机翼形状、迎角及来流条件不变的情况下,通常可以看到涡破裂形态的变化,即从螺旋破裂逐渐转化成泡状破裂又返回到螺旋破裂的过程.泡状破裂可以认为是螺旋破裂的一种特殊阶段.它与螺旋破裂并没有本质上的区别.从形态上看,泡状破裂中会出现涡核分叉,涡核中分离出一些带有涡量的流体微团,但总有一根涡丝(一部分涡核),自始至终存在,它或者表现成螺旋形态,或者由于自身的诱导形成了较复杂的缠绕形态.%Visualization test is performed at the water channel of BUAA. The vortex core is visualized by dye injection from a small tube located upstream the apex of a delta wing. The test results are recorded by a video camera connected to a computer and processed by Photoshop\\+ software. The test shows new findings in the following respects:(1) Besides the well known spiral and bubble forms of vortex breakdown, there are 3 other forms of vortex breakdown over delta wing found in the test. They are the frog-jump form, the double spiral form and the filiform spiral form.(2) It has also been found that there is a transition from the spiral form to the bubble form and then back to the spiral form in the test. Therefore it shows that the spiral form vortex breakdown over delta wing is often observed.(3) In a certain sense it can be said that the bubble form of vortex breakdown is a special case of the spiral form type. There is no essential difference between them. For the bubble form of vortex breakdown, there are branches of the vortex core and many elements carrying vorticity separated from the vortex core. However, there is at least one vortex filament that forms a spiral

  14. Heat transfer investigation of two Langley Research Center delta wing configurations at a Mach number of 10.5, volume 1

    Science.gov (United States)

    Eaves, R. H.; Buchanan, T. D.; Warmbrod, J. D.; Johnson, C. B.

    1972-01-01

    Heat transfer tests for two delta wing configurations were conducted in the hypervelocity wind tunnel. The 24-inch long models were tested at a Mach number of approximately 10.5 and at angles of attack of 20, 40, and 60 degrees over a length Reynolds number range from 5 million to 23 million on 4 May to 4 June 1971. Heat transfer results were obtained from model surface heat gage measurements and thermographic phosphor paint.

  15. 3D flow visualization and tomographic particle image velocimetry for vortex breakdown over a non-slender delta wing

    Science.gov (United States)

    Wang, ChengYue; Gao, Qi; Wei, RunJie; Li, Tian; Wang, JinJun

    2016-06-01

    Volumetric measurement for the leading-edge vortex (LEV) breakdown of a delta wing has been conducted by three-dimensional (3D) flow visualization and tomographic particle image velocimetry (TPIV). The 3D flow visualization is employed to show the vortex structures, which was recorded by four cameras with high resolution. 3D dye streaklines of the visualization are reconstructed using a similar way of particle reconstruction in TPIV. Tomographic PIV is carried out at the same time using same cameras with the dye visualization. Q criterion is employed to identify the LEV. Results of tomographic PIV agree well with the reconstructed 3D dye streaklines, which proves the validity of the measurements. The time-averaged flow field based on TPIV is shown and described by sections of velocity and streamwise vorticity. Combining the two measurement methods sheds light on the complex structures of both bubble type and spiral type of breakdown. The breakdown position is recognized by investigating both the streaklines and TPIV velocity fields. Proper orthogonal decomposition is applied to extract a pair of conjugated helical instability modes from TPIV data. Therefore, the dominant frequency of the instability modes is obtained from the corresponding POD coefficients of the modes based on wavelet transform analysis.

  16. The Study of Delta Wing Structure Plan of A Supersonic Aircraft%一种超音速飞机三角机翼结构方案研究

    Institute of Scientific and Technical Information of China (English)

    刘健; 杨华保; 王建; 尚琳

    2011-01-01

    针对某超音速飞机的三角翼,设计了带平行翼梁的梁式三角翼结构和带内撑梁的梁式三角翼结构两种方案;分析了三角翼两种结构方案的受力特点,并采用有限元方法对比分析了两种结构方案的强度和刚度特点.通过分析和比较得出了带平行翼梁的梁式三角翼结构受力特性更好,更适合于能够布置中央翼的三角翼飞机.%Two types of wing structure plan were designed for a supersonic aircraft, which were the delta wing structure containing parallel beams and the delta wing structure with support beams. The two types of wing structure's mechanics characteristics were analyzed, and their stiffness and strength were compared with FEA. Through analysis and compare of the two types of wing structure, the delta wing structure containing parallel beams is better than the other and is more suitable for the aircraft with delta wing which can be arranged the central wing.

  17. Wind Tunnel Investigation of Passive Porosity Applied to the Leading-Edge Extension and Leading-Edge Flaps on a Slender Wing at Subsonic Speed

    Science.gov (United States)

    Erickson, Gary E.

    2017-01-01

    A wind tunnel experiment was conducted in the NASA Langley Research Center 7- by 10-Foot High Speed Tunnel to determine the effects of passive surface porosity on the subsonic vortex flow interactions about a general research fighter configuration. Flow-through porosity was applied to the leading-edge extension, or LEX, and leading-edge flaps mounted to a 65deg cropped delta wing model as a potential vortex flow control technique at high angles of attack. All combinations of porous and nonporous LEX and flaps were investigated. Wing upper surface static pressure distributions and six-component forces and moments were obtained at a free-stream Mach number of 0.20 corresponding to a Reynolds number of 1.35(106) per foot, angles of attack up to 45deg, angles of sideslip of 0deg and +/-5deg, and leading-edge flap deflections of 0deg and 30deg.

  18. Experimental studies of vertical mixing patterns in open channel flow generated by two delta wings side-by-side

    Science.gov (United States)

    Vaughan, Garrett

    Open channel raceway bioreactors are a low-cost system used to grow algae for biofuel production. Microalgae have many promises when it comes to renewable energy applications, but many economic hurdles must be overcome to achieve an economic fuel source that is competitive with petroleum-based fuels. One way to make algae more competitive is to improve vertical mixing in algae raceway bioreactors. Previous studies show that mixing may be increased by the addition of mechanisms such as airfoils. The circulation created helps move the algae from the bottom to top surface for necessary photosynthetic exchange. This improvement in light utilization allowed a certain study to achieve 2.2-2.4 times the amount of biomass relative to bioreactors without airfoils. This idea of increasing mixing in open channel raceways has been the focus of the Utah State University (USU) raceway hydraulics group. Computational Fluid Dynamics (CFD), Acoustic Doppler Velocimetry (ADV), and Particle Image Velocimetry (PIV) are all methods used at USU to computationally and experimentally quantify mixing in an open channel raceway. They have also been used to observe the effects of using delta wings (DW) in increasing vertical mixing in the raceway. These efforts showed great potential in the DW in increasing vertical mixing in the open channel bioreactor. However, this research begged the question, does the DW help increase algae growth? Three algae growth experiments comparing growth in a raceway with and without DW were completed. These experiments were successful, yielding an average 27.1% increase in the biomass. The DW appears to be a promising method of increasing algae biomass production. The next important step was to quantify vertical mixing and understand flow patterns due to two DWs side-by-side. Raceway channels are wider as they increase in size; and arrays of DWs will need to be installed to achieve quality mixing throughout the bioreactor. Quality mixing was attained for

  19. Il teatro degli spiriti.

    Directory of Open Access Journals (Sweden)

    Chiara Pussetti

    2013-07-01

    Full Text Available Questo saggio è dedicato a un culto di possessione, in cui tutte ledonne, investite dagli spiriti degli uomini morti prima dell’iniziazione, compiono un percorso iniziatico parallelo a quello maschile, consentendo a queste anime, potenzialmente pericolose, di completare il cammino che non hanno potuto percorrere da vivi e quindi di raggiungere serenamente il mondo dei morti, come antenati protettori del villaggio

  20. Unsteady Low-Speed Windtunnel Test of a Straked Delta Wing, Oscillating in Pitch. Part 3. Plots of the Zeroth and First Harmonic Unsteady Pressure Distributions (Concluded) and Plots of Steady and First Harmonic Unsteady Overall Loads

    Science.gov (United States)

    1988-04-01

    3 CECTION 4 , ImCp 4 -4. ft. b C.p , SETO I SETO ETO ETO P. ; 12. -. . ’ . . . 2 ----.. . - . , . " . 9 . ., Ř ...’" . . . 44 -4 -1 2 .2 .4 .4. 0...34 . DELTA RUN . *4 MACH - .16 FREG . S.S0 Hz RCDFP = .24 SECTION I SECTION 2 SECTION 3 SECTION 4 2 IF ImCP .60 .2 .4 . .2 .4 . . . .0 .2 .4 .6 .9 2y’b 2~ t... Imcp 4 k 4. -0 .2 .4 .6 .8 2 4 .6 .e .e .2 .4 ,6, . .9 .2 .’ .6 .t, 2yb2y’b 2y’b " E LT LPNA . 24.,; de VOLP - 1.49 deg M *M. ITA RUN a 874 MACN .16

  1. Ingegneria degli acquiferi

    CERN Document Server

    Molfetta, Antonio

    2012-01-01

    Il testo fornisce le conoscenze necessarie per affrontare, con un approccio quantitativo, i molteplici aspetti connessi al flusso delle risorse idriche sotterranee (acque di falda) e alla propagazione e bonifica di contaminanti nei sistemi acquiferi. Vengono illustrate le proprietà fondamentali che definiscono la capacità di immagazzinamento, trasporto e rilascio dell’acqua negli acquiferi, e successivamente, descritte le metodiche per la determinazione di tali parametri tramite l’esecuzione e l’interpretazione di prove di falda, di pozzo e di laboratorio. A partire dalla classificazione chimico fisica-tossicologica dei contaminanti vengono, quindi, analizzati i meccanismi di propagazione e illustrate le soluzioni analitiche dell’equazione del trasporto di massa nei mezzi porosi. L’ultima parte del testo è dedicata alla caratterizzazione e bonifica degli acquiferi contaminati. Il testo è rivolto sia agli studenti universitari, sia ai professionisti che debbano affrontare con un approccio quantit...

  2. 插入双面有三角形翅片的金属带对热交换管中流动和传热特性的影响%Influence of Double-sided Delta-wing Tape Insert with Alternate-axes on Flow and Heat Transfer Characteristics in a Heat Exchanger Tube

    Institute of Scientific and Technical Information of China (English)

    Smith Eiamsa-ard; Pongjet Promvonge

    2011-01-01

    The convective heat transfer and friction behaviors of turbulent tube flow through a straight tape with double-sided delta wings (T-W) have been studied experimentally. In the current work, the T-W formed on the tape was used as vortex generators for enhancing the heat transfer coefficient by breakdown of thermal boundary layer and by mixing of fluid flow in tubes. The T-W characteristics are (1) T-W with forward/backward-wing arrangement, (2) T-W with alternate axis (T-WA), (3) three wing-width ratios and (4) wing-pitch ratios. The experimental result reveals that for using the T-W, the increases in the mean Nusselt number (Nu) and friction factor are, respectively, up to 165% and 14.8 times of the plain tube and the maximum thermal performance factor is 1.19. It is also obvious that the T-W with forward-wing gives higher heat transfer rate than one with backward-wing around 7%.The present investigation also shows that the heat transfer rate and friction factor obtained from the T-WA is higher than that from the T-W. In addition, the flow pattern and temperature fields in the T-W tube with both backward and forward wings were also examined numerically.

  3. 低背鳍对细长平板三角翼分离涡稳定性影响的研究%Effects of low dorsal fin on the stability of vortex flow over slender delta wing

    Institute of Scientific and Technical Information of China (English)

    孟宣市; 蔡晋生; 罗时钧; 刘锋

    2012-01-01

    对细长锥体分离涡稳定性判据进行了介绍,并应用该判据对细长体平板三角翼和加上两个不同高度背鳍组合体分离涡流场的稳定性进行了分析.为了验证理论分析的有效性,并观察气动力随迎角的变化,根据理论分析模型设计了实验模型,并在低速风洞进行了六分量天平测力实验,三角翼后掠角为82.5°实验迎角范围12°~32°,侧滑角范围-10°~十10°,实验雷诺数1.66×106.实验结果表明:在翼面上发生旋涡破裂前,单独细长平板三角翼的横向力/力矩在实验迎角范围内始终为零;加了两个不同高度的背鳍后,在一定迎角下,三角翼的横向力/力矩变得不为零.理论分析结果和实验结果在定性上吻合得很好,初步验证了有关文献关于细长锥体分离涡的稳定性理论.%A vortex stability theory for slender conical bodies which was proposed by the professors of NWPU was reviewed and used to analyze the asymmetric vortices characteristics of a flat-plate delta wing and its combinations. To verify the validity of the theoretical predictions and show the force development versus angle of attack, a wind tunnel test was conducted on a flat-plate delta wing of 82. 5 degrees sweep angle and its combinations using a six-component internal strain-gage balance. The angles of attack is at 12°~32° and sideslip within ±10°. Two fins of different heights were tested. The ratios of the local fin height to the local wing semi-span were 0. 3 and 0. 6 respectively. The Reynolds number is 1. 66 million. The measurement of the aerodynamic forces and moments clearly indicates that no lateral force occurs over wing-alone model at lower angles, but a steady force-asymmetry occurs over the wing-fin models at certain angles. The experimental results and the theoretical results are in good agreement qualitatively, it provides force measurement evidence of the validity of the vortex stability theory preliminarily.

  4. 双三角翼俯仰振荡运动的流场特性数值模拟%Numerical Simulation of Unsteady Flow Around Double-delta Wing During Pitching Motion

    Institute of Scientific and Technical Information of China (English)

    刘昕; 林敬周; 陈亮中; 肖春华

    2012-01-01

    建立了适用于双三角翼大迎角非定常分离流场模拟的数值方法,研究双三角翼俯仰振荡时的动态流场特性,给出动态流场结构和气动力性能随迎角的变化规律,重点考察了减缩频率、转轴位置、平均迎角和振幅等参数对动态流场迟滞效应和气动力曲线迟滞环的影响.研究结果表明:俯仰振荡到相同大迎角时上仰和下俯的流场存在明显差异;减缩频率对气动力迟滞效应的影响相对大于转轴位置;平均迎角的变化导致双三角翼背风区流场结构呈现不同流态,而振幅的大小决定这些流态的数目,事实上俯仰运动时如果跨越的流态数目越多则流场结构的动态响应滞后现象就越显著.通过数值分析,有利于提高对双三角翼在俯仰振荡运动条件下的非定常特性和流场滞后效应等非线性现象的认识.%Numerical methods capable for computing the separated unsteady flow around a double-delta wing are established in this paper. The variation of the dynamic flow fields and aerodynamic performances following the change of the angle of attack Is studied, which concentrates on the investigation of the influences of several motion parameters on the time-lag effects of the dynamic flow fields and the hysteresis loops of the aerodynamic coefficients, such as reduced frequency, the position of rotation axis, the averaged angle of attack and the pitching amplitude. The numerical results show that there is great difference in the flow structure between pitch-up and pitch-down states at the same large angle of attack. The time-lag effect caused by the reduced frequency is relatively greater than that by the position of rotation axis. The variation of the averaged angles of attack causes different streamline forms on the leeward side of the double-delta wing; and the span of the streamline forms, which is related to the pitching amplitude, determines how much the dynamic response of the flow

  5. Avian Wings

    Science.gov (United States)

    Liu, Tianshu; Kuykendoll, K.; Rhew, R.; Jones, S.

    2004-01-01

    This paper describes the avian wing geometry (Seagull, Merganser, Teal and Owl) extracted from non-contact surface measurements using a three-dimensional laser scanner. The geometric quantities, including the camber line and thickness distribution of airfoil, wing planform, chord distribution, and twist distribution, are given in convenient analytical expressions. Thus, the avian wing surfaces can be generated and the wing kinematics can be simulated. The aerodynamic characteristics of avian airfoils in steady inviscid flows are briefly discussed. The avian wing kinematics is recovered from videos of three level-flying birds (Crane, Seagull and Goose) based on a two-jointed arm model. A flapping seagull wing in the 3D physical space is re-constructed from the extracted wing geometry and kinematics.

  6. Embrittlement of reduced-activation ferritic/martensitic steels irradiated in HFIR at 300 deg. C and 400 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L. E-mail: ku2@ornl.gov; Sokolov, M.A.; Shiba, K.; Miwa, Y.; Robertson, J.P

    2000-12-01

    Miniature tensile and Charpy specimens of four ferritic/martensitic steels were irradiated at 300 deg. C and 400 deg. C in the high flux isotope reactor (HFIR) to a maximum dose of {approx}12 dpa. The steels were standard F82H (F82H-Std), a modified F82H (F82H-Mod), ORNL 9Cr-2WVTa, and 9Cr-2WVTa-2Ni, the 9Cr-2WVTa containing 2% Ni to produce helium by (n,{alpha}) reactions with thermal neutrons. More helium was produced in the F82H-Std than the F82H-Mod because of the presence of boron. Irradiation embrittlement in the form of an increase in the ductile-brittle transition temperature ({delta}DBTT) and a decrease in the upper-shelf energy (USE) occurred for all the steels. The two F82H steels had similar {delta}DBTTs after irradiation at 300 deg. C, but after irradiation at 400 deg. C, the {delta}DBTT for F82H-Std was less than for F82H-Mod. Under these irradiation conditions, little effect of the extra helium in the F82H-Std could be discerned. Less embrittlement was observed for 9Cr-2WVTa steel irradiated at 400 deg. C than for the two F82H steels. The 9Cr-2WVTa-2Ni steel with {approx}115 appm He had a larger {delta}DBTT than the 9Cr-2WVTa with {approx}5 appm He, indicating a possible helium effect.

  7. Winglets on low aspect ratio wings

    Science.gov (United States)

    Kuhlman, John M.; Liaw, Paul

    1987-01-01

    The drag reduction potentially available from the use of winglets at the tips of low aspect ratio (1.75-2.67) wings with pronounced (45-60 deg) leading edge sweep is assessed numerically for the case of a cruise design point at Mach of 0.8 and a lift coefficient of 0.3. Both wing-winglet and wing-alone design geometries are derived from a linear-theory, minimum induced drag design methodology. Relative performance is evaluated with a nonlinear extended small disturbance potential flow analysis code. Predicted lift coefficient/pressure drag coefficient increases at equal lift for the wing-winglet configurations over the wing-alone planform are of the order of 14.6-15.8, when boundary layer interaction is included.

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

    Science.gov (United States)

    Ware, George M.

    1960-01-01

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

  9. Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Urvina Bay coral radiocarbon (14C) timeseries. (90 deg W, 0.5 deg S) Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per...

  10. Elastic deformation and energy loss of flapping fly wings.

    Science.gov (United States)

    Lehmann, Fritz-Olaf; Gorb, Stanislav; Nasir, Nazri; Schützner, Peter

    2011-09-01

    During flight, the wings of many insects undergo considerable shape changes in spanwise and chordwise directions. We determined the origin of spanwise wing deformation by combining measurements on segmental wing stiffness of the blowfly Calliphora vicina in the ventral and dorsal directions with numerical modelling of instantaneous aerodynamic and inertial forces within the stroke cycle using a two-dimensional unsteady blade elementary approach. We completed this approach by an experimental study on the wing's rotational axis during stroke reversal. The wing's local flexural stiffness ranges from 30 to 40 nN m(2) near the root, whereas the distal wing parts are highly compliant (0.6 to 2.2 nN m(2)). Local bending moments during wing flapping peak near the wing root at the beginning of each half stroke due to both aerodynamic and inertial forces, producing a maximum wing tip deflection of up to 46 deg. Blowfly wings store up to 2.30 μJ elastic potential energy that converts into a mean wing deformation power of 27.3 μW. This value equates to approximately 5.9 and 2.3% of the inertial and aerodynamic power requirements for flight in this animal, respectively. Wing elasticity measurements suggest that approximately 20% or 0.46 μJ of elastic potential energy cannot be recovered within each half stroke. Local strain energy increases from tip to root, matching the distribution of the wing's elastic protein resilin, whereas local strain energy density varies little in the spanwise direction. This study demonstrates a source of mechanical energy loss in fly flight owing to spanwise wing bending at the stroke reversals, even in cases in which aerodynamic power exceeds inertial power. Despite lower stiffness estimates, our findings are widely consistent with previous stiffness measurements on insect wings but highlight the relationship between local flexural stiffness, wing deformation power and energy expenditure in flapping insect wings.

  11. Angel's Wings

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Angel's wings had fallen off. It started slowly,a couple of feathers breaking loose in the wind,floating away in carefree spirals, then in clumps in the shower, matted wet and clogging the drain,until one day he woke in a thick layer of white plumage, quills snagging on the stained sheets.

  12. Deformation characteristics of {delta} phase in the delta-processed Inconel 718 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.Y., E-mail: haiyanzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, S.H., E-mail: shzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cheng, M. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Z.X. [Beijing Institute of Aeronautica1 Materials, Beijing 100095 (China)

    2010-01-15

    The hot working characteristics of {delta} phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 deg. C and strain rate of 0.005 s{sup -1}, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like {delta} phase and the precipitation of spherical {delta} phase particles coexisted during the deformation, and the content of {delta} phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like {delta} phase was spheroidized and transferred to spherical {delta} phase particles. In the center with largest strain, the plate-like {delta} phase disappeared and spherical {delta} phase appeared in the interior of grains and grain boundaries.

  13. 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.

  14. Experimental Aerodynamic Characteristics of an Oblique Wing for the F-8 OWRA

    Science.gov (United States)

    Kennelly, Robert A., Jr.; Carmichael, Ralph L.; Smith, Stephen C.; Strong, James M.; Kroo, Ilan M.

    1999-01-01

    An experimental investigation was conducted during June-July 1987 in the NASA Ames 11-Foot Transonic Wind Tunnel to study the aerodynamic performance and stability and control characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing. This effort was part of the Oblique Wing Research Aircraft (OWRA) program performed in conjunction with Rockwell International. The Ames-designed, aspect ratio 10.47, tapered wing used specially designed supercritical airfoils with 0.14 thickness/chord ratio at the root and 0.12 at the 85% span location. The wing was tested at two different mounting heights above the fuselage. Performance and longitudinal stability data were obtained at sweep angles of 0deg, 30deg, 45deg, 60deg, and 65deg at Mach numbers ranging from 0.30 to 1.40. Reynolds number varied from 3.1 x 10(exp 6)to 5.2 x 10(exp 6), based on the reference chord length. Angle of attack was varied from -5deg to 18deg. The performance of this wing is compared with that of another oblique wing, designed by Rockwell International, which was tested as part of the same development program. Lateral-directional stability data were obtained for a limited combination of sweep angles and Mach numbers. Sideslip angle was varied from -5deg to +5deg. Landing flap performance was studied, as were the effects of cruise flap deflections to achieve roll trim and tailor wing camber for various flight conditions. Roll-control authority of the flaps and ailerons was measured. A novel, deflected wing tip was evaluated for roll-control authority at high sweep angles.

  15. Cloning and sequencing the degS-degU operon from an alkalophilic Bacillus-brevis

    CSIR Research Space (South Africa)

    Louw, M

    1994-10-01

    Full Text Available at the amino acid level to the B. subtilis degS-degU genes showed 74% and 84% similarity, respectively. On a multicopy vector the B. brevis degS-degU genes were found to cause hypersecretion of several extracellular enzymes in a B. subtilis rec (-) strain...

  16. Aerodynamic characteristics of a high-wing transport configuration with a over-the-wing nacelle-pylon arrangement

    Science.gov (United States)

    Henderson, W. P.; Abeyounis, W. K.

    1985-01-01

    An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects on the aerodynamic characteristics of a high-wing transport configuration of installing an over-the-wing nacelle-pylon arrangement. The tests are conducted at Mach numbers from 0.70 to 0.82 and at angles of attack from -2 deg to 4 deg. The configurational variables under study include symmetrical and contoured nacelles and pylons, pylon size, and wing leading-edge extensions. The symmetrical nacelles and pylons reduce the lift coefficient, increase the drag coefficient, and cause a nose-up pitching-moment coefficient. The contoured nacelles significantly reduce the interference drag, though it is still excessive. Increasing the pylon size reduces the drag, whereas adding wing leading-edge extension does not affect the aerodynamic characteristics significantly.

  17. Computational wing optimization and comparisons with experiment for a semi-span wing model

    Science.gov (United States)

    Waggoner, E. G.; Haney, H. P.; Ballhaus, W. F.

    1978-01-01

    A computational wing optimization procedure was developed and verified by an experimental investigation of a semi-span variable camber wing model in the NASA Ames Research Center 14 foot transonic wind tunnel. The Bailey-Ballhaus transonic potential flow analysis and Woodward-Carmichael linear theory codes were linked to Vanderplaats constrained minimization routine to optimize model configurations at several subsonic and transonic design points. The 35 deg swept wing is characterized by multi-segmented leading and trailing edge flaps whose hinge lines are swept relative to the leading and trailing edges of the wing. By varying deflection angles of the flap segments, camber and twist distribution can be optimized for different design conditions. Results indicate that numerical optimization can be both an effective and efficient design tool. The optimized configurations had as good or better lift to drag ratios at the design points as the best designs previously tested during an extensive parametric study.

  18. The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). I : The UV luminosity function of the central 12 sq.deg

    NARCIS (Netherlands)

    Boselli, A.; Boissier, S.; Heinis, S.; Cortese, L.; Ilbert, O.; Hughes, T.; Cucciati, O.; Davies, J.; Ferrarese, L.; Giovanelli, R.; Haynes, M. P.; Baes, M.; Balkowski, C.; Brosch, N.; Chapman, S. C.; Charmandaris, V.; Clemens, M. S.; Dariush, A.; Looze, I. De; Alighieri, S. di Serego; Duc, P. -A.; Durrell, P. R.; Emsellem, E.; Erben, T.; Fritz, J.; Garcia-Appadoo, D. A.; Gavazzi, G.; Grossi, M.; Jordán, A.; Hess, K. M.; Huertas-Company, M.; Hunt, L. K.; Kent, B. R.; Lambas, D. G.; Lancon, A.; MacArthur, L. A.; Madden, S. C.; Magrini, L.; Mei, S.; Momjian, E.; Olowin, R. P.; Papastergis, E.; Smith, M. W. L.; Solanes, J. M.; Spector, O.; Spekkens, K.; Taylor, J. E.; Valotto, C.; Driel, W. van; Verstappen, J.; Vlahakis, C.; Vollmer, B.; Xilouris, E. M.

    2011-01-01

    The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) is a complete blind survey of the Virgo cluster covering about 40 sq. deg. in the far UV (FUV, lambda_eff=1539A, Delta-lambda=442A) and about 120 sq. deg. in the near UV (NUV, lambda_eff=2316A, Delta-lambda=1060A). The goal of the survey is to

  19. Aerodynamics of a rigid curved kite wing

    CERN Document Server

    Maneia, Gianmauro; Tordella, Daniela; Iovieno, Michele

    2013-01-01

    A preliminary numerical study on the aerodynamics of a kite wing for high altitude wind power generators is proposed. Tethered kites are a key element of an innovative wind energy technology, which aims to capture energy from the wind at higher altitudes than conventional wind towers. We present the results obtained from three-dimensional finite volume numerical simulations of the steady air flow past a three-dimensional curved rectangular kite wing (aspect ratio equal to 3.2, Reynolds number equal to 3x10^6). Two angles of incidence -- a standard incidence for the flight of a tethered airfoil (6{\\deg}) and an incidence close to the stall (18{\\deg}) -- were considered. The simulations were performed by solving the Reynolds Averaged Navier-Stokes flow model using the industrial STAR-CCM+ code. The overall aerodynamic characteristics of the kite wing were determined and compared to the aerodynamic characteristics of the flat rectangular non twisted wing with an identical aspect ratio and section (Clark Y profil...

  20. Fisica degli atomi e dei nuclei

    CERN Document Server

    Bernardini, Carlo

    1965-01-01

    Evidenza della struttura atomica della materia ; le proprietà degli atomi e la meccanica atomica ; gli atomi e le radiazioni elettromagnetiche ; struttura microscopica dello stato gassoso ; struttura microscopica dello stato liquido ; struttura microscopica della stato solido ; proprietà elettriche e magnetiche delle sostanze ; proprietà dei nuclei degli atomi ; le particelle elementari.

  1. COSMOS Photometric Redshifts with 30-bands for 2-deg2

    CERN Document Server

    Ilbert, O; Salvato, M; Aussel, H; McCracken, H J; Sanders, D B; Scoville, N; Kartaltepe, J; Arnouts, S; Le Floc'h, E; Mobasher, B; Taniguchi, Y; Lamareille, F; Leauthaud, A; Sasaki, S; Thompson, D; Zamojski, M; Zamorani, G; Bardelli, S; Bolzonella, M; Bongiorno, A; Brusa, M; Caputi, K I; Carollo, C M; Contini, T; Cook, R; Coppa, G; Cucciati, O; De la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Hasinger, G; Iovino, A; Kampczyk, P; Kneib, J -P; Knobel, C; Kovac, K; Le Borgne, J F; Le Brun, V; Le Fèvre, O; Lilly, S; Looper, D; Maier, C; Mainieri, V; Mellier, Y; Mignoli, M; Murayama, T; Pellò, R; Peng, Y; Pérez-Montero, E; Renzini, A; Ricciardelli, E; Schiminovich, D; Scodeggio, M; Shioya, Y; Silverman, Joseph; Surace, J; Tanaka, M; Tasca, L; Tresse, L; Vergani, D; Zucca, E

    2008-01-01

    We present accurate photometric redshifts in the 2-deg2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrow bands covering the UV (GALEX), Visible-NIR (Subaru, CFHT, UKIRT and NOAO) and mid-IR (Spitzer/IRAC). A chi2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from VLT-VIMOS and Keck-DEIMOS. We develop and implement a new method which accounts for the contributions from emission lines (OII, Hbeta, Halpha and Ly) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e. Delta z = zs - zp) indicates a dispersion of sigma_{Delta z/(1+zs)}=0.007 at i<22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHTLS and COMBO-17 survey fields. At fainter magnitudes i<24 and z<1.25, the accuracy is sigma_{Delta z/(1+zs)}=0.012. The deep NIR and IRAC coverage enables the ph...

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

    Science.gov (United States)

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

    1976-01-01

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

  3. Selectively delta-doped Al(x)Ga(1-x)As/GaAs heterostructures with high two-dimensional electron-gas concentrations (n2DEG) of not less than 1.5 x 10 to the 12th/sq cm for field-effect transistors

    Science.gov (United States)

    Schubert, E. F.; Cunningham, J. E.; Tsang, W. T.; Timp, G. L.

    1987-10-01

    Selectively delta-doped heterostructures in the Al(x)Ga(1-x)As/GaAs material system, combining the delta-doping and selectively doped heterostructure concepts, are considered. From Shubnikov-de Haas measurements, two-dimensional electron-gas concentrations of 1.1 x 10 to the 12th/sq cm at 300 mK and at a spacer thickness of 25 A are found, and it is suggested that such high values are due to size quantization in Al(x)Ga(1-x)As and the localization of donor impurities within one atomic monolayer. Selectively delta-doped heterostructure transistors are fabricated, showing a transconductance of about 360 mS/mm at a gate length of 1.2 microns and a temperature of 300 K.

  4. Effect of a wing-tip mounted pusher turboprop on the aerodynamic characteristics of a semi-span wing

    Science.gov (United States)

    Patterson, J. C., Jr.; Bartlett, G. R.

    1985-01-01

    An exploratory investigation has been conducted at the NASA Langley Research Center to determine the installed performance of a wing tip-mounted pusher turboprop. Tests were conducted using a semispan model having an unswept, untapered wing with a air-driven motor located on the tip of the wing, with an SR-2 design high speed propeller installed on the rear shaft of the motor. All tests were conducted at a Mach number of 0.70, at angles of attack of approximately -2 to +4 deg, and at a Reynolds number of 3.82 million based on the wing chord of 13 inches. The data indicate that, as a result of locating the propeller behind the wing trailing edge, at the wingtip, in the cross flow of the tip vortex, it is possible to recover part of the vortex energy as an increase in propeller thrust and, therefore, a reduction in the lift-induced drag as well.

  5. Lift augmentation for highly swept wing aircraft

    Science.gov (United States)

    Rao, Dhanvada M. (Inventor)

    1993-01-01

    A pair of spaced slots, disposed on each side of an aircraft centerline and spaced well inboard of the wing leading edges, are provided in the wing upper surfaces and directed tangentially spanwise toward thin sharp leading wing edges of a highly swept, delta wing aircraft. The slots are individually connected through separate plenum chambers to separate compressed air tanks and serve, collectively, as a system for providing aircraft lift augmentation. A compressed air supply is tapped from the aircraft turbojet power plant. Suitable valves, under the control of the aircraft pilot, serve to selective provide jet blowing from the individual slots to provide spanwise sheets of jet air closely adjacent to the upper surfaces and across the aircraft wing span to thereby create artificial vortices whose suction generate additional lift on the aircraft. When desired, or found necessary, unequal or one-side wing blowing is employed to generate rolling moments for augmented lateral control. Trailing flaps are provided that may be deflected differentially, individually, or in unison, as needed for assistance in take-off or landing of the aircraft.

  6. Computational design of low aspect ratio wing-winglets for transonic wind-tunnel testing

    Science.gov (United States)

    Kuhlman, John M.; Brown, Christopher K.

    1989-01-01

    A computational design has been performed for three different low aspect ratio wing planforms fitted with nonplanar winglets; one of the three planforms has been selected to be constructed as a wind tunnel model for testing in the NASA LaRC 7 x 10 High Speed Wind Tunnel. A design point of M = 0.8, CL approx = 0.3 was selected, for wings of aspect ratio equal to 2.2, and leading edge sweep angles of 45 and 50 deg. Winglet length is 15 percent of the wing semispan, with a cant angle of 15 deg, and a leading edge sweep of 50 deg. Winglet total area equals 2.25 percent of the wing reference area. This report summarizes the design process and the predicted transonic performance for each configuration.

  7. Observational $\\Delta\

    CERN Document Server

    Hernández, Antonio García; Monteiro, Mário J P F G; Suárez, Juan Carlos; Reese, Daniel R; Pascual-Granado, Javier; Garrido, Rafael

    2015-01-01

    Delta Scuti ($\\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\\delta$ Sct stars.

  8. A Variable Control Structure Controller for the Wing Rock Phenomenon

    OpenAIRE

    2016-01-01

    This paper presents the design of a variable structure controller for the model of the wing rock phenomenon of a delta wing aircraft. It is considered to be a continue study of the last two researches for the same phenomena "Feedback linearization [15] and back stepping controller [14] ". A control technique is proposed to stabilize the aircraft phenomena. The solution presented in this paper give a guarantee of asymptotic convergence to zero of all variables of the system. MATLAB...

  9. The flow over a 'high' aspect ratio gothic wing at supersonic speeds

    Science.gov (United States)

    Narayan, K. Y.

    1975-01-01

    Results are presented of an experimental investigation on a nonconical wing which supports an attached shock wave over a region of the leading edge near the vertex and a detached shock elsewhere. The shock detachment point is determined from planform schlieren photographs of the flow field and discrepancies are shown to exist between this and the one calculated by applying the oblique shock equations normal to the leading edge. On a physical basis, it is argued that the shock detachment has to obey the two-dimensional law normal to the leading edges. From this, and from other measurements on conical wings, it is thought that the planform schlieren technique may not be particularly satisfactory for detecting shock detachment. Surface pressure distributions are presented and are explained in terms of the flow over related delta wings which are identified as a vertex delta wing and a local delta wing.

  10. Vortices around Dragonfly Wings

    OpenAIRE

    Kweon, Jihoon; Choi, Haecheon

    2009-01-01

    Dragonfly beats its wings independently, resulting in its superior maneuverability. Depending on the magnitude of phase difference between the fore- and hind-wings of dragonfly, the vortical structures and their interaction with wings become significantly changed, and so does the aerodynamic performance. In this study, we consider hovering flights of modelled dragonfly with three different phase differences (phi=-90, 90, 180 degrees). The three-dimensional wing shape is based on that of Aesch...

  11. A Stationary Vortex Phenomenon above a Low-Aspect-Ratio Wing

    Institute of Scientific and Technical Information of China (English)

    TANG Jian; ZHU Ke-Qin; TAN Guang-Kun

    2004-01-01

    @@ A stationary vortex phenomenon above a nondelta low-aspect-ratio wing was obtained in three-dimensional unsteady numerical simulation. Flow visualization is conducted in water channel using hydrogen bubbles. The results verify that there is a vortex trapped above the low-aspect-ratio wing and the stationary vortex consisted of two semi-balls and anti-rotation vortices which are different from the leading edge vortices on the delta wing.

  12. The Structure of Dark Molecular Gas in the Galaxy - I: A Pilot Survey for 18-cm OH Emission Towards $l \\approx 105^{\\deg}, b \\approx +1^{\\deg}$

    CERN Document Server

    Allen, Ronald J; Engelke, Philip D

    2015-01-01

    We report the first results from a survey for 1665, 1667, and 1720 MHz OH emission over a small region of the Outer Galaxy centered at $l \\approx 105.0\\deg , b \\approx +1.0\\deg$ . This sparse, high-sensitivity survey ($\\Delta Ta \\approx \\Delta Tmb \\approx 3.0 - 3.5$ mK rms in 0.55 km/s channels), was carried out as a pilot project with the Green Bank Telescope (GBT, FWHM $\\approx 7.6'$) on a 3 X 9 grid at $0.5\\deg$ spacing. The pointings chosen correspond with those of the existing $^{12}$CO(1-0) CfA survey of the Galaxy (FWHM $\\approx 8.4'$). With 2-hr integrations, 1667 MHz OH emission was detected with the GBT at $\\gtrsim 21$ of the 27 survey positions ($\\geq 78\\%$ ), confirming the ubiquity of molecular gas in the ISM as traced by this spectral line. With few exceptions, the main OH lines at 1665 and 1667 MHz appear in the ratio of 5:9 characteristic of LTE at our sensitivity levels. No OH absorption features are recorded in the area of the present survey, in agreement with the low levels of continuum bac...

  13. Delta robot

    NARCIS (Netherlands)

    Herder, J.L.; Van der Wijk, V.

    2010-01-01

    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  14. Delta robot

    NARCIS (Netherlands)

    Herder, J.L.; Van der Wijk, V.

    2010-01-01

    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  15. Replication of butterfly wing and natural lotus leaf structures by nanoimprint on silica sol-gel films

    Energy Technology Data Exchange (ETDEWEB)

    Saison, Tamar; Peroz, Christophe; Chauveau, Vanessa; Sondergard, Elin; Arribart, Herve [Unite mixte CNRS/Saint Gobain Saint Gobain Recherche, BP135, 93303 Aubervilliers (France); Berthier, Serge [Institut des Nanosciences de Paris, UMR 7588, CNRS, Universite Pierre et Marie Curie-Paris 6, 140 rue Lourmel, 75015 Paris (France)], E-mail: cperoz@lbl.gov

    2008-12-01

    An original and low cost method for the fabrication of patterned surfaces bioinspired from butterfly wings and lotus leaves is presented. Silica-based sol-gel films are thermally imprinted from elastomeric molds to produce stable structures with superhydrophobicity values as high as 160 deg. water contact angle. The biomimetic surfaces are demonstrated to be tuned from superhydrophobic to superhydrophilic by annealing between 200 deg. C and 500 deg. C.

  16. Compensated-power differential calorimeter -196 deg. C/400 deg. C; Calorimetre differentiel a puissance compensee -196 deg. C/400 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Bonjour, E.; Pierre, J.; Agagliate, S.; Bertrand, P.; Faivre, J.; Lagnier, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires, Section physico-chimie et basses temperatures

    1967-06-01

    A differential calorimetric device of original design is described. Its allows direct measurements of thermal effects (adsorption or release) during a linear rise of temperature. The self compensated power method which is applied by means of a very sensitive control system, gives a direct value of the different heat capacity between the sample and a dummy of it. The detection threshold is about {+-} 100 micro-watts to {+-} 250 micro-watts. Applications: - Generally measurements of enthalpy changes of massive or powdered samples. - Measurement of Wigner energy after low temperature irradiation (77 deg. K). - Measurements of energy release in low temperature (77 deg. K) cold worked metals. (authors) [French] On decrit un dispositif de calorimetrie differentielle, de conception originale, qui permet de mesurer directement des effets thermiques en absorption ou en degagement de chaleur, au cours d'une montee en temperature lineaire. La methode de compensation automatique de puissance qui est mise en oeuvre au moyen de cha es d'asservissement tres sensibles, conduit a une determination directe de la capacite calorifique differencielle entre l'echantillon et sa reference. Le seuil de detection est de l'ordre de {+-} 100 a {+-} 250 microwatts. Applications: - D'une facon generale, mesure des variations enthalpiques, sur echantillons massifs ou en poudre. - Mesure de l'energie Wigner apres irradiation a basse temperature (77 deg. K). - Mesure de l'energie restauree apres deformation des metaux a basse temperature (77 deg. K). (auteurs)

  17. Testimonianze di vittime degli anni di piombo

    DEFF Research Database (Denmark)

    Cecchini, Leonardo

    Testimonianze di vittime degli anni di piombo In un articolo pubblicato nel 2008 sulla webzine Nazione indiana Christian Raimo criticava quello che poi Giovanni De Luna qualche anno dopo nel suo libro La Repubblica del dolore (2011) ha chiamato “paradigma vittimario”; cioè la presenza predominante...

  18. METHOD OF MAKING DELTA ZIRCONIUM HYDRIDE MONOLITHIC MODERATOR PIECES

    Science.gov (United States)

    Vetrano, J.B.

    1962-01-23

    A method is given for preparing large, sound bodies of delta zirconium hydride. The method includes the steps of heating a zirconium body to a temperature of not less than l000 deg C, providing a hydrogen atmosphere for the zirconium body at a pressure not greater than one atmosphere, reducing the temperature slowly to 800 deg C at such a rate that cracks do not form while maintaining the hydrogen pressure substantially constant, and cooling in an atmosphere of hydrogen. (AEC)

  19. Comparison of PCBBs and CTs irradiated at 250 deg. C, 300 deg. C, and 350 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Rensman, J.; Nolles, H.N. [ECN-Energy Research Foundation, Research Unit NRG, Westerduinweg, Petten (Netherlands); Lucon, E. [SCK-CEN, Institute of Nuclear Material Science, Boeretang, Mol (Belgium); Spatig, P. [EPFL-CRDP, Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH Villigen PSI (Switzerland)

    2007-07-01

    Full text of publication follows: The fracture toughness of irradiated Eurofer steel is difficult to characterise. Several limitations are identified in this paper with respect to the conventional treatment of fracture data of BCC steels in the transition region. It is uncertain that the RPV Master Curve is applicable to unirradiated Eurofer, and low temperature irradiation adds more to this uncertainty. The lack of strain hardening and the dose variation within each batch are two complicating factors. An irradiation has been carried out in the BFR up to a nominal dose of 2.5 dpa at 250 deg. C, 300 deg. C, and 350 deg. C in sodium. Twelve small size pre-cracked bend specimens and eight mini-CT specimens have been irradiated in each temperature section. We analyse the effect of constraint and censoring limit, and the specimen geometry and loading configuration. The fracture data are treated in several ways that are proposed in open literature to investigate the effect of irradiation on a reference temperature like the ASTM E1921 T0. In addition, the relation between the tensile hardening, which is presented in a companion paper, and the shift calculated with the various methods is studied. (authors)

  20. Bacillus subtilis Two-Component System Sensory Kinase DegS Is Regulated by Serine Phosphorylation in Its Input Domain

    Science.gov (United States)

    Jers, Carsten; Kobir, Ahasanul; Søndergaard, Elsebeth Oline; Jensen, Peter Ruhdal; Mijakovic, Ivan

    2011-01-01

    Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity. The phosphorylation state of the response regulator DegU also does not confer a straightforward “on/off” response; it is fine-tuned and at different levels triggers different sub-regulons. Here we describe serine phosphorylation of the DegS sensing domain, which stimulates its kinase activity. We demonstrate that DegS phosphorylation can be carried out by at least two B. subtilis Hanks-type kinases in vitro, and this stimulates the phosphate transfer towards DegU. The consequences of this process were studied in vivo, using phosphomimetic (Ser76Asp) and non-phosphorylatable (Ser76Ala) mutants of DegS. In a number of physiological assays focused on different processes regulated by DegU, DegS S76D phosphomimetic mutant behaved like a strain with intermediate levels of DegU phosphorylation, whereas DegS S76A behaved like a strain with lower levels of DegU phophorylation. These findings suggest a link between DegS phosphorylation at serine 76 and the level of DegU phosphorylation, establishing this post-translational modification as an additional trigger for this two-component system. PMID:21304896

  1. Bacillus subtilis two-component system sensory kinase DegS is regulated by serine phosphorylation in its input domain.

    Directory of Open Access Journals (Sweden)

    Carsten Jers

    Full Text Available Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity. The phosphorylation state of the response regulator DegU also does not confer a straightforward "on/off" response; it is fine-tuned and at different levels triggers different sub-regulons. Here we describe serine phosphorylation of the DegS sensing domain, which stimulates its kinase activity. We demonstrate that DegS phosphorylation can be carried out by at least two B. subtilis Hanks-type kinases in vitro, and this stimulates the phosphate transfer towards DegU. The consequences of this process were studied in vivo, using phosphomimetic (Ser76Asp and non-phosphorylatable (Ser76Ala mutants of DegS. In a number of physiological assays focused on different processes regulated by DegU, DegS S76D phosphomimetic mutant behaved like a strain with intermediate levels of DegU phosphorylation, whereas DegS S76A behaved like a strain with lower levels of DegU phophorylation. These findings suggest a link between DegS phosphorylation at serine 76 and the level of DegU phosphorylation, establishing this post-translational modification as an additional trigger for this two-component system.

  2. Slotted Aircraft Wing

    Science.gov (United States)

    McLean, James D. (Inventor); Witkowski, David P. (Inventor); Campbell, Richard L. (Inventor)

    2006-01-01

    A swept aircraft wing includes a leading airfoil element and a trailing airfoil element. At least one full-span slot is defined by the wing during at least one transonic condition of the wing. The full-span slot allows a portion of the air flowing along the lower surface of the leading airfoil element to split and flow over the upper surface of the trailing airfoil element so as to achieve a performance improvement in the transonic condition.

  3. Subsonic loads on wings having sharp leading edges and tips

    Science.gov (United States)

    Kandil, O. A.; Mook, D. T.; Nayfeh, A. H.

    1976-01-01

    A vortex-lattice method for predicting the aerodynamics of wings having separation at the sharp edges in incompressible flows is extended to compressible subsonic flows using a modified Prandtl-Glauert transformation. Numerical results showing the effect of freestream Mach number on the aerodynamic coefficients are compared with available experimental data for several planforms. It is shown that the proposed method is suitable for predicting the aerodynamic loads on low-aspect wings at moderate angles of attack for high subsonic freestream Mach number. The method is limited to angles of attack up to 12 deg for high subsonic freestream Mach number and to angles of attack up to 20 deg for Mach number not exceeding 0.5.

  4. Computational Analysis of Powered Lift Augmentation for the LEAPTech Distributed Electric Propulsion Wing

    Science.gov (United States)

    Deere, Karen A.; Viken, Sally A.; Carter, Melissa B.; Viken, Jeffrey K.; Wiese, Michael R.; Farr, Norma L.

    2017-01-01

    A computational study of a distributed electric propulsion wing with a 40deg flap deflection has been completed using FUN3D. Two lift-augmentation power conditions were compared with the power-off configuration on the high-lift wing (40deg flap) at a 73 mph freestream flow and for a range of angles of attack from -5 degrees to 14 degrees. The computational study also included investigating the benefit of corotating versus counter-rotating propeller spin direction to powered-lift performance. The results indicate a large benefit in lift coefficient, over the entire range of angle of attack studied, by using corotating propellers that all spin counter to the wingtip vortex. For the landing condition, 73 mph, the unpowered 40deg flap configuration achieved a maximum lift coefficient of 2.3. With high-lift blowing the maximum lift coefficient increased to 5.61. Therefore, the lift augmentation is a factor of 2.4. Taking advantage of the fullspan lift augmentation at similar performance means that a wing powered with the distributed electric propulsion system requires only 42 percent of the wing area of the unpowered wing. This technology will allow wings to be 'cruise optimized', meaning that they will be able to fly closer to maximum lift over drag conditions at the design cruise speed of the aircraft.

  5. Computational Analysis of a Wing Designed for the X-57 Distributed Electric Propulsion Aircraft

    Science.gov (United States)

    Deere, Karen A.; Viken, Jeffrey K.; Viken, Sally A.; Carter, Melissa B.; Wiese, Michael R.; Farr, Norma L.

    2017-01-01

    A computational study of the wing for the distributed electric propulsion X-57 Maxwell airplane configuration at cruise and takeoff/landing conditions was completed. Two unstructured-mesh, Navier-Stokes computational fluid dynamics methods, FUN3D and USM3D, were used to predict the wing performance. The goal of the X-57 wing and distributed electric propulsion system design was to meet or exceed the required lift coefficient 3.95 for a stall speed of 58 knots, with a cruise speed of 150 knots at an altitude of 8,000 ft. The X-57 Maxwell airplane was designed with a small, high aspect ratio cruise wing that was designed for a high cruise lift coefficient (0.75) at angle of attack of 0deg. The cruise propulsors at the wingtip rotate counter to the wingtip vortex and reduce induced drag by 7.5 percent at an angle of attack of 0.6deg. The unblown maximum lift coefficient of the high-lift wing (with the 30deg flap setting) is 2.439. The stall speed goal performance metric was confirmed with a blown wing computed effective lift coefficient of 4.202. The lift augmentation from the high-lift, distributed electric propulsion system is 1.7. The predicted cruise wing drag coefficient of 0.02191 is 0.00076 above the drag allotted for the wing in the original estimate. However, the predicted drag overage for the wing would only use 10.1 percent of the original estimated drag margin, which is 0.00749.

  6. 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.

  7. Supersonic aerodynamic characteristics of a low-aspect-ratio missile model with wing and tail controls and with tails in line and interdigitated

    Science.gov (United States)

    Graves, E. B.

    1972-01-01

    A study has been made to determine the aerodynamic characteristics of a low-aspect ratio cruciform missile model with all-movable wings and tails. The configuration was tested at Mach numbers from 1.50 to 4.63 with the wings in the vertical and horizontal planes and with the wings in a 45 deg roll plane with tails in line and interdigitated.

  8. Global map of lithosphere thermal thickness on a 1 deg x 1 deg grid - digitally available

    DEFF Research Database (Denmark)

    Artemieva, Irina

    2014-01-01

    than 250 km) lithosphere is restrictedsolely to young Archean terranes (3.0–2.6 Ga), while in old Archean cratons (3.6–3.0 Ga) lithospheric roots donot extend deeper than 200–220 km.The TC1 model is presented by a set of maps, which show significant thermal heterogeneity within continentalupper mantle......This presentation reports a 1 deg 1 deg global thermal model for the continental lithosphere (TC1). The modelis digitally available from the author’s web-site: www.lithosphere.info.Geotherms for continental terranes of different ages (early Archean to present) are constrained by reliabledata...

  9. Error Due to Wing Bending in Single-Camera Photogrammetric Technique

    Science.gov (United States)

    Burner, Alpheus W., Jr.; Barrows, Danny A.

    2005-01-01

    The error due to wing bending introduced into single-camera photogrammetric computations used for the determination of wing twist or control surface angular deformation is described. It is shown that the error due to wing bending when determining main wing element-induced twist is typically less than 0.05deg at the wing tip and may not warrant additional correction. It is also shown that the angular error in control surface deformation due to bending can be as large as 1deg or more if the control surface is at a large deflection angle compared to the main wing element. A correction procedure suitable for control surface measurements is presented. Simulations of the error based on typical wind tunnel measurement geometry, and results from a controlled experimental test in the test section of the National Transonic Facility (NTF) are presented to confirm the validity of the method used for correction of control surface photogrammetric deformation data. An example of a leading edge (LE) slat measurement is presented to illustrate the error due to wing bending and its correction.

  10. The Development and Control of Axial Vortices over Swept Wings

    OpenAIRE

    Klute, Sandra M.

    1999-01-01

    The natural unsteadiness in the post-breakdown flowfield of a 75° sweep delta wing at 40° angle of attack was studied with dual and single point hot-wire anemometry in the Engineering Science and Mechanics (ESM) Wind Tunnel at a Reynolds number Re = 210,000. Data were taken in five crossflow planes surrounding the wing's trailing edge. Results showed a dominant narrowband Strouhal frequency of St = 1.5 covering approximately 80% of the area with lower-intensity broadband secondary freque...

  11. Installation effects of wing-mounted turbofan nacelle-pylons on a 1/17-scale, twin-engine, low-wing transport model

    Science.gov (United States)

    Pendergraft, Odis C., Jr.; Ingraldi, Anthony M.; Re, Richard J.; Kariya, Timmy T.

    1992-01-01

    A twin-engine, low-wing transport model, with a supercritical wing of aspect ratio 10.8 designed for a cruise Mach number of 0.77 and a lift coefficient of 0.55, was tested in the Langley 16-Foot Transonic Tunnel. The purpose of this test was to compare the wing-nacelle interference effects of flow-through nacelles simulating superfan engines (very high bypass ratio (BPR is approx. = 18) turbofan engines) with the wing-nacelle interference effects of current-technology turbofans (BPR is approx. = 6). Forces and moments on the complete model were measured with a strain-gage balance, and extensive external static-pressure measurements (383 orifice locations) were made on the wing, nacelles, and pylons of the model. Data were taken at Mach numbers from 0.50 to 0.80 and at model angles of attack from -4 deg to 8 deg. Test results indicate that flow-through nacelles with a very high bypass ratio can be installed on a low-wing transport model with a lower installation drag penalty than for a conventional turbofan nacelle at a design cruise Mach number of 0.77 and lift coefficient of 0.55.

  12. Bacillus subtilis Two-Component System Sensory Kinase DegS Is Regulated by Serine Phosphorylation in Its Input Domain

    DEFF Research Database (Denmark)

    Jers, Carsten; Kobir, Ahasanul; Søndergaard, Elsebeth Oline;

    2011-01-01

    Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity...

  13. Angiopatia diabetica e amputazione degli arti inferiori: valutazioni preliminari degli episodi di ricovero ripetuti

    Directory of Open Access Journals (Sweden)

    P. Trerotoli

    2003-05-01

    Full Text Available

    Obiettivi: l’obiettivo principale dello studio è stata la valutazione dei ricoveri ripetuti nei soggetti con vasculopatia diabetica, rispetto ai soggetti con vasculopatia non diabetica.

    Materiali e Metodi: sono state selezionate le SDO del triennio 1998-2000 contenenti, in uno dei campi di diagnosi, i codici di diabete mellito, con e senza complicanze (codici ICD9 ed ICD9CM, 250.—, vasculopatia periferica (440.2 e 440.8, ulcera periferica (707.1, 707.8, 707.9, gangrena (785.4. Le SDO con diagnosi di vasculopatia diabetica sono state considerate come angiopatie diabetiche (AD; le altre sono state attribuite agli angiopatici non diabetici (AND. Le SDO con diabete non complicato e arteriopatia periferica sono state eliminate. L’intervento di amputazione è stato individuato dalla presenza del codice ICD9CM di procedura 84.—. La ripetitività degli episodi è stata valutata usando il codice fiscale come identificativo del paziente. Risultati: sono state rilevate 5814 dimissioni di AD e 9010 di AND. Le amputazioni sono state 285 (4,90% negli AD e 485 (5,38% negli AND. I ricoveri ripetuti sono stati 13 negli AD e 12 negli AND. Le amputazioni sono state osservate verso il 4°-5° episodio di ricovero negli AD, mentre già dal 2° episodio negli AND. Le ulcere erano presenti nel 36,05% (il 36,5% nel primo episodio di ricovero, che resta costante negli episodi successivi degli AND e nel 10,97% degli AD (9,84% nel primo episodio, con un incremento fino al 20% del 5° episodio. Un episodio in day-hospital (DH si osserva nel 12,32% degli AD, contro il 4,20% degli AND.

    Conclusioni: l’accesso degli AD all’assistenza intraospedaliera avviene più frequentemente in DH, i passi successivi sono caratterizzati dalla comparsa dell’ulcera o gangrena e infine dall’amputazione. Nel gruppo degli AD è stato osservato un eccesso di ospedalizzazione, probabilmente per ripetitività del

  14. Wing Warping, Roll Control and Aerodynamic Optimization of Inflatable Wings

    Science.gov (United States)

    Simpson, Andrew

    2005-11-01

    The research presents work on aerodynamic control by warping inflatable wings. Inflatable wings are deformable by their nature. Mechanical manipulation of the wing's shape has been demonstrated to alter the performance and control the vehicle in flight by deforming the trailing edge of the wing near the wing tip. Predicting and correlating the forces required in deforming the wings to a particular shape and the deformation generated for a given internal pressure were conducted through the use of photogrammetry. This research focuses on optimizing the roll moments and aerodynamic performance of the vehicle, given the current level of wing warping ability. Predictions from lifting line theory applied to wing shape changes are presented. Comparisons from the experimental results are made with lifting line analysis for wings with arbitrary twist and the solutions are used to determine rolling moment and optimum L/D. Results from flight tests will also be presented.

  15. Delta III—an evolutionary delta growth

    Science.gov (United States)

    Arvesen, R. J.; Simpson, J. S.

    1996-03-01

    In order to remain competitive in the future and expand the McDonnell Douglas Aerospace market share, MDA has developed an expendable launch system strategy that devices cost-effective launch systems from the Delta II with a growth vehicle configuration called Delta III. The Delta III evolves from the Delta II launch system through development of a larger payload fairing (4-meter diameter), new cryogenically propelled upper stage, new first stage fuel tank, and larger strap-on solid rocket motors. We are developing the Delta III using Integrated Product Development Teams that capitalize on the experience base that has led us to a world record breaking mission success of 49 consecutive Delta II missions. The Delta III first-launch capability is currently planned for the spring of 1998 in support of our first spacecraft customer, Hughes Space and Communications International.

  16. Active Control of Flapping Wings Using Wing Deformation

    Science.gov (United States)

    Tokutake, Hiroshi; Sunada, Shigeru; Ohtsuka, Yukio

    A new method for the attitude control of a flapping-wing aircraft is proposed. In this method, the variations in wing deformation, that is, the feathering angle and the camber, are controlled by pulling the wing at a certain point with a thread connected to a servomotor. The experimental setup for verifying the practicability of this method was developed, and aerodynamic forces and wing deformation were measured. It was concluded that thread control caused effective wing deformation, and the variation in the deformation generated the pitching moment that controls the attitude of a flapping-wing aircraft.

  17. Wing motion measurement and aerodynamics of hovering true hoverflies.

    Science.gov (United States)

    Mou, Xiao Lei; Liu, Yan Peng; Sun, Mao

    2011-09-01

    Most hovering insects flap their wings in a horizontal plane (body having a large angle from the horizontal), called `normal hovering'. But some of the best hoverers, e.g. true hoverflies, hover with an inclined stroke plane (body being approximately horizontal). In the present paper, wing and body kinematics of four freely hovering true hoverflies were measured using three-dimensional high-speed video. The measured wing kinematics was used in a Navier-Stokes solver to compute the aerodynamic forces of the insects. The stroke amplitude of the hoverflies was relatively small, ranging from 65 to 85 deg, compared with that of normal hovering. The angle of attack in the downstroke (∼50 deg) was much larger that in the upstroke (∼20 deg), unlike normal-hovering insects, whose downstroke and upstroke angles of attack are not very different. The major part of the weight-supporting force (approximately 86%) was produced in the downstroke and it was contributed by both the lift and the drag of the wing, unlike the normal-hovering case in which the weight-supporting force is approximately equally contributed by the two half-strokes and the lift principle is mainly used to produce the force. The mass-specific power was 38.59-46.3 and 27.5-35.4 W kg(-1) in the cases of 0 and 100% elastic energy storage, respectively. Comparisons with previously published results of a normal-hovering true hoverfly and with results obtained by artificially making the insects' stroke planes horizontal show that for the true hoverflies, the power requirement for inclined stroke-plane hover is only a little (<10%) larger than that of normal hovering.

  18. Three dimensional steady and unsteady asymmetric flow past wings of arbitrary planforms

    Science.gov (United States)

    Kandil, O. A.; Atta, E. H.; Nayfeh, A. H.

    1978-01-01

    The nonlinear discrete vortex method is extended to treat the problem of asymmetric flows past a wing with leading edge separation, including steady and unsteady flows. The problem is formulated in terms of a body fixed frame of reference and the nonlinear-discrete vortex method is modified accordingly. Although the method is general, only examples of flows past delta wings are presented due to the availability of experimental data as well as approximate theories. Comparison of results with experimental results for a delta wing undergoing a steady rolling motion at zero angle of attack demonstrate the superiority of the present method over existing approximate theories in obtaining highly accurate loads. Numerical results for yawed wings at large angles of attack are also presented. In all cases, total load coefficients, pressure distributions, and shapes of the free vortex sheets are shown.

  19. The Delta 2 launcher

    Science.gov (United States)

    Ousley, Gilbert W., Sr.

    1991-12-01

    The utilization of the Delta 2 as the vehicle for launching Aristoteles into its near Sun synchronous orbit is addressed. Delta is NASA's most reliable launch vehicle and is well suited for placing the present Aristoteles spacecraft into a 400 m circular orbit. A summary of some of the Delta 2 flight parameters is presented. Diagrams of a typical Delta 2 two stage separation are included along with statistics on delta reliability and launch plans.

  20. Global map of lithosphere thermal thickness on a 1 deg x 1 deg grid - digitally available

    Science.gov (United States)

    Artemieva, Irina

    2014-05-01

    This presentation reports a 1 deg ×1 deg global thermal model for the continental lithosphere (TC1). The model is digitally available from the author's web-site: www.lithosphere.info. Geotherms for continental terranes of different ages (early Archean to present) are constrained by reliable data on borehole heat flow measurements (Artemieva and Mooney, 2001), checked with the original publications for data quality, and corrected for paleo-temperature effects where needed. These data are supplemented by cratonic geotherms based on xenolith data. Since heat flow measurements cover not more than half of the continents, the remaining areas (ca. 60% of the continents) are filled by the statistical numbers derived from the thermal model constrained by borehole data. Continental geotherms are statistically analyzed as a function of age and are used to estimate lithospheric temperatures in continental regions with no or low quality heat flow data. This analysis requires knowledge of lithosphere age globally. A compilation of tectono-thermal ages of lithospheric terranes on a 1 deg × 1 deg grid forms the basis for the statistical analysis. It shows that, statistically, lithospheric thermal thickness z (in km) depends on tectono-thermal age t (in Ma) as: z=0.04t+93.6. This relationship formed the basis for a global thermal model of the continental lithosphere (TC1). Statistical analysis of continental geotherms also reveals that this relationship holds for the Archean cratons in general, but not in detail. Particularly, thick (more than 250 km) lithosphere is restricted solely to young Archean terranes (3.0-2.6 Ga), while in old Archean cratons (3.6-3.0 Ga) lithospheric roots do not extend deeper than 200-220 km. The TC1 model is presented by a set of maps, which show significant thermal heterogeneity within continental upper mantle. The strongest lateral temperature variations (as large as 800 deg C) are typical of the shallow mantle (depth less than 100 km). A map of the

  1. An experimental study of the flow in a wing with a partial span drooped leading edge

    Science.gov (United States)

    Winkelmann, A. E.; Tsao, C. P.

    1981-01-01

    The flow field produced by a low aspect ratio wing (AR = 3.0) with a partial span leading edge droop was investigated in a series of low speed wind tunnel tests (Reynolds number based on 17.8 cm chord = 560,000). Photographs were obtained of surface oil flow patterns over an angle of attack range of alpha = 0 to 29 deg. Flow field surveys of the partially stalled wing at alpha = 25 deg were completed using a hot-wire probe, a split-film probe and a Conrad probe. The flow field survey data was presented using a color video display. The data indicated regions of apparent reversed flow in the separation region behind the wing and indicated the general cross-sectional shape of the separated wake flow.

  2. SpaRibs Geometry Parameterization for Wings with Multiple Sections using Single Design

    Science.gov (United States)

    De, Shuvodeep; Jrad, Mohamed; Locatelli, Davide; Kapania, Rakesh K.; Baker, Myles; Pak, Chan-Gi

    2017-01-01

    The SpaRibs topology of an aircraft wing has a significant effect on its structural behavior and stability as well as the flutter performance. The development of additive manufacturing techniques like Electron Beam Free Form Fabrication (EBF3) has made it feasible to manufacture aircraft wings with curvilinear spars, ribs (SpaRibs) and stiffeners. In this article a new global-local optimization framework for wing with multiple sections using curvilinear SpaRibs is described. A single design space is used to parameterize the SpaRibs geometry. This method has been implemented using MSC-PATRAN to create a broad range of SpaRibs topologies using limited number of parameters. It ensures C0 and C1 continuities in SpaRibs geometry at the junction of two wing sections with airfoil thickness gradient discontinuity as well as mesh continuity between all structural components. This method is advantageous in complex multi-disciplinary optimization due to its potential to reduce the number of design variables. For the global-local optimization the local panels are generated by an algorithm which is totally based on a set algebra on the connectivity matrix data. The great advantage of this method is that it is completely independent of the coordinates of the nodes of the finite element model. It is also independent of the order in which the elements are distributed in the FEM. The code is verified by optimizing of the CRM Baseline model at trim condition at Mach number equal to 0.85 for five different angle of attack (-2deg, 0deg,2deg,4deg and 6deg). The final weight of the wing is 19,090.61 lb. This value is comparable to that obtained by Qiang et al. 6 (19,269 lb).

  3. Global map of lithosphere thermal thickness on a 1 deg x 1 deg grid - digitally available

    DEFF Research Database (Denmark)

    Artemieva, Irina

    2014-01-01

    than 250 km) lithosphere is restrictedsolely to young Archean terranes (3.0–2.6 Ga), while in old Archean cratons (3.6–3.0 Ga) lithospheric roots donot extend deeper than 200–220 km.The TC1 model is presented by a set of maps, which show significant thermal heterogeneity within continentalupper mantle......This presentation reports a 1 deg 1 deg global thermal model for the continental lithosphere (TC1). The modelis digitally available from the author’s web-site: www.lithosphere.info.Geotherms for continental terranes of different ages (early Archean to present) are constrained by reliabledata...... of the continents, the remaining areas (ca. 60% ofthe continents) are filled by the statistical numbers derived from the thermal model constrained by boreholedata. Continental geotherms are statistically analyzed as a function of age and are used to estimate lithospherictemperatures in continental regions...

  4. OMP Peptides Activate the DegS Stress-Sensor Protease by a Relief of Inhibition Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Jungsan; Grant, Robert A.; Sauer, Robert T.; MIT

    2010-03-19

    In the E. coli periplasm, C-terminal peptides of misfolded outer-membrane porins (OMPs) bind to the PDZ domains of the trimeric DegS protease, triggering cleavage of a transmembrane regulator and transcriptional activation of stress genes. We show that an active-site DegS mutation partially bypasses the requirement for peptide activation and acts synergistically with mutations that disrupt contacts between the protease and PDZ domains. Biochemical results support an allosteric model, in which these mutations, active-site modification, and peptide/substrate binding act in concert to stabilize proteolytically active DegS. Cocrystal structures of DegS in complex with different OMP peptides reveal activation of the protease domain with varied conformations of the PDZ domain and without specific contacts from the bound OMP peptide. Taken together, these results indicate that the binding of OMP peptides activates proteolysis principally by relieving inhibitory contacts between the PDZ domain and the protease domain of DegS.

  5. La poesia sabiana degli Anni Venti

    Directory of Open Access Journals (Sweden)

    Atilij Rakar

    1975-11-01

    Full Text Available Muovendo da un confronto fra il Saba del primo Canzoniere e le Figure e canti coi quali l'opera del poeta triestino continua negli anni venti, l'autore cerca di individuare i caratteri che meglio definiscono la poesia sabiana di questo secondo periodo. Messi in evidenza alcuni temi su cui verte il discorso sabiano fin delle Poesie dell'adolescenza e giovanili, le opere degli anni venti si rivelano come esiti di un poliforme compendio in cui il poeta vuol chiarire il senso del cammino percorso e comp:tendere quelle che sono le ragioni prime del suo poetare. Si manifestano qui, anche in maniera esplicita, alcuni motivi fondamentali del Canzionere: basti pensare, ad esempio, a Il borgo che offre la chiave per l'interprezazione di tutto un filone della tematica sabiana, o alle Fughe, con le quali il poeta vuol esprimere l'essenza del proprio sentire. La poetica delle »figure« e dei »canti« composti negli anni venti, non segnerebbe dunque una conversione di Saba ai »miti della forma«, come inducono a credere anche certe apostrofi del poeta stesso, rna può esser definita solo se vista in funzione dei contenuti che determinano il suo formarsi.

  6. Spin Interference in Rashba 2DEG Systems

    Science.gov (United States)

    Nitta, Junsaku

    The gate controllable SOI provides useful information about spin interference.1 Spin interference effects are studied in two different interference loop structures. It is known that sample specific conductance fluctuations affect the conductance in the interference loop. By using array of many interference loops, we carefully pick up TRS Altshuler-Aronov-Spivak (AAS)-type oscillation which is not sample specific and depends on the spin phase. The experimentally obtained gate voltage dependence of AAS oscillations indicates that the spin precession angle can be controlled by the gate voltage.2 We demonstrate the time reversal Aharonov-Casher (AC) effect in small arrays of mesoscopic rings.3 By using an electrostatic gate we can control the spin precession angle rate and follow the AC phase over several interference periods. We also see the second harmonic of the AC interference, oscillating with half the period. The spin interference is still visible after more than 20π precession angle. We have proposed a Stern-Gerlach type spin filter based on the Rashba SOI.4 A spatial gradient of effective magnetic field due to the nonuniform SOI separates spin up and down electrons. This spin filter works even without any external magnetic fields and ferromagnetic contacts. We show the semiconductor/ferromagnet hybrid structure is an effective way to detect magnetization process of submicron magnets. The problem of the spin injection from ferromagnetic contact into 2DEG is also disicussed. Note from Publisher: This article contains the abstract only.

  7. Evaluation of reconstruction arc in myocardial SPECT imaging using a cardiac phantom. Comparison between 360deg and 180deg arcs

    Energy Technology Data Exchange (ETDEWEB)

    Kashikura, Kenichi [Japan Science and Technology Corp., Tokyo (Japan); Kashikura, Akemi; Terada, Shinichirou; Kobayashi, Hideki

    1996-10-01

    In order to investigate the effect of reconstruction arc on myocardial SPECT images, a series of phantom studies was performed with and without plastic chambers simulating perfusion defects using {sup 201}Tl and {sup 99m}Tc. Coefficient of variations (CV) of the counts among the ROIs and defect contrast were evaluated in 360deg and 180deg images reconstructed from the same 360deg projection data. Reconstruction processes were identical for all images. In the absence of defects, the CV of the counts were approximately the same in 360deg and 180deg images. The CV of the counts in the 360deg {sup 201}Tl image, among 4 defects located on the anterior, lateral, inferoposterior, and septal walls, was superior to those in the 180deg images. In contrast, in the {sup 99m}Tc images, the CV of the counts among the 4 defects in the 180deg image was superior to those of the 360deg image. The defect contrast was changed both by the location of the defect and by the reconstruction arc ({sup 201}Tl, {sup 99m}Tc). The defect contrast of the 180deg images, in both {sup 201}Tl and {sup 99m}Tc experiments, was closer to the true contrast value as calculated by the count ratio between myocardium and defect. Although the defect contrast in the anterior, lateral and septal walls was more emphasized in the 180deg images, the defect contrast in the inferoposterior wall was less emphasized in the 180deg images compared to the 360deg ({sup 201}Tl, {sup 99m}Tc). (author)

  8. Formation of aligned CrN nanoclusters in Cr-delta-doped GaN

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y K; Kimura, S; Emura, S; Hasegawa, S; Asahi, H [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)], E-mail: zhou21@sanken.osaka-u.ac.jp

    2009-02-11

    Cr-delta-doped GaN layers were grown by radio-frequency plasma-assisted molecular-beam epitaxy on GaN template substrates. Cr flux was supplied without nitrogen flow during Cr-delta-doping. Cr incorporation into a narrow thin layer region was confirmed with the depth profile measured by secondary ion mass spectrometry. Structural properties and Cr atom alignments were studied with transmission electron microscopy. It was found that Cr-delta-doped GaN layers were coherently grown with Cr or CrGa nanoclusters in the delta-doped region for low temperature growth (350, 500 deg. C). It was also found that aligned CrN nanoclusters (approximately 5 nm vertical thickness) with NaCl-type structure were formed in the delta-doped region for the growth at 700 deg. C.

  9. Precipitation in AISI 316L(N) during creep tests at 550 and 600 deg. C up to 10 years

    Energy Technology Data Exchange (ETDEWEB)

    Padilha, A.F. [University of Sao Paulo , Department of Metallurgical and Materials Engineering, Av. Prof. Mello Moraes 2463, CEP 05508-900, Sao Paulo (Brazil); Escriba, D.M. [University of Sao Paulo , Department of Metallurgical and Materials Engineering, Av. Prof. Mello Moraes 2463, CEP 05508-900, Sao Paulo (Brazil); Materna-Morris, E. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung I, P.O. Box 3640, 76021 Karlsruhe (Germany)]. E-mail: materna-morris@imf.fzk.de; Rieth, M. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung I, P.O. Box 3640, 76021 Karlsruhe (Germany); Klimenkov, M. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung I, P.O. Box 3640, 76021 Karlsruhe (Germany)

    2007-05-15

    The precipitation behaviour in the gauge lengths and in the heads of initially solution annealed type 316L(N) austenitic stainless steel specimens tested in creep at 550 and 600 deg. C for periods of up to 85 000 h has been studied using several metallographic techniques. Three phases were detected: M{sub 23}C{sub 6}, Laves, and sigma phase. The volume fraction of the precipitated sigma phase was significantly higher than that of carbides and the Laves phase. M{sub 23}C{sub 6} carbide precipitation occurred very rapidly and was followed by the sigma and Laves phases formation in the delta ferrite islands. Sigma and Laves phases precipitated at grain boundaries after longer times. Two different mechanisms of sigma phase precipitation have been proposed, one for delta ferrite decomposition and another for grain boundary precipitation. Small quantities of the Laves phase were detected in delta ferrite, at grain boundaries and inside the grains.

  10. The structures of Arabidopsis Deg5 and Deg8 reveal new insights into HtrA proteases

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China); University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China); Gao, Feng [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China); Fan, Haitian; Shan, Xiaoyue [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China); University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China); Sun, Renhua [Chinese Academy of Sciences, 20 Nanxincun, Haidian District, Beijing 100093 (China); University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China); Liu, Lin, E-mail: liulin@ibcas.ac.cn [Chinese Academy of Sciences, 20 Nanxincun, Haidian District, Beijing 100093 (China); Gong, Weimin, E-mail: liulin@ibcas.ac.cn [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China)

    2013-05-01

    The crystal structures of Arabidopsis Deg5 and Deg8 have been determined to resolutions of 2.6 and 2.0 Å, respectively, revealing novel structural features of HtrA proteases. Plant Deg5 and Deg8 are two members of the HtrA proteases, a family of oligomeric serine endopeptidases that are involved in a variety of protein quality-control processes. These two HtrA proteases are located in the thylakoid lumen and participate in high-light stress responses by collaborating with other chloroplast proteins. Deg5 and Deg8 degrade photodamaged D1 protein of the photosystem II reaction centre, allowing its in situ replacement. Here, the crystal structures of Arabidopsis thaliana Deg5 (S266A) and Deg8 (S292A) are reported at 2.6 and 2.0 Å resolution, respectively. The Deg5 trimer contains two calcium ions in a central channel, suggesting a link between photodamage control and calcium ions in chloroplasts. Previous structures of HtrA proteases have indicated that their regulation usually requires C-terminal PDZ domain(s). Deg5 is unique in that it contains no PDZ domain and the trimeric structure of Deg5 (S266A) reveals a novel catalytic triad conformation. A similar triad conformation is observed in the hexameric structure of the single PDZ-domain-containing Deg8 (S292A). These findings suggest a novel activation mechanism for plant HtrA proteases and provide structural clues to their function in light-stress response.

  11. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  12. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  13. Twin Flavor Chicken Wings

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Ingredients:1000g chicken wings,about,100g Shredded rape-seedleaves,100g black sesame seeds,7g salt,5g sugar,3gMSG,10g cooking wine,5g cassia bark,1000g cookingoil(actual consumption only 100 grams),one egg,anoptional amount of scallion,ginger root,starch and

  14. Neutron irradiation of silicon diodes at temperatures of +20deg C and -20deg C

    Energy Technology Data Exchange (ETDEWEB)

    Anghinolfi, F.; Glaser, M.; Heijne, E.H.M.; Jarron, P.; Lemeilleur, F.; Occelli, E.; Poppleton, A. (CERN, Geneva (Switzerland)); Bardos, R.; Gorfine, G.; Moorhead, G.; Taylor, G.; Tovey, S. (School of Physics, Univ. Melbourne, Parkville (Australia)); Bates, S.J.; Munday, D.J.; Parker, M.A. (Cavendish Lab., Univ. Cambridge (United Kingdom)); Bonino, R.; Clark, A.G.; Wu, X. (DPNC, Univ. Geneva (Switzerland)); Claussen, N.; Fretwurst, E.; Lindstroem, G.; Papendick, B.; Schulz, T.; Wunstorf, R. (Inst. fuer Experimentalphysik, Univ. Hamburg (Germany)); Goessling, C.; Klingenberg, R.; Pagel, H.; Pollmann, D.; Rolf, A. (Inst. fuer Physik, Univ. Dortmund (Germany)); Scampoli, P. (Dipt. di Fisica, Univ. Perugia (Italy) INFN, Sezione Perugia (Italy)); Weidberg, A.R. (Dept. of Nuclear Physics, Oxford Univ. (United Kingdom)); RD2 Collaboration

    1993-03-01

    We report measurements of the behaviour of silicon diodes when exposed to integrated neutron doses of up to 5x10[sup 13] neutrons/cm[sup 2]. The measurements have been made at diode temperatures between room temperature and -20deg C. From measurements of the diode leakage current and depletion voltage, and consequent evaluations of the effective impurity concentration, the temperature dependence of these quantities is discussed in terms of the annealing behaviour of the diodes. Comments are made on the suitability of silicon as a detector medium for particle physics experiments at future accelerators. (orig.).

  15. Theoretical-Numerical Study of Feasibility of Use of Winglets on Low Aspect Ration Wings at Subsonic and Transonic Mach Numbers to Reduce Drag

    Science.gov (United States)

    Kuhlman, John M.; Liaw, Paul; Cerney, Michael J.

    1988-01-01

    A numerical design study was conducted to assess the drag reduction potential of winglets installed on a series of low aspect ratio wings at a design point of M=0.8, C sub L=0.3. Wing-winglet and wing-alone design geometries were obtained for wings of aspect ratios between 1.75 and 2.67, having leading edge sweep angles between 45 and 60 deg. Winglet length was fixed at 15% of wing semispan. To assess the relative performance between wing-winglet and wing-alone configurations, the PPW nonlinear extended small disturbance potential flow code was utilized. This model has proven to yield plausible transonic flow field simulations for the series of low aspect ratio configurations selected. Predicted decreases in pressure drag coefficient for the wing-winglet configurations relative to the corresponding wing-alone planform are about 15% at the design point. Predicted decreases in wing-winglet total drag coefficient are about 12%, relative to the corresponding wing-alone design. Longer winglets (25% of the wing semispan) yielded decreases in the pressure drag of up to 22% and total drag of up to 16.4%. These predicted drag coefficient reductions are comparable to reductions already demonstrated by actual winglet designs installed on higher aspect ratio transport type aircraft.

  16. DegP Chaperone Suppresses Toxic Inner Membrane Translocation Intermediates

    Science.gov (United States)

    Braselmann, Esther; Chaney, Julie L.; Champion, Matthew M.

    2016-01-01

    The periplasm of Gram-negative bacteria includes a variety of molecular chaperones that shepherd the folding and targeting of secreted proteins. A central player of this quality control network is DegP, a protease also suggested to have a chaperone function. We serendipitously discovered that production of the Bordetella pertussis autotransporter virulence protein pertactin is lethal in Escherichia coli ΔdegP strains. We investigated specific contributions of DegP to secretion of pertactin as a model system to test the functions of DegP in vivo. The DegP chaperone activity was sufficient to restore growth during pertactin production. This chaperone dependency could be relieved by changing the pertactin signal sequence: an E. coli signal sequence leading to co-translational inner membrane (IM) translocation was sufficient to suppress lethality in the absence of DegP, whereas an E. coli post-translational signal sequence was sufficient to recapitulate the lethal phenotype. These results identify a novel connection between the DegP chaperone and the mechanism used to translocate a protein across the IM. Lethality coincided with loss of periplasmic proteins, soluble σE, and proteins regulated by this essential stress response. These results suggest post-translational IM translocation can lead to the formation of toxic periplasmic folding intermediates, which DegP can suppress. PMID:27626276

  17. DegP Chaperone Suppresses Toxic Inner Membrane Translocation Intermediates.

    Science.gov (United States)

    Braselmann, Esther; Chaney, Julie L; Champion, Matthew M; Clark, Patricia L

    2016-01-01

    The periplasm of Gram-negative bacteria includes a variety of molecular chaperones that shepherd the folding and targeting of secreted proteins. A central player of this quality control network is DegP, a protease also suggested to have a chaperone function. We serendipitously discovered that production of the Bordetella pertussis autotransporter virulence protein pertactin is lethal in Escherichia coli ΔdegP strains. We investigated specific contributions of DegP to secretion of pertactin as a model system to test the functions of DegP in vivo. The DegP chaperone activity was sufficient to restore growth during pertactin production. This chaperone dependency could be relieved by changing the pertactin signal sequence: an E. coli signal sequence leading to co-translational inner membrane (IM) translocation was sufficient to suppress lethality in the absence of DegP, whereas an E. coli post-translational signal sequence was sufficient to recapitulate the lethal phenotype. These results identify a novel connection between the DegP chaperone and the mechanism used to translocate a protein across the IM. Lethality coincided with loss of periplasmic proteins, soluble σE, and proteins regulated by this essential stress response. These results suggest post-translational IM translocation can lead to the formation of toxic periplasmic folding intermediates, which DegP can suppress.

  18. SMA actuators for morphing wings

    Science.gov (United States)

    Brailovski, V.; Terriault, P.; Georges, T.; Coutu, D.

    An experimental morphing laminar wing was developed to prove the feasibility of aircraft fuel consumption reduction through enhancement of the laminar flow regime over the wing extrados. The morphing wing prototype designed for subsonic cruise flight conditions (Mach 0.2 … 0.3; angle of attack - 1 … +2∘), combines three principal subsystems: (1) flexible extrados, (2) rigid intrados and (3) an actuator group located inside the wing box. The morphing capability of the wing relies on controlled deformation of the wing extrados under the action of shape memory alloys (SMA) actuators. A coupled fluid-structure model of the morphing wing was used to evaluate its mechanical and aerodynamic performances in different flight conditions. A 0.5 m chord and 1 m span prototype of the morphing wing was tested in a subsonic wind tunnel. In this work, SMA actuators for morphing wings were modeled using a coupled thermo-mechanical finite element model and they were windtunnel validated. If the thermo-mechanical model of SMA actuators presented in this work is coupled with the previously developed structureaerodynamic model of the morphing wing, it could serve for the optimization of the entire morphing wing system.

  19. Involvement of DEG5 and DEG8 proteases in the turnover of the photosystem II reaction center D1 protein under heat stress in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    SUN XuWu; WANG LiYuan; ZHANG LiXin

    2007-01-01

    Deg5,deg8 and the double mutant,deg5deg8 of Arabidopsis thaliana were used to study the physiological role of the DEG proteases in the repair cycle of photosystem II (PSII) under heat stress. PSII activity in deg mutants showed increased sensitivity to heat stress,and the extent of this effect was greater in the double mutant,deg5deg8,than in the single mutants,deg5 and deg8. Degradation of the D1 protein was slower in the mutants than in the WT plants. Furthermore,the levels of other PSII reaction center proteins tested remained relatively stable in the mutant and WT plants following high-temperature treatment. Thus,our results indicate that DEG5 and DEG8 may have synergistic function in degradation of D1 protein under heat stress.

  20. When wings touch wakes: understanding locomotor force control by wake wing interference in insect wings.

    Science.gov (United States)

    Lehmann, Fritz-Olaf

    2008-01-01

    Understanding the fluid dynamics of force control in flying insects requires the exploration of how oscillating wings interact with the surrounding fluid. The production of vorticity and the shedding of vortical structures within the stroke cycle thus depend on two factors: the temporal structure of the flow induced by the wing's own instantaneous motion and the flow components resulting from both the force production in previous wing strokes and the motion of other wings flapping in close proximity. These wake-wing interactions may change on a stroke-by-stroke basis, confronting the neuro-muscular system of the animal with a complex problem for force control. In a single oscillating wing, the flow induced by the preceding half stroke may lower the wing's effective angle of attack but permits the recycling of kinetic energy from the wake via the wake capture mechanism. In two-winged insects, the acceleration fields produced by each wing may strongly interact via the clap-and-fling mechanism during the dorsal stroke reversal. Four-winged insects must cope with the fact that the flow over their hindwings is affected by the presence of the forewings. In these animals, a phase-shift between the stroke cycles of fore- and hindwing modulates aerodynamic performance of the hindwing via leading edge vortex destruction and changes in local flow condition including wake capture. Moreover, robotic wings demonstrate that phase-lag during peak performance and the strength of force modulation depend on the vertical spacing between the two stroke planes and the size ratio between fore- and hindwing. This study broadly summarizes the most prominent mechanisms of wake-wing and wing-wing interactions found in flapping insect wings and evaluates the consequences of these processes for the control of locomotor forces in the behaving animal.

  1. The Prevalence of the 22 deg Halo in Cirrus Clouds

    Science.gov (United States)

    Diedenhoven, vanBastiaan

    2014-01-01

    Halos at 22 deg from the sun attributed to randomly-orientated, pristine hexagonal crystals are frequently observed through ice clouds. These frequent sightings of halos formed by pristine crystals pose an apparent inconsistency with the dominance of distorted, nonpristine ice crystals indicated by in situ and remote sensing data. Furthermore, the 46 deg halo, which is associated with pristine hexagonal crystals as well, is observed far less frequently than the 22 deg halo. Considering that plausible mechanisms that could cause crystal distortion such as aggregation, sublimation, riming and collisions are stochastic processes that likely lead to distributions of crystals with varying distortion levels, here the presence of the 22 deg and 46 deg halo features in phase functions of mixtures of pristine and distorted hexagonal ice crystals is examined. We conclude that the 22 deg halo feature is generally present if the contribution by pristine crystals to the total scattering cross section is greater than only about 10% in the case of compact particles or columns, and greater than about 40% for plates. The 46 deg halo feature is present only if the mean distortion level is low and the contribution of pristine crystals to the total scattering cross section is above about 20%, 50% and 70%, in the case of compact crystals, plates and columns, respectively. These results indicate that frequent sightings of 22 deg halos are not inconsistent with the observed dominance of distorted, non-pristine ice crystals. Furthermore, the low mean distortion levels and large contributions by pristine crystals needed to produce the 461 halo features provide a potential explanation of the common sighting of the 22 deg halo without any detectable 46 deg halo.

  2. Wing and body kinematics of takeoff and landing flight in the pigeon (Columba livia).

    Science.gov (United States)

    Berg, Angela M; Biewener, Andrew A

    2010-05-01

    Takeoff and landing are critical phases in a flight. To better understand the functional importance of the kinematic adjustments birds use to execute these flight modes, we studied the wing and body movements of pigeons (Columba livia) during short-distance free-flights between two perches. The greatest accelerations were observed during the second wingbeat of takeoff. The wings were responsible for the majority of acceleration during takeoff and landing, with the legs contributing only one-quarter of the acceleration. Parameters relating to aerodynamic power output such as downstroke amplitude, wingbeat frequency and downstroke velocity were all greatest during takeoff flight and decreased with each successive takeoff wingbeat. This pattern indicates that downstroke velocity must be greater for accelerating flight to increase the amount of air accelerated by the wings. Pigeons used multiple mechanisms to adjust thrust and drag to accelerate during takeoff and decelerate during landing. Body angle, tail angle and wing plane angles all shifted from more horizontal orientations during takeoff to near-vertical orientations during landing, thereby reducing drag during takeoff and increasing drag during landing. The stroke plane was tilted steeply downward throughout takeoff (increasing from -60+/-5 deg. to -47+/-1 deg.), supporting our hypothesis that a downward-tilted stroke plane pushes more air rearward to accelerate the bird forward. Similarly, the stroke plane tilted upward during landing (increasing from -1+/-2 deg. to 17+/-7 deg.), implying that an upward-tilted stroke plane pushes more air forward to slow the bird down. Rotations of the stroke plane, wing planes and tail were all strongly correlated with rotation of the body angle, suggesting that pigeons are able to redirect aerodynamic force and shift between flight modes through modulation of body angle alone.

  3. La formazione iniziale degli insegnanti in Italia

    Directory of Open Access Journals (Sweden)

    Carlo Cappa

    2013-07-01

    Full Text Available L’articolo è diviso in tre parti. La prima presenta gli elementi storici e di sfondo che occorre tenere presenti per comprendere l’evoluzione della formazione iniziale degli insegnanti verso gli attuali modelli, che pur essendo oggi tutti gestiti dalle università conservano una sensibile diversità a seconda che si tratti di formare maestri per la scuola dell’infanzia e primaria oppure professori di scuola secondaria di primo e secondo grado. La seconda parte analizza il passaggio, maturato tra la fine del secolo scorso e l’inizio del XXI secolo, della formazione dei maestri dalla scuola secondaria (Istituto magistrale all’università (Corso di laurea in Scienze della formazione primaria, e l’istituzione delle Scuole di Specializzazione per l’Insegnamento Secondario (SSIS fino alla soppressione di queste ultime, avvenuta nel 2009. La terza parte presenta il quadro attuale della formazione iniziale dei docenti in Italia con riguardo soprattutto agli insegnanti della scuola secondaria, per i quali – a differenza che per i maestri - sono intervenute dal 2010 importanti innovazioni legislative. Le SSIS sono state infatti sostituite con il Tirocinio Formativo Attivo (TFA, attualmente in fase di attuazione da parte delle università. Nella parte finale dell’articolo si traccia un primo bilancio dell’esperienza del TFA e si indicano alcuni problemi aperti. Il focus rimane sostanzialmente sulla formazione iniziale, in quanto in Italia la formazione in servizio, che pure non è del tutto assente, non è mai stata oggetto di una normativa né di una azione organica, ma avviene, quando avviene, sulla base di iniziative di specifici gruppi o associazioni.The article is organised in three parts. The first one illustrates the historical features and the institutional and political background that have to be taken into account in order to understand how initial teacher education and training has developed in Italy. Presently, all teacher

  4. Tabulated pressure measurements of a NASA supercritical-wing research airplane model with and without fuselage area-rule additions at Mach 0.25 to 1.00

    Science.gov (United States)

    Harris, C. D.; Bartlett, D. W.

    1972-01-01

    Basic pressure measurements were made on a 0.087-scale model of a supercritical wing research airplane in the Langley 8 foot transonic pressure tunnel at Mach numbers from 0.25 to 1.00 to determine the effects on the local aerodynamic loads over the wing and rear fuselage of area-rule additions to the sides of the fuselage. In addition, pressure measurements over the surface of the area-rule additions themselves were obtained at angles of sideslip of approximately - 5 deg, 0 deg, and 5 deg to aid in the structural design of the additions. Except for representative figures, results are presented in tabular form without analysis.

  5. Design optimization of deployable wings

    Science.gov (United States)

    Gaddam, Pradeep

    Morphing technology is an important aspect of UAV design, particularly in regards to deployable systems. The design of such system has an important impact on the vehicle's performance. The primary focus of the present research work was to determine the most optimum deployable wing design from 3 competing designs and develop one of the deployable wing designs to test in the research facility. A Matlab code was developed to optimize 3 deployable wing concepts inflatable, inflatable telescopic and rigid-folding wings based on a sequential optimization strategy. The constraints that were part of the code include the packaging constraints during its stowed state, fixed length of the deployed section and the minimum L/D constraint. This code resulted in determining the optimum weight of all the 3 designs, the most optimum weight design is the inflatable wing design. This is a result of the flexible skin material and also due to no rigid parts in the deployed wing section. Another goal of the research involved developing an inflatable telescopic wing. The prototype was tested in a wind tunnel, while the actual wing was tested in the altitude chamber to determine the deployment speed, input pressure, analyze and predict the deployment sequence and behavior of the wing at such high wind speeds and altitudes ranging from 60,000 ft to 90,000 ft. Results from these tests allowed us to conclude the deployment sequence of the telescopic wing followed from the root to the tip section. The results were used to analyze the deployment time of the wing. As expected the deployment time decreased with an increase in input pressure. The results also show us that as the altitude increases, the deployment speed of the wing also increased. This was demonstrated when the wing was tested at a maximum altitude pressure of 90,000ft, well above the design altitude of 60,000ft.

  6. Pressure distributions and oil-flow patterns for a swept circulation-control wing

    Science.gov (United States)

    Keener, Earl R.; Sanderfer, Dwight T.; Wood, Norman J.

    1987-01-01

    Pressure distributions and photographs of oil flow patterns are presented for a circulation control wing. The model was an aspect ratio four semispan wing mounted on the side wall of the NASA Ames Transonic Wind Tunnel. The airfoil was a 20 percent thick ellipse, modified with circular leading and trailing edges of 4 percent radius, and had a 25.4 cm constant chord. This configuration does not represent a specific wing design, but is generic. A full span, tangetial, rearward blowing, circulation control slot was incorporated ahead of the trailing edge on the upper surface. The wing was tested at Mach numbers from 0.3 to 0.75 at sweep angle of 0 to 45 deg with internal to external pressure ratios of 1.0 to 3.0. Lift and pitching momemt coefficients were obtained from measured pressure distributions at five span stations. When the conventional corrections resulting from sweep angle are applied to the lift and moment of circulation control sections, no additional corrections are necessary to account for changes in blowing efficiency. This is demonstrated for an aft sweep angle of 45 deg. An empirical technique for estimating the downwash distribution of a swept wing was validated.

  7. Wind tunnel tests on a tail-less swept wing span-distributed cargo aircraft configuration

    Science.gov (United States)

    Rao, D. M.; Huffman, J. K.

    1978-01-01

    The configuration consisted of a 30 deg -swept, untapered, untwisted wing utilizing a low-moment cambered airfoil of 20 percent streamwise thickness designed for low wave drag at M = 0.6, C sub L = 0.4. The tests covered a range of Mach numbers 0.3 to 0.725 and chord Reynolds number 1,100,000 to 2,040,000, angles of attack up to model buffet and sideslip angles + or - 4 deg. Configuration build up, wing pod filleting, airfoil modification and trailing edge control deflection effects were briefly investigated. Three wing tip vertical tail designs were also tested. Wing body filleting and a simple airfoil modification both produced increments to maximum lift/drag ratio. Addition of pods eliminated pitch instability of the basic wing. While the magnitude of these benefits probably was Reynolds number sensitive, they underline the potential for improving the aerodynamics of the present configuration. The cruise parameter (product of Mach number and lift/drag ratio) attained a maximum close to the airfoil design point. The configuration was found to be positively stable with normal control effectiveness about all three axes in the Mach number and C sub L range of interest.

  8. Apparent and partial molar volumes of long-chain alkyldimethylbenzylammonium chlorides and bromides in aqueous solutions at T=15 deg. C and T=25 deg. C[Alkyldimethylbenzylammonium chlorides; Alkyldimethylbenzylammonium bromides; Micellization; Density; Apparent molar volumes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Perez, A.; Ruso, J.M.; Nimo, J.; Rodriguez, J.R. E-mail: fmjulio@usc.es

    2003-12-01

    Density measurements of dodecyl- (C{sub 12}DBACl), tetradecyl- (C{sub 14}DBACl), hexadecyldimethylbenzylammonium chloride (C{sub 16}DBACl) and of decyl- (C{sub 10}DBABr) and dodecyldimethylbenzylammonium bromide (C{sub 12}DBABr) in aqueous solutions at T=15 deg. C and T=25 deg. C have been carried out. From these results, apparent and partial molar volumes were calculated. Positive deviations from the Debye-Hueckel limiting law provide evidence for limited association at concentrations below the critical micelle concentration. The change of the apparent molar volume upon micellization was calculated. The relevant parameters have been presented in function of the alkyl chain length. Apparent molar volumes of the present compounds in the micellar phase, V{sub phi}{sup m}, and the change upon micellization, {delta}V{sub phi}{sup m}, have been discussed in terms of temperature and type of counterion.

  9. Installation effects of long-duct pylon-mounted nacelles on a twin-jet transport model with swept supercritical wing

    Science.gov (United States)

    Lee, E. E., Jr.; Pendergraft, O. C., Jr.

    1985-01-01

    The installation interference effects of an underwing-mounted, long duct, turbofan nacelle were evaluated in the Langley 16-Foot Transonic Tunnel with two different pylon shapes installed on a twin engine transport model having a supercritical wing swept 30 deg. Wing, pylon, and nacelle pressures and overall model force data were obtained at Mach numbers from 0.70 to 0.83 and nominal angles of attack from -2 deg to 4 deg at an average unit Reynolds number of 11.9 x 1,000,000 per meter. The results show that adding the long duct nacelles to the supercritical wing, in the near sonic flow field, changed the magnitude and direction of flow velocities over the entire span, significantly reduced cruise lift, and caused large interference drag on the nacelle afterbody.

  10. An experimental study of spanwise flow effects on lift generation in flapping wings

    Science.gov (United States)

    Hong, Youngsun

    Using a combination of force transducer measurement to quantify net lift force, a high frame rate camera to quantify and subtract inertial contributions, and Digital Particle Image Velocimetry (DPIV) to calculate aerodynamic contributions in the spanwise plane, the contribution of spanwise flow to the generation of lift force in wings undergoing a pure flapping motion in hover is shown as a function of flapping angle throughout the flapping cycle. When flapping a flat plate wing and a wing of identical wing area and aspect ratio, but cambered in span (both wings in hover with no change in pitch), the spanwise cambered wing was found to generate a greater mean lift force through the whole flap cycle under the same acceleration. However, depending on the angle in flapping arc, the spanwise cambered wing can generate less lift than the flat wing. Additionally, since the lift force generated by the wingtip vortex in the spanwise plane resulting from the flapping motion has yet to be directly quantified, the wingtip vortex is investigated to determine precisely how it augments the lift force through the various phases in the flapping motion. Vortices in the vicinity of the wingtip generate lift force in the spanwise plane of flapping wings. In classical fixed wing aerodynamics, the presence of wing tip vortices has been shown to increase the lift locally near the tip. Also, the impingement of large vortices on the upper surface of delta wings is considered to contribute largely to the lift force at higher angles of attack. This study determined that vortices in the spanwise plane (streamwise vorticity) generate lift in a similar manner in flapping wings. Using a mechanical ornithopter with wings fabricated in-house, vortices were identified at several different locations along the span of the wing, and at numerous different points throughout the flapping cycle under a variety of operating conditions. The lift generated by these spanwise planar oriented vortices was

  11. Electromagnetic excitation of the delta resonance in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, J.S.; Dodge, W.R.; Lightbody J.W. Jr.; Maruyama, X.K.; Adler, J.h.; Hansen, K.; Schro-dash-barder, B.; Bernstein, A.M.; Blomqvist, K.I.; Cottman, B.H.; and others

    1987-03-01

    Inclusive cross sections for the proton and nuclear targets of A = 4, 9, 12, and 16 were measured for 537 and 730 MeV electrons scattered at 37.1 deg. Systematic features of the continuum scattering data are compared with other electron scattering data and with photoabsorption measurements. A model calculation based on the isobar-hole formalism is compared with the data in the delta resonance region.

  12. Aeropropulsive characteristics of twin nonaxisymmetric vectoring nozzles installed with forward-swept and aft-swept wings. [in the Langley 16 Foot Transonic Tunnel

    Science.gov (United States)

    Capone, F. J.

    1981-01-01

    An investigation was conducted in the Langley 16 Foot Transonic Tunnel to determine the aeropropulsive characteristics of a single expansion ramp nozzle (SERN) and a two dimensional convergent divergent nozzle (2-D C-D) installed with both an aft swept and a forward swept wing. The SERN was tested in both an upright and an inverted position. The effects of thrust vectoring at nozzle vector angles from -5 deg to 20 deg were studied. This investigation was conducted at Mach numbers from 0.40 to 1.20 and angles of attack from -2.0 deg to 16 deg. Nozzle pressure ratio was varied from 1.0 (jet off) to about 9.0. Reynolds number based on the wing mean geometric chord varied from about 3 million to 4.8 million, depending upon free stream number.

  13. Automated measurement of Drosophila wings

    Directory of Open Access Journals (Sweden)

    Mezey Jason

    2003-12-01

    Full Text Available Abstract Background Many studies in evolutionary biology and genetics are limited by the rate at which phenotypic information can be acquired. The wings of Drosophila species are a favorable target for automated analysis because of the many interesting questions in evolution and development that can be addressed with them, and because of their simple structure. Results We have developed an automated image analysis system (WINGMACHINE that measures the positions of all the veins and the edges of the wing blade of Drosophilid flies. A video image is obtained with the aid of a simple suction device that immobilizes the wing of a live fly. Low-level processing is used to find the major intersections of the veins. High-level processing then optimizes the fit of an a priori B-spline model of wing shape. WINGMACHINE allows the measurement of 1 wing per minute, including handling, imaging, analysis, and data editing. The repeatabilities of 12 vein intersections averaged 86% in a sample of flies of the same species and sex. Comparison of 2400 wings of 25 Drosophilid species shows that wing shape is quite conservative within the group, but that almost all taxa are diagnosably different from one another. Wing shape retains some phylogenetic structure, although some species have shapes very different from closely related species. The WINGMACHINE system facilitates artificial selection experiments on complex aspects of wing shape. We selected on an index which is a function of 14 separate measurements of each wing. After 14 generations, we achieved a 15 S.D. difference between up and down-selected treatments. Conclusion WINGMACHINE enables rapid, highly repeatable measurements of wings in the family Drosophilidae. Our approach to image analysis may be applicable to a variety of biological objects that can be represented as a framework of connected lines.

  14. Wind-tunnel investigation of a Fowler flap and spoiler for an advanced general aviation wing

    Science.gov (United States)

    Paulson, J. W., Jr.

    1976-01-01

    The wing was tested without fuselage or empennage and was fitted with approximately three-quarter span Fowler flaps and half span spoilers. The spoilers were hinged at the 70 percent chord point and vented when the flaps were deflected. Static longitudinal and lateral aerodynamic data were obtained over an angle of attack range of -8 deg to 22 deg for various flap deflections and positions, spoiler geometries, and vent lip geometries. Lateral characteristics indicate that the spoilers are generally adequate for lateral control. In general, the spoiler effectiveness increases with increasing angle of attack, increases with increasing flap deflections, and is influenced by vent lip geometry. In addition, the data show that some two-dimensional effects on spoiler effectiveness are reduced in the three-dimensional case. Results also indicate significant increase in lift coefficient as the Fowler flaps are deflected; when the flap was fully deflected, the maximum wing lift coefficient was increased about 96 percent.

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

    Science.gov (United States)

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

    1959-01-01

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

  16. Stiffness of desiccating insect wings

    Energy Technology Data Exchange (ETDEWEB)

    Mengesha, T E; Vallance, R R [Department of Mechanical Engineering, The George Washington University, 738 Phillips Hall, 801 22nd St NW, Washington, DC 20052 (United States); Mittal, R, E-mail: vallance@gwu.edu [Department of Mechanical Engineering, Johns Hopkins University, 126 Latrobe Hall, 3400 N Charles Street, Baltimore, MD 21218 (United States)

    2011-03-15

    The stiffness of insect wings is typically determined through experimental measurements. Such experiments are performed on wings removed from insects. However, the wings are subject to desiccation which typically leads to an increase in their stiffness. Although this effect of desiccation is well known, a comprehensive study of the rate of change in stiffness of desiccating insect wings would be a significant aid in planning experiments as well as interpreting data from such experiments. This communication presents a comprehensive experimental analysis of the change in mass and stiffness of gradually desiccating forewings of Painted Lady butterflies (Vanessa cardui). Mass and stiffness of the forewings of five butterflies were simultaneously measured every 10 min over a 24 h period. The averaged results show that wing mass declined exponentially by 21.1% over this time period with a time constant of 9.8 h, while wing stiffness increased linearly by 46.2% at a rate of 23.4 {mu}N mm{sup -1} h{sup -1}. For the forewings of a single butterfly, the experiment was performed over a period of 1 week, and the results show that wing mass declined exponentially by 52.2% with a time constant of 30.2 h until it reached a steady-state level of 2.00 mg, while wing stiffness increased exponentially by 90.7% until it reached a steady-state level of 1.70 mN mm{sup -1}. (communication)

  17. Delta hedging strategies comparison

    DEFF Research Database (Denmark)

    De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.

    2008-01-01

    In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model ...

  18. Beetle wings are inflatable origami

    Science.gov (United States)

    Chen, Rui; Ren, Jing; Ge, Siqin; Hu, David

    2015-11-01

    Beetles keep their wings folded and protected under a hard shell. In times of danger, they must unfold them rapidly in order for them to fly to escape. Moreover, they must do so across a range of body mass, from 1 mg to 10 grams. How can they unfold their wings so quickly? We use high-speed videography to record wing unfolding times, which we relate to the geometry of the network of blood vessels in the wing. Larger beetles have longer unfolding times. Modeling of the flow of blood through the veins successfully accounts for the wing unfolding speed of large beetles. However, smaller beetles have anomalously short unfolding times, suggesting they have lower blood viscosity or higher driving pressure. The use of hydraulics to unfold complex objects may have implications in the design of micro-flying air vehicles.

  19. AERODYNAMICS OF WING TIP SAILS

    Directory of Open Access Journals (Sweden)

    MUSHTAK AL-ATABI

    2006-06-01

    Full Text Available Observers have always been fascinated by soaring birds. An interesting feature of these birds is the existence of few feathers extending from the tip of the wing. In this paper, small lifting surfaces were fitted to the tip of a NACA0012 wing in a fashion similar to that of wing tip feathers. Experimental measurements of induced drag, longitudinal static stability and trailing vortex structure were obtained.The tests showed that adding wing tip surfaces (sails decreased the induced drag factor and increased the longitudinal static stability. Results identified two discrete appositely rotated tip vortices and showed the ability of wing tip surfaces to break them down and to diffuse them.

  20. Horizontal Symmetries $\\Delta(150)$ and $\\Delta(600)$

    CERN Document Server

    Lam, C S

    2013-01-01

    Using group theory of mixing to examine all finite subgroups of SU(3) with an order less than 512, we found recently that only the group $\\Delta(150)$ can give rise to a correct reactor angle $\\th_{13}$ of neutrino mixing without any free parameter. It predicts $\\sin^22\\th_{13}=0.11$ and a sub-maximal atmospheric angle with $\\sin^22\\th_{23}=0.94$, in good agreement with experiment. The solar angle $\\th_{12}$, the CP phase $\\d$, and the neutrino masses $m_i$ are left as free parameters. In this article we provide more details of this case, discuss possible gain and loss by introducing right-handed symmetries, and/or valons to construct dynamical models. A simple model is discussed where the solar angle agrees with experiment, and all its mixing parameters can be obtained from the group $\\Delta(600)$ by symmetry alone. The promotion of $\\Delta(150)$ to $\\Delta(600)$ is on the one hand analogous to the promotion of $S_3$ to $S_4$ in the presence of tribimaximal mixing, and on the other hand similar to the extens...

  1. Isotopic variations ({delta}{sup 13} C and {delta}{sup 18} O) in Siderastrea stellata (Cnidaria-Anthozoa), Itamaraca island, State of Pernambuco, Northeastern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Valderez P.; Sial, Alcides N. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Geologia. Lab. de Isotopos Estaveis; Mayeal, Elga M.; Exner, Marco Antonio [Pernambuco Univ., Recife, PE (Brazil). Dept. de Zoologia. Lab. de Macro e Megabentos

    1998-12-01

    Isotopic determinations for O and C were performed in coral skeletons collected in beach rocks from two localities (Orange and Catuama), Itamaraca Island, north littoral of the State of pernambuco, northeastern Brazil. Large variations of {delta}{sup 18} O and {delta}{sup 13} C in corals from both localities are found, the largest ones being observed at the Orange locality {delta}{sup 13} C in this locality varies from -0.8 to +1.8% PDB and {delta}{sup 1.8} O from -5.3 to -1.8% PDB, while at the Catuama locality, they vary from -1.8 to 0.1% PDB and -3.8 to -2.7% PDB, respectively. Large variations in {delta}{sup 18} O (up to 2.5%) coupled with weakly defined positive correlation between {delta}{sup 18} O and {delta}{sup 13} C, can be attributed to temperature variations as consequence of climatic perturbations. Temperature estimates, calculated from {delta}{sup 18} O values, assuming isotopic equilibrium with seawater, yield values between 24.9 deg C and 43.1 deg C at Orange, and from 28.4 deg C to 35 deg C at Catuama, all of them (expect one growth band from one sample) are high enough for the full development of the coral colony. Temperature average is 31.4 deg C at Orange, which is a little bit higher than that at Catuama, but both of them indicate thermal stress conditions. In all analyzed specimens, expect for one, at Orange, T increases was accompanied by decreasing in the organic activity, as suggested by corresponding negative {delta}{sup 13} C anomaly. Therefore, the observed bleaching is possibly related to thermal stress and the high T may be related to the El Nino-Southern Oscillation (ENSO) warning event. On the other hand, anthropogenic action at Orange, local of intense tourism throughout the year, coupled with high rate of sedimentation in the region, may contribute to the observed coral bleaching. (author)

  2. Hot deformation behavior of delta-processed superalloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-03-25

    Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

  3. The family of Deg/HtrA proteases in plants

    Directory of Open Access Journals (Sweden)

    Schuhmann Holger

    2012-04-01

    Full Text Available Abstract Background The Deg/HtrA family of ATP-independent serine endopeptidases is present in nearly all organisms from bacteria to human and vascular plants. In recent years, multiple deg/htrA protease genes were identified in various plant genomes. During genome annotations most proteases were named according to the order of discovery, hence the same names were sometimes given to different types of Deg/HtrA enzymes in different plant species. This can easily lead to false inference of individual protease functions based solely on a shared name. Therefore, the existing names and classification of these proteolytic enzymes does not meet our current needs and a phylogeny-based standardized nomenclature is required. Results Using phylogenetic and domain arrangement analysis, we improved the nomenclature of the Deg/HtrA protease family, standardized protease names based on their well-established nomenclature in Arabidopsis thaliana, and clarified the evolutionary relationship between orthologous enzymes from various photosynthetic organisms across several divergent systematic groups, including dicots, a monocot, a moss and a green alga. Furthermore, we identified a “core set” of eight proteases shared by all organisms examined here that might provide all the proteolytic potential of Deg/HtrA proteases necessary for a hypothetical plant cell. Conclusions In our proposed nomenclature, the evolutionarily closest orthologs have the same protease name, simplifying scientific communication when comparing different plant species and allowing for more reliable inference of protease functions. Further, we proposed that the high number of Deg/HtrA proteases in plants is mainly due to gene duplications unique to the respective organism.

  4. The calculation of steady non-linear transonic flow over finite wings with linear theory aerodynamics

    Science.gov (United States)

    Cunningham, A. M., Jr.

    1976-01-01

    The feasibility of calculating steady mean flow solutions for nonlinear transonic flow over finite wings with a linear theory aerodynamic computer program is studied. The methodology is based on independent solutions for upper and lower surface pressures that are coupled through the external flow fields. Two approaches for coupling the solutions are investigated which include the diaphragm and the edge singularity method. The final method is a combination of both where a line source along the wing leading edge is used to account for blunt nose airfoil effects; and the upper and lower surface flow fields are coupled through a diaphragm in the plane of the wing. An iterative solution is used to arrive at the nonuniform flow solution for both nonlifting and lifting cases. Final results for a swept tapered wing in subcritical flow show that the method converges in three iterations and gives excellent agreement with experiment at alpha = 0 deg and 2 deg. Recommendations are made for development of a procedure for routine application.

  5. Assembly modes of dragonfly wings.

    Science.gov (United States)

    Zhao, Hong-Xiao; Yin, Ya-Jun; Zhong, Zheng

    2011-12-01

    The assembly modes of dragonfly wings are observed through FEG-ESEM. Different from airplane wings, dragonfly wings are found to be assembled through smooth transition mode and global package mode. First, at the vein/membrane conjunctive site, the membrane is divided into upper and lower portions from the center layer and transited smoothly to the vein. Then the two portions pack the vein around and form the outer surface of the vein. Second, at the vein/spike conjunctive site, the vein and spike are connected smoothly into a triplet. Last, at the vein/membrane/spike conjunctive site, the membrane (i.e., the outer layer of the vein) transits smoothly to the spike, packs it around, and forms its outer layer. In short, the membrane looks like a closed coat packing the wing as a whole. The smooth transition mode and the global package mode are universal assembly modes in dragonfly wings. They provide us the references for better understanding of the functions of dragonfly wings and the bionic manufactures of the wings of flights with mini sizes.

  6. Laser Doppler velocimeter investigation of trailing vortices behind a semi-span swept wing in a landing configuration

    Science.gov (United States)

    Ciffone, D. L.; Orloff, K. L.; Grant, G. R.

    1973-01-01

    Measured axial and tangential velocity profiles in the near wake vortices of a semi-span model of the Convair 990 wing in the NASA-Ames 7- by 10-foot wind tunnel are presented. A scanning laser Doppler velocimeter was used to obtain data at two different downstream stations (0.49 and 1.25 wing spans) at various angles of attack and configurations from wing alone to wing plus nacelles, anti-shock bodies, and flaps deflected 27 deg (landing configuration). It is shown that the velocity distributions within the wake are quite sensitive to span loading. Specifically, it is illustrated that an aircraft flying at given lift coefficient (C SUB L), can substantially reduce its trailing vortex upset potential by deploying its flaps and altering its flight attitude to maintain the same C SUB L. This might be taken into consideration along with performance and noise considerations in the selection of aircraft approach lift over drag.

  7. On the width of N-Delta and Delta-Delta states

    CERN Document Server

    Niskanen, J A

    2016-01-01

    It is seen by a coupled-channel calculation that in the two-baryon N-Delta or Delta-Delta system the width of the state is greatly diminished due to the relative kinetic energy of the two baryons, since the internal energy of the particles, available for pionic decay, is smaller. A similar state dependent effect arises from the centrifugal barrier in N-Delta or Delta-Delta systems with non-zero orbital angular momentum. The double-Delta width can become even smaller than the free width of a single Delta. This has some bearing to the interpretation of the d'(2380) resonance recently discovered at COSY.

  8. Structural Analysis of a Dragonfly Wing

    NARCIS (Netherlands)

    Jongerius, S.R.; Lentink, D.

    2010-01-01

    Dragonfly wings are highly corrugated, which increases the stiffness and strength of the wing significantly, and results in a lightweight structure with good aerodynamic performance. How insect wings carry aerodynamic and inertial loads, and how the resonant frequency of the flapping wings is tuned

  9. Limiting Global Warming to 2 deg C and Beyond

    Science.gov (United States)

    Lea, D. W.

    2011-12-01

    This presentation addresses the question of how feasible is it to limit global warming to a specific temperature rise, whether 1.5, 2 or 3 deg C. Inherent in the idea of limiting global warming to a specific temperature level is the notion that future GHG emissions will be subject to a top-down international agreement. In the post-Copenhagen era, however, such an agreement is unlikely, and a bottoms-up approach of national pledges will likely have to serve as a surrogate for achieving emissions reduction. In this case, an additional question is what temperature targets are realistic under scenarios that are bounded by achievable national pledges as opposed to binding mandates. The question of feasibility depends largely on future emission pathways of CO2, other GHGs, black carbon and aerosols. Those pathways depend on many societal, technological and economic factors, but it is likely that the ultimate limiting factor is the maximum possible rate of absolute emission reduction. That rate is limited by how rapidly energy infrastructure can be turned over. Most studies suggest that an absolute emission reduction rate of 3.5% is the highest rate achievable. Climate sensitivity and the current cooling effect of aerosols and earth system responses such as the rate of ocean heat uptake and carbon cycle feedbacks determine how a specific emissions pathway translates into probable climate change. A useful framework for CO2 alone is provided by the newly emerging paradigm of cumulative emissions, which holds that peak temperature can be largely predicted by the total amount of carbon emitted, regardless of pathway. Most studies suggest that 1 Tt of cumulative carbon is equivalent to ~2 deg of peak warming. A consideration of these factors suggests that limiting warming to 1.5 deg C is no longer possible under any feasible economic scenario. For one, currently emitted GHGs are equivalent to a ~1.3 deg C warming commitment. This leaves very little room for future emissions

  10. Tropospheric ozone over a tropical Atlantic station in the Northern Hemisphere: Paramaribo, Surinam (6 deg N, 55 deg W)

    Energy Technology Data Exchange (ETDEWEB)

    Peters, W.; Krol, M.C. [Inst. for Marine and Atmospheric Research Utrecht (Netherlands); Fortuin, J.P.F.; Kelder, H.M. [Koninklijke Nederlandse Meteorologische Dienst, De Bilt (Netherlands); Thompson, A.M. [Goddard Space Flight Center, NASA, Greenbelt, MD (United States); Becker, C.R. [Meteorologische Dienst Suriname, Paramaribo (Suriname); Lelieveld, J.; Crutzen, P.J. [Max Planck Inst. fuer Chemie, Mainz (Germany)

    2004-02-01

    We present an analysis of 2.5 yr of weekly ozone soundings conducted at a new monitoring station in Paramaribo, Surinam (6 deg N, 55 deg W). This is currently one of only three ozone sounding stations in the Northern Hemisphere (NH) tropics, and the only one in the equatorial Atlantic region. Paramaribo is part of the Southern Hemisphere Additional Ozone Sounding program (SHADOZ). Owing to its position close to the equator, the inter-tropical convergence zone (ITCZ) passes over Paramaribo twice per year, which results in a semi-annual seasonality of many parameters including relative humidity and ozone. The dataset from Paramaribo is used to: (1) evaluate the ozone variability relative to precipitation, atmospheric circulation patterns and biomass burning; (2) contrast ozone at the NH equatorial Atlantic with that at nearby Southern Hemisphere (SH) stations Natal (6 deg S, 35 deg W) and Ascension (8 deg S, 14 deg W); (3) compare the seasonality of tropospheric ozone with a satellite-derived ozone product: tropical tropospheric ozone columns from the modified residual method (MR-TTOC). We find that Paramaribo is a distinctly Atlantic station. Despite its position north of the equator, it resembles nearby SH stations during most of the year. Transport patterns in the lower and middle troposphere during February and March differ from SH stations, which leads to a seasonality of ozone with two maxima. MR-TTOC over Paramaribo does not match the observed seasonality of ozone due to the use of a SH ozone sonde climatology in the MR method. The Paramaribo ozone record is used to suggest an improvement for Northern Hemisphere MR-TTOC retrievals. We conclude that station Paramaribo shows unique features in the region, and clearly adds new information to the existing SHADOZ record.

  11. geomorphology_delta

    Data.gov (United States)

    California Department of Resources — Surficial geology of the Delta area of California by Brian Atwater of the U.S. Geological Survey. Source maps are from the USGS publication MF-1401. This digital...

  12. Delta-Reliability

    OpenAIRE

    Eugster, P.; Guerraoui, R.; Kouznetsov, P.

    2001-01-01

    This paper presents a new, non-binary measure of the reliability of broadcast algorithms, called Delta-Reliability. This measure quantifies the reliability of practical broadcast algorithms that, on the one hand, were devised with some form of reliability in mind, but, on the other hand, are not considered reliable according to the ``traditional'' notion of broadcast reliability [HT94]. Our specification of Delta-Reliability suggests a further step towards bridging the gap between theory and...

  13. Delta Flow Modulator

    NARCIS (Netherlands)

    Stamhuis, Eize; Lengkeek, W

    2015-01-01

    A support structure (2) is installed in or near a water (50). The support structure is holding a deltalike-wing (3) under an angle of incidence relative to an incoming flow (54), caused by at least a prevailing current in the water, thus generating a vortex (77). The action of the vortex is

  14. Conceptual design and optimization methodology for box wing aircraft

    OpenAIRE

    Jemitola, Paul Olugbeji

    2012-01-01

    A conceptual design optimization methodology was developed for a medium range box wing aircraft. A baseline conventional cantilever wing aircraft designed for the same mis- sion and payload was also optimized alongside a baseline box wing aircraft. An empirical formula for the mass estimation of the fore and aft wings of the box wing aircraft was derived by relating conventional cantilever wings to box wing aircraft wings. The results indicate that the fore and aft wings would ...

  15. WINGS Data Release

    DEFF Research Database (Denmark)

    Moretti, A.; Poggianti, B. M.; Fasano, G.;

    2014-01-01

    Context. To effectively investigate galaxy formation and evolution, it is of paramount importance to exploit homogeneous data for large samples of galaxies in different environments. Aims. The WIde-field Nearby Galaxy-cluster Survey (WINGS) project aim is to evaluate physical properties of galaxies......, and on the cluster redshift, reaching on average 90% at V ≲ 21.7. Near-infrared photometric catalogs for 26 (in K) and 19 (in J) clusters are part of the database and the number of sources is 962 344 in K and 628 813 in J. Here again the completeness depends on the data quality, but it is on average higher than 90......% for J ≲ 20.5 and K ≲ 19.4. The IR subsample with a Sersic fit comprises 71 687 objects. A morphological classification is available for 39 923 galaxies. We publish spectroscopic data, including 6132 redshifts, 5299 star formation histories, and 4381 equivalent widths. Finally, a calculation of local...

  16. Analysis of Asymmetric Aircraft Aerodynamics Due to an Experimental Wing Glove

    Science.gov (United States)

    Hartshorn, Fletcher

    2011-01-01

    Aerodynamic analysis on a business jet with a wing glove attached to one wing is presented and discussed. If a wing glove is placed over a portion of one wing, there will be asymmetries in the aircraft as well as overall changes in the forces and moments acting on the aircraft. These changes, referred to as deltas, need to be determined and quantified to make sure the wing glove does not have a drastic effect on the aircraft flight characteristics. TRANAIR, a non-linear full potential solver was used to analyze a full aircraft, with and without a glove, at a variety of flight conditions and angles of attack and sideslip. Changes in the aircraft lift, drag and side force, along with roll, pitch and yawing moment are presented. Span lift and moment distributions are also presented for a more detailed look at the effects of the glove on the aircraft. Aerodynamic flow phenomena due to the addition of the glove and its fairing are discussed. Results show that the glove used here does not present a drastic change in forces and moments on the aircraft, but an added torsional moment around the quarter-chord of the wing may be a cause for some structural concerns.

  17. Static aeroelastic analysis of composite wing

    Science.gov (United States)

    Lee, IN; Hong, Chang Sun; Miura, Hirokazu; Kim, Seung KO

    1990-01-01

    A static aeroelastic analysis capability that can predict aerodynamic loads for the deformed shape of the composite wing has been developed. The finite element method (FEM) was used for composite plate structural analysis, and the linear vortex lattice method (VLM) was used for steady aerodynamic analysis. The final deformed shape of the wing due to applied forces is determined by iterative manner using FEM and VLM. FEM and VLM analysis are related by a surface spline interpolation procedure. The wing with Gr/Ep composite material has been investigated to see the wing deformation effect. Aerodynamic load change due to wing flexibility has been investigated. Also, the effect of fiber orientation and sweep angle on the deformation pattern and aerodynamic coefficients are examined. For a certain fiber orientation, the deflection and aerodynamic loading of the composite wing is very much reduced. The swept forward wing has more significant effect of wing flexibility on aerodynamic coefficient than the swept back wing does.

  18. Modello metodologico per il monitoraggio degli incidenti stradali in Trentino

    Directory of Open Access Journals (Sweden)

    P. Fateh-Moghadam

    2003-05-01

    Full Text Available

    Obiettivi: realizzazione di un’infrastruttura informatica, per l’unificazione tempestiva dei flussi sugli incidenti stradali (ISTAT-ACI e sanitari con la georeferenziazione degli eventi a partire dall’anno 2000.

    Materiali e Metodi: dall’archivio di Trentino emergenza sono stati estratti gli interventi per incidente stradale selezionando la combinazione: descrizione patologica: “traumatismi”, tipologia luogo: “strada”, tipologia incidente. Dai dati di ogni Pronto soccorso è stato costruito un archivio unico contenente il totale degli accessi e sono stati estratti gli accessi per “incidente stradale” e quelli per lesioni accidentali in generale. Dall’archivio SDO si sono selezionati sia i ricoveri con il criterio “3” alla variabile mtraav (=incidente stradale che quelli per traumatismi.

    Nell’ambito del progetto “Metodi informatici predittivi per la mitigazione del rischio da incidenti stradali” (Mitris, finanziato dal Ministero della Salute, è stata realizzata l’immissione tramite interfaccia internet o decodifica automatica dei verbali informatizzati delle Forze dell’ordine, e la contestuale realizzazione di un interfaccia WebGIS
    in grado di visualizzare la localizzazione degli incidenti stradali.

    Risultati: tramite la combinazione “data nascita”,
    “data incidente”, “sesso” è stato eseguito un primo collegamento tra gli archivi. Aggiungendo alla data incidente uno o più giorni, è stato costruito un nuovo archivio PS contenente il 97,4% degli eventi raccolti dalle forze dell’Ordine e contenuti nel data base Mitris. Approccio analogo è stato seguito per il linkage con SDO e 118. Tramite interfaccia WebGIS è stata creata una mappa degli incidenti interrogabile on-line, che oltre alla semplice localizzazione riporta dinamica e esiti con possibilità di produrre statistiche e grafici. Il sistema copre attualmente

  19. {\\delta}M Formalism

    CERN Document Server

    Talebian-Ashkezari, Alireza; Abolhasani, Ali Akbar

    2016-01-01

    We study the evolution of the "non-perturbative" metric perturbations in a Bianchi background in the long-wavelength limit. By applying the gradient expansion to the equations of motion we exhibit a generalized "Separate Universe" approach to the cosmological perturbation theory. Having found this consistent separate universe picture, we introduce the "{\\delta}M formalism" for calculating the evolution of the tensor perturbations in anisotropic inflation models in almost similar way as the so-called {\\delta}N formula for the super-horizon dynamics of the curvature perturbations. Likewise its ancestor, {\\delta}N formalism, this new method can substantially reduce the amount of calculations related to the evolution of the tensor modes.

  20. Exploratory investigation of lift induced on a swept wing by a two-dimensional partial-span deflected jet at Mach numbers from 0.20 to 1.30

    Science.gov (United States)

    Capone, F. J.

    1972-01-01

    An exploratory investigation was conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.20 to 1.30 to determine the induced lift characteristics of a body and swept-wing configuration having a partial-span two-dimensional propulsive nozzle with exhaust exit in the notch of the swept-wing trailing edge. The Reynolds number per meter varied from 4,900,000 to 14,030,000. The effects on wing-body characteristics of deflecting the propulsive jet in the flap mode at nominal exhaust-nozzle deflection angles of 0 deg and 30 deg were studied for two nozzle designs with different geometry and wing spans.

  1. Immagini dinamiche: appunti per un catalogo degli usi didattici

    Directory of Open Access Journals (Sweden)

    Filippo Bruni

    2013-03-01

    Full Text Available Le immagini dinamiche costituiscono un’importante risorsa per le attività didattiche. A partire da una riflessione storica, si evidenzia in primo luogo l’importanza di un loro uso efficace alla luce della classificazione operata da Clark e Lyons. In secondo luogo si segnalano alcune attività emergenti legate alla documentazione, al digital storytelling e alla formazione degli insegnanti.

  2. Technical Note: Using DEG CPCs at upper tropospheric temperatures

    CERN Document Server

    Wimmer, D; Nieminen, T; Duplissy, J; Ehrhart, S; Almeida, J; Rondo, L; Franchin, A; Kreissl, F; Manninen, H E; Kulmala, M; Curtius, J; Petäjä, T

    2014-01-01

    Over the last few years, several Condensation Particle Counters (CPC) capable of measuring in the sub-3 nm size range have been developed. Here we study the performance of Diethylene glycol (DEG) based CPCs at different temperatures during Cosmics Leaving Outdoor Droplets (CLOUD) measurements at CERN. The data shown here is the first set of verification measurements for sub-3 nm CPCs under upper tropospheric temperatures using atmospherically relevant aerosol particles. To put the results in perspective we calibrated the DEG-CPC at room temperature, resulting in a cut-off diameter of 1.4 nm. All diameters refer to mobility equivalent diameters in this manuscript. At upper tropospheric temperatures between −25 °C and −65 °C, we found cut-off sizes in the range of 2.5 and 2.8 nm. Due to low number concentration after size classification, the cut-off diameters have a high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG CPCs with different cut-off sizes together with other aeroso...

  3. Aircraft wing structural detail design (wing, aileron, flaps, and subsystems)

    Science.gov (United States)

    Downs, Robert; Zable, Mike; Hughes, James; Heiser, Terry; Adrian, Kenneth

    1993-01-01

    The goal of this project was to design, in detail, the wing, flaps, and ailerons for a primary flight trainer. Integrated in this design are provisions for the fuel system, the electrical system, and the fuselage/cabin carry-through interface structure. This conceptual design displays the general arrangement of all major components in the wing structure, taking into consideration the requirements set forth by the appropriate sections of Federal Aviation Regulation Part 23 (FAR23) as well as those established in the statement of work.

  4. Three-dimensional canard-wing shape optimization in aircraft cruise and maneuver environments

    Science.gov (United States)

    De Silva, B. M. E.; Carmichael, R. L.

    1978-01-01

    This paper demonstrates a numerical technique for canard-wing shape optimization at two operating conditions. For purposes of simplicity, a mean surface wing paneling code is employed for the aerodynamic calculations. The optimization procedures are based on the method of feasible directions. The shape functions for describing the thickness, camber, and twist are based on polynomial representations. The primary design requirements imposed restrictions on the canard and wing volumes and on the lift coefficients at the operating conditions. Results indicate that significant improvements in minimum drag and lift-to-drag ratio are possible with reasonable aircraft geometries. Calculations were done for supersonic speeds with Mach numbers ranging from 1 to 6. Planforms were mainly of a delta shape with aspect ratio of 1.

  5. Design of a wing shape for study of hypersonic crossflow transition in flight

    Science.gov (United States)

    Godil, A.; Bertelrud, A.

    1992-01-01

    Computational fluid dynamics methods were used in the design of a wing shape for study of hypersonic crossflow transition in flight. The flight experiment is to be performed on the delta wing of the first stage of a Pegasus launch vehicle as a piggy-back experiment to support boundary-layer stability code development and validation. The design goal is to obtain crossflow-induced transition at 20-40 percent of the chord for a flight Mach number of approximately six. The present paper describes the design and analysis process utilized to obtain desired glove shape. A variety of schemes were used in the design, ranging from simple empirical crossflow correlations to three-dimensional Navier-Stokes codes in conjunction with linear stability/N-factor computations. The sensitivity to various parameters, such as trajectory variations, allowable wing thickness, leading-edge radius and surface temperature, is also discussed.

  6. Book review. La forma degli animali. Adolf Portmann

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2013-09-01

    Full Text Available Nel 1931 il biologo Adolf Portmann era già talmente noto a livello internazionale per le sue ricerche da guadagnarsi la cattedra in zoologia nell'università della sua città natale, Basilea, all'età di appena 34 anni. All'attività di docente universitario ha sempre affiancato un'originale riflessione sul significato delle scienze della vita, imponendosi come una delle figure chiave nel dibattito tra biologia teoretica, estetica e antropologia filosofica. La forma degli animali, la sua opera più celebre, si pone al confine tra varie discipline e conserva un grande interesse ancora oggi che il dialogo tra estetica e biologia si è fatto nuovamente intenso. Pubblicata nel 1948 e in forma ampliata nel 1960 (da cui deriva questa prima edizione italiana a cura di Pietro Conte l'opera rappresenta il frutto più maturo delle sue ricerche "interdisciplinari".Un saggio che nasce dall'insoddisfazione nei confronti dei paradigmi scientifici consolidati e che ripropone l'idea morfologica in biologia sulla scorta del pensiero di J. W. Goethe il quale affermava che "tutto ciò che è deve anche dar cenno di sé e mostrarsi". Adolf Portmann è un convinto sostenitore che dalla forma si possano dedurne le complessive caratteristiche interne ed esterne degli animali. Secondo questa prospettiva la peculiare fisionomia dell'organismo dipende dalla congiunzione delle sue parti e dalle loro reciproche funzioni. Tuttavia l'autore non vede nello studio della forma l'alternativa al funzionalismo quanto, piuttosto, il suo necessario bilanciamento come dichiara nell'introduzione: "… per giungere alla conoscenza della vita animale di strade ce ne sono molte, e tutte possono contribuire ad arricchire la nostra esperienza. Questo lavoro si occupa della forma degli animali e si propone di mettere in luce la peculiare natura dell'aspetto visibile. Ci sono persone che si dedicano allo studio degli animali, conoscono moltissime specie, hanno imparato centinaia di nomi e

  7. A computational study of the wing-wing and wing-body interactions of a model insect

    Institute of Scientific and Technical Information of China (English)

    Xin Yu; Mao Sun

    2009-01-01

    The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of thebody are less than 2%. The reason for this is as following. During each down-or up-stroke, a wing produces a vortexring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex tings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.

  8. Aerodynamic control with passively pitching wings

    Science.gov (United States)

    Gravish, Nick; Wood, Robert

    Flapping wings may pitch passively under aerodynamic and inertial loads. Such passive pitching is observed in flapping wing insect and robot flight. The effect of passive wing pitch on the control dynamics of flapping wing flight are unexplored. Here we demonstrate in simulation and experiment the critical role wing pitching plays in yaw control of a flapping wing robot. We study yaw torque generation by a flapping wing allowed to passively rotate in the pitch axis through a rotational spring. Yaw torque is generated through alternating fast and slow upstroke and and downstroke. Yaw torque sensitively depends on both the rotational spring force law and spring stiffness, and at a critical spring stiffness a bifurcation in the yaw torque control relationship occurs. Simulation and experiment reveal the dynamics of this bifurcation and demonstrate that anomalous yaw torque from passively pitching wings is the result of aerodynamic and inertial coupling between the pitching and stroke-plane dynamics.

  9. Insect Evolution: The Origin of Wings.

    Science.gov (United States)

    Ross, Andrew

    2017-02-06

    The debate on the evolution of wings in insects has reached a new level. The study of primitive fossil insect nymphs has revealed that wings developed from a combination of the dorsal part of the thorax and the body wall.

  10. The Niger Delta Crisis

    African Journals Online (AJOL)

    chifaou.amzat

    2013-09-28

    Sep 28, 2013 ... lions de barils par jour à environ 1 million au plus fort de la crise du Delta ... (JTF) between 13 May 2009 and 4 October 2009 (the deadline for embrac- ..... He had just ended his welcome address as the occasion's chairman.

  11. Nacelle/pylon/wing integration on a transport model with a natural laminar flow nacelle

    Science.gov (United States)

    Lamb, M.; Aabeyounis, W. K.; Patterson, J. C., Jr.

    1985-01-01

    Tests were conducted in the Langley 16-Foot Transonic Tunnel at free-stream Mach numbers from 0.70 to 0.82 and angles of attack from -2.5 deg to 4.0 deg to determine if nacelle/pylon/wing integration affects the achievement of natural laminar flow on a long-duct flow-through nacelle for a high-wing transonic transport configuration. In order to fully assess the integration effect on a nacelle designed to achieve laminar flow, the effects of fixed and free nacelle transitions as well as nacelle longitudinal position and pylon contouring were obtained. The results indicate that the ability to achieve laminar flow on the nacelle is not significantly altered by nacelle/pylon/wing integration. The increment in installed drag between free and fixed transition for the nacelles on symmetrical pylons is essentially the calculated differences between turbulent and laminar flow on the nacelles. The installed drag of the contoured pylon is less than that of the symmetrical pylon. The installed drag for the nacelles in a rearward position is greater than that for the nacelles in a forward position.

  12. Span morphing using the GNATSpar wing

    OpenAIRE

    2016-01-01

    Rigid wings usually fly at sub-optimal conditions generating unnecessary aerodynamic loses represented in flight time, fuel consumption, and unfavourable operational characteristics. High aspect ratio wings have good range and fuel efficiency, but lack manoeuvrability. On the other hand, low aspect ratio wings fly faster and are more manoeuvrable, but have poor aerodynamic performance. Span morphing technology allows integrating both features in a single wing design and allows continuously ad...

  13. Structural Analysis of a Dragonfly Wing

    OpenAIRE

    Jongerius, S.R.; Lentink, D.

    2010-01-01

    Dragonfly wings are highly corrugated, which increases the stiffness and strength of the wing significantly, and results in a lightweight structure with good aerodynamic performance. How insect wings carry aerodynamic and inertial loads, and how the resonant frequency of the flapping wings is tuned for carrying these loads, is however not fully understood. To study this we made a three-dimensional scan of a dragonfly (Sympetrum vulgatum) fore- and hindwing with a micro-CT scanner. The scans c...

  14. Low Aspect-Ratio Wings for Wing-Ships

    DEFF Research Database (Denmark)

    Filippone, Antonino; Selig, M.

    1998-01-01

    Flying on ground poses technical and aerodynamical challenges. The requirements for compactness, efficiency, manouverability, off-design operation,open new areas of investigations in the fieldof aerodynamic analysis and design. A review ofthe characteristics of low-aspect ratio wings, in- and out...

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

    Science.gov (United States)

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

    1979-01-01

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

  16. Wing flutter boundary prediction using unsteady Euler aerodynamic method

    Science.gov (United States)

    Lee-Rausch, Elizabeth M.; Batina, John T.

    1993-01-01

    Modifications to an existing 3D implicit upwind Euler/Navier-Stokes code for the aeroelastic analysis of wings are described. These modifications include the incorporation of a deforming mesh algorithm and the addition of the structural equations of motion for their simultaneous time-integration with the governing flow equations. The paper gives a brief description of these modifications and presents unsteady calculations which check the modifications to the code. Euler flutter results for an isolated 45 deg swept-back wing are compared with experimental data for seven freestream Mach numbers which define the flutter boundary over a range of Mach number from 0.499 to 1.14. These comparisons show good agreement in flutter characteristics for freestream Mach numbers below unity. For freestream Mach numbers above unity, the computed aeroelastic results predict a premature rise in the flutter boundary as compared with the experimental boundary. Steady and unsteady contours of surface Mach number and pressure are included to illustrate the basic flow characteristics of the time-marching flutter calculations and to aid in identifying possible causes for the premature rise in the computational flutter boundary.

  17. Technical Note: Using DEG-CPCs at upper tropospheric temperatures

    Science.gov (United States)

    Wimmer, D.; Lehtipalo, K.; Nieminen, T.; Duplissy, J.; Ehrhart, S.; Almeida, J.; Rondo, L.; Franchin, A.; Kreissl, F.; Bianchi, F.; Manninen, H. E.; Kulmala, M.; Curtius, J.; Petäjä, T.

    2015-07-01

    Over the last few years, several condensation particle counters (CPCs) capable of measuring in the sub-3 nm size range have been developed. Here we study the performance of CPCs based on diethylene glycol (DEG) at different temperatures during Cosmics Leaving OUtdoor Droplets (CLOUD) measurements at CERN. The data shown here are the first set of verification measurements for sub-3 nm CPCs under upper tropospheric temperatures using atmospherically relevant aerosol particles. To put the results in perspective we calibrated the DEG-CPC at room temperature, resulting in a cut-off diameter of 1.4 nm. All diameters refer to mobility equivalent diameters in this paper. At upper tropospheric temperatures ranging from 246.15 K to 207.15 K, we found cut-off sizes relative to a particle size magnifier in the range of 2.5 to 2.8 nm. Due to low number concentration after size classification, the cut-off diameters have a high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG-CPCs with different cut-off sizes together with other aerosol instruments, we looked at the growth rates of aerosol population in the CLOUD chamber for particles smaller than 10 nm at different temperatures. A more consistent picture emerged when we normalized the growth rates to a fixed gas-phase sulfuric acid concentration. All of the instruments detected larger growth rates at lower temperatures, and the observed growth rates decreased as a function of temperature, showing a similar trend for all instruments. The theoretical calculations had a similar but much smaller temperature dependency.

  18. Mutations suppressing the loss of DegQ function in Bacillus subtilis (natto) poly-γ-glutamate synthesis.

    Science.gov (United States)

    Do, Thi-Huyen; Suzuki, Yuki; Abe, Naoki; Kaneko, Jun; Itoh, Yoshifumi; Kimura, Keitarou

    2011-12-01

    The degQ gene of Bacillus subtilis (natto), encoding a small peptide of 46 amino acids, is essential for the synthesis of extracellular poly-gamma-glutamate (γPGA). To elucidate the role of DegQ in γPGA synthesis, we knocked out the degQ gene in Bacillus subtilis (natto) and screened for suppressor mutations that restored γPGA synthesis in the absence of DegQ. Suppressor mutations were found in degS, the receptor kinase gene of the DegS-DegU two-component system. Recombinant DegS-His(6) mutant proteins were expressed in Escherichia coli cells and subjected to an in vitro phosphorylation assay. Compared with the wild type, mutant DegS-His(6) proteins showed higher levels of autophosphorylation (R208Q, M195I, L248F, and D250N), reduced autodephosphorylation (D250N), reduced phosphatase activity toward DegU, or a reduced ability to stimulate the autodephosphorylation activity of DegU (R208Q, D249G, M195I, L248F, and D250N) and stabilized DegU in the phosphorylated form. These mutant DegS proteins mimic the effect of DegQ on wild-type DegSU in vitro. Interestingly, DegQ stabilizes phosphorylated DegS only in the presence of DegU, indicating a complex interaction of these three proteins.

  19. Mutations Suppressing the Loss of DegQ Function in Bacillus subtilis (natto) Poly-γ-Glutamate Synthesis ▿ †

    Science.gov (United States)

    Do, Thi-Huyen; Suzuki, Yuki; Abe, Naoki; Kaneko, Jun; Itoh, Yoshifumi; Kimura, Keitarou

    2011-01-01

    The degQ gene of Bacillus subtilis (natto), encoding a small peptide of 46 amino acids, is essential for the synthesis of extracellular poly-gamma-glutamate (γPGA). To elucidate the role of DegQ in γPGA synthesis, we knocked out the degQ gene in Bacillus subtilis (natto) and screened for suppressor mutations that restored γPGA synthesis in the absence of DegQ. Suppressor mutations were found in degS, the receptor kinase gene of the DegS-DegU two-component system. Recombinant DegS-His6 mutant proteins were expressed in Escherichia coli cells and subjected to an in vitro phosphorylation assay. Compared with the wild type, mutant DegS-His6 proteins showed higher levels of autophosphorylation (R208Q, M195I, L248F, and D250N), reduced autodephosphorylation (D250N), reduced phosphatase activity toward DegU, or a reduced ability to stimulate the autodephosphorylation activity of DegU (R208Q, D249G, M195I, L248F, and D250N) and stabilized DegU in the phosphorylated form. These mutant DegS proteins mimic the effect of DegQ on wild-type DegSU in vitro. Interestingly, DegQ stabilizes phosphorylated DegS only in the presence of DegU, indicating a complex interaction of these three proteins. PMID:21965392

  20. The Codice digitale degli archivi veronesi. A research instrument

    Directory of Open Access Journals (Sweden)

    Andrea Brugnoli

    2014-04-01

    Full Text Available The Codice digitale degli archivi veronesi (Verona’s archives digital code ‹http://cdavr.dtesis.univr.it› makes available online the digital reproductions of the documents produced by corporate bodies and family of Verona between the eighth and twelfth century. The framework of the site reflects the current organisation of the archives. A brief description of the circumstances around the creation of each archive, the corporate body or individual responsible for it and its structure is provided. Each archival unit is identified by its key elements: chronological date, name and qualification of the notary, original/copy, main editions.

  1. The Codice digitale degli archivi veronesi. A research instrument

    Directory of Open Access Journals (Sweden)

    Andrea Brugnoli

    2014-04-01

    Full Text Available The Codice digitale degli archivi veronesi (Verona’s archives digital code ‹http://cdavr.dtesis.univr.it› makes available online the digital reproductions of the documents produced by corporate bodies and family of Verona between the eighth and twelfth century. The framework of the site reflects the current organisation of the archives. A brief description of the circumstances around the creation of each archive, the corporate body or individual responsible for it and its structure is provided. Each archival unit is identified by its key elements: chronological date, name and qualification of the notary, original/copy, main editions.

  2. Islam, rappresentanza degli interessi religiosi e diritto comune europeo *

    Directory of Open Access Journals (Sweden)

    Gianfranco Macrì

    2011-03-01

    Full Text Available Contributo destinato alla pubblicazione negli Atti del Convegno: Europa e Islam. Ridiscutere i fondamenti per la disciplina delle libertà religiose, svoltosi a Salerno il 3 dicembre 2007.SOMMARIO: Premessa - 1. La società «reticolare» europea: sistema di governance e valori unificanti - 2. Europa e fenomeno religioso - 3. La sostanza del Trattato di Lisbona e il ruolo delle organizzazioni religiose - 4. Il dibattito interno all’Islam europeo - 5. La Carta dei musulmani d’Europa - 6. La rappresentanza degli interessi religiosi dell’Islam in Europa - Conclusioni.

  3. Bat flight with bad wings: is flight metabolism affected by damaged wings?

    Science.gov (United States)

    Voigt, Christian C

    2013-04-15

    Infection of North American bats with the keratin-digesting fungus Geomyces destructans often results in holes and ruptures of wing membranes, yet it is unknown whether flight performance and metabolism of bats are altered by such injuries. I conducted flight experiments in a circular flight arena with Myotis albescens and M. nigricans individuals with an intact or ruptured trailing edge of one of the plagiopatagial membranes. In both species, individuals with damaged wings were lighter, had a higher aspect ratio (squared wing span divided by wing area) and an increased wing loading (weight divided by wing area) than conspecifics with intact wings. Bats with an asymmetric reduction of the wing area flew at similar speeds to conspecifics with intact wings but performed fewer flight manoeuvres. Individuals with damaged wings showed lower metabolic rates during flight than conspecifics with intact wings, even when controlling for body mass differences; the difference in mass-specific metabolic rate may be attributable to the lower number of flight manoeuvres (U-turns) by bats with damaged wings compared with conspecifics with intact wings. Possibly, bats compensated for an asymmetric reduction in wing area by lowering their body mass and avoiding flight manoeuvres. In conclusion, it may be that bats suffer from moderate wing damage not directly, by experiencing increased metabolic rate, but indirectly, by a reduced manoeuvrability and foraging success. This could impede a bat's ability to gain sufficient body mass before hibernation.

  4. The Wings for Angels Project

    Science.gov (United States)

    McMillan, Liberty; McMillan, Ellen; Ayers, Ann

    2012-01-01

    How can the spirits of critically ill children be raised? Alexis Weisel (co-president of the Monarch High School National Art Honor Society, 2010-2011) had this question in mind when she initiated and developed the Wings for Angels Project after hearing about the Believe in Tomorrow (BIT) organization through her art teacher, Ellen McMillan. The…

  5. Wings: Women Entrepreneurs Take Flight.

    Science.gov (United States)

    Baldwin, Fred D.

    1997-01-01

    Women's Initiative Networking Groups (WINGS) provides low- and moderate-income women in Appalachian Kentucky with training in business skills, contacts, and other resources they need to succeed as entrepreneurs. The women form informal networks to share business know-how and support for small business startup and operations. The program plans to…

  6. FLEXIBLE WING INDIVIDUAL DROP GLIDER

    Science.gov (United States)

    The feasibility of the paraglider concept as a means of descent for individual airborne troops is presented. Full-scale 22-foot inflatable wings and...in an effort to achieve system reliability. The feasibility of using the paraglider as a means of controlled delivery of airborne paratroopers was successfully demonstrated.

  7. [Winged scapula in lyme borreliosis].

    Science.gov (United States)

    Rausch, V; Königshausen, M; Gessmann, J; Schildhauer, T A; Seybold, D

    2016-06-01

    Here we present the case of a young patient with one-sided winged scapula and lyme borreliosis. This disease can be very delimitating in daily life. If non-operative treatment fails, dynamic or static stabilization of the scapula can be a therapeutic option.

  8. DELTAS: A new Global Delta Sustainability Initiative (Invited)

    Science.gov (United States)

    Foufoula-Georgiou, E.

    2013-12-01

    Deltas are economic and environmental hotspots, food baskets for many nations, home to a large part of the world population, and hosts of exceptional biodiversity and rich ecosystems. Deltas, being at the land-water interface, are international, regional, and local transport hubs, thus providing the basis for intense economic activities. Yet, deltas are deteriorating at an alarming rate as 'victims' of human actions (e.g. water and sediment reduction due to upstream basin development), climatic impacts (e.g. sea level rise and flooding from rivers and intense tropical storms), and local exploration (e.g. sand or aggregates, groundwater and hydrocarbon extraction). Although many efforts exist on individual deltas around the world, a comprehensive global delta sustainability initiative that promotes awareness, science integration, data and knowledge sharing, and development of decision support tools for an effective dialogue between scientists, managers and policy makers is lacking. Recently, the international scientific community proposed to establish the International Year of Deltas (IYD) to serve as the beginning of such a Global Delta Sustainability Initiative. The IYD was proposed as a year to: (1) increase awareness and attention to the value and vulnerability of deltas worldwide; (2) promote and enhance international and regional cooperation at the scientific, policy, and stakeholder level; and (3) serve as a launching pad for a 10-year committed effort to understand deltas as complex socio-ecological systems and ensure preparedness in protecting and restoring them in a rapidly changing environment. In this talk, the vision for such an international coordinated effort on delta sustainability will be presented as developed by a large number of international experts and recently funded through the Belmont Forum International Opportunities Fund. Participating countries include: U.S., France, Germany, U.K., India, Japan, Netherlands, Norway, Brazil, Bangladesh

  9. Review Results on Wing-Body Interference

    OpenAIRE

    Frolov Vladimir

    2016-01-01

    The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM) and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combin...

  10. Zoogeografia storica e attuale dei carnivori e degli ungulati italiani

    Directory of Open Access Journals (Sweden)

    Marco Masseti

    2003-10-01

    Full Text Available Come per la maggior parte degli altri paesi europei, anche l'attuale composizione delle specie a mammiferi italiane si prefigura in gran parte come il risultato della plurima e prolungata azione antropica condotta sull'ambiente naturale. Questa, avviatasi alcuni millenni or sono, condiziona oggi più che mai la ridefinizione degli equilibri ecologici del nostro Paese. All'interno dell'attuale teriofauna terrestre italiana viene segnalata la presenza di 18 specie di carnivori e di 9 artiodattili, che può rivelarsi in alcuni casi come il risultato di acclimatazioni e/o naturalizzazioni di specie esotiche avvenute in cronologie diverse, anche di epoca molto recente. All'interno dei confini biogeografici dell'Italia andrebbero anche annoverate quelle popolazioni del cervo pomellato medio-orientale, Axis axis (Erxleben, 1777, che sono state naturalizzate in epoca storica assai recente in Istria ed in alcune isole del golfo del Quarnaro (Brioni Maggiore, Cherso e Plauno. Considerazioni analoghe potrebbero forse essere condotte anche per la diffusione artificiale di Herpestes auropunctatus Hodgson, 1836, su alcune isole della Croazia. Le specie fitofaghe riferibili ai gruppi tassonomici dei lagomorfi e degli artiodattili, e che vengono convenzionalmente comprese nella categoria della cosiddetta "selvaggina", sono tra quelle che hanno più subito un'alterazione condotta in profondità dei quadri faunistici originari, proprio in virtù dell'interesse economico e culturale che ancora rappresentano. Nel caso particolare di queste specie di interesse venatorio ci troviamo quasi sempre di fronte a popolazioni che sono state sottoposte ad intensa gestione e che hanno subito frequenti estinzioni locali seguite da reiterate reintroduzioni. Attualmente, data l'espansione sia naturale che artificiale degli ecotipi indigeni e di quelli alloctoni, si osserva ormai una sovrapposizione degli areali, per cui sembra piuttosto difficile riuscire in

  11. Nacelle/pylon interference study on a 1/17th-scale, twin-engine, low-wing transport model

    Science.gov (United States)

    Pendergraft, Odis C., Jr.; Ingraldi, Anthony M.; Re, Richard J.; Kariya, Timmy T.

    1989-01-01

    NASA-Langley has conducted wind tunnel tests of a twin-engine, low-wing transport aircraft configuration with 10.8-aspect ratio supercritical wing, in order to ascertain and compare the wing/nacelle interference effects of through-flow nacelled simulating 'superfan' very high bypass ratio (BPR=20) turbofans and current-technology (BPR=6) turbofans. Measurements of model forces and moments have been obtained, together with extensive external static pressure measurement on the model's wings, nacelles, and pylons in the Mach 0.5-0.8 range, at angles of attack in the -4 to +8 deg range. The superfan nacelles exhibit a significant advantage over current-technology turbofan nacelles, when the superfan's SFC gains are taken into account.

  12. Review Results on Wing-Body Interference

    Directory of Open Access Journals (Sweden)

    Frolov Vladimir

    2016-01-01

    Full Text Available The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combinations may exceed the same value for an isolated wing. This result confirms an experimental data obtained by other authors earlier. Within a framework of the used mathematical models the investigations to optimize the wing-body combination were carried. The present results of the optimization problem for the wing-body combination allowed to select the optimal geometric characteristics for configuration to maximize the values of the lift-curve slopes of the wing-body combination. It was revealed that maximums of the lift-curve slopes for the optimal mid-wing configuration with elliptical cross-section body had a sufficiently large relative width of the body (more than 30% of the span wing.

  13. AST Composite Wing Program: Executive Summary

    Science.gov (United States)

    Karal, Michael

    2001-01-01

    The Boeing Company demonstrated the application of stitched/resin infused (S/RFI) composite materials on commercial transport aircraft primary wing structures under the Advanced Subsonic technology (AST) Composite Wing contract. This report describes a weight trade study utilizing a wing torque box design applicable to a 220-passenger commercial aircraft and was used to verify the weight savings a S/RFI structure would offer compared to an identical aluminum wing box design. This trade study was performed in the AST Composite Wing program, and the overall weight savings are reported. Previous program work involved the design of a S/RFI-base-line wing box structural test component and its associated testing hardware. This detail structural design effort which is known as the "semi-span" in this report, was completed under a previous NASA contract. The full-scale wing design was based on a configuration for a MD-90-40X airplane, and the objective of this structural test component was to demonstrate the maturity of the S/RFI technology through the evaluation of a full-scale wing box/fuselage section structural test. However, scope reductions of the AST Composite Wing Program pre-vented the fabrication and evaluation of this wing box structure. Results obtained from the weight trade study, the full-scale test component design effort, fabrication, design development testing, and full-scale testing of the semi-span wing box are reported.

  14. Topology of Vortex-Wing Interaction

    Science.gov (United States)

    McKenna, Chris; Rockwell, Donald

    2016-11-01

    Aircraft flying together in an echelon or V formation experience aerodynamic advantages. Impingement of the tip vortex from the leader (upstream) wing on the follower wing can yield an increase of lift to drag ratio. This enhancement is known to depend on the location of vortex impingement on the follower wing. Particle image velocimetry is employed to determine streamline topology in successive crossflow planes, which characterize the streamwise evolution of the vortex structure along the chord of the follower wing and into its wake. Different modes of vortex-follower wing interaction are created by varying both the spanwise and vertical locations of the leader wing. These modes are defined by differences in the number and locations of critical points of the flow topology, and involve bifurcation, attenuation, and mutual induction. The bifurcation and attenuation modes decrease the strength of the tip vortex from the follower wing. In contrast, the mutual induction mode increases the strength of the follower tip vortex. AFOSR.

  15. Periodic and Chaotic Flapping of Insectile Wings

    CERN Document Server

    Huang, Yangyang

    2015-01-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. The maximum power output of these flight muscles is insufficient to maintain such wing oscillations unless there is good elastic storage of energy in the insect flight system. Here, we explore the intrinsic self-oscillatory behavior of an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring. We study the wings behavior as a function of the total energy and spring stiffness. Three types of behavior are identified: end-over-end rotation, chaotic motion, and periodic flapping. Interestingly, the region of periodic flapping decreases as energy increases but is favored as stiffness increases. These findings are consistent with the fact that insect wings and flight muscles are stiff. They further imply that, by adjusting their muscle stiffness to the desired energy level, insects can maintain periodic flapping mechanically for a range of operating condit...

  16. Piezoelectrically actuated insect scale flapping wing

    Science.gov (United States)

    Mukherjee, Sujoy; Ganguli, Ranjan

    2010-04-01

    An energy method is used in order to derive the non-linear equations of motion of a smart flapping wing. Flapping wing is actuated from the root by a PZT unimorph in the piezofan configuration. Dynamic characteristics of the wing, having the same size as dragonfly Aeshna Multicolor, are analyzed using numerical simulations. It is shown that flapping angle variations of the smart flapping wing are similar to the actual dragonfly wing for a specific feasible voltage. An unsteady aerodynamic model based on modified strip theory is used to obtain the aerodynamic forces. It is found that the smart wing generates sufficient lift to support its own weight and carry a small payload. It is therefore a potential candidate for flapping wing of micro air vehicles.

  17. Environmental oil spill sensitivity atlas for the West Greenland (68 deg.-72 deg. N) coastal zone, 2nd revised edition

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, D.; Johansen, Kasper L.; Mosbech, A.; Boertmann, D.; Wegeberg, S.

    2012-12-15

    This oil spill sensitivity atlas covers the shoreline and the offshore areas of West Greenland between 68 deg. N and 72 deg. N. The coastal zone is divided into 199 shoreline segments and the offshore zone into 8 areas. A sensitivity index value is calculated for each segment/area, and each segment/area is subsequently ranked according to four degrees of sensitivity. Besides this general ranking a number of smaller areas are especially selected as they are of particular significance, they are especially vulnerable to oil spills and they have a size making oil spill response possible. The shoreline sensitivity ranking are shown on 37 maps (in scale 1:250,000), which also show the different elements included and the selected areas. Coast types, logistics and proposed response methods along the coasts are shown on another 37 maps. The sensitivities of the offshore zones are depicted on 4 maps, one for each season. Based on all the information, appropriate oil spill response methods have been assessed for each area. (Author)

  18. On the rms anisotropy at 7 deg and 10 deg observed in the COBE-DMR two year sky maps

    Science.gov (United States)

    Banday, A. J.; Gorski, K. M.; Tenorio, L.; Wright, E. L.; Smoot, G. F.; Lineweaver, C. H.; Kogut, A.; Hinshaw, G.; Bennett, C. L.

    1994-01-01

    The frequency-independent rms temperature fluctuations determined from the Cosmic Background Explorer-Differential Microwave Radiometer (COBE-DMR) two-year sky maps are used to infer the parameter Q(sub rms-PS), which characterizes the normalization of power-law models of primordial cosmological temperature anisotropy, for a forced fit to a scale-invariant Harrison-Zel'dovich (n = 1) spectral model. Using a joint analysis of the 7 deg and 10 deg 'cross'-rms derived from both the 53 and 90 GHz sky maps, we find Q(sub rms-PS) = 17.0(sub -2.1 sup +2.5) micro Kelvin when the low quadrupole is included, and Q(sub rms-PS) = 19.4(sub -2.1 sup +2.3) micro Kelvin excluding the quadrupole. These results are consistent with the n = 1 fits from more sensitive methods. The effect of the low quadrupole derived from the COBE-DMR data on the inferred Q(sub rms-PS) normalization is investigated. A bias to lower Q(sub rms-PS) is found when the quadrupole is included. The higher normalization for a forced n = 1 fit is then favored by the cross-rms technique.

  19. Timelike gamma* N -> Delta form factors and Delta Dalitz decay

    CERN Document Server

    Ramalho, G

    2012-01-01

    We extend a covariant model, tested before in the spacelike region for the physical and lattice QCD regimes, to a calculation of the gamma* N -> Delta reaction in the timelike region, where the square of the transfered momentum, q^2, is positive (q^2>0). We estimate the Dalitz decay Delta -> Ne+e- and the Delta distribution mass distribution function. The results presented here can be used to simulate the NN -> NNe+e- reactions at moderate beam kinetic energies.

  20. Steady vortex force theory and slender-wing flow diagnosis

    Institute of Scientific and Technical Information of China (English)

    Y.T.Yang; R.K.Zhang; Y.R.An; J.Z.Wu

    2007-01-01

    The concept vortex force in aerodynamics is sys-tematically examined based on a new steady vortex-force theory (Wu et al., Vorticity and vortex dynamics, Springer, 2006) which expresses the aerodynamic force (and moment) by the volume and boundary integrals of the Lamb vector.In this paper, the underlying physics of this theory is explo-red, including the general role of the Lamb vector in non-linear aerodynamics, its initial formation, and its relevance to the total-pressure non-uniformity. As a typical example, the theory is applied to the flow over a slender delta wing at a large angle of attack. The highly localized flow structures with high Lamb-vector peaks are identified in terms of their net contribution to various constituents of the total aerody-namic force. This vortex-force diagnosis sheds new light on the flow control and configuration optimization.

  1. Dislocation Majorana zero modes in perovskite oxide 2DEG

    Science.gov (United States)

    Chung, Suk Bum; Chan, Cheung; Yao, Hong

    2016-05-01

    Much of the current experimental efforts for detecting Majorana zero modes have been centered on probing the boundary of quantum wires with strong spin-orbit coupling. The same type of Majorana zero mode can also be realized at crystalline dislocations in 2D superconductors with the nontrivial weak topological indices. Unlike at an Abrikosov vortex, at such a dislocation, there is no other low-lying midgap state than the Majorana zero mode so that it avoids usual complications encountered in experimental detections such as scanning tunneling microscope (STM) measurements. We will show that, using the anisotropic dispersion of the t2g orbitals of Ti or Ta atoms, such a weak topological superconductivity can be realized when the surface two-dimensional electronic gas (2DEG) of SrTiO3 or KTaO3 becomes superconducting, which can occur through either intrinsic pairing or proximity to existing s-wave superconductors.

  2. Giant magnetic quadrupole resonance studied with 180 deg. electron scattering

    CERN Document Server

    Neumann-Cosel, P V

    1999-01-01

    The nuclei sup 4 sup 8 Ca and sup 9 sup 0 Zr were investigated in 180 deg. high-resolution inelastic electron scattering for momentum transfers q approx =0.35-0.8 fm sup - sup 1. Complete M2 strength distributions could be extracted in both nuclei up to excitation energies of about 15 MeV utilizing a fluctuation analysis technique. Second-RPA calculations successfully describe the experimentally observed strong fragmentation of the M2 mode. The quenching of the spin part is found to be comparable to the M1 case, contrary to previous claims suggesting a stronger reduction. A quantitative reproduction of the data requires the presence of appreciable orbital strength which can be interpreted as a torsional elastic vibration (the so-called twist mode).

  3. Laicità: finitezza degli ordini e governo delle differenze

    Directory of Open Access Journals (Sweden)

    Nicola Colaianni

    2013-12-01

    Full Text Available Testo della relazione al Convegno Nazionale dell’ADEC sul tema “Per una disciplina che cambia. Il diritto canonico e il diritto ecclesiastico nel tempo presente” (Bologna, 7-9 novembre 2013, destinata alla pubblicazione negli Atti del Convegno. Contributo non sottoposto a valutazioneSOMMARIO: 1. La laicità dei giudici – 2. La laicità dei giuristi – 3. Né regola né valore: un principio – 4. La finitezza degli ordini distinti: dalle materie miste alla sfera dell’indecidibile – 5. L’aconfessionalità sostanziale: a ex parte ecclesiae – 6. (segue: b ex parte status – 7. La laicità come governance delle differenze.

  4. LA FORMAZIONE DEGLI ETNICI NELLA RIFLESSIONE LINGUISTICA DI FRANCESCO CHERUBINI

    Directory of Open Access Journals (Sweden)

    Federica Guerini

    2016-09-01

    Full Text Available Il presente contributo si propone di fornire una descrizione della struttura del Vocabolario Patronimico di Francesco Cherubini e delle fonti empiriche consultate per la sua compilazione. Si accennerà poi a due questioni ricorrenti nel dibattito sulla formazione degli etnici in italiano, ovvero, la presenza di varianti allomorfiche o suppletive, e la motivazione morfo-pragmatica sottesa all’impiego di alcuni suffissi derivativi nella formazione di etnici e aggettivi deonomastici, cercando di chiarire quale attenzione tali tematiche abbiano ricevuto nella riflessione linguistica di Francesco Cherubini. Si formuleranno infine alcune osservazioni conclusive, evidenziando luci ed ombre del Vocabolario Patronimico e sottolineando alcuni degli spunti che tale opera ancora può offrire agli studiosi contemporanei. The formation of ethnic words in Francesco Cherubini’s reflection on language  The aim of this paper is to describe the structure and contents of Francesco Cherubini’s Vocabolario Patronimico, as well as the empirical sources consulted for its compilation. We will address two of the most common issues in the debate on the formation of ethnic nouns and adjectives in Italian, namely the existence of allomorphs and supplementary variants, and the morpho-pragmatic motivation displayed by some of the derivative suffixes occurring in ethnic nouns and adjectives derived from both personal and place names. We will offer a few observations on the place occupied by the above-mentioned issues in Cherubini’s thought and, by analyzing the strengths and weaknesses of the Vocabolario Patronimico, we will draw attention to a few topics which may be of some interest to contemporary scholars.

  5. Effects of wing locations on wing rock induced by forebody vortices

    Directory of Open Access Journals (Sweden)

    Ma Baofeng

    2016-10-01

    Full Text Available Previous studies have shown that asymmetric vortex wakes over slender bodies exhibit a multi-vortex structure with an alternate arrangement along a body axis at high angle of attack. In this investigation, the effects of wing locations along a body axis on wing rock induced by forebody vortices was studied experimentally at a subcritical Reynolds number based on a body diameter. An artificial perturbation was added onto the nose tip to fix the orientations of forebody vortices. Particle image velocimetry was used to identify flow patterns of forebody vortices in static situations, and time histories of wing rock were obtained using a free-to-roll rig. The results show that the wing locations can affect significantly the motion patterns of wing rock owing to the variation of multi-vortex patterns of forebody vortices. As the wing locations make the forebody vortices a two-vortex pattern, the wing body exhibits regularly divergence and fixed-point motion with azimuthal variations of the tip perturbation. If a three-vortex pattern exists over the wing, however, the wing-rock patterns depend on the impact of the highest vortex and newborn vortex. As the three vortices together influence the wing flow, wing-rock patterns exhibit regularly fixed-points and limit-cycled oscillations. With the wing moving backwards, the newborn vortex becomes stronger, and wing-rock patterns become fixed-points, chaotic oscillations, and limit-cycled oscillations. With further backward movement of wings, the vortices are far away from the upper surface of wings, and the motions exhibit divergence, limit-cycled oscillations and fixed-points. For the rearmost location of the wing, the wing body exhibits stochastic oscillations and fixed-points.

  6. Cosmic Galaxy-IGM HI Relation at ${\\it{z}}\\sim 2-3$ Probed in the COSMOS/UltraVISTA $1.6$ deg$^2$ Field

    CERN Document Server

    Mukae, Shiro; Kakiichi, Koki; Suzuki, Nao; Ono, Yoshiaki; Cai, Zheng; Inoue, Akio K; Chiang, Yi-Kuan; Shibuya, Takatoshi; Matsuda, Yuichi

    2016-01-01

    We present spatial correlations of galaxies and IGM neutral hydrogen HI in the COSMOS/UltraVISTA 1.62 deg$^2$ field. Our data consist of 13415 photo-$z$ galaxies at $z\\sim2-3$ with $K_s<23.4$ and the Ly$\\alpha$ forest absorptions in the background quasar spectra selected from SDSS data with no signature of damped Ly$\\alpha$ system contamination. We estimate a galaxy overdensity $\\delta_{gal}$ in an impact parameter of 2.5 pMpc, and calculate the Ly$\\alpha$ forest fluctuations $\\delta_{\\langle F\\rangle}$ whose negative values correspond to the strong Ly$\\alpha$ forest absorptions. We identify a weak anti-correlation between $\\delta_{gal}$ and $\\delta_{\\langle F\\rangle}$ with a Spearman's rank correlation coefficient of $-0.39$ suggesting that the galaxy overdensities and the Ly$\\alpha$ forest absorptions positively correlate in space at the $\\sim90\\%$ confidence level. This positive correlation indicates that high-$z$ galaxies exist around an excess of HI gas in the Ly$\\alpha$ forest. We find four cosmic vo...

  7. Delta II commercial space transportation

    Science.gov (United States)

    Meyers, J. F.

    1988-07-01

    Delta II is an upgraded variant of the Delta family of launch vehicles that has been in use by NASA since 1960. Among the design improvements incorporated by Delta II is a cryogenic-propellant second stage, a 2.89-m diameter satellite-protecting nose fairing, graphite/epoxy solid rocket motor cases, and 12:1 main engine expansion nozzle. The manufacturer/operator offers Delta II customers a dedicated, single satellite launch capability fully tailored to the given spacecraft's unique mission requirements.

  8. Role of wing morphing in thrust generation

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available In this paper, we investigate the role of morphing on flight dynamics of two birds by simulating the flow over rigid and morphing wings that have the characteristics of two different birds, namely the Giant Petrel and Dove Prion. The simulation of a flapping rigid wing shows that the root of the wing should be placed at a specific angle of attack in order to generate enough lift to balance the weight of the bird. However, in this case the generated thrust is either very small, or even negative, depending on the wing shape. Further, results show that morphing of the wing enables a significant increase in the thrust and propulsive efficiency. This indicates that the birds actually utilize some sort of active wing twisting and bending to produce enough thrust. This study should facilitate better guidance for the design of flapping air vehicles.

  9. Rotor/Wing Interactions in Hover

    Science.gov (United States)

    Young, Larry A.; Derby, Michael R.

    2002-01-01

    Hover predictions of tiltrotor aircraft are hampered by the lack of accurate and computationally efficient models for rotor/wing interactional aerodynamics. This paper summarizes the development of an approximate, potential flow solution for the rotor-on-rotor and wing-on-rotor interactions. This analysis is based on actuator disk and vortex theory and the method of images. The analysis is applicable for out-of-ground-effect predictions. The analysis is particularly suited for aircraft preliminary design studies. Flow field predictions from this simple analytical model are validated against experimental data from previous studies. The paper concludes with an analytical assessment of the influence of rotor-on-rotor and wing-on-rotor interactions. This assessment examines the effect of rotor-to-wing offset distance, wing sweep, wing span, and flaperon incidence angle on tiltrotor inflow and performance.

  10. Experimental Study on the Wing Formation of a Paraglider Canopy Cell (Inflatable Wing)

    Science.gov (United States)

    Yamamori, Keitaro; Umemura, Akira; Hishida, Manabu

    This study focuses on the formation mechanism of para-foil canopy. Three types of model wing, which represent each cell of para-foil canopy (a rigid wing with air intake, an inflatable wing and a cassette model) were prepared to explore the effects of air intake on inflatable wing formation in wind tunnel experiments. The flow fields both outside and inside of the wings were investigated, together with the process that the flexible wing inflates to form a wing. It was found that the robust nature of canopy is derived from the concaving deformation of the leading edge at small angles of attack, and the enhanced outward suction pressure acting on the leading edge, which are caused by the flexibility of the wing as well as the pressure of air intake in sacrifice of increased drag coefficient.

  11. Experimental Investigation on Limit Cycle Wing Rock Effect on Wing Body Configuration Induced by Forebody Vortices

    National Research Council Canada - National Science Library

    Rong, Zhen; Deng, Xueying; Ma, Baofeng; Wang, Bing

    2016-01-01

    ...° swept wing configuration undergoing a limit cycle oscillation using a synchronous measurement and control technique of wing rock/particle image velocimetry/dynamic pressure associated with the time...

  12. Morphing fixed wing MAV modeling using VAM

    OpenAIRE

    2012-01-01

    The design and implementation of a morphing Micro Air Vehicle (MAV) wing using a smart composite is attempted in this research work. Control surfaces actuated by traditional servos are difficult to instrument and fabricate on thin composite-wings of MAVs. Piezoelectric Fiber Reinforced Composites (PFRCs) are the chosen smart structural materials in the current work for incorporation onto fixed-wing MAVs to simultaneously perform the dual functions of structural load-bearing and actuatio...

  13. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

  14. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia wh

  15. Peat compaction in deltas : implications for Holocene delta evolution

    NARCIS (Netherlands)

    van Asselen, S.|info:eu-repo/dai/nl/304838101

    2010-01-01

    Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

  16. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia wh

  17. 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.

  18. Veins improve fracture toughness of insect wings.

    Directory of Open Access Journals (Sweden)

    Jan-Henning Dirks

    Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

  19. Subtractive Structural Modification of Morpho Butterfly Wings.

    Science.gov (United States)

    Shen, Qingchen; He, Jiaqing; Ni, Mengtian; Song, Chengyi; Zhou, Lingye; Hu, Hang; Zhang, Ruoxi; Luo, Zhen; Wang, Ge; Tao, Peng; Deng, Tao; Shang, Wen

    2015-11-11

    Different from studies of butterfly wings through additive modification, this work for the first time studies the property change of butterfly wings through subtractive modification using oxygen plasma etching. The controlled modification of butterfly wings through such subtractive process results in gradual change of the optical properties, and helps the further understanding of structural optimization through natural evolution. The brilliant color of Morpho butterfly wings is originated from the hierarchical nanostructure on the wing scales. Such nanoarchitecture has attracted a lot of research effort, including the study of its optical properties, its potential use in sensing and infrared imaging, and also the use of such structure as template for the fabrication of high-performance photocatalytic materials. The controlled subtractive processes provide a new path to modify such nanoarchitecture and its optical property. Distinct from previous studies on the optical property of the Morpho wing structure, this study provides additional experimental evidence for the origination of the optical property of the natural butterfly wing scales. The study also offers a facile approach to generate new 3D nanostructures using butterfly wings as the templates and may lead to simpler structure models for large-scale man-made structures than those offered by original butterfly wings.

  20. Analysis of bat wings for morphing

    Science.gov (United States)

    Leylek, Emily A.; Manzo, Justin E.; Garcia, Ephrahim

    2008-03-01

    The morphing of wings from three different bat species is studied using an extension of the Weissinger method. To understand how camber affects performance factors such as lift and lift to drag ratio, XFOIL is used to study thin (3% thickness to chord ratio) airfoils at a low Reynolds number of 100,000. The maximum camber of 9% yielded the largest lift coefficient, and a mid-range camber of 7% yielded the largest lift to drag ratio. Correlations between bat wing morphology and flight characteristics are covered, and the three bat wing planforms chosen represent various combinations of morphological components and different flight modes. The wings are studied using the extended Weissinger method in an "unmorphed" configuration using a thin, symmetric airfoil across the span of the wing through angles of attack of 0°-15°. The wings are then run in the Weissinger method at angles of attack of -2° to 12° in a "morphed" configuration modeled after bat wings seen in flight, where the camber of the airfoils comprising the wings is varied along the span and a twist distribution along the span is introduced. The morphed wing configurations increase the lift coefficient over 1000% from the unmorphed configuration and increase the lift to drag ratio over 175%. The results of the three different species correlate well with their flight in nature.

  1. A 360-deg Digital Image Correlation system for materials testing

    Science.gov (United States)

    Genovese, K.; Cortese, L.; Rossi, M.; Amodio, D.

    2016-07-01

    The increasing research interest toward natural and advanced engineered materials demands new experimental protocols capable of retrieving highly dense sets of experimental data on the full-surface of samples under multiple loading conditions. Such information, in fact, would allow to capture the possible heterogeneity and anisotropy of the material by using up-to-date inverse characterization methods. Although the development of object-specific test protocols could represent the optimal choice to address this need, it is unquestionable that universal testing machines (UTM) remain the most widespread and versatile option to test materials and components in both academic and industrial contexts. A major limitation of performing standard material tests with UTM, however, consists in the scarce information obtainable with the commonly associated sensors since they provide only global (LVDTs, extensometers, 2D-video analyzers) or local (strain gages) measures of displacement and strain. This paper presents a 3D Digital Image Correlation (DIC) system developed to perform highly accurate full-surface 360-deg measurements on either standard or custom-shaped samples under complex loading within universal testing machines. To this aim, a low cost and easy to setup video rig was specifically designed to overcome the practical limitations entailed with the integration of a multi-camera system within an already existing loading frame. In particular, the proposed system features a single SLR digital camera moved through multiple positions around the specimen by means of a large rotation stage. A proper calibration and data-processing procedure allows to automatically merge the experimental data obtained from the multiple views with an accuracy of 10-2 m m . The results of a full benchmarking of the metrological performances of the system are here reported and discussed together with illustrative examples of full-360-deg shape and deformation measurements on a Grade X65 steel

  2. The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). I: The UV luminosity function of the central 12 sq.deg

    CERN Document Server

    Boselli, A; Heinis, S; Cortese, L; Ilbert, O; Hughes, T; Cucciati, O; Davies, J; Ferrarese, L; Giovanelli, R; Haynes, M P; Baes, M; Balkowski, C; Brosch, N; Chapman, S C; Charmandaris, V; Clemens, M S; Dariush, A; De Looze, I; Alighieri, S di Serego; Duc, P -A; Durrell, P R; Emsellem, E; Erben, T; Fritz, J; Garcia-Appadoo, D A; Gavazzi, G; Grossi, M; Jordán, A; Hess, K M; Huertas-Company, M; Hunt, L K; Kent, B R; Lambas, D G; Lancon, A; MacArthur, L A; Madden, S C; Magrini, L; Mei, S; Momjian, E; Olowin, R P; Papastergis, E; Smith, M W L; Solanes, J M; Spector, O; Spekkens, K; Taylor, J E; Valotto, C; van Driel, W; Verstappen, J; Vlahakis, C; Vollmer, B; Xilouris, E M

    2011-01-01

    The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) is a complete blind survey of the Virgo cluster covering about 40 sq. deg. in the far UV (FUV, lambda_eff=1539A, Delta-lambda=442A) and about 120 sq. deg. in the near UV (NUV, lambda_eff=2316A, Delta-lambda=1060A). The goal of the survey is to study the ultraviolet (UV) properties of galaxies in a rich cluster environment, spanning a wide luminosity range from giants to dwarfs, and regardless of prior knowledge of their star formation activity. The UV data will be combined with those in other bands (optical: NGVS; far-infrared - submm: HeViCS; HI: ALFALFA) and with our multizone chemo-spectrophotometric models of galaxy evolution to make a complete and exhaustive study of the effects of the environment on the evolution of galaxies in high density regions. We present here the scientific objectives of the survey, describing the observing strategy and briefly discussing different data reduction techniques. Using UV data already in-hand for the central 12 sq. de...

  3. Projection moire interferometry measurements of micro air vehicle wings

    Science.gov (United States)

    Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

    2001-11-01

    Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat's wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

  4. $\\Delta$-N Electromagnetic Transition

    CERN Document Server

    Loan, M

    1999-01-01

    The EM ratio for a free Delta electromagnetic transition is discussed within the frame work of nonrelativistic approach. Such an approach gives a good account of data for a free Delta but is less important for an intrinsically relativistic nuclear many body problem.

  5. Mida pakub Delta? / Teele Kurm

    Index Scriptorium Estoniae

    Kurm, Teele

    2011-01-01

    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  6. Delta Electroproduction in 12-C

    Energy Technology Data Exchange (ETDEWEB)

    Steven McLauchlan

    2003-01-31

    The Delta-nucleus potential is a crucial element in the understanding of the nuclear system. Previous electroexcitation measurements in the delta region reported a Q2 dependence of the delta mass indicating that this potential is dependent on the momentum of the delta. Such a dependence is not observed for protons and neutrons in the nuclear medium. This thesis presents the experimental study of the electroexcitation of the delta resonance in 12C, performed using the high energy electron beam at the Thomas Jefferson National Accelerator Facility, and the near 4(pie) acceptance detector CLAS that enables the detection of the full reaction final state. Inclusive, semi inclusive, and exclusive cross sections were measured with an incident electron beam energy of 1.162GeV over the Q2 range 0.175-0.475 (GeV/c)2. A Q2 dependence of the delta mass was only observed in the exclusive measurements indicating that the delta-nucleus potential is affected by the momentum of the delta.

  7. Mida pakub Delta? / Teele Kurm

    Index Scriptorium Estoniae

    Kurm, Teele

    2011-01-01

    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  8. Aerodynamic Loads at Mach Numbers from 0.70 to 2.22 on an Airplane Model Having a Wing and Canard of Triangular Plan Form and Either Single or Twin Vertical Tails Supplement I-Tabulated Data for the Model with Single Vertical Tails. Supplement 1; Tabulated Data for the Model with Single Vertical Tail

    Science.gov (United States)

    Peterson, Victor L.; Menees, Gene P.

    1961-01-01

    Tabulated results of a wind-tunnel investigation of the aerodynamic loads on a canard airplane model with a single vertical tail are presented for Mach numbers from 0.70 to 2.22. The Reynolds number for the measurements was 2.9 x 10(exp 6) based on the wing mean aerodynamic chord. The results include local static pressure coefficients measured on the wing, body, and vertical tail for angles of attack from -4 deg to + 16 deg, angles of sideslip of 0 deg and 5.3 deg, vertical-tail settings of 0 deg and 5 deg, and nominal canard deflections of 0 deg and 10 deg. Also included are section force and moment coefficients obtained from integrations of the local pressures and model-component force and moment coefficients obtained from integrations of the section coefficients. Geometric details of the model and the locations of the pressure orifices are shown. An index to the data contained herein is presented and definitions of nomenclature are given.

  9. Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

    Science.gov (United States)

    Du, Hai; Shi, Zhiwei; Cheng, Keming; Wei, Dechen; Li, Zheng; Zhou, Danjie; He, Haibo; Yao, Junkai; He, Chengjun

    2016-06-01

    Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

  10. LE ZANZARE ITALIANE: GENERALITÀ E IDENTIFICAZIONE DEGLI ADULTI (DIPTERA, CULICIDAE

    Directory of Open Access Journals (Sweden)

    Francesco Severini

    2009-12-01

    Full Text Available Nel presente lavoro vengono riportate le informazioni essenziali su tassonomia e biologia nonché sugli aspetti ecologici degli adulti dei Culicidi italiani. Attualmente la fauna culicidica italiana comprende 64 specie appartenenti a 2 sottofamiglie e 8 generi. Alla sottofamiglia Anophelinae appartiene soltanto il genere Anopheles, presente con 16 specie raggruppate in due sottogeneri. Alla sottofamiglia Culicinae appartengono i rimanenti 7 generi: Aedes con 6 specie raggruppate in 3 sottogeneri, Coquillettidia con 2 specie, Ochlerotatus con 20 specie raggruppate in 3 sottogeneri, Culex con 12 specie raggruppate in 4 sottogeneri, Culiseta con 6 specie raggruppate in 3 sottogeneri, Orthopodomyia e Uranotaenia con una specie ognuna. In questo contesto vengono fornite le chiavi di identificazione specifica per le zanzare adulte, in italiano e in inglese. Le chiavi sono corredate da un’ampia iconografia (figure 1-75. Alle chiavi fa seguito la diagnosi morfologica dell’adulto di ogni specie con note sulla relativa biologia e distribuzione. Per ulteriori approfondimenti viene riportata la bibliografia completa sulle zanzare della fauna italiana dal 1960 ed i precedenti lavori più autorevoli.

  11. Come e cosa desidera la narrativa italiana degli anni Zero

    Directory of Open Access Journals (Sweden)

    Gianluigi Simonetti

    2013-05-01

    Full Text Available L'articolo analizza il trattamento del tema del desiderio - erotico e amoroso - nel romanzo italiano degli ultimi anni, impegnandosi nell'esame ravvicinato di alcuni testi esemplari. La campionatura vuole da un lato isolare alcune opere rappresentative della situazione attuale della narrativa contemporanea, dall'altro  proporre un'ipotesi categoriale che seziona il campo di studio in tre parti; il sondaggio sembra infatti suggerire che le dinamiche del desiderio vengono rese in maniera specifica nei diversi ambiti della letteratura di consumo, in quella di 'nobile intrattenimento' e in quella 'forte' e letterariamente più ambiziosa. L'analisi formale risulta insomma integrata a una prospettiva di stroria dello stile, secondo un metodo che permette di utilizzare la figuralità letteraria come 'indicatore sociologico' di processi politici (e forse antropologici in atto.

  12. Le caratteristiche degli acquirenti e venditori di abitazioni

    Directory of Open Access Journals (Sweden)

    Erika Ghiraldo

    2011-12-01

    Full Text Available L’incrocio dei dati contenuti nelle dichiarazioni dei redditi con quelli contenuti negli archivi della Pubblicità Immobiliare (ex Conservatorie rende disponibili molte informazioni sulle caratteristiche dei contraenti che hanno effettuato una compravendita di unità immobiliari. Considerando principalmente le compravendite di unità immobiliari del settore residenziale effettuate da persone fisiche sono trattate informazioni sul reddito dichiarato al fisco, l’età e l’attività di lavoro prevalente. È fornito un quadro sintetico della distribuzione delle compravendite, in termini di Numero di Transazioni Normalizzate (NTN e per dimensione delle abitazioni, per ciascuna caratteristica sia per gli acquirenti che per i venditori. La disponibilità dell’informazione sulla residenza dei soggetti consente, inoltre, di condurre un’analisi sulla provenienza degli acquirenti rispetto al luogo di ubicazione dell’immobile compravenduto. E’ possibile così analizzare la composizione del mercato distinguendo la quota di acquisti imputabile a soggetti residenti nello stesso Comune di ubicazione dell’immobile (mercato comunale dalla quota alimentata da soggetti residenti in altro Comune di una stessa provincia (mercato infraprovinciale o di altra provincia (mercato extra-provinciale. Quest’ultima indagine risulta molto interessante se effettuata su singole città. Sono, quindi, riportati i risultati dell’analisi per i mercati delle città di Milano, Roma e Napoli.

  13. Mackenzie River Delta, Canada

    Science.gov (United States)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789. The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  14. DELTA 3D PRINTER

    Directory of Open Access Journals (Sweden)

    ȘOVĂILĂ Florin

    2016-07-01

    Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.

  15. Ice-Accretion Test Results for Three Large-Scale Swept-Wing Models in the NASA Icing Research Tunnel

    Science.gov (United States)

    Broeren, Andy P.; Potapczuk, Mark G.; Lee, Sam; Malone, Adam M.; Paul, Benard P., Jr.; Woodard, Brian S.

    2016-01-01

    Icing simulation tools and computational fluid dynamics codes are reaching levels of maturity such that they are being proposed by manufacturers for use in certification of aircraft for flight in icing conditions with increasingly less reliance on natural-icing flight testing and icing-wind-tunnel testing. Sufficient high-quality data to evaluate the performance of these tools is not currently available. The objective of this work was to generate a database of ice-accretion geometry that can be used for development and validation of icing simulation tools as well as for aerodynamic testing. Three large-scale swept wing models were built and tested at the NASA Glenn Icing Research Tunnel (IRT). The models represented the Inboard (20% semispan), Midspan (64% semispan) and Outboard stations (83% semispan) of a wing based upon a 65% scale version of the Common Research Model (CRM). The IRT models utilized a hybrid design that maintained the full-scale leading-edge geometry with a truncated afterbody and flap. The models were instrumented with surface pressure taps in order to acquire sufficient aerodynamic data to verify the hybrid model design capability to simulate the full-scale wing section. A series of ice-accretion tests were conducted over a range of total temperatures from -23.8 deg C to -1.4 deg C with all other conditions held constant. The results showed the changing ice-accretion morphology from rime ice at the colder temperatures to highly 3-D scallop ice in the range of -11.2 deg C to -6.3 deg C. Warmer temperatures generated highly 3-D ice accretion with glaze ice characteristics. The results indicated that the general scallop ice morphology was similar for all three models. Icing results were documented for limited parametric variations in angle of attack, drop size and cloud liquid-water content (LWC). The effect of velocity on ice accretion was documented for the Midspan and Outboard models for a limited number of test cases. The data suggest that

  16. The Realization and Study of Optical Wings

    Science.gov (United States)

    Artusio-Glimpse, Alexandra Brae

    Consider the airfoil: a carefully designed structure capable of stable lift in a uniform air flow. It so happens that air pressure and radiation (light) pressure are similar phenomena because each transfer momentum to flow-disturbing objects. This, then, begs the question: does an optical analogue to the airfoil exist? Though an exceedingly small effect, scientists harness radiation pressure in a wide gamut of applications from micromanipulation of single biological particles to the propulsion of large spacecrafts called solar sails. We introduce a cambered, refractive rod that is subjected to optical forces analogous to those seen in aerodynamics, and I call this analogue the optical wing. Flight characteristics of optical wings are determined by wing shape and material in a uniform radiation field. Theory predicts the lift force and axial torque are functions of the wing's angle of attack with stable and unstable orientations. These structures can operate as intensity-dependent, parametrically driven oscillators. In two-dimensions, the wings exhibit bistability when analyzed in an accelerating frame. In three-dimensions, the motion of axially symmetric spinning hemispherical wings is analogous to a spinning top. Experiments on semi-buoyant wings in water found semicylindrically shaped, refractive microparticles traversed a laser beam and rotated to an illumination-dependent stable orientation. Preliminary tests aid in the development of a calibrated force measurement experiment to directly evaluate the optical forces and torque on these samples. A foundational study of the optical wing, this work contributes to future advancements of flight-by-light.

  17. Biaxial mechanical characterization of bat wing skin.

    Science.gov (United States)

    Skulborstad, A J; Swartz, S M; Goulbourne, N C

    2015-04-21

    The highly flexible and stretchable wing skin of bats, together with the skeletal structure and musculature, enables large changes in wing shape during flight. Such compliance distinguishes bat wings from those of all other flying animals. Although several studies have investigated the aerodynamics and kinematics of bats, few have examined the complex histology and mechanical response of the wing skin. This work presents the first biaxial characterization of the local deformation, mechanical properties, and fiber kinematics of bat wing skin. Analysis of these data has provided insight into the relationships among the structural morphology, mechanical properties, and functionality of wing skin. Large spatial variations in tissue deformation and non-negligible fiber strains in the cross-fiber direction for both chordwise and spanwise fibers indicate fibers should be modeled as two-dimensional elements. The macroscopic constitutive behavior was anisotropic and nonlinear, with very low spanwise and chordwise stiffness (hundreds of kilopascals) in the toe region of the stress-strain curve. The structural arrangement of the fibers and matrix facilitates a low energy mechanism for wing deployment and extension, and we fabricate examples of skins capturing this mechanism. We propose a comprehensive deformation map for the entire loading regime. The results of this work underscore the importance of biaxial field approaches for soft heterogeneous tissue, and provide a foundation for development of bio-inspired skins to probe the effects of the wing skin properties on aerodynamic performance.

  18. The BLAST View of the Star Forming Region in Aquila (ell=45deg,b=0deg)

    CERN Document Server

    Rivera-Ingraham, Alana; Bock, James J; Chapin, Edward L; Devlin, Mark J; Dicker, Simon R; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Marsden, Gaelen; Martin, Peter G; Mauskopf, Philip; Netterfield, Calvin B; Olmi, Luca; Patanchon, Guillaume; Rex, Marie; Scott, Douglas; Semisch, Christopher; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V

    2010-01-01

    We have carried out the first general submillimeter analysis of the field towards GRSMC 45.46+0.05, a massive star forming region in Aquila. The deconvolved 6 deg^2 (3\\degree X 2\\degree) maps provided by BLAST in 2005 at 250, 350, and 500 micron were used to perform a preliminary characterization of the clump population previously investigated in the infrared, radio, and molecular maps. Interferometric CORNISH data at 4.8 GHz have also been used to characterize the Ultracompact HII regions (UCHIIRs) within the main clumps. By means of the BLAST maps we have produced an initial census of the submillimeter structures that will be observed by Herschel, several of which are known Infrared Dark Clouds (IRDCs). Our spectral energy distributions of the main clumps in the field, located at ~7 kpc, reveal an active population with temperatures of T~35-40 K and masses of ~10^3 Msun for a dust emissivity index beta=1.5. The clump evolutionary stages range from evolved sources, with extended HII regions and prominent IR ...

  19. Transonic Free-Flight Investigation of the Longitudinal Aerodynamic Characteristics of a 1/10-Scale Steel-Wing Model of the Northrop MX-775A Missile with Leading-Edge Extensions, Inboard Trailing-Edge Flaps, and a Speed Brake on the Vertical Tail

    Science.gov (United States)

    Arbic, R. G.

    1955-01-01

    Results are presented of a free-flight investigation between Mach numbers of 0.7 to 1.3 and Reynolds numbers of 3.1 x 10(exp 6) to 7.0 x 10(exp 6) to determine the longitudinal aerodynamic characteristics of the Northrop MX-775A missile. This missile has a weng, body, and vertical tail, but has no horizontal tail. The basic wing plan form has an aspect ratio of 5.5, 45 deg of sweepback of the 0.406 streamwise chord line, and a taper ratio of 0.4. A 1/10-scale steel-wing model of the missile was flown with modifications to the basic wing plan form consisting of leading-edge chord-extensions deflected 7 deg downward together with the forward 15 percent of the wing chord, and inboard trailing-edge flaps deflected 5 deg downward. In addition, the model had a static-pressure tube mounted at the tip of the vertical tail for position-error measurements and had a speed brake also mounted on the vertical tail to trim the model to positive lift coefficients and to permit determination of the trim and drag effectiveness of the brake. The data are uncorrected for the effects of wing elasticity, but experimental wing influence coefficients are presented.

  20. Effects of leading edge sweep angle and design lift coefficient on performance of a modified arrow wing at a design Mach number of 2.6

    Science.gov (United States)

    Mack, R. J.

    1974-01-01

    Wing models were tested in the high-speed section of the Langley Unitary Plan wind tunnel to study the effects of the leading-edge sweep angle and the design lift coefficient on aerodynamic performance and efficiency. The models had leading-edge sweep angles of 69.44 deg, 72.65 deg, and 75.96 deg which correspond to values of the design Mach-number-sweep-angle parameter (beta cotangent A) sub DES of 0.6, 0.75, and 0.9, respectively. For each sweep angle, camber surfaces having design lift coefficients of 0,0.08, and 0.12 at a design Mach number of 2.6 were generated. The wind-tunnel tests were conducted at Mach numbers of 2.3, 2.6, and 2.96 with a stagnation temperature of 338.7 K (150 F) and a Reynolds number per meter of 9.843 times 10 to the 6th power. The results of the tests showed that only a moderate sweeping of the wing leading edge aft of the Mach line along with a small-to-moderate amount of camber and twist was needed to significantly improve the zero-lift (flat camber surface) wing performance and efficiency.

  1. WORLD DELTAS AND THEIR EVOLUTION

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In August 1998, an international symposium on the world deltas was held in New Orleans, Louisiana, USA. This symposium attracted discussion about more than 25 deltas from around the world with emphasis placed on those that are most densely populated and impacted by humans. Keynote papers printed details about the physical, biological, engineering and socioeconomic aspects of six deltas including the Mississippi, Nile, Ganges-Brahmaputra, Rhine-Meuse, Changjiang and Po. The main purpose of this symposium was to inform scientists, engineers and decision-makers about information that is currently available and to provide them a basis for working in such environments.

  2. Dynamical Casimir effect with $\\delta-\\delta^{\\prime}$ mirrors

    CERN Document Server

    Silva, Jeferson Danilo L; Alves, Danilo T

    2016-01-01

    We calculate the spectrum and the total rate of created particles for a real massless scalar field in $1+1$ dimensions, in the presence of a partially transparent moving mirror simulated by a Dirac $\\delta-\\delta^{\\prime}$ point interaction. We show that, strikingly, a partially reflecting mirror can produce a larger number of particles in comparison with a perfectly reflecting one. In the limit of a perfect mirror, our formulas recover those found in the literature for the Robin boundary condition.

  3. Photoluminescence of a High Mobility 2DEG in the Fractional Quantum Hall Effect Regime

    Science.gov (United States)

    Smirnov, D.; Rudenkov, V. V.; Ashkinadze, B. M.; Cohen, E.; Christianen, P. C. M.; Maan, J. C.; Pfeiffer, L. N.

    The magneto-PL spectra of modulation-doped, ultra-high mobility GaAs/AlGaAs single heterojunctions (HJs) were studied under a perpendicularly applied magnetic field up to 33 T and at temperatures of 0.3 and 1.2 K. The spectra show remarkable intensity redistribution between free (bulk) exciton and 2DEG-hole PL channels occurring at electron filling factors, ν = 2 and 1. At 0.3 K, significant 2DEG-hole PL spectral changes are observed near ν = 2/3 and 1/3. Several heterojunctions with 2DEG density in the range of n2D - (1 - 2.7) · 1011 cm-2 display similar features. These spectral peculiarities are attributed to the modification of the 2DEG energy spectrum caused by the e-e interaction, in particular, the recombination of valence hole with the composite (fractionally-charged) particles of the magnetized 2DEG. In HJs with lower n2D < 1011 cm-2, the observed PL evolution at ν < 1 is mainly determined by an intensity redistribution between the σ+ and σ- circularly-polarized free exciton PL components. In this case, the exciton energy is lower than the energy of the 2DEG-hole system, so that the free excitons do not dissociate near the magnetized 2DEG and thus, the 2DEG-hole PL is barely observed.

  4. Habitat variation and wing coloration affect wing shape evolution in dragonflies.

    Science.gov (United States)

    Outomuro, D; Dijkstra, K-D B; Johansson, F

    2013-09-01

    Habitats are spatially and temporally variable, and organisms must be able to track these changes. One potential mechanism for this is dispersal by flight. Therefore, we would expect flying animals to show adaptations in wing shape related to habitat variation. In this work, we explored variation in wing shape in relation to preferred water body (flowing water or standing water with tolerance for temporary conditions) and landscape (forested to open) using 32 species of dragonflies of the genus Trithemis (80% of the known species). We included a potential source of variation linked to sexual selection: the extent of wing coloration on hindwings. We used geometric morphometric methods for studying wing shape. We also explored the phenotypic correlation of wing shape between the sexes. We found that wing shape showed a phylogenetic structure and therefore also ran phylogenetic independent contrasts. After correcting for the phylogenetic effects, we found (i) no significant effect of water body on wing shape; (ii) male forewings and female hindwings differed with regard to landscape, being progressively broader from forested to open habitats; (iii) hindwings showed a wider base in wings with more coloration, especially in males; and (iv) evidence for phenotypic correlation of wing shape between the sexes across species. Hence, our results suggest that natural and sexual selection are acting partially independently on fore- and hindwings and with differences between the sexes, despite evidence for phenotypic correlation of wing shape between males and females.

  5. Design, fabrication, and characterization of multifunctional wings to harvest solar energy in flapping wing air vehicles

    Science.gov (United States)

    Perez-Rosado, Ariel; Gehlhar, Rachel D.; Nolen, Savannah; Gupta, Satyandra K.; Bruck, Hugh A.

    2015-06-01

    Currently, flapping wing unmanned aerial vehicles (a.k.a., ornithopters or robotic birds) sustain very short duration flight due to limited on-board energy storage capacity. Therefore, energy harvesting elements, such as flexible solar cells, need to be used as materials in critical components, such as wing structures, to increase operational performance. In this paper, we describe a layered fabrication method that was developed for realizing multifunctional composite wings for a unique robotic bird we developed, known as Robo Raven, by creating compliant wing structure from flexible solar cells. The deformed wing shape and aerodynamic lift/thrust loads were characterized throughout the flapping cycle to understand wing mechanics. A multifunctional performance analysis was developed to understand how integration of solar cells into the wings influences flight performance under two different operating conditions: (1) directly powering wings to increase operation time, and (2) recharging batteries to eliminate need for external charging sources. The experimental data is then used in the analysis to identify a performance index for assessing benefits of multifunctional compliant wing structures. The resulting platform, Robo Raven III, was the first demonstration of a robotic bird that flew using energy harvested from solar cells. We developed three different versions of the wing design to validate the multifunctional performance analysis. It was also determined that residual thrust correlated to shear deformation of the wing induced by torsional twist, while biaxial strain related to change in aerodynamic shape correlated to lift. It was also found that shear deformation of the solar cells induced changes in power output directly correlating to thrust generation associated with torsional deformation. Thus, it was determined that multifunctional solar cell wings may be capable of three functions: (1) lightweight and flexible structure to generate aerodynamic forces, (2

  6. Accelerated transformation of brushite to octacalcium phosphate in new biomineralization media between 36.5 deg. C and 80 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Temizel, Neslihan; Girisken, Giray; Tas, A. Cuneyt, E-mail: cuneyt-tas@ouhsc.edu

    2011-07-20

    This study investigated the hydrothermal transformation of brushite (dicalcium phosphate dihydrate, DCPD, CaHPO{sub 4}.2H{sub 2}O) into octacalcium phosphate (OCP, Ca{sub 8}(HPO{sub 4}){sub 2}(PO{sub 4}){sub 4}.5H{sub 2}O) in seven different newly developed biomineralization media, all inspired from the commercial DMEM solutions, over the temperature range of 36.5 deg. C to 90 deg. C with aging times varying between 1 h and 6 days. DCPD powders used in this study were synthesized in our laboratory by using a wet-chemical technique. DCPD was found to transform into OCP in the Ca{sup 2+}, Mg{sup 2+}, Na{sup +}, K{sup +}, HCO{sub 3}{sup -}, Cl{sup -} and H{sub 2}PO{sub 4}{sup -} containing aqueous biomineralization media in less than 72 h at 36.5 deg. C, without stirring. The same medium was able to convert DCPD into OCP in about 2 h at 75-80 deg. C, again without a need for stirring. Samples were characterized by using powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). - Research highlights: {yields} New biomineralization solutions developed to convert DCPD into OCP at 36.5 deg. C to 80 deg. C. {yields} DCPD powder was the starting material. {yields} OCP was synthesized under static conditions (no need for stirring). {yields} OCP was synthesized in sealed glass media bottles in solutions free of Hepes or Tris. {yields} OCP can be synthesized at 75-80 deg. C in only 2 hours in the above solutions without stirring.

  7. PARAMETRIC DESIGN OF DELTA ROBOT

    Directory of Open Access Journals (Sweden)

    Mert Gürgen

    2016-09-01

    Full Text Available This article describes a sophisticated determination and presentation of a workspace volume for a delta robot, with consideration of its kinematic behavior. With the help of theoretical equations, optimization is performed with the aid of the stiffness and dexterity analysis. Theoretical substructure is coded in Matlab and three-dimensional (3D data for delta robot are developed in computer-aided design (CAD environment. In later stages of the project, both 3D and theoretical data are linked together and thus, with the changing design parameter of the robot itself, the Solidworks CAD output adapts and regenerates output with a new set of parameters. To achieve an optimum workspace volume with predefined parameters, a different set of robot parameters are iterated through design optimization in Matlab, and the delta robot design is finalized and illustrated in the 3D CAD environment, Solidworks. This study provides a technical solution to accomplish a generic delta robot with optimized workspace volume.

  8. Flexure fatigue testing of 90 deg graphite/epoxy composites

    Science.gov (United States)

    Peck, Ann Nancy W.

    1995-01-01

    3-point flexure tests of 90 deg graphite/epoxy specimens. Investigations will include the volume scale effect as well as frequency and span-to-thickness ratio effects. Prior to the start of the experimental study, an analytical study using finite element modeling will be performed to investigate the span-to-thickness effect. The ratio of transverse flexure stress to shear stress will be monitored and its values predicted by the FEM analysis compared with the value obtained using a 'strength of materials' based approach.

  9. AtDeg2 – a chloroplast protein with dual protease/chaperone activity

    Directory of Open Access Journals (Sweden)

    Przemysław Jagodzik

    2014-07-01

    Full Text Available Chloroplast protease AtDeg2 (an ATP-independent serine endopeptidase is cytosolically synthesized as a precursor, which is imported into the chloroplast stroma and deprived of its transit peptide. Then the mature protein undergoes routing to its functional location at the stromal side of thylakoid membrane. In its linear structure AtDeg2 molecule contains the protease domain with catalytic triad (HDS and two PDZ domains (PDZ1 and PDZ2. In vivo AtDeg2 most probably exists as a supposedly inactive haxamer, which may change its oligomeric stage to form active 12-mer, or 24-mer. AtDeg2 has recently been demonstrated to exhibit dual protease/chaperone function. This review is focused on the current awareness with regard to AtDeg2 structure and functional significance.

  10. Patologie sociali, resistenze e difese degli insegnanti nell’istituzione scolastica: Considerazioni cliniche e pedagogiche

    Directory of Open Access Journals (Sweden)

    Tommaso Fratini

    2014-12-01

    Full Text Available L’articolo prende in esame il tema di alcune resistenze e difese degli insegnanti all’interno dell’istituzione scolastica. Partendo dall’attuale condizione di emergenza della scuola italiana e rifacendosi al concetto di patologia sociale di Giuseppe Di Chiara, viene argomentato come tali resistenze coprano le angosce persecutorie degli insegnanti nel loro lavoro scolastico quotidiano nel rapporto con gli allievi. L’articolo, tra le varie forme di patologia istituzionale, affronta principalmente il tema di quelle che presiedono alle resistenze degli insegnanti al lavoro introspettivo con il proprio mondo interno, conseguenza e ulteriore cagione di sensi di colpa nel rapporto con gli allievi e di fenomeni di burnout lavorativo degli stessi insegnanti. Tali fenomeni vanno nella direzione del rinforzo sia di un atteggiamento di chiusura verso la collaborazione con professionisti esterni all’istituzione scolastica, sia di un atteggiamento di minore empatia e vicinanza emotiva con la realtà interna degli allievi.

  11. Interval Finite Element Analysis of Wing Flutter

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaojun; Qiu Zhiping

    2008-01-01

    The influences of uncertainties in structural parameters on the flutter speed of wing are studied. On the basis of the deterministic flutter analysis model of wing, the uncertainties in structural parameters are considered and described by interval numbers. By virtue of first-order Taylor series expansion, the lower and upper bound curves of the transient decay rate coefficient versus wind velocity are given. So the interval estimation of the flutter critical wind speed of wing can be obtained, which is more reasonable than the point esti- mation obtained by the deterministic flutter analysis and provides the basis for the further non-probabilistic interval reliability analysis of wing flutter. The flow chart for interval finite element model of flutter analysis of wing is given. The proposed interval finite element model and the stochastic finite element model for wing flutter analysis are compared by the examples of a three degrees of freedorn airfoil and fuselage and a 15° swepthack wing, and the results have shown the effectiveness and feasibility of the presented model. The prominent advantage of the proposed interval finite element model is that only the bounds of uncertain parameters axe required, and the probabilistic distribution densities or other statistical characteristics are not needed.

  12. In the wings of physics

    CERN Document Server

    Jacob, Maurice René Michel

    1995-01-01

    In physics research, many activities occur backstage or to continue the theatrical metaphor, in the wings of physics. This book focuses on two such activities: the editing of physics journals and the operation of physical societies. The author was editor of Physics Letters B for particle physics and then of Physics Reports for a total of 18 years, as well as being president of the French Physical Society and later of the European Physical Society. This book puts together papers dealing with such activities which he has written at various times in his career. It takes the reader into the inner circles of scientific editing and of physical societies. Each introduced by a foreword, these papers can be read separately.

  13. Induce Drag Reduction of an Airplane Wing

    Directory of Open Access Journals (Sweden)

    Md. Fazle Rabbi

    2015-06-01

    Full Text Available This work describes the aerodynamic characteristics for aircraft wing model with and without slotted winglet. When an aircraft moves forward with a high speed then a small circulatory motion of air is created at the wingtip due to the pressure difference between the upper and lower surface of the wing is called vortices. This circulatory fluid tends to leak from lower to upper surface of wing which causes downward motion is called “downwash” and generates a component of the local lift force in the direction of the free stream called induced drag. Downwash causes reduction of lift and contribute induced drag to the total drag. Drag reduction for aerial vehicles has a range of positive ramifications: reduced fuel consumption, larger operational range, greater endurance and higher achievable speeds. An experimental study is conducted to examine the potentiality of slotted winglet for the reduction of induced drag, and for the improvement of lift coefficient without increasing the span of aircraft wing. The model composed of a swept wing built from NACA 0012 airfoil. The test conducted in subsonic wind tunnel of 1m×1m rectangular test section at flow speed 25m/s placing the wing without winglet, wing with winglet at 30° inclination, wing with winglet at 60° inclination, and wing with winglet at 70° inclination at angle of attack ranging from 0 to 16 degree. The test result shows 20- 25% reduction in drag coefficient and 10-20% increase in lift coefficient by using slotted winglet.

  14. Temperature dependent dynamics of DegP-trimer: A molecular dynamics study.

    Science.gov (United States)

    Rai, Nivedita; Ramaswamy, Amutha

    2015-01-01

    DegP is a heat shock protein from high temperature requirement protease A family, which reacts to the environmental stress conditions in an ATP independent way. The objective of the present analysis emerged from the temperature dependent functional diversity of DegP between chaperonic and protease activities at temperatures below and above 28 °C, respectively. DegP is a multimeric protein and the minimal functional unit, DegP-trimer, is of great importance in understanding the DegP pathway. The structural aspects of DegP-trimer with respect to temperature variation have been studied using molecular dynamics simulations (for 100 ns) and principal component analysis to highlight the temperature dependent dynamics facilitating its functional diversity. The DegP-trimer revealed a pronounced dynamics at both 280 and 320 K, when compared to the dynamics observed at 300 K. The LA loop is identified as the highly flexible region during dynamics and at extreme temperatures, the residues 46-80 of LA loop express a flip towards right (at 280) and left ( at 320 K) with respect to the fixed β-sheet connecting the LA loop of protease for which Phe46 acts as one of the key residues. Such dynamics of LA loop facilitates inter-monomeric interaction with the PDZ1 domain of the neighbouring monomer and explains its active participation when DegP exists as trimer. Hence, the LA loop mediated dynamics of DegP-trimer is expected to provide further insight into the temperature dependent dynamics of DegP towards the understanding of its assembly and functional diversity in the presence of substrate.

  15. Temperature dependent dynamics of DegP-trimer: A molecular dynamics study

    Directory of Open Access Journals (Sweden)

    Nivedita Rai

    2015-01-01

    Full Text Available DegP is a heat shock protein from high temperature requirement protease A family, which reacts to the environmental stress conditions in an ATP independent way. The objective of the present analysis emerged from the temperature dependent functional diversity of DegP between chaperonic and protease activities at temperatures below and above 28 °C, respectively. DegP is a multimeric protein and the minimal functional unit, DegP-trimer, is of great importance in understanding the DegP pathway. The structural aspects of DegP-trimer with respect to temperature variation have been studied using molecular dynamics simulations (for 100 ns and principal component analysis to highlight the temperature dependent dynamics facilitating its functional diversity. The DegP-trimer revealed a pronounced dynamics at both 280 and 320 K, when compared to the dynamics observed at 300 K. The LA loop is identified as the highly flexible region during dynamics and at extreme temperatures, the residues 46–80 of LA loop express a flip towards right (at 280 and left ( at 320 K with respect to the fixed β-sheet connecting the LA loop of protease for which Phe46 acts as one of the key residues. Such dynamics of LA loop facilitates inter-monomeric interaction with the PDZ1 domain of the neighbouring monomer and explains its active participation when DegP exists as trimer. Hence, the LA loop mediated dynamics of DegP-trimer is expected to provide further insight into the temperature dependent dynamics of DegP towards the understanding of its assembly and functional diversity in the presence of substrate.

  16. Study of interaction of a pair of longitudinal vortices with a horseshoe vortex around a wing. 2nd Report. Behavior of the interacting flow field controlled passively; Tsubasa mawari no bateikei uzu to tateuzu no kansho ni kansuru kenkyu. 2. Judo seigyosareta nagareba no kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, H. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Shizawa, T.; Honami, S. [Science University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1999-12-25

    This paper presents the behavior of a passively controlled horseshoe vortex at the root of NACA0024 wing which is established on a turbulent boundary layer, A pair of vortex generators of half delta wing is installed upstream of the wing. The flow field of the optimally controlled horseshoe vortex both in case of Common Flow Up (CFUC) and Common Flow Down Configuration (CFDC) is carefully investigated by an X-array hot-wire. In case of CFUC, the horseshoe vortex is not shifted from the wing, because the longitudinal vortex is restrained. The interacted vortex presents a circular profile, in a optimally controlled case. In case of CFDC, the interacted vortex that has strong vorticity by the pairing process is shifted away from the wing. Then, the high momentum fluid flow penetrates between the wing and the vortex. (author)

  17. Static aeroelastic analysis for generic configuration wing

    Science.gov (United States)

    Lee, IN; Miura, Hirokazu; Chargin, Mladen K.

    1991-01-01

    A static aeroelastic analysis capability that calculates flexible air loads for generic configuration wings was developed. It was made possible by integrating a finite element structural analysis code (MSC/NASTRAN) and a panel code of aerodynamic analysis based on linear potential flow theory. The framework already built in MSC/NASTRAN was used, and the aerodynamic influence coefficient matrix was computed externally and inserted in the NASTRAN by means of a DMAP program. It was shown that deformation and flexible air loads of an oblique wing configuration including asymmetric wings can be calculated reliably by this code both in subsonic and supersonic speeds.

  18. CineVersum BlackWing Four

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    从BlackWing One到现在最新推出的BlackWing Four,一直以来C1ndVersum所带来的投影机都受到了不少投影机爱好者的关注,其帅气的外形搭配独特的欧美系画面风格,让人印象深刻。BlackWingFour是Cine Versum最为强悍的家庭影院投影机之一,

  19. Generic Wing-Body Aerodynamics Data Base

    Science.gov (United States)

    Holst, Terry L.; Olsen, Thomas H.; Kwak, Dochan (Technical Monitor)

    2001-01-01

    The wing-body aerodynamics data base consists of a series of CFD (Computational Fluid Dynamics) simulations about a generic wing body configuration consisting of a ogive-circular-cylinder fuselage and a simple symmetric wing mid-mounted on the fuselage. Solutions have been obtained for Nonlinear Potential (P), Euler (E) and Navier-Stokes (N) solvers over a range of subsonic and transonic Mach numbers and angles of attack. In addition, each solution has been computed on a series of grids, coarse, medium and fine to permit an assessment of grid refinement errors.

  20. Low-speed aerodynamic performance of a high-aspect-ratio supercritical-wing transport model equipped with full-span slat and part-span double-slotted flaps

    Science.gov (United States)

    Morgan, H. L., Jr.; Paulson, J. W., Jr.

    1979-01-01

    An investigation was conducted in the Langley V/STOL tunnel to determine the static longitudinal and lateral-directional aerodynamic characteristics of an advanced high-aspect-ratio supercritical-wing transport model equipped with a full-span leading-edge slat and part-span double-slotted trailing-edge flaps. This wide-body transport model was also equipped with spoiler and aileron control surfaces, flow-through nacelles, landing gear, movable horizontal tails, and interchangeable wing tips with aspect ratios of 10 and 12. The model was tested with leading-edge slat and trailing-edge flap combinations representative of cruise, climb, takeoff, and landing wing configurations. The tests were conducted at free-stream conditions corresponding to Reynolds numbers (based on mean geometric chord) of 0.97 to 1.63 x 10 to the 6th power and corresponding Mach numbers of 0.12 to 0.20, through an angle-of-attack range of -2 deg to 24 deg and a sideslip-angle range of -10 deg to 5 deg.

  1. Active Dihedral Control System for a Torisionally Flexible Wing

    Science.gov (United States)

    Kendall, Greg T. (Inventor); Lisoski, Derek L. (Inventor); Morgan, Walter R. (Inventor); Griecci, John A. (Inventor)

    2015-01-01

    A span-loaded, highly flexible flying wing, having horizontal control surfaces mounted aft of the wing on extended beams to form local pitch-control devices. Each of five spanwise wing segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other wing segments, to minimize inter-segment loads. Wing dihedral is controlled by separately controlling the local pitch-control devices consisting of a control surface on a boom, such that inboard and outboard wing segment pitch changes relative to each other, and thus relative inboard and outboard lift is varied.

  2. AFM Study of Structure Influence on Butterfly Wings Coloration

    Directory of Open Access Journals (Sweden)

    Dinara Sultanovna Dallaeva

    2012-01-01

    Full Text Available This study describes the structural coloration of the butterfly Vanessa Atalanta wings and shows how the atomic force microscopy (AFM can be applied to the study of wings morphology and wings surface behavior under the temperature. The role of the wings morphology in colors was investigated. Different colors of wings have different topology and can be identified by them. AFM in semi-contact mode was used to study the wings surface. The wing surface area, which is close to the butterfly body, has shiny brown color and the peak of surface roughness is about 600 nm. The changing of morphology at different temperatures is shown.

  3. An experimental investigation of nacelle-pylon installation on an unswept wing at subsonic and transonic speeds

    Science.gov (United States)

    Carlson, J. R.; Compton, W. B., III

    1984-01-01

    A wind tunnel investigation was conducted to determine the aerodynamic interference associated with the installation of a long duct, flow-through nacelle on a straight unswept untapered supercritical wing. Experimental data was obtained for the verification of computational prediction techniques. The model was tested in the 16-Foot Transonic Tunnel at Mach numbers from 0.20 to 0.875 and at angles of attack from about 0 deg to 5 deg. The results of the investigation show that strong viscous and compressibility effects are present at the transonic Mach numbers. Numerical comparisons show that linear theory is adequate for subsonic Mach number flow prediction, but is inadequate for prediction of the extreme flow conditions that exist at the transonic Mach numbers.

  4. DrawWing, a program for numerical description of insect wings

    Directory of Open Access Journals (Sweden)

    Adam Tofilski

    2004-05-01

    Full Text Available There is usually a pattern of veins on an insect wing. This pattern is species-specific and is used taxonomically. For example, the coordinates of some characteristic points on the wing are used to compare vein patterns. The characteristic points are often vein junctions or vein ends. A tool is presented that enables automatic identification of vein junctions. An image of an insect wing is used to determine the wing outline and veins. The vein skeleton is obtained using a thinning algorithm. Bezier splines are fitted to both the wing outline and the vein skeleton. The splines are saved in an encapsulated postscript file. Another output file in text format contains the coordinates of vein junctions. Both the program and its source code are available under GNU General Public License at [www.cyf-kr.edu.pl/~rotofils/drawwing.html]. The program presented in this paper automatically provides a numerical description of an insect wing. It converts an image of an insect wing to a list of coordinates of vein junctions, and a wing diagram that can be used as an illustration. Coordinates of the vein junctions extracted by the program from wing images were used successfully to discriminate between males of Dolichovespula sylvestris and Dolichovespula saxonica.

  5. Fruit fly scale robots can hover longer with flapping wings than with spinning wings.

    Science.gov (United States)

    Hawkes, Elliot W; Lentink, David

    2016-10-01

    Hovering flies generate exceptionally high lift, because their wings generate a stable leading edge vortex. Micro flying robots with a similar wing design can generate similar high lift by either flapping or spinning their wings. While it requires less power to spin a wing, the overall efficiency depends also on the actuator system driving the wing. Here, we present the first holistic analysis to calculate how long a fly-inspired micro robot can hover with flapping versus spinning wings across scales. We integrate aerodynamic data with data-driven scaling laws for actuator, electronics and mechanism performance from fruit fly to hummingbird scales. Our analysis finds that spinning wings driven by rotary actuators are superior for robots with wingspans similar to hummingbirds, yet flapping wings driven by oscillatory actuators are superior at fruit fly scale. This crossover is driven by the reduction in performance of rotary compared with oscillatory actuators at smaller scale. Our calculations emphasize that a systems-level analysis is essential for trading-off flapping versus spinning wings for micro flying robots.

  6. Resilin in dragonfly and damselfly wings and its implications for wing flexibility.

    Science.gov (United States)

    Donoughe, Seth; Crall, James D; Merz, Rachel A; Combes, Stacey A

    2011-12-01

    Although there is mounting evidence that passive mechanical dynamics of insect wings play an integral role in insect flight, our understanding of the structural details underlying insect wing flexibility remains incomplete. Here, we use comparative morphological and mechanical techniques to illuminate the function and diversity of two mechanisms within Odonata wings presumed to affect dynamic wing deformations: flexible resilin vein-joints and cuticular spikes. Mechanical tests show that joints with more resilin have lower rotational stiffness and deform more in response to a load applied to an intact wing. Morphological studies of 12 species of Odonata reveal that resilin joints and cuticular spikes are widespread taxonomically, yet both traits display a striking degree of morphological and functional diversity that follows taxonomically distinct patterns. Interestingly, damselfly wings (suborder Zygoptera) are mainly characterized by vein-joints that are double-sided (containing resilin both dorsally and ventrally), whereas dragonfly wings (suborder Epiprocta) are largely characterized by single-sided vein-joints (containing resilin either ventrally or dorsally, but not both). The functional significance and diversity of resilin joints and cuticular spikes could yield insight into the evolutionary relationship between form and function of wings, as well as revealing basic principles of insect wing mechanical design.

  7. Parametric weight evaluation of joined wings by structural optimization

    Science.gov (United States)

    Miura, Hirokazu; Shyu, Albert T.; Wolkovitch, Julian

    1988-01-01

    Joined-wing aircraft employ tandem wings having positive and negative sweep and dihedral, arranged to form diamond shapes in both plan and front views. An optimization method was applied to study the effects of joined-wing geometry parameters on structural weight. The lightest wings were obtained by increasing dihedral and taper ratio, decreasing sweep and span, increasing fraction of airfoil chord occupied by structural box, and locating the joint inboard of the front wing tip.

  8. Alleviation of whirl-flutter on a joined-wing tilt-rotor aircraft configuration using active controls

    Science.gov (United States)

    Vanaken, Johannes M.

    1991-01-01

    The feasibility of using active controls to delay the onset of whirl-flutter on a joined-wing tilt rotor aircraft was investigated. The CAMRAD/JA code was used to obtain a set of linear differential equations which describe the motion of the joined-wing tilt-rotor aircraft. The hub motions due to wing/body motion is a standard input to CAMRAD/JA and were obtained from a structural dynamics model of a representative joined-wing tilt-rotor aircraft. The CAMRAD/JA output, consisting of the open-loop system matrices, and the airframe free vibration motion were input to a separate program which performed the closed-loop, active control calculations. An eigenvalue analysis was performed to determine the flutter stability of both open- and closed-loop systems. Sensor models, based upon the feedback of pure state variables and based upon hub-mounted sensors, providing physically measurable accelerations, were evaluated. It was shown that the onset of tilt-rotor whirl-flutter could be delayed from 240 to above 270 knots by feeding back vertical and span-wise accelerations, measured at the rotor hub, to the longitudinal cyclic pitch. Time response calculations at a 270-knot cruise condition showed an active cyclic pitch control level of 0.009 deg, which equates to a very acceptable 9 pound active-control force applied at the rotor hub.

  9. Coriolis effects enhance lift on revolving wings.

    Science.gov (United States)

    Jardin, T; David, L

    2015-03-01

    At high angles of attack, an aircraft wing stalls. This dreaded event is characterized by the development of a leading edge vortex on the upper surface of the wing, followed by its shedding which causes a drastic drop in the aerodynamic lift. At similar angles of attack, the leading edge vortex on an insect wing or an autorotating seed membrane remains robustly attached, ensuring high sustained lift. What are the mechanisms responsible for both leading edge vortex attachment and high lift generation on revolving wings? We review the three main hypotheses that attempt to explain this specificity and, using direct numerical simulations of the Navier-Stokes equations, we show that the latter originates in Coriolis effects.

  10. Left-Wing Extremism: The Current Threat

    Energy Technology Data Exchange (ETDEWEB)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  11. Mallard age and sex determination from wings

    Science.gov (United States)

    Carney, S.M.; Geis, A.D.

    1960-01-01

    This paper describes characters on the wing plumage of the mallard that indicate age and sex. A key outlines a logical order in which to check age and sex characters on wings. This method was tested and found to be more than 95 percent reliable, although it was found that considerable practice and training with known-age specimens was required to achieve this level of accuracy....The implications of this technique and the sampling procedure it permits are discussed. Wing collections could provide information on production, and, if coupled with a banding program could permit seasonal population estimates to be calculated. In addition, representative samples of wings would provide data to check the reliability of several other waterfowl surveys.

  12. Trajectory Optimization Design for Morphing Wing Missile

    Institute of Scientific and Technical Information of China (English)

    Ruisheng Sun; Chao Ming; Chuanjie Sun

    2015-01-01

    This paper presents a new particle swarm optimization ( PSO) algorithm to optimize the trajectory of morphing⁃wing missile so as to achieve the enlargement of the maximum range. Equations of motion for the two⁃dimensional dynamics are derived by treating the missile as an ideal controllable mass point. An investigation of aerodynamic characteristics of morphing⁃wing missile with varying geometries is performed. After deducing the optimizing trajectory model for maximizing range, a type of discrete method is put forward for taking optimization control problem into nonlinear dynamic programming problem. The optimal trajectory is solved by using PSO algorithm and penalty function method. The simulation results suggest that morphing⁃wing missile has the larger range than the fixed⁃shape missile when launched at supersonic speed, while morphing⁃wing missile has no obvious range increment than the fixed⁃shape missile at subsonic speed.

  13. Molecular determinants of bat wing development.

    Science.gov (United States)

    Sears, K E

    2008-01-01

    The specialization of the forelimb into a wing allowed bats to become the only mammals to achieve powered flight. Recent studies in developmental biology have begun to elucidate the molecular mechanisms behind elements of this important morphological transformation. Specifically, researchers have identified molecular changes contributing to: the formation of the bat wing membrane, the elongation of skeletal elements of the bat wing and the reduction of the bat ulna. The general picture emerging from this research is that small changes in the expression of genes critical to many aspects of development have driven large changes in bat wing morphology. Thus, bats can be added to the growing list of groups in which expression changes in key developmental genes have been linked to the evolution of morphological innovations (e.g. early bilaterians, cetaceans, insects).

  14. Analysis of the Wing Tsun Punching Methods

    Directory of Open Access Journals (Sweden)

    Jeff Webb

    2012-07-01

    Full Text Available The three punching techniques of Wing Tsun, while few in number, represent an effective approach to striking with the closed fist. At first glance, the rather short stroke of each punch would seem disproportionate to the amount of power it generates. Therefore, this article will discuss the structure and body mechanics of each punch, in addition to the various training methods employed for developing power. Two of the Wing Tsun punches, namely the lifting punch and the hooking punch, are often confused with similar punches found in Western boxing. The key differences between the Wing Tsun and boxing punches, both in form and function, will be discussed. Finally, the strategy for applying the Wing Tsun punches will serve as the greatest factor in differentiating them from the punches of other martial arts styles.

  15. Using Paraffin with -10 deg C to 10 deg C Melting Point for Payload Thermal Energy Storage in SpaceX Dragon Trunk

    Science.gov (United States)

    Choi, Michael K.

    2013-01-01

    A concept of using paraffin wax phase change material (PCM) with a melting point between -10 deg C and 10 deg C for payload thermal energy storage in a Space Exploration Technologies (SpaceX) Dragon trunk is presented. It overcomes the problem of limited heater power available to a payload with significant radiators when the Dragon is berthed to the International Space Station (ISS). It stores adequate thermal energy to keep a payload warm without power for 6 hours during the transfer from the Dragon to an ExPRESS logistics carrier (ELC) on the ISS.

  16. Far-infrared and submillimeter survey of the galactic plane from l = 11.5 deg to l = 17.5 deg

    Science.gov (United States)

    Campbell, M. F.; Niles, D. W.; Silverberg, R. F.; Hauser, M. G.; Stier, M. T.; Kelsall, T.; Hoffmann, W. F.; Thronson, H. A., Jr.

    1984-01-01

    Medium resolution (11 min) maps of the galactic plane are presented from l = 11.5 deg to l = 17.5 deg at wavelengths of 93 microns, 154 microns, and 190 microns. The maps are interpreted in terms of the temperature and spatial structure of diffuse far-infrared/submillimeter sources associated with evolved H II regions and a continuous ridge of galactic emission. The emission regions are found to be more extended at the longer wavelengths which implies that there must be a range of dust temperatures in the sources. The properties of the galactic ridge are similar to those of the sources.

  17. Cross Service Fixed-Wing Cost Estimation

    Science.gov (United States)

    2016-05-17

    clarify the costing methods for O&S costs for fixed-wing delivery platforms with the intent of extending the research to other cross- service mission costs...proof-of-concept, this project will concentrate on equating equitable cross- service costs for fixed-wing munitions delivery platforms. The method of... delivery is an essential part of the AoA, especially when the project proposed is the replacement of current missile systems. The services have

  18. Wetting Characteristics of Insect Wing Surfaces

    Institute of Scientific and Technical Information of China (English)

    Doyoung Byun; Jongin Hong; Saputra; Jin Hwan Ko; Young Jong Lee; Hoon Cheol Park; Bong-Kyu Byun; Jennifer R. Lukes

    2009-01-01

    Biological tiny structures have been observed on many kinds of surfaces such as lotus leaves, which have an effect on the coloration of Morpho butterflies and enhance the hydrophobicity of natural surfaces. We investigated the micro-scale and nano-scale structures on the wing surfaces of insects and found that the hierarchical multiple roughness structures help in enhancing the hydrophobicity. After examining 10 orders and 24 species of flying Pterygotan insects, we found that micro-scale and nano-scale structures typically exist on both the upper and lower wing surfaces of flying insects. The tiny structures such as denticle or setae on the insect wings enhance the hydrophobicity, thereby enabling the wings to be cleaned more easily. And the hydrophobic insect wings undergo a transition from Cassie to Wenzel states at pitch/size ratio of about 20. In order to examine the wetting characteristics on a rough surface, a biomimetic surface with micro-scale pillars is fabricated on a silicon wafer,which exhibits the same behavior as the insect wing, with the Cassie-Wenzel transition occurring consistently around a pitch/width value of 20.

  19. Quantification of metallic iodides in fucus vesiculosus and serratus heated at 80 deg, 550 deg and 1 000 deg; Quantification des iodures metalliques dans des cendres d'algues. Analyse de fucus vesiculosus et serratus chauffees a 80 degres, 550 degre et 1000 degre

    Energy Technology Data Exchange (ETDEWEB)

    Aujollet, Y. [Direction Generale de la Surete Nucleaire et de la Radioprotection (DGSNR), 75 - Paris (France)

    2004-02-01

    Metallic iodides in aqueous phase of Fucus ashes were measured by gamma spectrometry. Before the measurements, different samples of Fucus were heated at 80 deg C (Fucus vesiculosus), 550 deg C (Fucus serratus) and 1 000 deg C (Fucus serratus). The first results gave 63% of iodide salts in Fucus vesiculosus heated at 80 deg C, 27% of iodide salts in Fucus serratus (550 deg C) and no result for ashes of Fucus serratus heated at 1 000 deg C, because there was not enough mass of product for a good analysis by gamma spectrometry. (author)

  20. Numerical study of the trailing vortex of a wing with wing-tip blowing

    Science.gov (United States)

    Lim, Hock-Bin

    1994-01-01

    Trailing vortices generated by lifting surfaces such as helicopter rotor blades, ship propellers, fixed wings, and canard control surfaces are known to be the source of noise, vibration, cavitation, degradation of performance, and other hazardous problems. Controlling these vortices is, therefore, of practical interest. The formation and behavior of the trailing vortices are studied in the present research. In addition, wing-tip blowing concepts employing axial blowing and spanwise blowing are studied to determine their effectiveness in controlling these vortices and their effects on the performance of the wing. The 3D, unsteady, thin-layer compressible Navier-Stokes equations are solved using a time-accurate, implicit, finite difference scheme that employs LU-ADI factorization. The wing-tip blowing is simulated using the actuator plane concept, thereby, not requiring resolution of the jet slot geometry. Furthermore, the solution blanking feature of the chimera scheme is used to simplify the parametric study procedure for the wing-tip blowing. Computed results are shown to compare favorably with experimental measurements. It is found that axial wing-tip blowing, although delaying the rolling-up of the trailing vortices and the near-field behavior of the flowfield, does not dissipate the circulation strength of the trailing vortex farther downstream. Spanwise wing-tip blowing has the effect of displacing the trailing vortices outboard and upward. The increased 'wing-span' due to the spanwise wing-tip blowing has the effect of lift augmentation on the wing and the strengthening of the trailing vortices. Secondary trailing vortices are created at high spanwise wing-tip blowing intensities.

  1. Tarawa Stable Isotope (delta 18O, delta 13C) and Mineralogy Data for 1959 to 1979

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Tarawa Atoll, Republic of Kiribati (1 deg N, 172 deg E). Water depth: 2-4m. Coral species Hydnophora microconos. Time span: 1959-79 at monthly resolution....

  2. Student Difficulties with the Dirac Delta Function

    CERN Document Server

    Wilcox, Bethany R

    2014-01-01

    The Dirac delta function is a standard mathematical tool used in multiple topical areas in the undergraduate physics curriculum. While Dirac delta functions are usually introduced in order to simplify a problem mathematically, students often struggle to manipulate and interpret them. To better understand student difficulties with the delta function at the upper-division level, we examined responses to traditional exam questions and conducted think-aloud interviews. Our analysis was guided by an analytical framework that focuses on how students activate, construct, execute, and reflect on the Dirac delta function in physics. Here, we focus on student difficulties using the delta function to express charge distributions in the context of junior-level electrostatics. Challenges included: invoking the delta function spontaneously, constructing two- and three-dimensional delta functions, integrating novel delta function expressions, and recognizing that the delta function can have units.

  3. Applications of Kinetic Inductance: Parametric Amplifier & Phase Shifter, 2DEG Coupled Co-planar Structures & Microstrip to Slotline Transition at RF Frequencies

    Science.gov (United States)

    Surdi, Harshad

    Kinetic inductance springs from the inertia of charged mobile carriers in alternating electric fields and it is fundamentally different from the magnetic inductance which is only a geometry dependent property. The magnetic inductance is proportional to the volume occupied by the electric and magnetic fields and is often limited by the number of turns of the coil. Kinetic inductance on the other hand is inversely proportional to the density of electrons or holes that exert inertia, the unit mass of the charge carriers and the momentum relaxation time of these charge carriers, all of which can be varied merely by modifying the material properties. Highly sensitive and broadband signal amplifiers often broaden the field of study in astrophysics. Quantum-noise limited travelling wave kinetic inductance parametric amplifiers offer a noise figure of around 0.5 K +/- 0.3 K as compared to 20 K in HEMT signal amplifiers and can be designed to operate to cover the entire W-band (75 GHz -- 115 GHz). The research cumulating to this thesis involves applying and exploiting kinetic inductance properties in designing a W-band orthogonal mode transducer, quadratic gain phase shifter with a gain of ~49 dB over a meter of microstrip transmission line. The phase shifter will help in measuring the maximum amount of phase shift Deltaφmax(I) that can be obtained from half a meter transmission line which helps in predicting the gain of a travelling wave parametric amplifier. In another project, a microstrip to slot line transition is designed and optimized to operate at 150 GHz and 220 GHz frequencies, that is used as a part of horn antenna coupled microwave kinetic inductance detector proposed to operate from 138 GHz to 250 GHz. In the final project, kinetic inductance in a 2D electron gas (2DEG) is explored by design, simulation, fabrication and experimentation. A transmission line model of a 2DEG proposed by Burke (1999), is simulated and verified experimentally by fabricating a

  4. In situ observations of BrO over Antarctica - ER-2 aircraft results from 54 deg S to 72 deg S latitude

    Science.gov (United States)

    Brune, W. H.; Anderson, J. G.; Chan, K. R.

    1989-01-01

    Bromine monoxide was observed in situ during nine flights of the NASA ER-2 aircraft from Punta Arenas, Chile (54 deg S latitude), to 72 deg S latitude over the Palmer Peninsula, Antarctica. The first flight for the BrO detection system was on August 28. The distribution of BrO inside the chemically perturbed region defined by greatly elevated ClO abundances was different from that found just outside. Inside, the BrO mixing ratio was 6.1 + or - 1.1 pptv above the 440 K potential temperature surface, 4.7 + or - 2.0 pptv between the 400 and 440 K surfaces, and less than 4 pptv below the 400 K surface. At high latitudes outside the chemically perturbed region, the BrO mixing ratio was 5.4 + or - 1.4 pptv near the 450 K surface, but decreased to 2.9 + or - 1.2 pptv at the 420 K surface. The abundance of BrO showed no discernible temporal trend during the course of the nine flights. Away from the south polar region, at latitudes between 47 deg S and 37 deg N and potential temperatures between 435 and 500 K (18.5- to 20.7-km altitude), the BrO mixing ratio was 0.5-3.0 pptv.

  5. Populists in Parliament : Comparing Left-Wing and Right-Wing Populism in the Netherlands

    NARCIS (Netherlands)

    Otjes, Simon; Louwerse, Tom

    2015-01-01

    In parliament, populist parties express their positions almost every day through voting. There is great diversity among them, for instance between left-wing and right-wing populist parties. This gives rise to the question: is the parliamentary behaviour of populists motivated by their populism or by

  6. Aerodynamics of two-dimensional flapping wings in tandem configuration

    Science.gov (United States)

    Lua, K. B.; Lu, H.; Zhang, X. H.; Lim, T. T.; Yeo, K. S.

    2016-12-01

    This paper reports a fundamental investigation on the aerodynamics of two-dimensional flapping wings in tandem configuration in forward flight. Of particular interest are the effects of phase angle (φ) and center-to-center distance (L) between the front wing and the rear wing on the aerodynamic force generation at a Reynolds number of 5000. Both experimental and numerical methods were employed. A force sensor was used to measure the time-history aerodynamic forces experienced by the two wings and digital particle image velocimetry was utilized to obtain the corresponding flow structures. Both the front wing and the rear wing executed the same simple harmonic motions with φ ranging from -180° to 180° and four values of L, i.e., 1.5c, 2c, 3c, and 4c (c is the wing chord length). Results show that at fixed L = 2c, tandem wings perform better than the sum of two single wings that flap independently in terms of thrust for phase angle approximately from -90° to 90°. The maximum thrust on the rear wing occurs during in-phase flapping (φ = 0°). Correlation of transient thrust and flow structure indicates that there are generally two types of wing-wake interactions, depending on whether the rear wing crosses the shear layer shed from the front wing. Finally, increasing wing spacing has similar effect as reducing the phase angle, and an approximate mathematical model is derived to describe the relationship between these two parameters.

  7. Simplified 2DEG carrier concentration model for composite barrier AlGaN/GaN HEMT

    Energy Technology Data Exchange (ETDEWEB)

    Das, Palash, E-mail: d.palash@gmail.com; Biswas, Dhrubes, E-mail: d.palash@gmail.com [Indian Institute of Technology Kharagpur, Kharagpur - 721302, West Bengal (India)

    2014-04-24

    The self consistent solution of Schrodinger and Poisson equations is used along with the total charge depletion model and applied with a novel approach of composite AlGaN barrier based HEMT heterostructure. The solution leaded to a completely new analytical model for Fermi energy level vs. 2DEG carrier concentration. This was eventually used to demonstrate a new analytical model for the temperature dependent 2DEG carrier concentration in AlGaN/GaN HEMT.

  8. Strumentazione multisensore selettiva per il monitoraggio in continuo degli odori nel settore ambientale

    OpenAIRE

    Giuliani, Stefano

    2012-01-01

    2010 - 2011 L’odore indotto dall’esercizio degli impianti di ingegneria sanitaria ambientale è ritenuto la causa principale di disturbo che la popolazione residente nelle vicinanze avverte. Sebbene alle emissioni odorigene sia solo raramente associato un reale rischio tossicologico-sanitario, sia per la natura raramente pericolosa degli odoranti che per le concentrazioni generalmente molto basse, nell’immaginario collettivo, ai cattivi odori si associano spesso condizioni di “non salubrità...

  9. Experimental measurement of the solubility of bismuth phases in water vapor from 220 deg. C to 300 deg. C: Implications for ore formation

    Energy Technology Data Exchange (ETDEWEB)

    Kruszewski, Jason M. [Department of Geological Sciences, University of Idaho, Moscow, ID 83844-3022 (United States); Wood, Scott A., E-mail: swood@uidaho.edu [Department of Geological Sciences, University of Idaho, Moscow, ID 83844-3022 (United States)

    2009-04-15

    Preliminary measurements were carried out of the solubility of the O{sub 2-}buffering assemblage bismuth + bismite (Bi{sub 2}O{sub 3}) in aqueous liquid-vapor and vapor-only systems at temperatures of 220, 250 and 300 deg. C. All experiments were carried out in Ti reaction vessels and were designed such that the Bi solids were contained in a silica tube that prevented contact with liquid water at any time during the experiment. Two blank (no Bi solids present) liquid-vapor experiments at 220 deg. C yielded Bi concentrations ({+-}1{sigma}) in the condensed liquid of 0.22 {+-} 0.02 mg/L, whereas the solubility measurements at this temperature yielded an average value of approximately 6 {+-} 9 mg/L, with replicate experiments ranging from 0.3 to 26 mg/L. Although the 6 mg/L value is associated with a considerable degree of uncertainty, the experiments do indicate transport of Bi through the vapor phase. Measured Bi concentrations in the condensed liquid at 250 deg. C were in the same range as those at 220 deg. C, whereas those at 300 deg. C were significantly lower (i.e., all below the blank value). Vapor-only experiments necessarily contained much smaller initial volumes of water, thereby making the results more susceptible to contamination. Single blank runs at 220 and 300 deg. C yielded Bi concentrations of 82 and 16 mg/L, respectively. Measured concentrations ({+-}1{sigma}) of Bi in the vapor-only solubility experiments at 220 deg. C were 235 {+-} 78 mg/L for an initial water volume of 0.5 mL, and at 300 deg. C were 56 {+-} 30 mg/L and 33 {+-} 21 for initial water volumes of 1 and 2 mL, respectively, suggesting strong preferential partitioning of Bi into the vapor. The results indicate a negative dependence of Bi solubility on temperature, but are inconclusive with respect to the dependence of Bi solubility on water density or fugacity. The experiments reported here suggest that significant Bi transport is possible in the vapor phase. Comparison of the liquid

  10. The Unsteady Aerodynamics of a Delta Wing Undergoing Large Amplitude Pitching Motions

    Science.gov (United States)

    1992-04-01

    sequentially rather than simultaneously. The software used to control the data acquisition was written in part using National Instruments LabView 2.0. Im...0.50] n-- -Ross Pll EAMMENE. * 0.46 . 50 - 0-40 o 30 20 10 0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 t/At * k = 0.03 (f = 0. 19 -H) * k = 0.09 (f

  11. Experimental Assessment of Vortex Retaining Cavity Flaps for Maneuverability Improvement on Delta Wing Fighter Aircraft.

    Science.gov (United States)

    1985-12-01

    PoplarvilleD Mississippi. He attended Poplarville’s public school system and graduated with honors In May 1976. He entered Mississippi State University and...8217 degree. Permanent Address: Rural Route 4, Box 460 - Poplarville , Mississippi 39470 VIT-1 UNCLASSIFIED _ SECURITY CLASSIFICATION OF THIS PAGE REPORT

  12. Evaluation of myocardial SPECT imaging reconstructed from 270deg projection data. A study using a cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    Kashikura, Kenichi [Japan Science and Technology Corp., Akita (Japan). Akita Lab.; Kobayashi, Hideki; Kashikura, Akemi

    1997-01-01

    SPECT reconstruction is commonly performed using 360deg or 180deg projection data. However, it is also possible to reconstruct SPECT images using other projection data arcs. The purpose of this study was to characterize images obtained by limiting the projection data to 270deg by discarding the projection views with severe attenuation. A series of phantom studies was performed with and without plastic chambers simulating perfusion defects using {sup 201}Tl and {sup 99m}Tc. Images using 270deg, 360deg, and 180deg projection arcs were identically reconstructed from the same data. In the absence of plastic chambers, intraslice uniformity in a given slice was assessed by computing the coefficient of variation (CV) of average counts in 8 ROIs within the slice. Interslice uniformity was assessed by computing the CV of average counts in five short axial slices. With plastic chambers in place, the variability in defect contrasts was assessed by computing the CV of defect contrasts in 4 chambers, located on the anterior, lateral, inferoposterior, and septal walls. The intraslice uniformity of the 270deg images were considerably inferior to those of the 360deg and 180deg images. The interslice uniformity was highest in the 360deg images, and lowest in the 180deg images. The variation in defect contrasts in the 270deg image was higher than those of the other two images. The 270deg images showed a high defect contrast in the septum and high counts in the anterior and anteroseptal wall. Because a large variation in defect contrasts within a segment might result in false positive or negative in diagnosis, 270deg imaging is not recommended over 360deg or 180deg imaging. (author)

  13. {Delta}I = 3/2 and {Delta}S = 2 Hyperon decays in chiral perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    He, X.G. [University of Melbourne, Parkville, VIC (Australia). School of Physics; Valencia, G. [Iowa State University, Ames, Iowa (United States). Department of Physics and Astronomy

    1997-05-01

    We study the| {Delta}I| = 3/2 and |{Delta}S| = 2 amplitudes for hyperon decays of the form B {yields} B`{pi} at lowest order in chiral perturbation theory. At this order, the {Delta}I = 3/2 amplitudes depend on only one constant. We extract the value of this constant from experiment and find a reasonable description of these processes within experimental errors. The same constant determines the {Delta}S = 2 transitions which, in the standard model, are too small to be observed. We find that new physics with parity odd {Delta}S = 2 interactions can produce observable rates in hyperon decays while evading the bounds from K{sup 0} - K-bar{sup 0} mixing. (authors) 10 refs., 3 tabs.

  14. Reactive versus anticipative adaptive management of Deltas: The Sacramento-San Joaquin Delta and the Rhine-Meuse Delta compared

    NARCIS (Netherlands)

    Vlieg, T.J.; Zandvoort, M.

    2013-01-01

    In this paper Californian Adaptive Management (AM) and Dutch Adaptive Delta Management (ADM) are compared. The concepts are introduced in a policy context to deal with prevailing types of uncertainty in water management in the Californian Sacramento-San Joaquin Delta and the Dutch Rhine-Meuse Delta

  15. Facts About Delta Pi Epsilon

    Science.gov (United States)

    Delta Pi Epsilon Journal, 1976

    1976-01-01

    The article discusses the purpose and structure of Delta Pi Epsilon and the general qualifications for membership. Service projects and publications, research awards, timely facts, the year of each chapter's origination, national presidents, and executive secretaries for the last 40 years are listed. (BP)

  16. Flow field of flexible flapping wings

    Science.gov (United States)

    Sallstrom, Erik

    The agility and maneuverability of natural fliers would be desirable to incorporate into engineered micro air vehicles (MAVs). However, there is still much for engineers to learn about flapping flight in order to understand how such vehicles can be built for efficient flying. The goal of this study is to develop a methodology for capturing high quality flow field data around flexible flapping wings in a hover environment and to interpret it to gain a better understanding of how aerodynamic forces are generated. The flow field data was captured using particle image velocimetry (PIV) and required that measurements be taken around a repeatable flapping motion to obtain phase-averaged data that could be studied throughout the flapping cycle. Therefore, the study includes the development of flapping devices with a simple repeatable single degree of freedom flapping motion. The acquired flow field data has been examined qualitatively and quantitatively to investigate the mechanisms behind force production in hovering flight and to relate it to observations in previous research. Specifically, the flow fields have been investigated around a rigid wing and several carbon fiber reinforced flexible membrane wings. Throughout the whole study the wings were actuated with either a sinusoidal or a semi-linear flapping motion. The semi-linear flapping motion holds the commanded angular velocity nearly constant through half of each half-stroke while the sinusoidal motion is always either accelerating or decelerating. The flow fields were investigated by examining vorticity and vortex structures, using the Q criterion as the definition for the latter, in two and three dimensions. The measurements were combined with wing deflection measurements to demonstrate some of the key links in how the fluid-structure interactions generated aerodynamic forces. The flow fields were also used to calculate the forces generated by the flapping wings using momentum balance methods which yielded

  17. Two distinct E3 ubiquitin ligases have complementary functions in the regulation of delta and serrate signaling in Drosophila.

    Directory of Open Access Journals (Sweden)

    Roland Le Borgne

    2005-04-01

    Full Text Available Signaling by the Notch ligands Delta (Dl and Serrate (Ser regulates a wide variety of essential cell-fate decisions during animal development. Two distinct E3 ubiquitin ligases, Neuralized (Neur and Mind bomb (Mib, have been shown to regulate Dl signaling in Drosophila melanogaster and Danio rerio, respectively. While the neur and mib genes are evolutionarily conserved, their respective roles in the context of a single organism have not yet been examined. We show here that the Drosophila mind bomb (D-mib gene regulates a subset of Notch signaling events, including wing margin specification, leg segmentation, and vein determination, that are distinct from those events requiring neur activity. D-mib also modulates lateral inhibition, a neur- and Dl-dependent signaling event, suggesting that D-mib regulates Dl signaling. During wing development, expression of D-mib in dorsal cells appears to be necessary and sufficient for wing margin specification, indicating that D-mib also regulates Ser signaling. Moreover, the activity of the D-mib gene is required for the endocytosis of Ser in wing imaginal disc cells. Finally, ectopic expression of neur in D-mib mutant larvae rescues the wing D-mib phenotype, indicating that Neur can compensate for the lack of D-mib activity. We conclude that D-mib and Neur are two structurally distinct proteins that have similar molecular activities but distinct developmental functions in Drosophila.

  18. Hydrological and Climatic Significance of Martian Deltas

    Science.gov (United States)

    Di Achille, G.; Vaz, D. A.

    2017-10-01

    We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

  19. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2010-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta. The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  20. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2011-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta.The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  1. On the modelling of river delta formation

    NARCIS (Netherlands)

    Geleynse, N.

    2013-01-01

    This thesis presents approaches to the modelling of river delta formation. In particular, it provides results of numerical stratigraphic-morphodynamic modelling of river delta formation under various environmental forcings.

  2. Adaptive delta management: Roots and branches

    NARCIS (Netherlands)

    Timmermans, J.S.; Haasnoot, M.; Hermans, L.M.; Kwakkel, J.H.; Rutten, M.M.; Thissen, W.A.H.

    2015-01-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy, metropoli

  3. Delta Vegetation and Land Use [ds292

    Data.gov (United States)

    California Department of Resources — Vegetation and land use are mapped for the approximately 725,000 acres constituting the Legal Delta portion of the Sacramento and San Joaquin River Delta area....

  4. Flapping wing aerodynamics: from insects to vertebrates.

    Science.gov (United States)

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight.

  5. Antifatigue properties of dragonfly Pantala flavescens wings.

    Science.gov (United States)

    Li, Xiu-Juan; Zhang, Zhi-Hui; Liang, Yun-Hong; Ren, Lu-Quan; Jie, Meng; Yang, Zhi-Gang

    2014-05-01

    The wing of a dragonfly is thin and light, but can bear high frequent alternating stress and present excellent antifatigue properties. The surface morphology and microstructure of the wings of dragonfly Pantala flavescens were observed using SEM in this study. Based on the biological analysis method, the configuration, morphology, and structure of the vein were studied, and the antifatigue properties of the wings were investigated. The analytical results indicated that the longitudinal veins, cross veins, and membrane of dragonfly wing form a optimized network morphology and spacially truss-like structure which can restrain the formation and propagation of the fatigue cracks. The veins with multilayer structure present high strength, flexibility, and toughness, which are beneficial to bear alternating load during the flight of dragonfly. Through tensile-tensile fatigue failure tests, the results were verified and indicate that the wings of dragonfly P. flavescens have excellent antifatigue properties which are the results of the biological coupling and synergistic effect of morphological and structural factors.

  6. Principle of bio-inspired insect wing rotational hinge design

    Science.gov (United States)

    Fei, Fan

    A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is shown to be applicable to a wide range of wing designs with different sizes and shapes. With the selected hinge stiffness value, aspects of the rotational joint design is discussed and an integrated wing-hinge structure design using laminated carbon fiber and polymer film is presented. Manufacturing process of such composite structure is developed to achieve high accuracy and repeatability. The yielded hinge stiffness is verified by measurements. To validate the proposed model, flapping wing experiments were conducted. A flapping actuation set up is built using DC motor and a controller is implemented on a microcontroller to track desired wing stroke kinematic. Wing stroke and rotation kinematic were extracted using a high speed camera and the lift generation is evaluated. A total of 49 flapping experiments were presented, experimental data shows good correlation with the model's prediction. With the wing rotational hinge stiffness designed so that the rotational resonant frequency is twice as the stroke frequency, the resulting wing rotation generates near optimal lift. With further simulation, the proposed model shows low sensitivity to wing parameter variation. As a result, giving a design parameter of a flapping wing robot platform, the proposed principle can

  7. DRE-Enhanced Swept-Wing Natural Laminar Flow at High Reynolds Numbers

    Science.gov (United States)

    Malik, Mujeeb; Liao, Wei; Li, Fe; Choudhari, Meelan

    2013-01-01

    Nonlinear parabolized stability equations and secondary instability analyses are used to provide a computational assessment of the potential use of the discrete roughness elements (DRE) technology for extending swept-wing natural laminar flow at chord Reynolds numbers relevant to transport aircraft. Computations performed for the boundary layer on a natural laminar flow airfoil with a leading-edge sweep angle of 34.6deg, free-stream Mach number of 0.75 and chord Reynolds numbers of 17 x 10(exp 6), 24 x 10(exp 6) and 30 x 10(exp 6) suggest that DRE could delay laminar-turbulent transition by about 20% when transition is caused by stationary crossflow disturbances. Computations show that the introduction of small wavelength stationary crossflow disturbances (i.e., DRE) also suppresses the growth of most amplified traveling crossflow disturbances.

  8. Discrete-Roughness-Element-Enhanced Swept-Wing Natural Laminar Flow at High Reynolds Numbers

    Science.gov (United States)

    Malik, Mujeeb; Liao, Wei; Li, Fei; Choudhari, Meelan

    2015-01-01

    Nonlinear parabolized stability equations and secondary-instability analyses are used to provide a computational assessment of the potential use of the discrete-roughness-element technology for extending swept-wing natural laminar flow at chord Reynolds numbers relevant to transport aircraft. Computations performed for the boundary layer on a natural-laminar-flow airfoil with a leading-edge sweep angle of 34.6 deg, freestream Mach number of 0.75, and chord Reynolds numbers of 17 × 10(exp 6), 24 × 10(exp 6), and 30 × 10(exp 6) suggest that discrete roughness elements could delay laminar-turbulent transition by about 20% when transition is caused by stationary crossflow disturbances. Computations show that the introduction of small-wavelength stationary crossflow disturbances (i.e., discrete roughness element) also suppresses the growth of most amplified traveling crossflow disturbances.

  9. A simple analytical aerodynamic model of Langley Winged-Cone Aerospace Plane concept

    Science.gov (United States)

    Pamadi, Bandu N.

    1994-01-01

    A simple three DOF analytical aerodynamic model of the Langley Winged-Coned Aerospace Plane concept is presented in a form suitable for simulation, trajectory optimization, and guidance and control studies. The analytical model is especially suitable for methods based on variational calculus. Analytical expressions are presented for lift, drag, and pitching moment coefficients from subsonic to hypersonic Mach numbers and angles of attack up to +/- 20 deg. This analytical model has break points at Mach numbers of 1.0, 1.4, 4.0, and 6.0. Across these Mach number break points, the lift, drag, and pitching moment coefficients are made continuous but their derivatives are not. There are no break points in angle of attack. The effect of control surface deflection is not considered. The present analytical model compares well with the APAS calculations and wind tunnel test data for most angles of attack and Mach numbers.

  10. Limited junctional diversity of V delta 5-J delta 1 rearrangement in multiple sclerosis patients.

    Science.gov (United States)

    Nowak, J S; Michałowska-Wender, G; Januszkiewicz, D; Wender, M

    1997-01-01

    T-cell receptor (TCR) delta gene repertoire, as assessed by V delta-J delta rearrangements, has been analyzed in nine multiple sclerosis (MS) cases and in 30 healthy individuals by seminested PCR technique. Among the V delta-J delta junctional diversities studied, the most striking result has been observed in V delta 5-J delta 1 rearrangement. The detection of repeated V delta 5-J delta 1 nucleotide sequences in all analyzed clones from seven out of nine patients studied proved the monoclonal nature of gamma delta T-cells with V delta 5-J delta 1 rearrangement. The clonal nature of this rearrangement proved by PAGE and sequencing analysis may suggest an antigen-driven expansion of gamma delta T cells and argues for a significant role of gamma delta T-cells with V delta 5-J delta 1 rearrangement in MS pathogenesis. However, it cannot be excluded that clonal expansion of these lymphocytes may represent secondary change to central nervous system damage.

  11. Reflections on Development Strategy of Pearl River Delta: In Comparison with Yangtze River Delta

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>1. A comparison between Pearl River Delta and Yangtze River Delta 1.1 Basic conditions 1.1.1 Location, area and scope Located in the southeast of Guangdong Province, the Pearl River Delta (PRD) as an economic zone is a compound delta

  12. Deletion of degQ gene enhances outer membrane vesicle production of Shewanella oneidensis cells.

    Science.gov (United States)

    Ojima, Yoshihiro; Mohanadas, Thivagaran; Kitamura, Kosei; Nunogami, Shota; Yajima, Reiki; Taya, Masahito

    2017-04-01

    Shewanella oneidensis is a Gram-negative facultative anaerobe that can use a wide variety of terminal electron acceptors for anaerobic respiration. In this study, S. oneidensis degQ gene, encoding a putative periplasmic serine protease, was cloned and expressed. The activity of purified DegQ was inhibited by diisopropyl fluorophosphate, a typical serine protease-specific inhibitor, indicating that DegQ is a serine protease. In-frame deletion and subsequent complementation of the degQ were carried out to examine the effect of envelope stress on the production of outer membrane vesicles (OMVs). Analysis of periplasmic proteins from the resulting S. oneidensis strain showed that deletion of degQ induced protein accumulation and resulted in a significant decrease in protease activity within the periplasmic space. OMVs from the wild-type and mutant strains were purified and observed by transmission electron microscopy. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the OMVs showed a prominent band at ~37 kDa. Nanoliquid chromatography-tandem mass spectrometry analysis identified three outer membrane porins (SO3896, SO1821, and SO3545) as dominant components of the band, suggesting that these proteins could be used as indices for comparing OMV production by S. oneidensis strains. Quantitative evaluation showed that degQ-deficient cells had a fivefold increase in OMV production compared with wild-type cells. Thus, the increased OMV production following the deletion of DegQ in S. oneidensis may be responsible for the increase in envelope stress.

  13. Aeroelastic Analysis of Modern Complex Wings

    Science.gov (United States)

    Kapania, Rakesh K.; Bhardwaj, Manoj K.; Reichenbach, Eric; Guruswamy, Guru P.

    1996-01-01

    A process is presented by which aeroelastic analysis is performed by using an advanced computational fluid dynamics (CFD) code coupled with an advanced computational structural dynamics (CSD) code. The process is demonstrated on an F/A-18 Stabilator using NASTD (an in-house McDonnell Douglas Aerospace East CFD code) coupled with NASTRAN. The process is also demonstrated on an aeroelastic research wing (ARW-2) using ENSAERO (an in-house NASA Ames Research Center CFD code) coupled with a finite element wing-box structures code. Good results have been obtained for the F/A-18 Stabilator while results for the ARW-2 supercritical wing are still being obtained.

  14. Transonic flow theory of airfoils and wings

    Energy Technology Data Exchange (ETDEWEB)

    Garabedian, P R

    1976-01-01

    Supercritical wing technology is expected to have a significant influence on the next generation of commercial aircraft. Computational fluid dynamics is playing a central role in the development of new supercritical wing sections. One of the principal tools is a fast and reliable code that simulates two-dimensional wind tunnel data for transonic flow at high Reynolds numbers. This is used widely by industry to assess drag creep and drag rise. Codes for the design of shockless airfoils by the hodograph method have not been so well received because they usually require a lot of trial and error. However, a more advanced mathematical approach makes it possible to assign the pressure as a function of the arc length and then obtain a shockless airfoil that nearly achieves the given distribution of pressure. This tool should enable engineers to design families of transonic airfoils more easily both for airplane wings and for compressor blades in cascade.

  15. Active Aeroelastic Tailoring of High-Aspect-Ratio Composite Wings

    Science.gov (United States)

    2005-09-01

    34 - 26000 , ......... . . . ...... . . .... .. .......................... ... - - ----------- 21000 ... ........... ~0 50 LOAD... ISO 5: B s mission....f Figure 5: Basic mission profile 7 Figure 6: Baseline single-wing and joined-wing vehicles 3.1 Baseline vehicles Three sets

  16. Decoupler pylon: wing/store flutter suppressor

    Science.gov (United States)

    Reed, W. H., III (Inventor)

    1982-01-01

    A device for suspending a store from a support such as an aircraft wing and more specifically for increasing the flutter speed of an aircraft flying with attached store and reducing the sensitivity of flutter to changes in the pitch inertia and center of gravity location of the store is described. It comprises softspring where the store pitch mode is decoupled from support modes and a low frequency active control mechanism which maintains store alignment. A pneumatic suspension system both isolates the store in pitch and, under conditions of changing mean load, aligns the store with the wing to which it is attached.

  17. Spanwise transition section for blended wing-body aircraft

    Science.gov (United States)

    Hawley, Arthur V. (Inventor)

    1999-01-01

    A blended wing-body aircraft includes a central body, a wing, and a transition section which interconnects the body and the wing on each side of the aircraft. The two transition sections are identical, and each has a variable chord length and thickness which varies in proportion to the chord length. This enables the transition section to connect the thin wing to the thicker body. Each transition section has a negative sweep angle.

  18. Design and aerodynamic characteristics of a span morphing wing

    Science.gov (United States)

    Yu, Yuemin; Liu, Yanju; Leng, Jinsong

    2009-03-01

    Flight vehicles are often designed to function around a primary operating point such as an efficient cruise or a high maneuverability mode. Performance and efficiency deteriorate rapidly as the airplane moves towards other portions of the flight envelope. One solution to this quandary is to radically change the shape of the aircraft. This yields both improved efficiency and a larger flight envelope. This global shape change is an example of morphing aircraft . One concept of morphing is the span morphing wing in which the wingspan is varied to accommodate multiple flight regimes. This type of design allows for at least two discreet modes of the aircraft. The original configuration, in which the extensible portion of the wing is fully retracted, yields a high speed dash mode. Fully extending the wing provides the aircraft with a low speed mode tailored for fine tracking and loiter tasks. This paper discusses the design of a span morphing wing that permits a change in the aspect ratio while simultaneously supporting structural wing loads. The wing cross section is maintained by NACA 4412 rib sections . The span morphing wing was investigated in different configurations. The wing area and the aspect ratio of the span morphing wing increase as the wings pan increases. Computational aerodynamics are used to estimate the performance and dynamic characteristics of each wing shape of this span morphing wing as its wingspan is changed. Results show that in order to obtain the same lift, the conventional wing requires a larger angle of attach(AOA) than that of the span morphing wing.The lift of the span morphing wing increases as the wing span ,Mach number and AOA increases.

  19. Ornithopter type flapping wings for autonomous micro air vehicles

    OpenAIRE

    2015-01-01

    In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings a...

  20. Phosphorylated DegU Manipulates Cell Fate Differentiation in the Bacillus subtilis Biofilm

    Science.gov (United States)

    Marlow, Victoria L.; Porter, Michael; Hobley, Laura; Kiley, Taryn B.; Swedlow, Jason R.; Davidson, Fordyce A.

    2014-01-01

    Cell differentiation is ubiquitous and facilitates division of labor and development. Bacteria are capable of multicellular behaviors that benefit the bacterial community as a whole. A striking example of bacterial differentiation occurs throughout the formation of a biofilm. During Bacillus subtilis biofilm formation, a subpopulation of cells differentiates into a specialized population that synthesizes the exopolysaccharide and the TasA amyloid components of the extracellular matrix. The differentiation process is indirectly controlled by the transcription factor Spo0A that facilitates transcription of the eps and tapA (tasA) operons. DegU is a transcription factor involved in regulating biofilm formation. Here, using a combination of genetics and live single-cell cytological techniques, we define the mechanism of biofilm inhibition at high levels of phosphorylated DegU (DegU∼P) by showing that transcription from the eps and tapA promoter regions is inhibited. Data demonstrating that this is not a direct regulatory event are presented. We demonstrate that DegU∼P controls the frequency with which cells activate transcription from the operons needed for matrix biosynthesis in favor of an off state. Subsequent experimental analysis led us to conclude that DegU∼P functions to increase the level of Spo0A∼P, driving cell fate differentiation toward the terminal developmental process of sporulation. PMID:24123822

  1. Analysis of the thin layer of Galactic warm ionized gas in the range 20 < l < 30 deg, -1.5 < b < +1.5 deg

    CERN Document Server

    Paladini, R; Davies, R D; Giard, M

    2005-01-01

    We present an analysis of the thin layer of Galactic warm ionized gas at an angular resolution ~ 10'. This is carried out using radio continuum data at 1.4 GHz, 2.7 GHz and 5 GHz in the coordinate region 20 < l < 30 deg, -1.5 < b < +1.5 deg. For this purpose, we evaluate the zero level of the 2.7 and 5 GHz surveys using auxiliary data at 2.3 GHz and 408 MHz. The derived zero level corrections are T_{zero}(2.7 GHz)=0.15 +/- 0.06 K and T_{zero}(5 GHz)=0.1 +/- 0.05 K. We separate the thermal (free-free) and non-thermal (synchrotron) component by means of a spectral analysis performed adopting an antenna temperature spectral index -2.1 for the free-free emission, a realistic spatial distribution of indices for the synchrotron radiation and by fitting, pixel-by-pixel, the Galactic spectral index. We find that at 5 GHz, for |b| = 0 deg, the fraction of thermal emission reaches a maximum value of 82%, while at 1.4 GHz, the corresponding value is 68%. In addition, for the thermal emission, the analysis in...

  2. SAS-2 observations of the diffuse gamma radiation in the galactic latitude interval 10 deg absolute b or equal to 90 deg

    Science.gov (United States)

    Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Oegelman, H. B.; Oezel, M. E.; Tuemer, T.

    1977-01-01

    An analysis of all of the second small astronomy satellite gamma-ray data for galactic latitudes with the absolute value of b 10 deg has shown that the intensity varies with galactic latitude, being larger near 10 deg than 90 deg. For energies above 100 MeV the gamma-ray data are consistent with a latitude distribution of the form I(b) = C sub 1 + C sub 2/sin b, with the second term being dominant. This result suggests that the radiation above 100 MeV is coming largely from local regions of the galactic disk. Between 35 and 100 MeV, a similar equation is also a good representation of the data, but here the two terms are comparable. These results indicate that the diffuse radiation above 35 MeV consists of two parts, one with a relatively hard galactic component and the other an isotropic, steep spectral component which extrapolates back well to the low energy diffuse radiation. The steepness of the diffuse isotropic component places significant constraints on possible theoretical models of this radiation.

  3. What is $\\Delta m^2_{ee}$ ?

    CERN Document Server

    Parke, Stephen

    2016-01-01

    The current short baseline reactor experiments, Daya Bay and RENO (Double Chooz) have measured (or are capable of measuring) an effective $\\Delta m^2$ associated with the atmospheric oscillation scale of 0.5 km/MeV in electron anti-neutrino disappearance. In this paper, I compare and contrast the different definitions of such an effective $\\Delta m^2$ and argue that the simple, L/E independent, definition given by $\\Delta m^2_{ee} \\equiv \\cos^2 \\theta_{12} \\Delta m^2_{31}+ \\sin^2 \\theta_{12} \\Delta m^2_{32}$, i.e. "the $\

  4. Study of interaction of a pair of longitudinal vortices with a horseshoe vortex around a wing. 1st Report. Potential for passive controlling by a pair of vortex generators; Tsubasa mawari no bateikei uzu to tateuzu no kansho ni kansuru kenkyu. 1. Ittsui no uzu hasseiki ni yoru judo seigyoho no teian

    Energy Technology Data Exchange (ETDEWEB)

    Hara, H.; Takahashi, M. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Ikeda, K. [Toshiba Corp., Tokyo (Japan); Shizawa, T.; Honami, S. [Science University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1999-12-25

    This paper presents a potential for a passive control of a horseshoe vortex at the root of the wing. NACA0024 wing is established on a turbulent boundary layer. A pair of vortex generators of halt delta wing is installed upstream of the wing. The controlled horseshoe vortex is tested qualitatively by flow visualization technique. Also, the potential for controlling is quantitatively investigated by wall static pressure and total pressure. The horseshoe vortex is remarkably controlled in Common Flow Up Configuration (CFUC) of vortex generators. The distortion of the total pressure contours is diminished by 49% and the vortex is located closer to the wing. In case of Common Flow Down Configuration (CFDC), the mass flow averaged pressure loss is decreased by 29% compared with the case without a pair of vortex generators. (author)

  5. Titanium honeycomb structure. [for supersonic aircraft wing structure

    Science.gov (United States)

    Davis, R. A.; Elrod, S. D.; Lovell, D. T.

    1972-01-01

    A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks.

  6. How swifts control their glide performance with morphing wings

    NARCIS (Netherlands)

    Lentink, D.; Muller, U. K.; Stamhuis, E. J.; de Kat, R.; van Gestel, W.; Veldhuis, L. L. M.; Henningsson, P.; Hedenstrom, A.; Videler, J. J.

    2007-01-01

    Gliding birds continually change the shape and size of their wings(1-6), presumably to exploit the profound effect of wing morphology on aerodynamic performance(7-9). That birds should adjust wing sweep to suit glide speed has been predicted qualitatively by analytical glide models(2,10), which extr

  7. A Wind Tunnel Investigation of Joined Wing Scissor Morphing

    Science.gov (United States)

    2006-06-01

    wing stalls when the rear wing stalls [23]. While this improves efficiency it also decreases the wetted area while maintaining the same lifting...Analysis and Optimization on Joined-Wing Configurations. Dir. Dong-Hwan Lee and P. C. Chen. Slide Program. Zona Technology. 2. Bagwill, Tracy L., and

  8. How swifts control their glide performance with morphing wings

    NARCIS (Netherlands)

    Lentink, D.; Müller, U.K.; Stamhuis, E.J.; Kat, de R.; Gestel, van W.J.H.; Veldhuis, L.L.M.; Henningsson, P.; Hedenström, A.; Videler, J.J.; Leeuwen, van J.L.

    2007-01-01

    Gliding birds continually change the shape and size of their wings1, 2, 3, 4, 5, 6, presumably to exploit the profound effect of wing morphology on aerodynamic performance7, 8, 9. That birds should adjust wing sweep to suit glide speed has been predicted qualitatively by analytical glide models2, 10

  9. [delta-Aminolevulinate dehydratase deficiency].

    Science.gov (United States)

    Fujita, H; Ishida, N; Akagi, R

    1995-06-01

    delta-Aminolevulinate dehydratase (ALAD: E. C. 4.2.1.24), the second enzyme in the heme biosynthetic pathway, condenses two moles of delta-aminolevulinic acid to form porphobilinogen. ALAD deficiency is well known to develop signs and symptoms of typical hepatic porphyria, and classified into three categories as follows: (i) ALAD porphyria, a genetic defect of the enzyme, (ii) tyrosinemia type I, a genetic defect of fumarylacetoacetase in the tyrosine catabolic pathway, producing succinylacetone (a potent inhibitor of ALAD), and (iii) ALAD inhibition by environmental hazards, such as lead, trichloroethylene, and styrene. In the present article, we will describe molecular and biochemical mechanisms to cause the enzyme defect to discuss the significance of ALAD defect on human health.

  10. Periodicity in Delta-modulated feedback control

    Institute of Scientific and Technical Information of China (English)

    Xiaohua XIA; Guanrong CHEN; Rudong GAI; Alan S. I. ZINOBER

    2008-01-01

    The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The existence of periodic points of all orders of Sigma-Delta modulation with "leaky" integration is completely characterized by some interesting groups of polynomials with "sign" coefficients. The results are naturally generalized to Sigma-Delta modulations with multiple delays, Delta-modulations in the "downlink", unbalanced Delta-modulations and systems with two-level quantized feedback. Further extensions relate to the existence of periodic points arising from Delta-modulated feedback control of a stable linear system in an arbitrary direction, for which some necessary and sufficient conditions are given.

  11. Entendiendo Delta desde las Humanidades

    OpenAIRE

    José Calvo Tello

    2016-01-01

    Stylometry is one of the research areas in greater development within Digital Humanities. However, few studies have worked until recently with texts in Spanish and even less so from Spanish-speaking countries. The aim of this paper is to present in Spanish, and without prior statistical knowledge from the reader, one of the main methods used in stylometry, the measure of textual distance Burrows’ Delta. This paper explains this measure using a very small corpus of proverbs and then checks the...

  12. Faint HI 21-cm Emission Line Wings at Forbidden-Velocities

    CERN Document Server

    Kang, Ji-hyun

    2007-01-01

    We present the results of a search for faint HI 21-cm emission line wings at velocities forbidden by Galactic rotation in the Galactic plane using the Leiden/Dwingeloo HI Survey data and the HI Southern Galactic Plane Survey data. These ``forbidden-velocity wings (FVWs)'' appear as protruding excessive emission in comparison with their surroundings in limited (< 2 deg) spatial regions over velocity extent more than ~20 km/s in large-scale (l-v) diagrams. Their high-velocities imply that there should be some dynamical phenomena associated. We have identified 87 FVWs. We present their catalog, and discuss their distribution and statistical properties. We found that 85% of FVWs are not coincident with known supernova remnants (SNRs), galaxies, or high-velocity clouds. Their natures are currently unknown. We suspect that many of them are fast-moving HI shells and filaments associated with the oldest SNRs that are essentially invisible except via their HI line emission. We discuss other possible origins.

  13. The costae presenting in high-temperature-induced vestigial wings of Drosophila: implications for anterior wing margin formation

    Indian Academy of Sciences (India)

    Daxiang Yang

    2007-01-01

    It has long been noted that high temperature produces great variation in wing forms of the vestigial mutant of Drosophila. Most of the wings have defects in the wing blade and partially formed wing margin, which are the result of autonomous cell death in the presumptive wing blade or costal region of the wing disc. The vestigial gene ($vg$) and the interaction of Vg protein with other gene products are well understood. With this biochemical knowledge, reinvestigations of the high-temperature-induced vestigial wings and the elucidation of the molecular mechanism underlying the large-scale variation of the wing forms may provide insight into further understanding of development of the wing of Drosophila. As a first step of such explorations, I examined high-temperature-induced (29°C) vestigial wings. In the first part of this paper, I provide evidences to show that the proximal and distal costae in these wings exhibit regular and continuous variation, which suggests different developmental processes for the proximal and distal costal sections. Judging by the costae presenting in the anterior wing margin, I propose that the proximal and distal costal sections are independent growth units. The genes that regulate formation of the distal costal section also strongly affect proliferation of cells nearby; however, the same phenomenon has not been found in the proximal costal section. The distal costal section seems to be an extension of the radius vein. vestigial, one of the most intensely researched temperature-sensitive mutations, is a good candidate for the study of marginal vein formation. In the second part of the paper, I regroup the wing forms of these wings, chiefly by comparison of venation among these wings, and try to elucidate the variation of the wing forms according to the results of previous work and the conclusions reached in the first part of this paper, and provide clues for further researches.

  14. A 189 MHz, 2400 deg{sup 2} POLARIZATION SURVEY WITH THE MURCHISON WIDEFIELD ARRAY 32-ELEMENT PROTOTYPE

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, G.; Greenhill, L. J.; De Oliveira-Costa, A. [Harvard-Smithsonian Center for Astrophysics, Garden Street 60, Cambridge, MA 02138 (United States); Mitchell, D. A. [The University of Melbourne, Melbourne (Australia); Ord, S. M.; Arcus, W.; Arora, B. S. [International Centre for Radio Astronomy Research, Curtin University, Perth (Australia); Hazelton, B. J.; Morales, M. F. [University of Washington, Seattle, WA (United States); Gaensler, B. M.; Subrahmanyan, R.; Wayth, R. B.; Lenc, E.; Briggs, F. H. [CAASTRO, 44 Rosenhill Street, Redfern, NSW 2016 (Australia); Shankar, N. Udaya [Raman Research Institute, Bangalore (India); Williams, C. L. [MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA (United States); Barnes, D. G. [Swinburne University of Technology, Melbourne (Australia); Bowman, J. D. [Arizona State University, Tempe, AZ (United States); Bunton, J. D. [CSIRO Astronomy and Space Science, NSW (Australia); Cappallo, R. J., E-mail: gbernardi@cfa.harvard.edu [MIT Haystack Observatory, Westford, MA (United States); and others

    2013-07-10

    We present a Stokes I, Q and U survey at 189 MHz with the Murchison Widefield Array 32 element prototype covering 2400 deg{sup 2}. The survey has a 15.6 arcmin angular resolution and achieves a noise level of 15 mJy beam{sup -1}. We demonstrate a novel interferometric data analysis that involves calibration of drift scan data, integration through the co-addition of warped snapshot images, and deconvolution of the point-spread function through forward modeling. We present a point source catalog down to a flux limit of 4 Jy. We detect polarization from only one of the sources, PMN J0351-2744, at a level of 1.8% {+-} 0.4%, whereas the remaining sources have a polarization fraction below 2%. Compared to a reported average value of 7% at 1.4 GHz, the polarization fraction of compact sources significantly decreases at low frequencies. We find a wealth of diffuse polarized emission across a large area of the survey with a maximum peak of {approx}13 K, primarily with positive rotation measure values smaller than +10 rad m{sup -2}. The small values observed indicate that the emission is likely to have a local origin (closer than a few hundred parsecs). There is a large sky area at {alpha} {>=} 2{sup h}30{sup m} where the diffuse polarized emission rms is fainter than 1 K. Within this area of low Galactic polarization we characterize the foreground properties in a cold sky patch at ({alpha}, {delta}) = (4{sup h}, -27. Degree-Sign 6) in terms of three-dimensional power spectra.

  15. Electrical spin injection and detection in high mobility 2DEG systems

    Science.gov (United States)

    Ciorga, M.

    2016-11-01

    In this review paper we present the current status of research related to the topic of electrical spin injection and detection in two-dimensional electron gas (2DEG) systems, formed typically at the interface between two III-V semiconductor compounds. We discuss both theoretical aspects of spin injection in case of ballistic transport as well as give an overview of available reports on spin injection experiments performed on 2DEG structures. In the experimental part we focus particularly on our recent work on all-semiconductor structures with a 2DEG confined at an inverted GaAs/(Al,Ga)As interface and with a ferromagnetic semiconductor (Ga,Mn)As employed as a source of spin-polarized electrons.

  16. Ten deg off-axis tensile test for intralaminar shear characterization of fiber composites

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1976-01-01

    A combined theoretical and experimental investigation was conducted to assess the suitability of the 10 deg off-axis tensile test specimen for the intralaminar shear characterization of unidirectional composites. Composite mechanics, a combined-stress failure criterion, and a finite element analysis were used to determine theoretically the stress-strain variation across the specimen width and the relative stress and strain magnitudes at the 10 deg plane. Strain gages were used to measure the strain variation across the specimen width at specimen midlength and near the end tabs. Specimens from Mod-I/epoxy, T-300/epoxy, and S-glass/epoxy were used in the experimental program. It was found that the 10 deg off-axis tensile test specimen is suitable for intralaminar shear characterization and it is recommended that it should be considered as a possible standard test specimen for such a characterization.

  17. Giovanni Degli Alessandri: i primi anni del direttorato agli Uffizi fra nuovi e vecchi ruoli

    Directory of Open Access Journals (Sweden)

    Chiara Pasquinelli

    2011-11-01

    Full Text Available La figura di Giovanni Degli Alessandri (1765-1830, presidente dell’Accademia di Belle Arti di Firenze e direttore degli Uffizi tra gli anni napoleonici e la Restaurazione di Ferdinando III d’Asburgo-Lorena, è quella di un personaggio chiave nella politica artistica fiorentina, e toscana più in generale. Nel saggio si esaminano i primi anni del suo direttorato alla Galleria, i rapporti con Antonio Canova, il suo ruolo all’interno dell’entourage di Elisa Baciocchi Bonaparte, oltre a considerare alcuni spunti legati al rinnovamento degli Uffizi, nonché la delicata vicenda del passaggio in città di Dominique-Vivant Denon, direttore del Louvre. L’obbiettivo è quello di introdurre elementi di approfondimento relativamente a una figura molto nota ma poco studiata.

  18. Aerodynamic Interactions Between Contralateral Wings and Between Wings and Body of a Model Insect at Hovering and Small Speed Motions

    Institute of Scientific and Technical Information of China (English)

    LIANG Bin; SUN Mao

    2011-01-01

    In this paper,we study the aerodynamic interactions between the contralateral wings and between the body and wings of a model insect,when the insect is hovering and has various translational and rotational motions,using the method numerically solving the Navier-Stokes equations over moving overset grids.The aerodynamic interactional effects are identified by comparing the results of a complete model insect,the corresponding wing pair,single wing and body without the wings.Horizontal,vertical and lateral translations and roll,pitch and yaw rotations at small speeds are considered.The results indicate that for the motions considered,both the interaction between the contralateral wings and the interaction between the body and wings are weak.The changes in the forces and moments of a wing due to the contralateral wing interaction,of the wings due to the presence of the body,and of the body due to the presence of the wings are generally less than 4.5%.Results show that aerodynamic forces of wings and body can be measured or computed separately in the analysis of flight stability and control of hovering insects.

  19. Aerodynamic comparison of a butterfly-like flapping wing-body model and a revolving-wing model

    Science.gov (United States)

    Suzuki, Kosuke; Yoshino, Masato

    2017-06-01

    The aerodynamic performance of flapping- and revolving-wing models is investigated by numerical simulations based on an immersed boundary-lattice Boltzmann method. As wing models, we use (i) a butterfly-like model with a body and flapping-rectangular wings and (ii) a revolving-wing model with the same wings as the flapping case. Firstly, we calculate aerodynamic performance factors such as the lift force, the power, and the power loading of the two models for Reynolds numbers in the range of 50-1000. For the flapping-wing model, the power loading is maximal for the maximum angle of attack of 90°, a flapping amplitude of roughly 45°, and a phase shift between the flapping angle and the angle of attack of roughly 90°. For the revolving-wing model, the power loading peaks for an angle of attack of roughly 45°. In addition, we examine the ground effect on the aerodynamic performance of the revolving-wing model. Secondly, we compare the aerodynamic performance of the flapping- and revolving-wing models at their respective maximal power loadings. It is found that the revolving-wing model is more efficient than the flapping-wing model both when the body of the latter is fixed and where it can move freely. Finally, we discuss the relative agilities of the flapping- and revolving-wing models.

  20. Fiber-optically sensorized composite wing

    Science.gov (United States)

    Costa, Joannes M.; Black, Richard J.; Moslehi, Behzad; Oblea, Levy; Patel, Rona; Sotoudeh, Vahid; Abouzeida, Essam; Quinones, Vladimir; Gowayed, Yasser; Soobramaney, Paul; Flowers, George

    2014-04-01

    Electromagnetic interference (EMI) immune and light-weight, fiber-optic sensor based Structural Health Monitoring (SHM) will find increasing application in aerospace structures ranging from aircraft wings to jet engine vanes. Intelligent Fiber Optic Systems Corporation (IFOS) has been developing multi-functional fiber Bragg grating (FBG) sensor systems including parallel processing FBG interrogators combined with advanced signal processing for SHM, structural state sensing and load monitoring applications. This paper reports work with Auburn University on embedding and testing FBG sensor arrays in a quarter scale model of a T38 composite wing. The wing was designed and manufactured using fabric reinforced polymer matrix composites. FBG sensors were embedded under the top layer of the composite. Their positions were chosen based on strain maps determined by finite element analysis. Static and dynamic testing confirmed expected response from the FBGs. The demonstrated technology has the potential to be further developed into an autonomous onboard system to perform load monitoring, SHM and Non-Destructive Evaluation (NDE) of composite aerospace structures (wings and rotorcraft blades). This platform technology could also be applied to flight testing of morphing and aero-elastic control surfaces.

  1. Applications of a transonic wing design method

    Science.gov (United States)

    Campbell, Richard L.; Smith, Leigh A.

    1989-01-01

    A method for designing wings and airfoils at transonic speeds using a predictor/corrector approach was developed. The procedure iterates between an aerodynamic code, which predicts the flow about a given geometry, and the design module, which compares the calculated and target pressure distributions and modifies the geometry using an algorithm that relates differences in pressure to a change in surface curvature. The modular nature of the design method makes it relatively simple to couple it to any analysis method. The iterative approach allows the design process and aerodynamic analysis to converge in parallel, significantly reducing the time required to reach a final design. Viscous and static aeroelastic effects can also be accounted for during the design or as a post-design correction. Results from several pilot design codes indicated that the method accurately reproduced pressure distributions as well as the coordinates of a given airfoil or wing by modifying an initial contour. The codes were applied to supercritical as well as conventional airfoils, forward- and aft-swept transport wings, and moderate-to-highly swept fighter wings. The design method was found to be robust and efficient, even for cases having fairly strong shocks.

  2. Conceptual Study of Rotary-Wing Microrobotics

    Science.gov (United States)

    2008-03-27

    xx  I.  Introduction ...Edge TPV Thermo-Photovoltaic CONCEPTUAL STUDY OF ROTARY-WING MICROROBOTICS I. Introduction Flying micro-robots offer unimaginable military...Tweezers 1989 1 cm3 inch robot 1991 Magnetostrictive mover in pipe 1992 Insect-based robot 1993 Ciliary-motion conveyor 1994 Pipe inspection robot

  3. Mother Nature inspires new wind turbine wing

    DEFF Research Database (Denmark)

    Sønderberg Petersen, L.

    2007-01-01

    The sight of a bird of prey hanging immobile in the air while its wings continuously adjust themselves slightly in relation to the wind in order to keep the bird in the same position in the air, is a sight that most of us have admired, including the windenergy scientists at Risø DTU. They have st...

  4. Can Wing Tip Vortices Be Accurately Simulated?

    Science.gov (United States)

    2011-07-01

    additional tail buffeting.2 In commercial applications, winglets have been installed on passenger aircraft to minimize vortex formation and reduce lift...air. In military applications, wing tip In commercial applications, winglets have been installed on passenger aircraft to minimize increases with downstream distances.

  5. Hybrid Wing Body Configuration Scaling Study

    Science.gov (United States)

    Nickol, Craig L.

    2012-01-01

    The Hybrid Wing Body (HWB) configuration is a subsonic transport aircraft concept with the potential to simultaneously reduce fuel burn, noise and emissions compared to conventional concepts. Initial studies focused on very large applications with capacities for up to 800 passengers. More recent studies have focused on the large, twin-aisle class with passenger capacities in the 300-450 range. Efficiently scaling this concept down to the single aisle or smaller size is challenging due to geometric constraints, potentially reducing the desirability of this concept for applications in the 100-200 passenger capacity range or less. In order to quantify this scaling challenge, five advanced conventional (tube-and-wing layout) concepts were developed, along with equivalent (payload/range/technology) HWB concepts, and their fuel burn performance compared. The comparison showed that the HWB concepts have fuel burn advantages over advanced tube-and-wing concepts in the larger payload/range classes (roughly 767-sized and larger). Although noise performance was not quantified in this study, the HWB concept has distinct noise advantages over the conventional tube-and-wing configuration due to the inherent noise shielding features of the HWB. NASA s Environmentally Responsible Aviation (ERA) project will continue to investigate advanced configurations, such as the HWB, due to their potential to simultaneously reduce fuel burn, noise and emissions.

  6. Migration on Wings Aerodynamics and Energetics

    CERN Document Server

    Kantha, Lakshmi

    2012-01-01

    This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

  7. Topology Optimization of an Aircraft Wing

    Science.gov (United States)

    2015-06-11

    baseline products were built in Solidworks prior to the optimization process. Loading on the wing was applied for multiple aerodynamic profiles generating...redesign and placement of the fuel tank was desired. A simple model of the baseline tank was built in Solidworks to estimate the total volume. Overall

  8. Challenges, Approaches and Experiences from Asian Deltas and the Rhine-Meuse Delta : Regional Training Workshop on Delta Planning and Management

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2013-01-01

    River delta's, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Ayeyarwady Delta (Myanmar), Nile (Egypt) and Ciliwung Delta (Indonesia) are developing rapidly and are characterised by large-scale urbanisation and industrialization processes. They are facing serious planning ch

  9. Reclutamento e formazione dei poliziotti: il caso degli ufficiali della gendarmeria francese

    Directory of Open Access Journals (Sweden)

    François Dieu

    2007-04-01

    Full Text Available Partendo dal caso degli ufficiali della gendarmeria francese, questo articolo illustra il modo in cui il reclutamento e la formazione possono contribuire, informalmente, alla ripartizione del potere nelle organizzazioni di polizia. Tramite la diversità delle vie di reclutamento si costituisce, di fatto, un vero e proprio sistema di "caste", con una stratificazione degli ufficiali in tre livelli gerarchici, che produce, al di là dei principi meritocratici, delle ineguaglianze manifeste nella ripartizione del potere nell'organizzazione della gendarmeria.

  10. The effect of furnace annealing and surface crystallization on the anisotropy, {delta}E and magnetoimpedance effects in Fe{sub 71}Cr{sub 7}Si{sub 9}B{sub 13} amorphous wires

    Energy Technology Data Exchange (ETDEWEB)

    Bayri, N; Kolat, V S; Atalay, F E; Atalay, S [Physics Department, Science and Arts Faculty, Inonu University, 44069 Malatya (Turkey)

    2004-11-21

    The dependence of the magnetization loops, coercivity, anisotropy constant, {delta}E and magnetoimpedance (MI) effects in positively magnetostrictive Fe{sub 71}Cr{sub 7}Si{sub 9}B{sub 13} amorphous wires on annealing conditions were studied. Samples were annealed at temperatures of 440 deg. C and 460 deg. C for durations between 0.3 and 300 min. The results indicate that progressive annealing first leads to relief of internal stresses and annealing of wires at 460 deg. C for 60 min produces the minimum coercivity of about 1 A m{sup -1}. Further annealing increases the coercivity and anisotropy, due to partial crystallization at the surface. It was found that the anisotropy changes its direction to the circumferential direction with the surface crystallization. The maximum change in Young's modulus was measured to be about 75% in a partly surface crystalline sample. It was observed that the magnitude of the MI effect of the stress relieved sample could exceed 200% at 1 MHz.

  11. Aircraft energy efficiency laminar flow control wing design study

    Science.gov (United States)

    Bonner, T. F., Jr.; Pride, J. D., Jr.; Fernald, W. W.

    1977-01-01

    An engineering design study was performed in which laminar flow control (LFC) was integrated into the wing of a commercial passenger transport aircraft. A baseline aircraft configuration was selected and the wing geometry was defined. The LFC system, with suction slots, ducting, and suction pumps was integrated with the wing structure. The use of standard aluminum technology and advanced superplastic formed diffusion bonded titanium technology was evaluated. The results of the design study show that the LFC system can be integrated with the wing structure to provide a structurally and aerodynamically efficient wing for a commercial transport aircraft.

  12. Aerodynamics on a transport aircraft type wing-body model

    Science.gov (United States)

    Schmitt, V.

    1982-01-01

    The DFLR-F4 wing-body combination is studied. The 1/38 model is formed by a 9.5 aspect ratio transonic wing and an Airbus A 310 fuselage. The F4 wing geometrical characteristics are described and the main experimental results obtained in the S2MA wind tunnel are discussed. Both wing-fuselage interferences and viscous effects, which are important on the wing due to a high rear loading, are investigated by performing 3D calculations. An attempt is made to find their limitations.

  13. Investigation and design of a C-Wing passenger aircraft

    OpenAIRE

    Karan BIKKANNAVAR; Scholz, Dieter

    2016-01-01

    A novel nonplanar wing concept called C-Wing is studied and implemented on a commercial aircraft to reduce induced drag which has a significant effect on fuel consumption. A preliminary sizing method which employs an optimization algorithm is utilized. The Airbus A320 aircraft is used as a reference aircraft to evaluate design parameters and to investigate the C-Wing design potential beyond current wing tip designs. An increase in aspect ratio due to wing area reduction at 36m span results in...

  14. Low-speed aerodynamic performance of an aspect-ratio-10 supercritical-wing transport model equipped with a full-span slat and part-span and full-span double-slotted flaps

    Science.gov (United States)

    Morgan, H. L., Jr.

    1981-01-01

    An investigation was conducted in the Langley 4 by 7 Meter Tunnel to determine the static longitudinal and lateral directional aerodynamic characteristics of an advanced aspect ratio 10 supercritical wing transport model equipped with a full span leading edge slat as well as part span and full span trailing edge flaps. This wide body transport model was also equipped with spoiler and aileron roll control surfaces, flow through nacelles, landing gear, and movable horizontal tails. Six basic wing configurations were tested: (1) cruise (slats and flaps nested), (2) climb (slats deflected and flaps nested), (3) part span flap, (4) full span flap, (5) full span flap with low speed ailerons, and (6) full span flap with high speed ailerons. Each of the four flapped wing configurations was tested with leading edge slat and trailing edge flaps deflected to settings representative of both take off and landing conditions. Tests were conducted at free stream conditions corresponding to Reynolds number of 0.97 to 1.63 x 10 to the 6th power and corresponding Mach numbers of 0.12 to 0.20, through an angle of attack range of 4 to 24, and a sideslip angle range of -10 deg to 5 deg. The part and full span wing configurations were also tested in ground proximity.

  15. Normal-Force and Hinge-Moment Characteristics at Transonic Speeds of Flap-Type Ailerons at Three Spanwise Locations on a 4-Percent-Thick Sweptback-Wing-Body Model and Pressure-Distribution Measurements on an Inboard Aileron

    Science.gov (United States)

    Runckel, Jack F.; Hieser, Gerald

    1961-01-01

    An investigation has been conducted at the Langley 16-foot transonic tunnel to determine the loading characteristics of flap-type ailerons located at inboard, midspan, and outboard positions on a 45 deg. sweptback-wing-body combination. Aileron normal-force and hinge-moment data have been obtained at Mach numbers from 0.80 t o 1.03, at angles of attack up to about 27 deg., and at aileron deflections between approximately -15 deg. and 15 deg. Results of the investigation indicate that the loading over the ailerons was established by the wing-flow characteristics, and the loading shapes were irregular in the transonic speed range. The spanwise location of the aileron had little effect on the values of the slope of the curves of hinge-moment coefficient against aileron deflection, but the inboard aileron had the greatest value of the slope of the curves of hinge-moment coefficient against angle of attack and the outboard aileron had the least. Hinge-moment and aileron normal-force data taken with strain-gage instrumentation are compared with data obtained with pressure measurements.

  16. A highly-segmented [Delta]E-time-of-flight wall as forward detector of the 4[pi]-system for charged particles at the SIS/ESR accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Gobbi, A.; Augustinski, G.; Bock, R.; Charity, R.J.; Fan, Z.G.; Freifelder, R.; Hildenbrand, K.D.; Jeong, S.C.; Marquardt, M.; Reisdorf, W.; Schuell, D.; Sodan, U.; Tanaka, M.H.; Teh, K.M.; Weinert, J.; Wessels, J.P. (Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)); Alard, J.P.; Bastid, N.; Boussange, S.; Crouau, M.; Daudon, F.; Dupieux, P.; Fayard, C.; Fraysse, L.; Jorio, M.; Mayade, S.; Montarou, G.; Montbel, I.; Morel, P.; Sahuc, E.; Savinel, G.; Vincent, D. (Lab. de Physique Corpusculaire, Univ. Clermont-Ferrand, Aubiere (France)); Basrak, Z.; Caplar, R.; Cindro, N.; Hoelbling, S. (Rudjer Boskovic Inst., Zagreb (Croatia)); Belayev, I.M.; Frolov, S.; Korchagin, Y.; Lebedev, A.; Smolyankin, S.; Zhilin, A.V. (Inst. for Experimental and Theoretical Physics, Moscow (Russia)); Blaich, T. (Inst. fuer Kernchemie, Univ. Mainz (Germany)); Boccaccio, P. (Ist. Nazionale di Fisica Nucleare, Lab. Nazionali Legnaro, Padua (Italy)); Buta, A.; Legrand, I.; Moisa, D.; Petrovici, M

    1993-01-01

    At the SIS/ESR accelerator facility at GSI in Darmstadt the 4[pi]-detector system FOPI is under construction at present. It is designed for the investigation of central collisions of heavy ions in the energy range up to 2 A GeV. As phase I of this detector a forward wall has been built and used in various experiments. It comprizes a total number of 764 scintillators with an additional shell of 188 thin [Delta]E-detectors in front of it and covers the full azimuth of the polar angles from 1deg to 30deg. The velocity and the nuclear charge of the fragments are determined by a combined time-of-flight and [Delta]E measurements. (orig.).

  17. Migration in Deltas: An Integrated Analysis

    Science.gov (United States)

    Nicholls, Robert J.; Hutton, Craig W.; Lazar, Attila; Adger, W. Neil; Allan, Andrew; Arto, Inaki; Vincent, Katharine; Rahman, Munsur; Salehin, Mashfiqus; Sugata, Hazra; Ghosh, Tuhin; Codjoe, Sam; Appeaning-Addo, Kwasi

    2017-04-01

    Deltas and low-lying coastal regions have long been perceived as vulnerable to global sea-level rise, with the potential for mass displacement of exposed populations. The assumption of mass displacement of populations in deltas requires a comprehensive reassessment in the light of present and future migration in deltas, including the potential role of adaptation to influence these decisions. At present, deltas are subject to multiple drivers of environmental change and often have high population densities as they are accessible and productive ecosystems. Climate change, catchment management, subsidence and land cover change drive environmental change across all deltas. Populations in deltas are also highly mobile, with significant urbanization trends and the growth of large cities and mega-cities within or adjacent to deltas across Asia and Africa. Such migration is driven primarily by economic opportunity, yet environmental change in general, and climate change in particular, are likely to play an increasing direct and indirect role in future migration trends. The policy challenges centre on the role of migration within regional adaptation strategies to climate change; the protection of vulnerable populations; and the future of urban settlements within deltas. This paper reviews current knowledge on migration and adaptation to environmental change to discern specific issues pertinent to delta regions. It develops a new integrated methodology to assess present and future migration in deltas using the Volta delta in Ghana, Mahanadi delta in India and Ganges-Brahmaputra-Meghna delta across India and Bangladesh. The integrated method focuses on: biophysical changes and spatial distribution of vulnerability; demographic changes and migration decision-making using multiple methods and data; macro-economic trends and scenarios in the deltas; and the policies and governance structures that constrain and enable adaptation. The analysis is facilitated by a range of

  18. Large capacity oblique all-wing transport aircraft

    Science.gov (United States)

    Galloway, Thomas L.; Phillips, James A.; Kennelly, Robert A., Jr.; Waters, Mark H.

    1996-01-01

    Dr. R. T. Jones first developed the theory for oblique wing aircraft in 1952, and in subsequent years numerous analytical and experimental projects conducted at NASA Ames and elsewhere have established that the Jones' oblique wing theory is correct. Until the late 1980's all proposed oblique wing configurations were wing/body aircraft with the wing mounted on a pivot. With the emerging requirement for commercial transports with very large payloads, 450-800 passengers, Jones proposed a supersonic oblique flying wing in 1988. For such an aircraft all payload, fuel, and systems are carried within the wing, and the wing is designed with a variable sweep to maintain a fixed subsonic normal Mach number. Engines and vertical tails are mounted on pivots supported from the primary structure of the wing. The oblique flying wing transport has come to be known as the Oblique All-Wing (OAW) transport. This presentation gives the highlights of the OAW project that was to study the total concept of the OAW as a commercial transport.

  19. Multiple cues for winged morph production in an aphid metacommunity.

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrparvar

    Full Text Available Environmental factors can lead individuals down different developmental pathways giving rise to distinct phenotypes (phenotypic plasticity. The production of winged or unwinged morphs in aphids is an example of two alternative developmental pathways. Dispersal is paramount in aphids that often have a metapopulation structure, where local subpopulations frequently go extinct, such as the specialized aphids on tansy (Tanacetum vulgare. We conducted various experiments to further understand the cues involved in the production of winged dispersal morphs by the two dominant species of the tansy aphid metacommunity, Metopeurum fuscoviride and Macrosiphoniella tanacetaria. We found that the ant-tended M. fuscoviride produced winged individuals predominantly at the beginning of the season while the untended M. tanacetaria produced winged individuals throughout the season. Winged mothers of both species produced winged offspring, although in both species winged offspring were mainly produced by unwinged females. Crowding and the presence of predators, effects already known to influence wing production in other aphid species, increased the percentage of winged offspring in M. tanacetaria, but not in M. fuscoviride. We find there are also other factors (i.e. temporal effects inducing the production of winged offspring for natural aphid populations. Our results show that the responses of each aphid species are due to multiple wing induction cues.

  20. Mimicking unfolding motion of a beetle hind wing

    Institute of Scientific and Technical Information of China (English)

    MUHAMMAD Azhar; PARK Hoon C; HWANG Do Y; BYUN Doyoung; GOO Nam S

    2009-01-01

    This paper presents an experimental research aiming to realize an artificial hind wing that can mimic the wing unfolding motion of Allomyrina dichotoma, an insect in coleopteran order. Based on the understanding of working principles of beetle wing folding/unfolding mechanisms, the hind wing unfolding motion is mimicked by a combination of creative ideas and state-of-art artificial muscle actuator. In this work, we devise two types of artificial wings and the successfully demonstrate that they can be unfolded by actuation of shape memory alloy wires to provide actuation force at the wing base and along the leading edge vein. The folding/unfolding mechanisms may provide an insight for portable nano/micro air vehicles with morphing wings.

  1. Preliminary study of effects of winglets on wing flutter

    Science.gov (United States)

    Doggett, R. V., Jr.; Farmer, M. G.

    1976-01-01

    Some experimental flutter results are presented over a Mach number range from about 0.70 to 0.95 for a simple, swept, tapered, flat-plate wing model having a planform representative of subsonic transport airplanes and for the same wing model equipped with two different upper surface winglets. Both winglets had the same planform and area (about 2 percent of the basic-wing area); however, one weighed about 0.3 percent of the basic-wing weight, and the other weighed about 1.8 percent of the wing weight. The addition of the lighter winglet reduced the wing-flutter dynamic pressure by about 3 percent; the heavier winglet reduced the wing-flutter dynamic pressure by about 12 percent. The experimental flutter results are compared at a Mach number of 0.80 with analytical flutter results obtained by using doublet-lattice and lifting-surface (kernel-function) unsteady aerodynamic theories.

  2. Casimir force between $\\delta-\\delta^{\\prime}$ mirrors transparent at high frequencies

    CERN Document Server

    Braga, Alessandra N; Alves, Danilo T

    2016-01-01

    We investigate, in the context of a real massless scalar field in $1+1$ dimensions, models of partially reflecting mirrors simulated by Dirac $\\delta-\\delta^{\\prime}$ point interactions. In the literature, these models do not exhibit full transparency at high frequencies. In order to provide a more realistic feature for these models, we propose a modified $\\delta-\\delta^{\\prime}$ point interaction that enables to achieve full transparency in the limit of high frequencies. Taking this modified $\\delta-\\delta^{\\prime}$ model into account, we investigate the Casimir force, comparing our results with those found in the literature.

  3. Evolving deltas: Conceptualising coevolution with engineered interventions

    Science.gov (United States)

    Welch, Amy; Nicholls, Robert; Lazar, Attila

    2017-04-01

    Mid to low latitude deltas have been populated for thousands of years due to their fertile soil and coastal location. This has led to an alteration in the land cover of deltas to primary agriculture and dense rural settlements and more recently, major cities and megacities have developed on or adjacent to many deltas. Deltas may be prosperous in terms of their outputs and services; however, they are also susceptible to many hazards due to their location and low-lying nature. Hazards include storm surges, fluvial flooding and erosion of both coastal and riverine areas, as well as subsidence, relative sea-level rise and pollution. This can have severe impacts on the delta, its population and its services. Therefore engineered interventions have been used for some time to protect the population and the valuable land from the consequences of hazards. Coevolution can be described as a feedback loop between nature and humans: each has an effect on how the other behaves and hence this inter-dependence interaction continues. Therefore the natural evolution of the delta interacts with engineered interventions, such as promoting accelerated subsidence over time, necessitating further adaptation. The deltaic landscape and associated livelihoods are thus the result of this co-evolution process between natural delta processes and engineered interventions. This presentation will identify and discuss various drivers and consequences of large scale engineered interventions, comparing and contrasting the management approaches taken in five populated deltas (Ganges-Brahmaputra-Meghna, Yangtze, Rhine-Meuse-Scheldt, Mekong and Nile). The type of engineered intervention and management approaches had a direct effect on the coevolution of deltas, with each of the deltas being at different stages in terms of extent of coevolution. A qualitative timeline of the typical steps of coevolution between the human system and the delta system of the studied deltas was produced. The major

  4. Degradation of PsbO by the Deg protease HhoA Is thioredoxin dependent.

    Directory of Open Access Journals (Sweden)

    Irma N Roberts

    Full Text Available The widely distributed members of the Deg/HtrA protease family play an important role in the proteolysis of misfolded and damaged proteins. Here we show that the Deg protease rHhoA is able to degrade PsbO, the extrinsic protein of the Photosystem II (PSII oxygen-evolving complex in Synechocystis sp. PCC 6803 and in spinach. PsbO is known to be stable in its oxidized form, but after reduction by thioredoxin it became a substrate for recombinant HhoA (rHhoA. rHhoA cleaved reduced eukaryotic (specifically, spinach PsbO at defined sites and created distinct PsbO fragments that were not further degraded. As for the corresponding prokaryotic substrate (reduced PsbO of Synechocystis sp. PCC 6803, no PsbO fragments were observed. Assembly to PSII protected PsbO from degradation. For Synechocystis sp. PCC 6803, our results show that HhoA, HhoB, and HtrA are localized in the periplasma and/or at the thylakoid membrane. In agreement with the idea that PsbO could be a physiological substrate for Deg proteases, part of the cellular fraction of the three Deg proteases of Synechocystis sp. PCC 6803 (HhoA, HhoB, and HtrA was detected in the PSII-enriched membrane fraction.

  5. The air oxidation behavior of lanthanum ion implanted zirconium at 500 deg. C

    CERN Document Server

    Peng, D Q; Chen, X W; Zhou, Q G

    2003-01-01

    The beneficial effect of lanthanum ion implantation on the oxidation behavior of zirconium at 500 deg. C has been studied. Zirconium specimens were implanted by lanthanum ions using a MEVVA source at energy of 40 keV with a fluence range from 1x10 sup 1 sup 6 to 1x10 sup 1 sup 7 ions/cm sup 2 at maximum temperature of 130 deg. C, The weight gain curves were measured after being oxidized in air at 500 deg. C for 100 min, which showed that a significant improvement was achieved in the oxidation behavior of zirconium ion implanted with lanthanum compared with that of the as-received zirconium. The valence of the oxides in the scale was analyzed by X-ray photoemission spectroscopy; and then the depth distributions of the elements in the surface of the samples were obtained by Auger electron spectroscopy. Glancing angle X-ray diffraction at 0.3 deg. incident angles was employed to examine the modification of its phase transformation because of the lanthanum ion implantation in the oxide films. It was obviously fou...

  6. Exploring a possible origin of a 14 deg y-normal spin tilt at RHIC polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-06-15

    A possible origin of a 14 deg y-normal spin n0 tilt at the polarimeter is in snake angle defects. This possible cause is investigated by scanning the snake axis angle µ, and the spin rotation angle at the snake, φ, in the vicinity of their nominal values.

  7. A Byzantine chant collection from Sicily: a collaboration between Copenhagen and Piana degli Albanesi (Palermo)

    DEFF Research Database (Denmark)

    Sanfratello, Giuseppe

    2016-01-01

    The aim of this paper is to give an account of the collaboration between a collector of the Byzantine chant tradition of Piana degli Albanesi (Palermo) in Sicily, namely fr. Bartolomeo Di Salvo, and the editorial board of the Monumenta Musicae Byzantinae, i.e. an institution under the aegis......, Collections, Ethnomusicology, Critical edition, Monumenta Musicae Byzantinae (MMB)...

  8. Delta hepatitis agent: structural and antigenic properties of the delta-associated particle.

    Science.gov (United States)

    Bonino, F; Hoyer, B; Shih, J W; Rizzetto, M; Purcell, R H; Gerin, J L

    1984-01-01

    Delta agent (delta) was serially passaged to a second and third hepatitis B surface antigen (HBsAg) carrier chimpanzee, using as inoculum the peak delta antigen (delta Ag) serum of an animal previously infected with human serum. The characteristics of serially transmitted delta Ag were similar to those described in first-passage animals. It was consistently detected before the development of anti-delta, in association with a 35- to 37-nm subpopulation of HBsAg particles and a unique low-molecular-weight (5.5 X 10(5)) RNA. RNase susceptibility of the delta-associated RNA and release of delta Ag activity upon treatment of delta-associated particles with detergent revealed that this particle is organized into a virion-like form with the RNA and delta Ag as internal components within a coat of HBsAg. Surface determinants of the delta-associated particle other than HBsAg were not detected by radioimmunoprecipitation experiments, using sera of humans and chimpanzees convalescent from delta hepatitis. The HBsAg-associated particle is the "candidate agent" of delta hepatitis. Images PMID:6698598

  9. The Niger Delta Amnesty Program

    Directory of Open Access Journals (Sweden)

    Benjamin A. Okonofua

    2016-06-01

    Full Text Available The armed conflict between militias and government forces in Nigeria’s Niger Delta region has spanned for more than two decades, defying all solutions. A disarmament, demobilization, and reintegration (DDR program was established in August 2015 in effort to end the violence and has remained in place. It is a radically different approach from past approaches that displayed zero tolerance to all political challenges to oil production or the allocation of oil profits. The approach appeared to be immediately successful in that it forced a ceasefire, engaged militants in planned programs to rehabilitate and reintegrate them into civilian society, and opened up the oil wells (many of which had been shut due to the crisis with the effect of increasing government revenue, which depends 85% on oil exports. Yet, few studies have attempted to understand the dynamics within the country that are responsible for the design and implementation of this broad policy shift or to understand whether and how the current initiative is able to end the conflict and institute peace beyond the short term. This study, therefore, is important because it provides a critical perspective that anticipates and explains emerging issues with the Niger Delta Amnesty Program, which have implications for DDR adaptation and implementation all over the world. Ultimately, the research demonstrates how the DDR program both transforms the Niger Delta conflict and becomes embroiled in intense contestations not only about the mechanism for transforming the targeted population but also whether and how the program incorporates women who are being deprioritized by the program.

  10. Analysis and Synthesis of Delta Operator Systems

    CERN Document Server

    Yang, Hongjiu; Shi, Peng; Zhao, Ling

    2012-01-01

    This book is devoted to analysis and design on delta operator systems. When sampling is fast, a dynamical system will become difficult to control, which can be seen in wide real world applications. Delta operator approach is very effective to deal with fast sampling systems. Moreover, it is easy to observe and analyze the control effect with different sampling periods in delta operator systems. The framework of this book has been carefully constructed for delta operator systems to handle sliding mode control, time delays, filter design, finite frequency and networked control. These problems indeed are especially important and significant in automation and control systems design. Through the clear framework of the book, readers can easily go through the learning process on delta operator systems via a precise and comfortable learning sequence. Following this enjoyable trail, readers will come out knowing how to use delta operator approach to deal with control problems under fast sampling case. This book should...

  11. Effect of wing mass in free flight by a butterfly-like 3D flapping wing-body model

    Science.gov (United States)

    Suzuki, Kosuke; Okada, Iori; Yoshino, Masato

    2016-11-01

    The effect of wing mass in free flight of a flapping wing is investigated by numerical simulations based on an immersed boundary-lattice Boltzmann method. We consider a butterfly-like 3D flapping wing-model consisting of two square wings with uniform mass density connected by a rod-shaped body. We simulate free flights of the wing-body model with various mass ratios of the wing to the whole of the model. As a result, it is found that the lift and thrust forces decrease as the mass ratio increases, since the body with a large mass ratio experiences large vertical and horizontal oscillations in one period and consequently the wing tip speed relatively decreases. In addition, we find the critical mass ratio between upward flight and downward flight for various Reynolds numbers. This work was supported by JSPS KAKENHI Grant Number JP16K18012.

  12. Delta Clipper - Design for supportability

    Science.gov (United States)

    Smiljanic, Ray R.; Conrad, Charles; Spaulding, Ed; Gisburne, Don

    1993-07-01

    The 'Delta Clipper' Single Stage Rocket Technology (SSRT) currently under development in the DC-X program will implement reliability-centered maintenance and support, involving on-equipment/off-equipment two-level maintenance, a logistics and spares pipeline, and a minimization of 'blue suit' skill-level personnel. Attention is given to the range of SSRT features that are to be validated via the DC-X test program; these prominently involve LRUs replaceability and accessibility, standardization and interchangeability, and 'aircraft-like' automated data collection.

  13. Climate change and the Delta

    Science.gov (United States)

    Dettinger, Michael; Anderson, Jamie; Anderson, Michael L.; Brown, Larry R.; Cayan, Daniel; Maurer, Edwin P.

    2016-01-01

    Anthropogenic climate change amounts to a rapidly approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic variability, complex water-management systems have been developed, even as the Delta’s natural ecosystems have been largely devastated. Climate change is projected to challenge these management and ecological systems in different ways that are characterized by different levels of uncertainty. For example, there is high certainty that climate will warm by about 2°C more (than late-20th-century averages) by mid-century and about 4°C by end of century, if greenhouse-gas emissions continue their current rates of acceleration. Future precipitation changes are much less certain, with as many climate models projecting wetter conditions as drier. However, the same projections agree that precipitation will be more intense when storms do arrive, even as more dry days will separate storms. Warmer temperatures will likely enhance evaporative demands and raise water temperatures. Consequently, climate change is projected to yield both more extreme flood risks and greater drought risks. Sea level rise (SLR) during the 20th century was about 22cm, and is projected to increase by at least 3-fold this century. SLR together with land subsidence threatens the Delta with greater vulnerabilities to inundation and salinity intrusion. Effects on the Delta ecosystem that are traceable to warming include SLR, reduced snowpack, earlier snowmelt and larger storm-driven streamflows, warmer and longer summers, warmer summer water temperatures, and water-quality changes. These changes and their uncertainties will challenge the operations of water projects and uses throughout the Delta’s watershed and delivery areas. Although the effects of climate change on Delta ecosystems may be profound, the end results are difficult to predict, except that native species will fare worse than invaders. Successful

  14. Phosphorylation of DegU is essential for activation of amyE expression in Bacillus subtilis

    Indian Academy of Sciences (India)

    Monica Gupta; K Krishnamurthy Rao

    2014-12-01

    Alpha ()-amylase (amyE) is one of the major exo-enzymes secreted by Bacillus subtilis during the post-exponential phase. The DegS-DegU two-component system regulates expression of majority of post-exponentially expressed genes in B. subtilis. It has been demonstrated that varying levels of the phosphorylated form of DegU (DegU-P) control different cellular processes. Exo-protease production is observed when effective concentration of DegU-P rises in the cell, whereas swarming motility is favoured at very low amounts of DegU-P. In this study we show that like other exo-proteases, expression of amyE is positively regulated by increase in DegU-P levels in the cell. We also demonstrate that residues at the DNA-binding helix-turn-helix (HTH) motif of DegU are necessary for the amyE expression. This observation is further reinforced by demonstrating the direct interaction of DegU on amyE promoter.

  15. AromaDeg, a novel database for phylogenomics of aerobic bacterial degradation of aromatics.

    Science.gov (United States)

    Duarte, Márcia; Jauregui, Ruy; Vilchez-Vargas, Ramiro; Junca, Howard; Pieper, Dietmar H

    2014-01-01

    Understanding prokaryotic transformation of recalcitrant pollutants and the in-situ metabolic nets require the integration of massive amounts of biological data. Decades of biochemical studies together with novel next-generation sequencing data have exponentially increased information on aerobic aromatic degradation pathways. However, the majority of protein sequences in public databases have not been experimentally characterized and homology-based methods are still the most routinely used approach to assign protein function, allowing the propagation of misannotations. AromaDeg is a web-based resource targeting aerobic degradation of aromatics that comprises recently updated (September 2013) and manually curated databases constructed based on a phylogenomic approach. Grounded in phylogenetic analyses of protein sequences of key catabolic protein families and of proteins of documented function, AromaDeg allows query and data mining of novel genomic, metagenomic or metatranscriptomic data sets. Essentially, each query sequence that match a given protein family of AromaDeg is associated to a specific cluster of a given phylogenetic tree and further function annotation and/or substrate specificity may be inferred from the neighboring cluster members with experimentally validated function. This allows a detailed characterization of individual protein superfamilies as well as high-throughput functional classifications. Thus, AromaDeg addresses the deficiencies of homology-based protein function prediction, combining phylogenetic tree construction and integration of experimental data to obtain more accurate annotations of new biological data related to aerobic aromatic biodegradation pathways. We pursue in future the expansion of AromaDeg to other enzyme families involved in aromatic degradation and its regular update. Database URL: http://aromadeg.siona.helmholtz-hzi.de

  16. Convective mass transfer enhancement in a membrane channel by delta winglets and their comparison with rectangular winglets☆

    Institute of Scientific and Technical Information of China (English)

    Jingchun Min; Bingqiang Zhang

    2015-01-01

    Numerical calculations were conducted to simulate the flow and mass transfer in narrow membrane channels equipped with delta winglets, which are often used as longitudinal vortex generators to enhance heat transfer in heat exchanger applications. The channel consists of an impermeable solid wall and a membrane. The delta winglets are attached to the solid wal surface to enhance the mass transfer near the membrane surface and sup-press the concentration polarization. The winglet performance was evaluated in terms of concentration polariza-tion factor versus consumed pumping power. Calculations were implemented for NaCl solution flow in a membrane channel having a height of 2.0 mm for Reynolds numbers ranging from 400 to 1000. The delta wing-lets were optimized under equal pumping power condition, and the results of optimization suggest winglet height of 5/6 of the channel height, aspect ratio of 2.0, attack angle of 30°, and a winglet interval equal to the chan-nel height. The optimal delta winglets were compared with the optimal rectangular winglets we found previous-ly, and it is shown that the rectangular winglets yield a somewhat better performance than the delta winglets. © 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  17. From Natural to Design River Deltas

    Science.gov (United States)

    Giosan, Liviu

    2016-04-01

    Productive and biologically diverse, deltaic lowlands attracted humans since prehistory and may have spurred the emergence of the first urban civilizations. Deltas continued to be an important nexus for economic development across the world and are currently home for over half a billion people. But recently, under the double whammy of sea level rise and inland sediment capture behind dams, they have become the most threatened coastal landscape. Here I will address several deceptively simple questions to sketch some unexpected answers using example deltas from across the world from the Arctic to the Tropics, from the Danube to the Indus, Mississippi to Godavari and Krishna, Mackenzie to Yukon. What is a river delta? What is natural and what is not in a river delta? Are the geological and human histories of a delta important for its current management? Is maintaining a delta the same to building a new one? Can we design better deltas than Nature? These answers help us see clearly that survival of deltas in the next century depends on human intervention and is neither assured nor simple to address or universally applicable. Empirical observations on the hydrology, geology, biology and biochemistry of deltas are significantly lagging behind modeling capabilities endangering the applicability of numerical-based reconstruction solutions and need to be ramped up significantly and rapidly across the world.

  18. Charged current weak electroproduction of $\\Delta$ resonance

    CERN Document Server

    Alvarez-Ruso, L; Vacas, M J V

    1998-01-01

    We study the weak production of $\\Delta$ (i.e. $e^{-} + p \\to \\Delta^{0}+ energy range corresponding to the Mainz and TJNAF electron accelerators. The differential cross sections $\\sigma(\\theta)$ are found to be of the order of $ 10^{-39}$ cm$^2$/sr, over a range of angles which increases with energy. The possibility of observing these reactions with the high luminosities available at these accelerators, and studying the weak N-$\\Delta$ transition form factors through these reactions is discussed. The production cross section of N$^*(1440)$ in the kinematic region of $\\Delta$ production is also estimated and found to be small.

  19. Delta Semantics Defined By Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

    This report is identical to an earlier version of May 1978 except that Chapter 5 has been revised. A new paper: "A Petri Net Definition of a System Description Language", DAIMI, April 1979, 20 pages, extends the Petri net model to include a data state representing the program variables. Delta...... and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

  20. SNC 80 and related delta opioid agonists.

    Science.gov (United States)

    Calderon, S N; Coop, A

    2004-01-01

    The discovery of the selective delta (delta) opioid agonists SNC 80 and BW373U86, which possess a diarylmethylpiperazine structure unique among opioids, was a major advance in the field of delta-opioid ligands. Much research has been performed to uncover the structure-activity relationships (SAR) of this class of ligands and also to compare the diarylmethylpiperazines with the traditional morphinan-based delta opioids. This review focuses on the development of the SAR of this unique series of ligands, and discusses questions which remain unanswered.

  1. Effects of Dragonfly Wing Structure on the Dynamic Performances

    Institute of Scientific and Technical Information of China (English)

    Huaihui Ren; Xishu Wang; Xudong Li; Yinglong Chen

    2013-01-01

    The configurations of dragonfly wings,including the corrugations of the chordwise cross-section,the microstructure of the longitudinal veins and membrane,were comprehensively investigated using the Environmental Scanning Electron Microscopy (ESEM).Based on the experimental results reported previously,the multi-scale and multi-dimensional models with different structural features of dragonfly wing were created,and the biological dynamic behaviors of wing models were discussed through the Finite Element Method (FEM).The results demonstrate that the effects of different structural features on dynamic behaviors of dragonfly wing such as natural frequency/modal,bending/torsional deformation,reaction force/torque are very significant.The corrugations of dragonfly wing along the chordwise can observably improve the flapping frequency because of the greater structural stiffness of wings.In updated model,the novel sandwich microstructure of the longitudinal veins remarkably improves the torsional deformation of dragonfly wing while it has a little effect on the flapping frequency and bending deformation.These integrated structural features can adjust the deformation of wing oneself,therefore the flow field around the wings can be controlled adaptively.The fact is that the flights of dragonfly wing with sandwich microstructure of longitudinal veins are more efficient and intelligent.

  2. Hi-GAL, the Herschel infrared Galactic Plane Survey: photometric maps and compact source catalogues. First data release for Inner Milky Way: +68{\\deg}> l > -70{\\deg}

    CERN Document Server

    Molinari, S; Elia, D; Pestalozzi, M; Traficante, A; Pezzuto, S; Swinyard, B M; Noriega-Crespo, A; Bally, J; Moore, T J T; Plume, R; Zavagno, A; di Giorgio, A M; Liu, S J; Pilbratt, G L; Mottram, J C; Russeil, D; Piazzo, L; Veneziani, M; Benedettini, M; Calzoletti, L; Faustini, F; Natoli, P; Piacentini, F; Merello, M; Palmese, A; Del Grande, R; Polychroni, D; Rygl, K L J; Polenta, G; Barlow, M J; Bernard, J -P; Martin, P G; Testi, L; Ali, B; Andrè, P; Beltrán, M T; Billot, N; Brunt, C; Carey, S; Cesaroni, R; Compiègne, M; Eden, D; Fukui, Y; Garcia-Lario, P; Hoare, M G; Huang, M; Joncas, G; Lim, T L; Lord, S D; Martinavarro-Armengol, S; Motte, F; Paladini, R; Paradis, D; Peretto, N; Robitaille, T; Schilke, P; Schneider, N; Schulz, B; Sibthorpe, B; Strafella, F; Thompson, M A; Umana, G; Ward-Thompson, D; Wyrowski, F

    2016-01-01

    (Abridged) We present the first public release of high-quality data products (DR1) from Hi-GAL, the {\\em Herschel} infrared Galactic Plane Survey. Hi-GAL is the keystone of a suite of continuum Galactic Plane surveys from the near-IR to the radio, and covers five wavebands at 70, 160, 250, 350 and 500 micron, encompassing the peak of the spectral energy distribution of cold dust for 8 l > -70{\\deg} in a |b|<1{\\deg} latitude strip. Photometric maps have been produced with the ROMAGAL pipeline, that optimally capitalizes on the excellent sensitivity and stability of the bolometer arrays of the {\\em Herschel} PACS and SPIRE photometric cameras, to deliver images of exquisite quality and dynamical range, absolutely calibrated with {\\em Planck} and {\\em IRAS}, and recovering extended emission at all wavelengths and all spatial scales. The compact source catalogues have been generated with the CuTEx algorithm, specifically developed to optimize source detection and extraction in the extreme conditions of intens...

  3. $\\Delta$ decay in nuclear medium

    CERN Document Server

    Jain, B K; Kundu, Bijoy

    1996-01-01

    Proton-nucleus collisions, where the beam proton gets excited to the delta resonance and then decays to p\\pi ^+, either inside or outside the nuclear medium, are studied. Cross-sections for various kinematics for the (p,p' \\pi ^+) reaction between 500 MeV and 1 GeV beam energy are calculated to see the effects of the nuclear medium on the propagation and decay of the resonance. The cross-sections studied include proton energy spectra in coincidence with the pion, four momentum transfer distributions, and the invariant p\\pi^+ mass distributions. We find that the effect of the nuclear medium on these cross-sections mainly reduces their magnitudes. Comparing these cross-sections with those considering the decay of the delta outside the nucleus only, we further find that at 500 MeV the two sets of cross-sections have large differences, while by 1 GeV the differences between them become much smaller.

  4. Interceptive management of winged maxillary central incisors

    Directory of Open Access Journals (Sweden)

    Mamta Dali

    2013-01-01

    Full Text Available Introduction: Winged maxillary incisors are a well-recognized clinical finding, which can result in psychological trauma to children at growing age. Interceptive treatment is usually carried out in mixed dentition period in order to reduce the severity of a developing malocclusion in future. Case Report: This paper reports a case of 6-years-old female patient with winged maxillary central incisor being treated with derotation technique using the beggs brackets along with nance palatal arch space maintainer. Discussion: The major advantages in carrying out this treatment with fixed brackets are the ease with which the force magnitude and vector can be controlled much more precisely than with a removable appliance, minimal discomfort to the patient and reduces the need for patient co-operation.

  5. The Crest Wing Wave Energy Device

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of a continuation of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC), in the following referred to as ‘Phase 2'. The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave...... to generate power. Model tests have been performed using scale models (length scale 1:30), provided by WaveEnergyFyn, in regular and irregular wave states that can be found in Assessment of Wave Energy Devices. Best Practice as used in Denmark (Frigaard et al., 2008). The tests were carried out at Dept....... of Civil Engineering, Aalborg University (AAU) in the 3D deep water wave tank. The displacement and force applied to a power take off system, provided by WaveEnergyFyn, were measured and used to calculate mechanical power available to the power take off....

  6. Charge Capacity of Piezoelectric Membrane Wings

    Science.gov (United States)

    Grybas, Matthew; Hubner, J. Paul

    2015-11-01

    Micro air vehicles (MAVs) have small wings often fabricated with flexible frames and membranes. These membranes flex and vibrate. Piezoelectric films have the ability to convert induced stress or strain into electrical energy. Thus, it is of interest to investigate if piezoelectric films can be used as a structural member of an MAV wing and generate both lift and energy through passive vibrations. Both a shaker test and a wind tunnel test have been conducted to characterize and assess energy production and aerodynamic characteristics including lift, drag and efficiency. The piezoelectric film has been successful as a lifting surface and produces a measurable charge. This work was supported by NSF REU Site Award 1358991.

  7. WOODEN DOOR WINGS OF ADIYAMAN GREAT MOSQUE

    Directory of Open Access Journals (Sweden)

    Muhammet ARSLAN

    2010-06-01

    Full Text Available Woodworking which is in the most important Turk art branches have been used especially in Anatolia land readily. Wooden material that is seen on architectural units such as mimbar, ambo, wings of door and window, lectern has an important particularly with its ornamental figures. Wooden composition on the north and east doors of Adıyaman Great Mosque was built by Dulkadir Principality but regulated again in the last period of Ottoman Empire, is a theme which is exemined detailedly in Turk art. In this article, it is tried to determined ornamentel and tecnical characteristics of wooden door wings of Adıyaman Great Mosque belongs to early XX. century and the place of them in Turk art.

  8. Origin and diversification of wings: Insights from a neopteran insect.

    Science.gov (United States)

    Medved, Victor; Marden, James H; Fescemyer, Howard W; Der, Joshua P; Liu, Jin; Mahfooz, Najmus; Popadić, Aleksandar

    2015-12-29

    Winged insects underwent an unparalleled evolutionary radiation, but mechanisms underlying the origin and diversification of wings in basal insects are sparsely known compared with more derived holometabolous insects. In the neopteran species Oncopeltus fasciatus, we manipulated wing specification genes and used RNA-seq to obtain both functional and genomic perspectives. Combined with previous studies, our results suggest the following key steps in wing origin and diversification. First, a set of dorsally derived outgrowths evolved along a number of body segments including the first thoracic segment (T1). Homeotic genes were subsequently co-opted to suppress growth of some dorsal flaps in the thorax and abdomen. In T1 this suppression was accomplished by Sex combs reduced, that when experimentally removed, results in an ectopic T1 flap similar to prothoracic winglets present in fossil hemipteroids and other early insects. Global gene-expression differences in ectopic T1 vs. T2/T3 wings suggest that the transition from flaps to wings required ventrally originating cells, homologous with those in ancestral arthropod gill flaps/epipods, to migrate dorsally and fuse with the dorsal flap tissue thereby bringing new functional gene networks; these presumably enabled the T2/T3 wing's increased size and functionality. Third, "fused" wings became both the wing blade and surrounding regions of the dorsal thorax cuticle, providing tissue for subsequent modifications including wing folding and the fit of folded wings. Finally, Ultrabithorax was co-opted to uncouple the morphology of T2 and T3 wings and to act as a general modifier of hindwings, which in turn governed the subsequent diversification of lineage-specific wing forms.

  9. CFD Analysis of UAV Flying Wing

    Directory of Open Access Journals (Sweden)

    Vasile PRISACARIU

    2016-09-01

    Full Text Available Numerical methods for solving equations describing the evolution of 3D fluid experienced a significant development closely related to the progress of information systems. Today, especially in the field of fluid mechanics, numerical simulations allow the study of gas-thermodynamic confirmed by experimental techniques in wind tunnel conditions and actual flight tests for modeling complex aircraft. The article shows a case of numerical analysis of the lifting surface on the UAV type flying wing.

  10. X-38 on B-52 Wing Pylon

    Science.gov (United States)

    1997-01-01

    A unique, close-up view of the X-38 (Crew Return Vehicle) under the wing of NASA's B-52 mothership prior to launch of the lifting-body research vehicle. The photo was taken from the observation window of the B-52 bomber as it banked in flight. The X-38 Crew Return Vehicle (CRV) research project is designed to develop the technology for a prototype emergency crew return vehicle or lifeboat for the International Space Station.

  11. Maintenance cost study of rotary wing aircraft

    Science.gov (United States)

    1977-01-01

    The feasibility was studied of predicting rotary wing operation maintenance costs by using several aircraft design factors for the aircraft dynamic systems. The dynamic systems considered were engines, drives and transmissions, rotors, and flight controls. Multiple regression analysis was used to correlate aircraft design and operational factors with manhours per flight hour, and equations for each dynamic system were developed. Results of labor predictions using the equations compare favorably with actual values.

  12. Autonomous Deicing System For Airplane Wing

    Science.gov (United States)

    Hickman, G. A.; Gerardi, J. J.

    1993-01-01

    Prototype autonomous deicing system for airplane includes network of electronic and electromechanical modules at various locations in wings and connected to central data-processing unit. Small, integrated solid-state device, using long coils installed under leading edge, exciting small vibrations to detect ice and larger vibrations to knock ice off. In extension of concept, outputs of vibration sensors and other sensors used to detect rivet-line fractures, fatigue cracks, and other potentially dangerous defects.

  13. Mother Nature inspires new wind turbine wing

    DEFF Research Database (Denmark)

    Sønderberg Petersen, L.

    2007-01-01

    The sight of a bird of prey hanging immobile in the air while its wings continuously adjust themselves slightly in relation to the wind in order to keep the bird in the same position in the air, is a sight that most of us have admired, including the windenergy scientists at Risø DTU. They have st...... started transferring the principle to wind turbine blades to make them adaptive...

  14. Comparative assessment of the vulnerability and resilience of deltas : extended version with 14 deltas : synthesis report

    NARCIS (Netherlands)

    Bucx, T.; Driel, van W.F.; Boer, de H.; Graas, S.; Langenberg, V.; Marchand, M.; Guchte, van de C.

    2014-01-01

    Worldwide, deltas host dense populations and are important centres of agricultural and industrial production, and economic activity. Many deltas are areas of great ecological importance as well, featuring wetlands of high and unique biodiversity. Deltas are vulnerable to changes by natural forces an

  15. $\\Delta I=4$ and $\\Delta I=8$ bifurcations in rotational bands of diatomic molecules

    CERN Document Server

    Bonatsos, Dennis; Lalazissis, G A; Drenska, S B; Minkov, N; Raychev, P P; Roussev, R P; Bonatsos, Dennis

    1996-01-01

    It is shown that the recently observed $\\Delta I=4$ bifurcation seen in superdeformed nuclear bands is also occurring in rotational bands of diatomic molecules. In addition, signs of a $\\Delta I=8$ bifurcation, of the same order of magnitude as the $\\Delta I=4$ one, are observed both in superdeformed nuclear bands and rotational bands of diatomic molecules.

  16. INFLUENCE OF THE DELTA-DELTA-MESON COUPLING ON NUCLEON AND DELTA PROPERTIES IN NUCLEAR-MATTER

    NARCIS (Netherlands)

    DEJONG, F; MALFLIET, R

    1994-01-01

    We introduce a scalar and a vector DELTADELTA-meson vertex in the relativistic Dirac-Brueckner model for nuclear matter and investigate the consequences. We find small effects on the effective nucleon properties. The effects in the DELTA sector are more profound, although the DELTA is still effectiv

  17. Environmental fatigue behaviors of wrought and cast stainless steels in 310 .deg. C Deoxygenated Water

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Pyung Yeon

    2011-02-15

    Environmental fatigue behaviors of wrought type 316LN stainless steel and cast CF8M stainless steel were investigated. LCF tests were performed at fixed strain rate of 0.04%/s with 0.4%, 0.6%, 0.8%, 1.0% strain amplitudes in 310 .deg. C deoxygenated water environment. In addition, to analyze microstructure effect on fatigue behavior, low cycle fatigue tests in air environment were performed at fixed strain rate of 0.4%/s, 0.04%/s with 0.4%, 0.8% strain amplitudes. It was shown that the low cycle fatigue life of CF8M in a 310 .deg. C deoxygenated water environment was slightly longer than that of 316LN. On the other hand, the low cycle fatigue life of CF8M in a 310 .deg. C air environment was slightly shorter than that of 316LN or was similar with that of 316LN. Through OM observation and phase image analysis, it was confirmed that the ferrite content of CF8M tested in a 310 .deg. C deoxygenated water environment was larger than that of CF8M tested in a 310 .deg. C air environment. It was shown that the ferrite phase fraction of CF8M tested in 310 .deg. C deoxygenated water environment was approximately 26∼28% and that of CF8M tested in air environment was approximately 10∼12%. The difference of ferrite content in CF8M results in superior tensile properties as higher ferrite content. Furthermore, the difference of ferrite content in CF8M might be the cause of different result of fatigue life between CF8M and 316LN depending on environment. In this study, focused on CF8M having 26∼28% ferrite content, to understand the causes of these differences in a 310 .deg. C deoxygenated water environment, fracture surface and crack morphology were observed. And material factors like microstructure, mechanical properties factors like stress behavior during fatigue life, factors by environmentally assisted cracking (EAC) like hydrogen induced cracking (HIC) and chemical compositions of both materials were analyzed. Mainly in a 310 .deg. C deoxygenated water environment, the

  18. 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.

  19. Functional analysis of genes differentially expressed in the Drosophila wing disc: role of transcripts enriched in the wing region.

    Science.gov (United States)

    Jacobsen, Thomas L; Cain, Donna; Paul, Litty; Justiniano, Steven; Alli, Anwar; Mullins, Jeremi S; Wang, Chun Ping; Butchar, Jon P; Simcox, Amanda

    2006-12-01

    Differential gene expression is the major mechanism underlying the development of specific body regions. Here we assessed the role of genes differentially expressed in the Drosophila wing imaginal disc, which gives rise to two distinct adult structures: the body wall and the wing. Reverse genetics was used to test the function of uncharacterized genes first identified in a microarray screen as having high levels of expression in the presumptive wing. Such genes could participate in elaborating the specific morphological characteristics of the wing. The activity of the genes was modulated using misexpression and RNAi-mediated silencing. Misexpression of eight of nine genes tested caused phenotypes. Of 12 genes tested, 10 showed effective silencing with RNAi transgenes, but only 3 of these had resulting phenotypes. The wing phenotypes resulting from RNAi suggest that CG8780 is involved in patterning the veins in the proximal region of the wing blade and that CG17278 and CG30069 are required for adhesion of wing surfaces. Venation and apposition of the wing surfaces are processes specific to wing development providing a correlation between the expression and function of these genes. The results show that a combination of expression profiling and tissue-specific gene silencing has the potential to identify new genes involved in wing development and hence to contribute to our understanding of this process. However, there are both technical and biological limitations to this approach, including the efficacy of RNAi and the role that gene redundancy may play in masking phenotypes.

  20. Pourbaix diagrams for the system copper-chlorine at 5-100 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Beverskog, B. [Studsvik Material AB, Nykoeping (Sweden); Puigdomenech, I. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    1998-04-01

    Pourbaix diagrams for the copper-chlorine system in the temperature interval 5-100 deg C have been revised. Predominance diagrams for dissolved copper containing species have also been calculated. Two different total concentrations of each dissolved element, 10{sup -4} and 10{sup -6} molal for copper and 0.2 and 1.5 molal for chlorine have been used in the calculations. Chloride is the predominating chlorine species in aqueous solutions. Presence of chloride increases the corrosion regions of copper at the expense of the immunity and passivity regions in the Pourbaix diagrams. CuCl{sub 2} {center_dot} 3Cu(OH){sub 2} is the only copper-chloride solid phase that forms at the concentrations of chlorine studied. However, its stability area decreases with increasing temperature. The ion CuCl{sub 2}{sup -} predominates at all temperatures at [Cl(aq)]{sub tot}=0.2 molal and this reduces the immunity and passivity areas. A corrosion region exists between the immunity and passivity regions at 100 deg C at [Cu(aq)]{sub tot}=10{sup -6} and [Cl(aq)]{sub tot}=0.2 molal. At the chlorine concentration of 1.5 molal the corrosion region exists in the whole temperature range investigated. The ion CuCl{sub 3}{sup 2-} predominates at 5-25 and 100 deg C, while CuCl{sub 2}{sup -} predominates at 50-80 deg C at [Cl(aq)]{sub tot=}1-5 molal. A copper concentration of 10{sup -4} molal reduces the corrosion areas due to expansion of the immunity and passivity areas. However, a corrosion region still exists between the immunity and passivity regions at all investigated temperatures at pH{sub {Tau}}<9.5 and 1.5 molal chloride concentration. According to our calculations the copper canisters in the deep nuclear waste repository should not corrode at the copper concentration of 10{sup -6} molal and the chloride concentration of 0.2 molal. However, at 80-100 deg C the equilibrium potentials postulated for the Swedish nuclear repository are dangerously close to a corrosion situation. According to

  1. Book review, Igiene e Tecnologie degli Alimenti di Origine Animale Giampaolo Colavita (a cura di

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2008-09-01

    Full Text Available Igiene e Tecnologie degli Alimenti di Origine Animale si avvale del contributo di 33 autori, tutti soci dell’Associazione Italiana Veterinari Igienisti (AIVI, che garantiscono l’appropriata trattazione di una materia estremamente vasta e dinamica. Il manuale nasce da un’iniziativa finalizzata alla realizzazione di un testo che rifletta e possa soddisfare le esigenze didattiche degli insegnamenti di un’ampia serie di materie universitarie: Igiene e Tecnologie degli Alimenti di Origine Animale della Facoltà di Medicina Veterinaria, di Agraria, nei corsi di Scienze e Tecnologie Alimentari, di Scienze e Tecnologie delle Produzioni Animali, nel corso di laurea in Tecniche della Prevenzione nell’ambiente e nei Luoghi di Lavoro, nonché in altri corsi di studio dove si insegnano le discipline relative all’igiene e alla sicurezza degli alimenti.Sono stati trattati gran parte degli alimenti di origine animale, i prodotti a base di carne, il latte e i prodotti derivati, i prodotti della pesca freschi e trasformati, i prodotti dell’alveare, le uova e gli ovoprodotti. Di particolare interesse appare il capitolo riguardante la diagnostica analitica degli alimenti, considerato che le moderne metodologie analitiche risultano fondamentali per affrontare le tematiche legate all’igiene e alla sicurezza alimentare.Il volume ha una finalità prevalentemente didattica ma è comunque rivolto a tutti coloro che operano nel campo dell’Igiene e delle Tecnologie Alimentari. Infatti, visti gli argomenti trattati come le tossinfezioni e le intossicazioni alimentari, la conservazione, il confezionamento e l’etichettatura dei prodotti alimentari, anche i professionisti del settore possono trarre dal testo elementi utili per la loro attività. Per esempio argomenti quali l’analisi del rischio, le attività di audit ed i sistemi di accreditamento e di certificazione sono particolarmente utili per chi opera nelle Aziende Sanitarie Locali e negli Istituti

  2. Numerical simulation of entry flow over blunt swept-wing planes

    Science.gov (United States)

    Li, C. P.

    1992-01-01

    Viscous, heat-conducting flow with chemical and vibrational relaxation processes of the constituent gases surrounding winged spacecraft is considered in the continuum regime. The Navier-Stokes equations are appended by additional vibrational energy and species rate equations and supplemented by the equations of state and the phenomenological laws based on mixture rules or collisional cross sections. Numerical convective flux can be obtained from several forms of one-dimensional Riemann solver, with or without entropy correction. High-order accuracy is obtained from two types of reconstructive interpolation. A number of explicit and implicit numerical schemes have been implemented as a means to yield converged solutions. Both shock-fitting, finite-difference and shock-capturing, finite-volume techniques have been tested for configurations such as a sphere, double ellipsoid, blunt-edge delta wing, a European Hermes vehicle, and the U.S. Shuttle Orbiter. The shock-fitting code provides excellent results only for simple configurations, whereas the shock-capturing code leads to overall satisfying solutions for complex geometries.

  3. Control and navigation system for a fixed-wing unmanned aerial vehicle

    Science.gov (United States)

    Zhai, Ruiyong; Zhou, Zhaoying; Zhang, Wendong; Sang, Shengbo; Li, Pengwei

    2014-03-01

    This paper presents a flight control and navigation system for a fixed-wing unmanned aerial vehicle (UAV) with low-cost micro-electro-mechanical system (MEMS) sensors. The system is designed under the inner loop and outer loop strategy. The trajectory tracking navigation loop is the outer loop of the attitude loop, while the attitude control loop is the outer loop of the stabilization loop. The proportional-integral-derivative (PID) control was adopted for stabilization and attitude control. The three-dimensional (3D) trajectory tracking control of a UAV could be approximately divided into lateral control and longitudinal control. The longitudinal control employs traditional linear PID feedback to achieve the desired altitude of the UAV, while the lateral control uses a non-linear control method to complete the desired trajectory. The non-linear controller can automatically adapt to ground velocity change, which is usually caused by gust disturbance, thus the UAV has good wind resistance characteristics. Flight tests and survey missions were carried out with our self-developed delta fixed-wing UAV and MEMS-based autopilot to confirm the effectiveness and practicality of the proposed navigation method.

  4. Control and navigation system for a fixed-wing unmanned aerial vehicle

    Directory of Open Access Journals (Sweden)

    Ruiyong Zhai

    2014-02-01

    Full Text Available This paper presents a flight control and navigation system for a fixed-wing unmanned aerial vehicle (UAV with low-cost micro-electro-mechanical system (MEMS sensors. The system is designed under the inner loop and outer loop strategy. The trajectory tracking navigation loop is the outer loop of the attitude loop, while the attitude control loop is the outer loop of the stabilization loop. The proportional-integral-derivative (PID control was adopted for stabilization and attitude control. The three-dimensional (3D trajectory tracking control of a UAV could be approximately divided into lateral control and longitudinal control. The longitudinal control employs traditional linear PID feedback to achieve the desired altitude of the UAV, while the lateral control uses a non-linear control method to complete the desired trajectory. The non-linear controller can automatically adapt to ground velocity change, which is usually caused by gust disturbance, thus the UAV has good wind resistance characteristics. Flight tests and survey missions were carried out with our self-developed delta fixed-wing UAV and MEMS-based autopilot to confirm the effectiveness and practicality of the proposed navigation method.

  5. The effects of corrugation and wing planform on the aerodynamic force production of sweeping model insect wings

    Institute of Scientific and Technical Information of China (English)

    Guoyu Luo; Mao Sun

    2005-01-01

    The effects of corrugation and wing planform (shape and aspect ratio) on the aerodynamic force production of model insect wings in sweeping (rotating after an initial start) motion at Reynolds number 200 and 3500 at angle of attack 40° are investigated, using the method of computational fluid dynamics. A representative wing corrugation is considered. Wing-shape and aspect ratio (AR) of ten representative insect wings are considered; they are the wings of fruit fly, cranefly, dronefly, hoverfly, ladybird, bumblebee, honeybee, lacewing (forewing), hawkmoth and dragonfly (forewing), respectively (AR of these wings varies greatly,from 2.84 to 5.45). The following facts are shown.(1) The corrugated and flat-plate wings produce approximately the same aerodynamic forces. This is because for a sweeping wing at large angle of attack, the length scale of the corrugation is much smaller than the size of the separated flow region or the size of the leading edge vortex (LEV). (2) The variation in wing shape can have considerable effects on the aerodynamic force; but it has only minor effects on the force coefficients when the velocity at r2 (the radius of the second moment of wing area) is used as the reference velocity; i.e.the force coefficients are almost unaffected by the variation in wing shape. (3) The effects of AR are remarkably small:when AR increases from 2.8 to 5.5, the force coefficients vary only slightly; flowfield results show that when AR is relatively large, the part of the LEV on the outer part of the wings sheds during the sweeping motion. As AR is increased, on one hand,the force coefficients will be increased due to the reduction of 3-dimensional flow effects; on the other hand, they will be decreased due to the shedding of pan of the LEV; these two effects approximately cancel each other, resulting in only minor change of the force coefficients.

  6. Analysis and Flexible Structural Modeling for Oscillating Wing Utilizing Aeroelasticity

    Institute of Scientific and Technical Information of China (English)

    Shao Ke; Wu Zhigang; Yang Chao

    2008-01-01

    Making use of modal characteristics of the natural vibration of flexible structure to design the oscillating wing aircraft is proposed.A series of equations concerning the oscillating wing of flexible structures are derived. The kinetic equation for aerodynamic force coupled with elastic movement is set up, and relevant formulae are derived. The unsteady aerodynamic one in that formulae is revised. The design principle, design process and range of application of such oscillating wing analytical method are elaborated. A flexible structural oscillating wing model is set up, and relevant time response analysis and frequency response analysis are conducted. The analytical results indicate that adopting the new-type driving way for the oscillating wing will not have flutter problems and will be able to produce propulsive force. Furthermore, it will consume much less power than the fixed wing for generating the same lift.

  7. Fiber Optic Wing Shape Sensing on NASA's Ikhana UAV

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Ko, William L.; Piazza, Anthony

    2008-01-01

    This document discusses the development of fiber optic wing shape sensing on NASA's Ikhana vehicle. The Dryden Flight Research Center's Aerostructures Branch initiated fiber-optic instrumentation development efforts in the mid-1990s. Motivated by a failure to control wing dihedral resulting in a mishap with the Helios aircraft, new wing displacement techniques were developed. Research objectives for Ikhana included validating fiber optic sensor measurements and real-time wing shape sensing predictions; the validation of fiber optic mathematical models and design tools; assessing technical viability and, if applicable, developing methodology and approaches to incorporate wing shape measurements within the vehicle flight control system; and, developing and flight validating approaches to perform active wing shape control using conventional control surfaces and active material concepts.

  8. Compound Wing Vertical Takeoff and Landing Small Unmanned Aircraft System

    Science.gov (United States)

    Logan, Michael J. (Inventor); Motter, Mark A. (Inventor); Deloach, Richard (Inventor); Vranas, Thomas L. (Inventor); Prendergast, Joseph M. (Inventor); Lipp, Brittney N. (Inventor)

    2017-01-01

    Systems, methods, and devices are provided that enable robust operations of a small unmanned aircraft system (sUAS) using a compound wing. The various embodiments may provide a sUAS with vertical takeoff and landing capability, long endurance, and the capability to operate in adverse environmental conditions. In the various embodiments a sUAS may include a fuselage and a compound wing comprising a fixed portion coupled to the fuselage, a wing lifting portion outboard of the fixed portion comprising a rigid cross member and a controllable articulating portion configured to rotate controllable through a range of motion from a horizontal position to a vertical position, and a freely rotating wing portion outboard of the wing lifting portion and configured to rotate freely based on wind forces incident on the freely rotating wing portion.

  9. Video measurements of instantaneous forces of flapping wing vehicles

    Science.gov (United States)

    Jennings, Alan; Mayhew, Michael; Black, Jonathan

    2015-12-01

    Flapping wings for small aerial vehicles have revolutionary potential for maneuverability and endurance. Ornithopters fail to achieve the performance of their biological equivalents, despite extensive research on how animals fly. Flapping wings produce peak forces due to the stroke reversal of the wing. This research demonstrates in-flight measurements of an ornithopter through the use of image processing, specifically measuring instantaneous forces. Results show that the oscillation about the flight path is significant, being about 20% of the mean velocity and up to 10 g's. Results match forces with deformations of the wing to contrast the timing and wing shape of the upstroke and the downstroke. Holding the vehicle fixed (e.g. wind tunnel testing or simulations) structural resonance is affected along with peak forces, also affecting lift. Non-contact, in-flight measurements are proposed as the best method for matching the flight conditions of flapping wing vehicles.

  10. Vortex Interaction on Low Aspect Ratio Membrane Wings

    Science.gov (United States)

    Waldman, Rye M.; Breuer, Kenneth S.

    2013-11-01

    Inspired by the flight of bats and by recent interest in Micro Air Vehicles, we present measurements on the steady and unsteady behavior of low aspect ratio membrane wings. We conduct wind tunnel experiments with coupled force, kinematic, and flow field measurements, both on the wing and in the near wake. Membrane wings interact strongly with the vortices shed from the leading- and trailing-edges and the wing tips, and the details of the membrane support play an important role in the fluid-structure interaction. Membranes that are supported at the wing tip exhibit less membrane flutter, more coherent tip vortices, and enhanced lift. The interior wake can exhibit organized spanwise vortex shedding, and shows little influence from the tip vortex. In contrast, membranes with an unsupported wing tip show exaggerated static deformation, significant membrane fluttering and a diffuse, unsteady tip vortex. The unsteady tip vortex modifies the behavior of the interior wake, disrupting the wake coherence.

  11. Simplifying a wing: diversity and functional consequences of digital joint reduction in bat wings.

    Science.gov (United States)

    Bahlman, Joseph W; Price-Waldman, Rosalyn M; Lippe, Hannah W; Breuer, Kenneth S; Swartz, Sharon M

    2016-07-01

    Bat wings, like other mammalian forelimbs, contain many joints within the digits. These joints collectively affect dynamic three-dimensional (3D) wing shape, thereby affecting the amount of aerodynamic force a wing can generate. Bats are a speciose group, and show substantial variation in the number of wing joints. Additionally, some bat species have joints with extensor but no flexor muscles. While several studies have examined the diversity in number of joints and presence of muscles, musculoskeletal variation in the digits has not been interpreted in phylogenetic, functional or ecological contexts. To provide this context, the number of joints and the presence/absence of muscles are quantified for 44 bat species, and are mapped phylogenetically. It is shown that, relative to the ancestral state, joints and muscles were lost multiple times from different digits and in many lineages. It is also shown that joints lacking flexors undergo cyclical flexion and extension, in a manner similar to that observed in joints with both flexors and extensors. Comparison of species with contrasting feeding ecologies demonstrates that species that feed primarily on non-mobile food (e.g. fruit) have fewer fully active joints than species that catch mobile prey (e.g. insects). It is hypothesized that there is a functional trade-off between energetic savings and maneuverability. Having fewer joints and muscles reduces the mass of the wing, thereby reducing the energetic requirements of flapping flight, and having more joints increases the assortment of possible 3D wing shapes, thereby enhancing the range and fine control of aerodynamic force production and thus maneuverability.

  12. Incompressible Turbulent Wing-Body Junction Flow

    Science.gov (United States)

    Krishnamurthy, R.; Cagle, Corey D.; Chandra, S.

    1998-01-01

    The overall objective of this study is to contribute to the optimized design of fan bypass systems in advanced turbofan engines. Increasing the engine bypass ratios have provided a major boost in engine performance improvement over the last fifty years. An engine with high bypass ratio (11-16:1) such as the Advanced Ducted Propulsion (ADP) is being developed and is expected to provide an additional 25% improvement in overall efficiency over the early turbofans. Such significant improvements in overall efficiency would reduce the cost per seat mile, which is a major government and Industry challenge for the 21th century. The research is part of the Advanced Subsonic Technology (AST) program that involves a NASA, U.S. Industry and FAA partnership with the goal of a safe and highly productive global air transportation system. The immediate objective of the study is to perform numerical simulation of duct-strut interactions to elucidate the loss mechanisms associated with this configuration that is typical of advanced turbofan engines such as ADP. However, at present experimental data for a duct-strut configuration are not available. Thus, as a first step a wing-body junction flow would be studied and is the specific objective of the present study. At the outset it is to be recognized that while duct-strut interaction flow is similar to that of wing-body junction flows, there are some differences owing to the presence of a wall at both ends of the strut. Likewise, some differences are due to the sheared inflow (as opposed to a uniform inflow) velocity profile. It is however expected that some features of a wing-body junction flow would persist. Next, some of the salient aspects of the complex flow near a wing-body junction, as revealed by various studies reported in the literature will be reviewed. One of the principle characteristics of the juncture flow, is the presence of the mean flow components in a plane perpendicular to the direction of the oncoming free

  13. Electromagnetic excitation of the Delta(1232) resonance

    Energy Technology Data Exchange (ETDEWEB)

    V. Pascalutsa; M. Vanderhaeghen; Shin Nan Yang

    2006-09-05

    We review the description of the lowest-energy nucleon excitation--the Delta(1232)-resonance. Much of the recent effort has been focused on the precision measurements of the nucleon to Delta transition by means of electromagnetic probes. We review the results of those measurements and confront them with the state-of-the-art calculations based on chiral effective-field theories (EFT), lattice QCD, and QCD-inspired models. Some of the theoretical approaches are reviewed in detail. In particular, we describe the chiral EFT of QCD in the energy domain of the Delta-resonance, and its applications to the electromagnetic nucleon-to-Delta transition (gamma N Delta). We also describe the recent dynamical and unitary-isobar models of pion electroproduction which are extensively used in the extraction of the gamma* N Delta form factors from experiment. Furthermore, we discuss the link of the gamma* N Delta form factors to generalized parton distributions (GPDs), as well as the predictions of perturbative QCD for these transition form factors. The present status of understanding the Delta-resonance properties and the nature of its excitation is summarized.

  14. Structure and replication of hepatitis delta virus

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... Unidade de Biologia Molecular, Centro de Malária e outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, ... molecules of both delta antigens (Ryu et al., 1993). This ..... Glenn JS, Watson JA, Havel CM, White JO (1992). ... HDV RNA encoding the large delta antigen cannot replicate. J. Gen.

  15. Generalised CP and $\\Delta (96)$ Family Symmetry

    CERN Document Server

    Ding, Gui-Jun

    2014-01-01

    We perform a comprehensive study of the $\\Delta (96)$ family symmetry combined with the generalised CP symmetry $H_{\\rm{CP}}$. We investigate the lepton mixing parameters which can be obtained from the original symmetry $\\Delta (96)\\rtimes H_{\\rm{CP}}$ breaking to different remnant symmetries in the neutrino and charged lepton sectors, namely $G_{\

  16. Delta Blues Scholarship and Imperialist Nostalgia.

    Science.gov (United States)

    Nye, William P.

    When Delta blues are considered to be "folk music," the genre is inextricably tied to the neocolonial, sharecropping system of cotton production characteristic of the Mississippi Delta region between the Civil War and World War II. "Imperialist nostalgia," then, arises in accounts which pay primary and positive tribute to blues…

  17. The delta opioid receptor tool box.

    Science.gov (United States)

    Vicente-Sanchez, Ana; Segura, Laura; Pradhan, Amynah A

    2016-12-03

    In recent years, the delta opioid receptor has attracted increasing interest as a target for the treatment of chronic pain and emotional disorders. Due to their therapeutic potential, numerous tools have been developed to study the delta opioid receptor from both a molecular and a functional perspective. This review summarizes the most commonly available tools, with an emphasis on their use and limitations. Here, we describe (1) the cell-based assays used to study the delta opioid receptor. (2) The features of several delta opioid receptor ligands, including peptide and non-peptide drugs. (3) The existing approaches to detect delta opioid receptors in fixed tissue, and debates that surround these techniques. (4) Behavioral assays used to study the in vivo effects of delta opioid receptor agonists; including locomotor stimulation and convulsions that are induced by some ligands, but not others. (5) The characterization of genetically modified mice used specifically to study the delta opioid receptor. Overall, this review aims to provide a guideline for the use of these tools with the final goal of increasing our understanding of delta opioid receptor physiology.

  18. Winging of scapula due to serratus anterior tear

    Institute of Scientific and Technical Information of China (English)

    Varun Kumar Singh; Gauresh Shantaram Vargaonkar

    2014-01-01

    Winging of scapula occurs most commonly due to injury to long thoracic nerve supplying serratus anterior muscle.Traumatic injury to serratus anterior muscle itself is very rare.We reported a case of traumatic winging of scapula due to tear of serratus anterior muscle in a 19-year-old male.Winging was present in neutral position and in extension of right shoulder joint but not on "push on wall" test.Patient was managed conservatively and achieved satisfactory result.

  19. The aerodynamic and structural study of flapping wing vehicles

    OpenAIRE

    2013-01-01

    This thesis reports on the aerodynamic and structural study carried out on flapping wings and flapping vehicles. Theoretical and experimental investigation of aerodynamic forces acting on flapping wings in simple harmonic oscillations is undertaken in order to help conduct and optimize the aerodynamic and structural design of flapping wing vehicles. The research is focused on the large scale ornithopter design of similar size and configuration to a hang glider. By means of Theodorsen’s th...

  20. Wing shape of dengue vectors from around the world

    OpenAIRE

    Henry, A; Thongsripong, P.; Fonseca-Gonzalez, I.; Jaramillo-Ocampo, N.; Dujardin, Jean-Pierre

    2010-01-01

    Wing shape is increasingly utilized in species identification and characterization. For dengue vectors Aedes aegypti and Aedes albopictus, it could be used as a complement for ensuring accurate diagnostic of damaged specimens. However, the impact of world migration on wing shape is unknown. Has the spread of these invasive species increased shape variation to the extent of producing interspecific overlapping? To answer this question, the geometric patterns of wing venation in Ae. aegypti and ...

  1. Entendiendo Delta desde las Humanidades

    Directory of Open Access Journals (Sweden)

    José Calvo Tello

    2016-05-01

    Full Text Available Stylometry is one of the research areas in greater development within Digital Humanities. However, few studies have worked until recently with texts in Spanish and even less so from Spanish-speaking countries. The aim of this paper is to present in Spanish, and without prior statistical knowledge from the reader, one of the main methods used in stylometry, the measure of textual distance Burrows’ Delta. This paper explains this measure using a very small corpus of proverbs and then checks the results in a corpus of Spanish novels. Both data and Python scripts are available to the community through GitHub, commented step by step so that you can play and visualize each step.

  2. Jiaxing: Delicacy of the Yangtze River Delta

    Institute of Scientific and Technical Information of China (English)

    WUXINYI; WANGNAN

    2004-01-01

    THE yangtze River Delta,where the Yangtzc River crosses China's east coast,has one of the country's most dynamic economies.In 1976Jcan Gottmann.a french geographer,called shanghai and its neighboring Yangtze River Delta the world's "sixth largest megalopolis." The Yangtze River Delta has 15 cities. Its territory accounts for one percent of China's total, 5.8 percent of hthe population, and 19.5 percent of the national GDP.In terms of both aggregate economy and growth speed, the Delta currently leads China and could likely be the "enginc" of the world's future economic growth. Located at the juncition of Shanghai Jiangsu and Zhejiang, Jiaxing City holds a central economic belt. It is within 100 kilometers of Shanghai, Hangzhou and Suzhou. In 200 and 2003, Jiaxing's GDP growth rate was first in Zhejiang Province and second among the 1.5 Delta cities.

  3. Sea level variabilities in the Gulf Stream between Cape Hatteras and 50 deg W - A Geosat study

    Science.gov (United States)

    Vazquez, Jorge; Zlotnicki, Victor; Fu, Lee-Lueng

    1990-01-01

    Sea level variabilities in the Gulf Stream between Cape Hatteras and 50 deg W were examined by studying sea level residuals, relative to a 2-yr mean sea level, obtained from Geosat altimetry data for the period between November 1986 and December 1988. An array of sea-level time series was constructed for a region bounded by 30 deg N and 45 deg N in latitude and by 80 deg W and 50 deg W longitude. It is shown that the spectral characteristics of this time series varies with geographic location along the Gulf Stream path. Concurrent NOAA IR images are used to aid in the interpretation of sea level observations in terms of the variability of the stream's path, demonstrating the synergistic value of the combination of satellite-altimeter and IR data.

  4. Creep crack growth in a reactor pressure vessel steel at 360 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Rui Wu; Seitisleam, F.; Sandstroem, R. [Swedish Institute for Metals Research, Stockholm (Sweden)

    1998-12-31

    Plain creep (PC) and creep crack growth (CCG) tests at 360 deg C and post metallography were carried out on a low alloy reactor pressure vessel steel (ASTM A508 class 2) with different microstructures. Lives for the CCG tests were shorter than those for the PC tests and this is more pronounced for simulated heat affected zone microstructure than for the parent metal at longer lives. For the CCG tests, after initiation, the cracks grew constantly and intergranularly before they accelerated to approach rupture. The creep crack growth rate is well described by C*. The relations between reference stress, failure time and steady crack growth rate are presented for the CCG tests. It is demonstrated that the failure stress due to CCG is considerably lower than the yield stress at 360 deg C. Consequently, the CCG will control the static strength of a reactor vessel. (orig.) 17 refs.

  5. The first winter solstice observed at the meridian line of Santa Maria degli Angeli in Rome

    CERN Document Server

    Sigismondi, Costantino

    2014-01-01

    The page written by the astronomer Francesco Bianchini (1662-1729) and containing the data of the 1701 winter solstice observed at Santa Maria degli Angeli is presented for the first time in figure 2 and widely discussed along this paper. The great meridian line in the Basilica of Santa Maria degli Angeli in Rome was built in 1701/1702 with the scope to measure the Obliquity of the Earth's orbit in the following eight centuries, upon the will of pope Clement XI. During the winter solstice of 1701 the first measurements of the obliquity have been realized by Francesco Bianchini, the astronomer who designed the meridian line, upgrading the similar instrument realized by Giandomenico Cassini in San Petronio, Bononia. In this paper the accuracy of the data observed by Francesco Bianchini is discussed and compared with up-to-date ephemerides. The modern situation of this historical instrument is also presented.

  6. Isothermal section at 1400 deg. C of the Ti-Zr-Sn system

    Energy Technology Data Exchange (ETDEWEB)

    Saltykov, V.A. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)], E-mail: ssaltykov@ipms.kiev.ua; Meleshevich, K.A.; Samelyuk, A.V.; Verbytska, O.M.; Bulanova, M.V. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)

    2008-07-14

    By the methods of X-ray diffraction, metallography and microprobe examinations the character of phase equilibria at 1400 deg. C is studied for the Ti-(Ti,Zr){sub 5}Sn{sub 3}-Zr region of the Ti-Zr-Sn system. The isothermal section at 1400 deg. C is constructed. This is similar to the solidus surface and is characterized by two 3-phase regions: <{beta}Ti,Zr> + Ti{sub 3}Sn + (Ti,Zr){sub 5}Sn{sub 3} and Ti{sub 3}Sn + Ti{sub 2}Sn + (Ti,Zr){sub 5}Sn{sub 3}. Solubility of Sn in <{beta}Ti,Zr> solid solution is between 10 and 15 at.% Sn. Solubility of zirconium in Ti{sub 3}Sn is about 12 at.%.

  7. Iron oxidation kinetics study by using infrared spectral emissivity measurements below 570deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Campo, Leire del [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologi' a, Universidad del Pai' s Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Perez-Saez, Raul B. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologi' a, Universidad del Pai' s Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)], E-mail: raul.perez@ehu.es; Tello, Manuel J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologi' a, Universidad del Pai' s Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)

    2008-01-15

    The oxidation kinetics of iron below 570deg. C is investigated through the dependence of the spectral emissivity on the surface oxidation state. Using the theory of radiative effects of thin films, the oxide scale thickness is obtained as a function of time. A parabolic growth has been observed in all the cases, and applying Wagner's theory, the oxidation parabolic rate constants have been calculated at four temperatures. The temperature dependence of these results has additionally been used to obtain the activation energy of the oxidation process in iron. The parabolic rate constants and activation energy values are in good agreement with the theoretical predictions, and this suggests that the lattice diffusion mechanisms for the high temperature magnetite growth also occur until 400deg. C. The experimental results are also useful to test the applicability of emissivity measurements for in situ oxidation kinetics studies in the spectral range where the scales are optically thin.

  8. Millimeter and sub-millimeter heterodyne mixing based on 2DEG hot-electron bolometers

    Science.gov (United States)

    Wang, Kai; Bell, Matthew; Ramaswamy, Rahul; Sergeev, Andrei; Strasser, Gottfried; Mitin, Vladimir

    2010-03-01

    We investigate GHz and THz heterodyne mixer based on the electron heating effect of a two-dimensional electron gas (2DEG) by electromagnetic radiation at liquid nitrogen temperatures (77K). The devices are fabricated from AlGaAs/GaAs heterostructures with a channel width of 150 μm and lengths varying from 3-20 μm. Steady-state measurements are used to investigate electron heating in these devices and determine basic parameters, such as electron-phonon energy relaxation time and electron heat capacity. We perform mixing experiments at ˜100 GHz frequency range with two Gunn diodes as the radiation sources, and find that electron heating is the primary mixing mechanism at these frequencies. For the mixing experiments at ˜ 2 terahertz range, a quantum cascade laser (QCL) is employed as the local oscillator. To optimize our device, we also investigate electron kinetics and transport properties in the 2DEG hot-electron bolometer.

  9. Investigation and design of a C-Wing passenger aircraft

    Directory of Open Access Journals (Sweden)

    Karan BIKKANNAVAR

    2016-06-01

    Full Text Available A novel nonplanar wing concept called C-Wing is studied and implemented on a commercial aircraft to reduce induced drag which has a significant effect on fuel consumption. A preliminary sizing method which employs an optimization algorithm is utilized. The Airbus A320 aircraft is used as a reference aircraft to evaluate design parameters and to investigate the C-Wing design potential beyond current wing tip designs. An increase in aspect ratio due to wing area reduction at 36m span results in a reduction of required fuel mass by 16%. Also take-off mass savings were obtained for the aircraft with C-Wing configuration. The effect of a variations of height to span ratio (h/b of C-Wings on induced drag factor k, is formulated from a vortex lattice method and literature based equations. Finally the DOC costing methods used by the Association of European Airlines (AEA was applied to the existing A320 aircraft and to the C-Wing configuration obtaining a reduction of 6% in Direct Operating Costs (DOC for the novel concept resulted. From overall outcomes, the C-Wing concept suggests interesting aerodynamic efficiency and stability benefits.

  10. Technicians prepare the inflatable wing on Paresev 1-C

    Science.gov (United States)

    1963-01-01

    This photo shows the Paresev (Paraglider Research Vehicle) space frame receiving a new wing. Frank Fedor and a technician helper are attaching a half-scale version of an inflatable wing in a hangar at NASA Flight Research Center at Edwards, California. The Paresev in this configuration was called the 1-C and was expected to closely approximate the aerodynamic characteristics that would be encountered with the Gemini space capsule with a parawing extended. The whole wing was not inflatable; the three chambers that acted as spars and supported the wing inflated.

  11. Aeroelastic Deformation and Buckling of Inflatable Wings under Dynamic Loads

    Science.gov (United States)

    Simpson, Andrew; Smith, Suzanne; Jacob, Jamey

    2006-11-01

    Inflatable wings have recently been used to control a vehicle in flight via wing warping. Internal pressure is required to maintain wing shape and externally mounted mechanical actuators are used to asynchronously deform the wing semi-spans for control. Since the rigidity of the inflatable wing varies as a function of inflation pressure, there is a need to relate the wing shape with aerodynamic loads. Via wind tunnel tests, span-wise deformations, twist and flutter have been observed under certain dynamic loading conditions. Photogrammetry techniques are used to measure the static aeroelastic deformation of the wings and videogrammetry is used to examine the dynamic shape changes (flutter). The resulting shapes can be used to determine corresponding aerodynamic characteristics. For particular inflation pressures, buckling can be induced at sufficiently high dynamic loads either through high dynamic pressure or large angle of attack. This results in a set of critical loading parameters. An inflatable winged vehicle would require operation within these limits. The focus of the presentation will be on defining and exploring the unsuitable operating conditions and the effects these conditions have on the operation of the wing.

  12. Embedded Fiber Optic Shape Sensing for Aeroelastic Wing Components Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As the aerospace industry continues to push for greater vehicle efficiency, performance, and longevity, properties of wing aeroelasticity and flight dynamics have...

  13. Design, Fabrication and Testing Of Flapping Wing Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    K. P. Preethi Manohari Sai

    2016-01-01

    Full Text Available Flapping flight has the potential to revolutionize micro air vehicles (MAVs due to increased aerodynamic performance, improved maneuverability and hover capabilities. The purpose of this project is to design and fabrication of flapping wing micro air vehicle. The designed MAV will have a wing span of 40cm. The drive mechanism will be a gear mechanism to drive the flapping wing MAV, along with one actuator. Initially, a preliminary design of flapping wing MAV is drawn and necessary calculation for the lift calculation has been done. Later a CAD model is drawn in CATIA V5 software. Finally we tested by Flying.

  14. MEMS wing technology for a battery-powered ornithopter

    OpenAIRE

    2000-01-01

    The objective of this project is to develop a battery-powered ornithopter (flapping-wing) Micro Aerial Vehicle (MAV) with MEMS wings. In this paper, we present a novel MEMS-based wing technology that we developed using titanium-alloy metal as wingframe and parylene C as wing membrane. MEMS technology enables systematic research in terms of repeatablility, size control, and weight minimization. We constructed a high quality low-speed wind tunnel with velocity uniformity of 0.5% and speeds from...

  15. Experimental investigations of the functional morphology of dragonfly wings

    Institute of Scientific and Technical Information of China (English)

    H.Rajabi; A.Darvizeh

    2013-01-01

    Nowadays,the importance of identifying the flight mechanisms of the dragonfly,as an inspiration for designing flapping wing vehicles,is well known.An experimental approach to understanding the complexities of insect wings as organs of flight could provide significant outcomes for design purposes.In this paper,a comprehensive investigation is carried out on the morphological and microstructural features of dragonfly wings.Scanning electron microscopy (SEM) and tensile testing are used to experimentally verify the functional roles of different parts of the wings.A number of SEM images of the elements of the wings,such as the nodus,leading edge,trailing edge,and vein sections,which play dominant roles in strengthening the whole structure,are presented.The results from the tensile tests indicate that the nodus might be the critical region of the wing that is subjected to high tensile stresses.Considering the patterns of the longitudinal corrugations of the wings obtained in this paper,it can be supposed that they increase the load-bearing capacity,giving the wings an ability to tolerate dynamic loading conditions.In addition,it is suggested that the longitudinal veins,along with the leading and trailing edges,are structural mechanisms that further improve fatigue resistance by providing higher fracture toughness,preventing crack propagation,and allowing the wings to sustain a significant amount of damage without loss of strength.

  16. Complexity analyses of multi-wing chaotic systems

    Institute of Scientific and Technical Information of China (English)

    He Shao-Bo; Sun Ke-Hui; Zhu Cong-Xu

    2013-01-01

    The complexities of multi-wing chaotic systems based on the modified Chen system and a multi-segment quadratic function are investigated by employing the statistical complexity measure (SCM) and the spectral entropy (SE) algorithm.How to choose the parameters of the SCM and SE algorithms is discussed.The results show that the complexity of the multi-wing chaotic system does not increase as the number of wings increases,and it is consistent with the results of the Grassberger-Procaccia (GP) algorithm and the largest Lyapunov exponent (LLE) of the multi-wing chaotic system.

  17. Complexity analyses of multi-wing chaotic systems

    Science.gov (United States)

    He, Shao-Bo; Sun, Ke-Hui; Zhu, Cong-Xu

    2013-05-01

    The complexities of multi-wing chaotic systems based on the modified Chen system and a multi-segment quadratic function are investigated by employing the statistical complexity measure (SCM) and the spectral entropy (SE) algorithm. How to choose the parameters of the SCM and SE algorithms is discussed. The results show that the complexity of the multi-wing chaotic system does not increase as the number of wings increases, and it is consistent with the results of the Grassberger—Procaccia (GP) algorithm and the largest Lyapunov exponent (LLE) of the multi-wing chaotic system.

  18. PUMA-PUblication MAnagement: sistemi per la gestione delle pubblicazioni degli enti di ricerca

    OpenAIRE

    Biagioni, Stefania

    2005-01-01

    Lo scopo di questa presentazione ? quello di illustrare i) come ? stato realizzato un ciclo gestionale completo dell'informazione: dall'inserimento dei metadati e dei documenti digitali alla restituzione degli stessi all'utente finale; ii) come sono stati resi accessibili via web, a livelli diversi e secondo viste diverse l'informazione prodotta; iii) come siano stati creati servizi differenti utilizzando gli stessi oggetti. Vengono illustrati i sistemi utilizzati presso il CNR di Pisa per la...

  19. Proteomica degli exosomi urinari per la ricerca di biomarcatori nella nefropatia diabetica e nelle tubulopatie ereditarie

    OpenAIRE

    Corbetta,

    2015-01-01

    Le urine costituiscono il fluido biologico di elezione nella ricerca di biomarcatori per le patologie renali in quanto possono essere raccolte in modo semplice e non invasivo; una strategia per la semplificazione del proteoma urinario è rappresentata dall’isolamento degli exosomi urinari (UE), nanovescicole di membrana (30-100 nm) rilasciate dalle cellule epiteliali nello spazio urinario. In questo lavoro abbiamo focalizzato l’attenzione sulla nefropatia diabetica (DN), una comune complicazio...

  20. Observation of Polar Mesosphere Summer Echoes using the Northernmost MST Radar at Eureka (80 deg N)

    Science.gov (United States)

    Swarnalingam, N.; Hocking, W.; Janches, D.; Drummond, J.

    2017-01-01

    We investigate long-term Polar Mesosphere Summer Echoes (PMSEs) observations conducted by the northern most geographically located MST radar at Eureka (80 deg N, 86 deg W). While PMSEs are a well recognized summer phenomenon in the polar regions, previous calibrated studies at Resolute Bay and Eureka using 51.5 MHz and33 MHz radars respectively, showed that PMSE backscatter signal strengths are relatively weak in the polar cap sites, compared to the auroral zone sites (Swarnalingam et al., 2009b; Singer et al., 2010). Complications arise with PMSEs in which the echo strength is controlled by the electrons, which are, in turn, influenced by heavily charged ice particles as well as the variability in the D-region plasma. In recent years, PMSE experiments were conducted inside the polar cap utilizing a 51 MHz radar located at Eureka. In this paper, we investigate calibrated observations, conducted during 2009-2015. Seasonal and diurnal variations of the backscatter signal strengths are discussed and compared to previously published results from the ALOMAR radar, which is a radar of similar design located in the auroral zone at Andenes, Norway (69 deg N, 16 deg E). At Eureka, while PMSEs are present with a daily occurrence rate which is comparable to the rate observed at the auroral zone site for at least two seasons, they show a great level of inter-annual variability. The occurrence rate for the strong echoes tends to be low. Furthermore, comparison of the absolute backscatter signal strengths at these two sites clearly indicates that the PMSE backscatter signal strength at Eureka is weak. Although this difference could be caused by several factors, we investigate the intensity of the neutral air turbulence at Eureka from the measurements of the Doppler spectrum of the PMSE backscatter signals. We found that the level of the turbulence intensity at Eureka is weak relative to previously reported results from three high latitude sites.

  1. Survey of the sky at the 8. 7 and 14. 4 GHz frequencies in the 0 deg - 4 deg declination range

    Energy Technology Data Exchange (ETDEWEB)

    Amirkhanyan, V.R.; Gorshkov, A.G.; Kapustkin, A.A.; Konnikova, V.K.; Lazutkin, A.N.; Larionov, M.G.; Nikanorov, A.S.; Sidorenkov, V.N.; Ugol' kova, L.S.; Khromov, O.I. (Moskovskij Gosudarstvennyj Univ. (USSR). Gosudarstvennyj Astronomicheskij Inst. ' ' GAISh' ' )

    Using the RATAN-600 radiotelescope of the USSR Academy of Sciences (from March 1979 to January 1980) the sky is observed at the 8.7 and 14.4 GHz frequencies in the 0-4 deg declination range. Lists of 82 and 24 radiosources detected at the given frequencies are presented. Six radiosources are detected for the first time. Right ascension and declination, as well as the maximum values of radio-frequency radiation fluxes are given. The problems of measuring accuracies of fluxes and coordinates and the problem of validity of detected radiosources are discussed. On the basis of comparison of the data obtained with those in other works the systematic deviation in fluxes of sources is not more than 7%.

  2. Submillimeter wavelength survey of the galactic plane from l = -5 deg to l = +62 deg - Structure and energetics of the inner disk

    Science.gov (United States)

    Hauser, M. G.; Silverberg, R. F.; Stier, M. T.; Kelsall, T.; Gezari, D. Y.; Dwek, E.; Walser, D.; Mather, J. C.; Cheung, L. H.

    1984-01-01

    Observational results are presented from a new large-scale survey of the first quadrant of the galactic plane at wavelengths of 150, 250, and 300 microns, with a 10 x 10 arcmin beam. The emission detected in the survey arises from compact sources, most of which are identified with known peaks of 5 GHz or CO emission, or both, and from an underlying diffuse background with a typical angular width of about 0.9 deg (FWHM) which accounts for most of the emission. A total of 80 prominent discrete sources are identified and characterized, of which about half have not previously been reported at far-infrared wavelengths. The total infrared luminosity within the solar circle is about 1 to 2 x 10 to the 10th solar luminosity, and is probably emitted by dust that resides in molecular clouds.

  3. Submillimeter wavelength survey of the galactic plane from l = -5 deg to l = +62 deg: Structure and energetics of the inner disk

    Science.gov (United States)

    Hauser, M. G.; Silverberg, R. F.; Stier, M. T.; Kelsall, T.; Gezari, D. Y.; Dwek, E.; Walser, D.; Mather, J. C.; Cheung, L. H.

    1984-01-01

    Results from a large scale survey of the first quadrant of the Milky Way galactic plane at wavelengths of 150, 250, and 300 microns with a 10x10 arcmin beam are presented. The emission detected in the survey arises from compact sources, most of which are identified with known peaks of 5 GHz and/or CO emission, and from an underlying diffuse background with a typical angular width of approximately 0.9 deg (FWHM) which accounts for most of the emission. A total of 80 prominent discrete sources were identified and characterized, of which about half were not previously reported at far infrared wavelengths. The total infrared luminosity within the solar circle is approximately 1 to 2x10 to the 10th power L sub 0, and is probably emitted by dust that resides in molecular clouds.

  4. Prediction of span loading of straight-wing/propeller combinations up to stall. [propeller slipstreams and wing loading

    Science.gov (United States)

    Mcveigh, M. A.; Gray, L.; Kisielowski, E.

    1975-01-01

    A method is presented for calculating the spanwise lift distribution on straight-wing/propeller combinations. The method combines a modified form of the Prandtl wing theory with a realistic representation of the propeller slipstream distribution. The slipstream analysis permits calculations of the nonuniform axial and rotational slipstream velocity field of propeller/nacelle combinations. This nonuniform field was then used to calculate the wing lift distribution by means of the modified Prandtl wing theory. The theory was developed for any number of nonoverlapping propellers, on a wing with partial or full-span flaps, and is applicable throughout an aspect ratio range from 2.0 and higher. A computer program was used to calculate slipstream characteristics and wing span load distributions for a number of configurations for which experimental data are available, and favorable comparisons are demonstrated between the theoretical predictions and the existing data.

  5. submitter Technical Note: Using DEG-CPCs at upper tropospheric temperatures

    CERN Document Server

    Wimmer, D; Nieminen, T; Duplissy, J; Ehrhart, S; Almeida, J; Rondo, L; Franchin, A; Kreissl, F; Bianchi, F; Manninen, H E; Kulmala, M; Curtius, J; Petäjä, T

    2015-01-01

    Over the last few years, several condensation particle counters (CPCs) capable of measuring in the sub-3 nm size range have been developed. Here we study the performance of CPCs based on diethylene glycol (DEG) at different temperatures during Cosmics Leaving OUtdoor Droplets (CLOUD) measurements at CERN. The data shown here are the first set of verification measurements for sub-3 nm CPCs under upper tropospheric temperatures using atmospherically relevant aerosol particles. To put the results in perspective we calibrated the DEG-CPC at room temperature, resulting in a cut-off diameter of 1.4 nm. All diameters refer to mobility equivalent diameters in this paper. At upper tropospheric temperatures ranging from 246.15 K to 207.15 K, we found cut-off sizes relative to a particle size magnifier in the range of 2.5 to 2.8 nm. Due to low number concentration after size classification, the cut-off diameters have a high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG-CPCs with different c...

  6. Sexy DEG/ENaC channels involved in gustatory detection of fruit fly pheromones.

    Science.gov (United States)

    Pikielny, Claudio W

    2012-11-06

    Hydrocarbon pheromones on the cuticle of Drosophila melanogaster modulate the complex courtship behavior of males. Recently, three members of the degenerin/epithelial Na+ channel (DEG/ENaC) family of sodium channel subunits, Ppk25, Ppk23, and Ppk29 (also known as Nope), have been shown to function in gustatory perception of courtship-modulating contact pheromones. All three proteins are required for the activation of male courtship by female pheromones. Specific interactions between two of them have been demonstrated in cultured cells, suggesting that, in a subset of cells where they are coexpressed, these three subunits function within a common heterotrimeric DEG/ENaC channel. Such a DEG/ENaC channel may be gated by pheromones, either directly or indirectly, or alternatively may control the excitability of pheromone-sensing cells. In addition, these studies identify taste neurons that respond specifically to courtship-modulating pheromones and mediate their effects on male behavior. Two types of pheromone-sensing taste neurons, F and M cells, have been defined on the basis of their specific response to either female or male pheromones. These reports set the stage for the dissection of the molecular and cellular mechanisms that mediate gustatory detection of contact pheromones.

  7. EDD, a novel phosphotransferase domain common to mannose transporter EIIA, dihydroxyacetone kinase, and DegV.

    Science.gov (United States)

    Kinch, Lisa N; Cheek, Sara; Grishin, Nick V

    2005-02-01

    Using a recently developed program (SCOPmap) designed to automatically assign new protein structures to existing evolutionary-based classification schemes, we identify a evolutionarily conserved domain (EDD) common to three different folds: mannose transporter EIIA domain (EIIA-man), dihydroxyacetone kinase (Dak), and DegV. Several lines of evidence support unification of these three folds into a single superfamily: statistically significant sequence similarity detected by PSI-BLAST; "closed structural grouping" using DALI Z-scores (each protein inside a group finds all other group members with scores higher than those to proteins outside the group) that includes only these proteins sharing a unique alpha-helical hairpin at the C-terminus and excludes all other proteins with similar topology; similar domain fusions connect Dak and DegV, and genomic neighborhood organizations connect Dak and EIIA-man. Finally, both Dak and EIIA-man perform similar phosphotransfer reactions, suggesting a phosphotransferase activity for the DegV-like family of proteins, whose function other than lipid binding revealed in the crystal structure remains unknown.

  8. Folding wings like a cockroach: a review of transverse wing folding ensign wasps (Hymenoptera: Evaniidae: Afrevania and Trissevania.

    Directory of Open Access Journals (Sweden)

    István Mikó

    Full Text Available We revise two relatively rare ensign wasp genera, whose species are restricted to Sub-Saharan Africa: Afrevania and Trissevania. Afrevania longipetiolata sp. nov., Trissevania heatherae sp. nov., T. hugoi sp. nov., T. mrimaensis sp. nov. and T. slideri sp. nov. are described, males and females of T. anemotis and Afrevania leroyi are redescribed, and an identification key for Trissevaniini is provided. We argue that Trissevania mrimaensis sp. nov. and T. heatherae sp. nov. populations are vulnerable, given their limited distributions and threats from mining activities in Kenya. We hypothesize that these taxa together comprise a monophyletic lineage, Trissevaniini, tr. nov., the members of which share the ability to fold their fore wings along two intersecting fold lines. Although wing folding of this type has been described for the hind wing of some insects four-plane wing folding of the fore wing has never been documented. The wing folding mechanism and the pattern of wing folds of Trissevaniini is shared only with some cockroach species (Blattodea. It is an interesting coincidence that all evaniids are predators of cockroach eggs. The major wing fold lines of Trissevaniini likely are not homologous to any known longitudinal anatomical structures on the wings of other Evaniidae. Members of the new tribe share the presence of a coupling mechanism between the fore wing and the mesosoma that is composed of a setal patch on the mesosoma and the retinaculum of the fore wing. While the setal patch is an evolutionary novelty, the retinaculum, which originally evolved to facilitate fore and hind wing coupling in Hymenoptera, exemplifies morphological exaptation. We also refine and clarify the Semantic Phenotype approach used in previous taxonomic revisions and explore the consequences of merging new with existing data. The way that semantic statements are formulated can evolve in parallel, alongside improvements to the ontologies themselves.

  9. Folding wings like a cockroach: a review of transverse wing folding ensign wasps (Hymenoptera: Evaniidae: Afrevania and Trissevania).

    Science.gov (United States)

    Mikó, István; Copeland, Robert S; Balhoff, James P; Yoder, Matthew J; Deans, Andrew R

    2014-01-01

    We revise two relatively rare ensign wasp genera, whose species are restricted to Sub-Saharan Africa: Afrevania and Trissevania. Afrevania longipetiolata sp. nov., Trissevania heatherae sp. nov., T. hugoi sp. nov., T. mrimaensis sp. nov. and T. slideri sp. nov. are described, males and females of T. anemotis and Afrevania leroyi are redescribed, and an identification key for Trissevaniini is provided. We argue that Trissevania mrimaensis sp. nov. and T. heatherae sp. nov. populations are vulnerable, given their limited distributions and threats from mining activities in Kenya. We hypothesize that these taxa together comprise a monophyletic lineage, Trissevaniini, tr. nov., the members of which share the ability to fold their fore wings along two intersecting fold lines. Although wing folding of this type has been described for the hind wing of some insects four-plane wing folding of the fore wing has never been documented. The wing folding mechanism and the pattern of wing folds of Trissevaniini is shared only with some cockroach species (Blattodea). It is an interesting coincidence that all evaniids are predators of cockroach eggs. The major wing fold lines of Trissevaniini likely are not homologous to any known longitudinal anatomical structures on the wings of other Evaniidae. Members of the new tribe share the presence of a coupling mechanism between the fore wing and the mesosoma that is composed of a setal patch on the mesosoma and the retinaculum of the fore wing. While the setal patch is an evolutionary novelty, the retinaculum, which originally evolved to facilitate fore and hind wing coupling in Hymenoptera, exemplifies morphological exaptation. We also refine and clarify the Semantic Phenotype approach used in previous taxonomic revisions and explore the consequences of merging new with existing data. The way that semantic statements are formulated can evolve in parallel, alongside improvements to the ontologies themselves.

  10. Basal Complex and Basal Venation of Odonata Wings: Structural Diversity and Potential Role in the Wing Deformation

    Science.gov (United States)

    Rajabi, H.; Ghoroubi, N.; Malaki, M.; Darvizeh, A.; Gorb, S. N.

    2016-01-01

    Dragonflies and damselflies, belonging to the order Odonata, are known to be excellent fliers with versatile flight capabilities. The ability to fly over a wide range of speeds, high manoeuvrability and great agility are a few characteristics of their flight. The architecture of the wings and their structural elements have been found to play a major role in this regard. However, the precise influence of individual wing components on the flight performance of these insects remains unknown. The design of the wing basis (so called basal complex) and the venation of this part are responsible for particular deformability and specific shape of the wing blade. However, the wing bases are rather different in representatives of different odonate groups. This presumably reflects the dimensions of the wings on one hand, and different flight characteristics on the other hand. In this article, we develop the first three-dimensional (3D) finite element (FE) models of the proximal part of the wings of typical representatives of five dragonflies and damselflies families. Using a combination of the basic material properties of insect cuticle, a linear elastic material model and a nonlinear geometric analysis, we simulate the mechanical behaviour of the wing bases. The results reveal that although both the basal venation and the basal complex influence the structural stiffness of the wings, it is only the latter which significantly affects their deformation patterns. The use of numerical simulations enabled us to address the role of various wing components such as the arculus, discoidal cell and triangle on the camber formation in flight. Our study further provides a detailed representation of the stress concentration in the models. The numerical analysis presented in this study is not only of importance for understanding structure-function relationship of insect wings, but also might help to improve the design of the wings for biomimetic micro-air vehicles (MAVs). PMID:27513753

  11. Differentiation of Boc-protected alpha,delta-/delta,alpha- and beta,delta-/delta,beta-hybrid peptide positional isomers by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Raju, G; Ramesh, V; Srinivas, R; Sharma, G V M; Shoban Babu, B

    2010-06-01

    Two new series of Boc-N-alpha,delta-/delta,alpha- and beta,delta-/delta,beta-hybrid peptides containing repeats of L-Ala-delta(5)-Caa/delta(5)-Caa-L-Ala and beta(3)-Caa-delta(5)-Caa/delta(5)-Caa-beta(3)-Caa (L-Ala = L-alanine, Caa = C-linked carbo amino acid derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion trap tandem mass spectrometry (MS/MS). MS(n) spectra of protonated isomeric peptides produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The dipeptide positional isomers are differentiated by the collision-induced dissociation (CID) of the protonated peptides. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-L-Ala-delta-Caa-OCH(3) (1), whereas it is totally absent for its positional isomer Boc-NH-delta-Caa-L-Ala-OCH(3) (7), instead it shows significant loss of t-butanol. On the other hand, second isomeric pair shows significant loss of t-butanol and loss of acetone for Boc-NH-delta-Caa-beta-Caa-OCH(3) (18), whereas these are insignificant for its positional isomer Boc-NH-beta-Caa-delta-Caa-OCH(3) (13). The tetra- and hexapeptide positional isomers also show significant differences in MS(2) and MS(3) CID spectra. It is observed that 'b' ions are abundant when oxazolone structures are formed through five-membered cyclic transition state and cyclization process for larger 'b' ions led to its insignificant abundance. However, b(1)(+) ion is formed in case of delta,alpha-dipeptide that may have a six-membered substituted piperidone ion structure. Furthermore, ESI negative ion MS/MS has also been found to be useful for differentiating these isomeric peptide acids. Thus, the results of MS/MS of pairs of di-, tetra-, and hexapeptide positional isomers provide peptide sequencing information and distinguish the positional isomers.

  12. Dynamics and control of robotic aircraft with articulated wings

    Science.gov (United States)

    Paranjape, Aditya Avinash

    There is a considerable interest in developing robotic aircraft, inspired by birds, for a variety of missions covering reconnaissance and surveillance. Flapping wing aircraft concepts have been put forth in light of the efficiency of flapping flight at small scales. These aircraft are naturally equipped with the ability to rotate their wings about the root, a form of wing articulation. This thesis covers some problems concerning the performance, stability and control of robotic aircraft with articulated wings in gliding flight. Specifically, we are interested in aircraft without a vertical tail, which would then use wing articulation for longitudinal as well as lateral-directional control. Although the dynamics and control of articulated wing aircraft share several common features with conventional fixed wing aircraft, the presence of wing articulation presents several unique benefits as well as limitations from the perspective of performance and control. One of the objective of this thesis is to understand these features using a combination of theoretical and numerical tools. The aircraft concept envisioned in this thesis uses the wing dihedral angles for longitudinal and lateral-directional control. Aircraft with flexible articulated wings are also investigated. We derive a complete nonlinear model of the flight dynamics incorporating dynamic CG location and the changing moment of inertia. We show that symmetric dihedral configuration, along with a conventional horizontal tail, can be used to control flight speed and flight path angle independently of each other. This characteristic is very useful for initiating an efficient perching maneuver. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. We compute the turning performance limitations that arise due to the use of wing dihedral for yaw control

  13. Numerical simulation of X-wing type biplane flapping wings in 3D using the immersed boundary method.

    Science.gov (United States)

    Tay, W B; van Oudheusden, B W; Bijl, H

    2014-09-01

    The numerical simulation of an insect-sized 'X-wing' type biplane flapping wing configuration is performed in 3D using an immersed boundary method solver at Reynolds numbers equal to 1000 (1 k) and 5 k, based on the wing's root chord length. This X-wing type flapping configuration draws its inspiration from Delfly, a bio-inspired ornithopter MAV which has two pairs of wings flapping in anti-phase in a biplane configuration. The objective of the present investigation is to assess the aerodynamic performance when the original Delfly flapping wing micro-aerial vehicle (FMAV) is reduced to the size of an insect. Results show that the X-wing configuration gives more than twice the average thrust compared with only flapping the upper pair of wings of the X-wing. However, the X-wing's average thrust is only 40% that of the upper wing flapping at twice the stroke angle. Despite this, the increased stability which results from the smaller lift and moment variation of the X-wing configuration makes it more suited for sharp image capture and recognition. These advantages make the X-wing configuration an attractive alternative design for insect-sized FMAVS compared to the single wing configuration. In the Reynolds number comparison, the vorticity iso-surface plot at a Reynolds number of 5 k revealed smaller, finer vortical structures compared to the simulation at 1 k, due to vortices' breakup. In comparison, the force output difference is much smaller between Re = 1 k and 5 k. Increasing the body inclination angle generates a uniform leading edge vortex instead of a conical one along the wingspan, giving higher lift. Understanding the force variation as the body inclination angle increases will allow FMAV designers to optimize the thrust and lift ratio for higher efficiency under different operational requirements. Lastly, increasing the spanwise flexibility of the wings increases the thrust slightly but decreases the efficiency. The thrust result is similar to one of the

  14. The energetic cost of variations in wing span and wing asymmetry in the zebra finch Taeniopygia guttata.

    Science.gov (United States)

    Hambly, C; Harper, E J; Speakman, J R

    2004-10-01

    Asymmetry is a difference in the sizes of bilaterally paired structures. Wing asymmetry may have an effect on the kinematics of flight, with knock-on effects for the energetic cost of flying. In this study the 13C-labelled bicarbonate technique was used to measure the energy expended during the flight of zebra finches Taeniopygia guttata, prior to and after experimental manipulation to generate asymmetry and a change in wing span by trimming the primary feathers. In addition, simultaneous high-speed video footage enabled differences in flight kinematics such as flight speed, wing amplitude, up- and downstroke duration and wing beat frequency to be examined. In 10 individuals, the primary feathers on the right wing were trimmed first, by 0.5 cm, and then by an additional 0.5 cm in six of these individuals. In a separate 'control' group (N=7), approximately 0.25 cm was trimmed off the primary feathers of both wings, to produce the same reduction in wing span as 0.5 cm trimmed from one wing, while maintaining symmetry. When birds were manipulated to become asymmetric they maintained flight speed. They also increased the left wing amplitude and decreased the right up- and downstroke durations to counteract the changes in wing shape, which meant that they had an increase in wing beat frequency. When the wing area was reduced while maintaining symmetry, birds flew with slower flight speed. In this case wing amplitude did not change and wing upstroke slightly decreased, causing an increased wing beat frequency. The mean flight cost in the pre-manipulated birds was 1.90+/-0.1 W. There was a slight increase in flight cost with both of the asymmetry manipulations (0.5 cm, increase of 0.04 W; 1.0 cm, increase of 0.12 W), neither of which reached statistical significance. There was, however, a significantly increased flight cost when the wing span was reduced without causing asymmetry (increase of 0.45 W; paired t-test T=2.3, P=0.03).

  15. Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

    Science.gov (United States)

    Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

    2010-03-24

    To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

  16. Wing Force & Moment Characterization of Flapping Wings for Micro Air Vehicle Application

    Science.gov (United States)

    2005-02-21

    is that position of the wing where φ = Φ0 as shown in Fig. 3(B). When Φ0 6= 0, the motion is called asymetric flapping. When Φ0 = 0, the motion is...For symmetric rotation, Ψ0 = 0, otherwise the motion is refered to as asymetric rotation. Angle of attack The angle of attack is the angle between

  17. Repeatable Manufacture of Wings for Flapping Wing Micro Air Vehicles Using Microelectromechanical System (MEMS) Fabrication Techniques

    Science.gov (United States)

    2011-03-01

    104 A1.5 Dragonfly ......................................................................................................... 106 A1.6...in the size range being investigated include bats, swallows, hummingbirds, butterflies, beetles, dragonflies , and moths. A short synopsis of the...a MAV wing. Dragonflies are precise and controlled flyers, with the ability to hover and accelerate quickly, both from a dead stop as well as

  18. Contributions of the NASA Langley Research Center to the DARPA/AFRL/NASA/ Northrop Grumman Smart Wing Program

    Science.gov (United States)

    Florance, Jennifer P.; Burner, Alpheus W.; Fleming, Gary A.; Martin, Christopher A.

    2003-01-01

    An overview of the contributions of the NASA Langley Research Center (LaRC) to the DARPA/AFRL/NASA/ Northrop Grumman Corporation (NGC) Smart Wing program is presented. The overall objective of the Smart Wing program was to develop smart** technologies and demonstrate near-flight-scale actuation systems to improve the aerodynamic performance of military aircraft. NASA LaRC s roles were to provide technical guidance, wind-tunnel testing time and support, and Computational Fluid Dynamics (CFD) analyses. The program was divided into two phases, with each phase having two wind-tunnel entries in the Langley Transonic Dynamics Tunnel (TDT). This paper focuses on the fourth and final wind-tunnel test: Phase 2, Test 2. During this test, a model based on the NGC Unmanned Combat Air Vehicle (UCAV) concept was tested at Mach numbers up to 0.8 and dynamic pressures up to 150 psf to determine the aerodynamic performance benefits that could be achieved using hingeless, smoothly-contoured control surfaces actuated with smart materials technologies. The UCAV-based model was a 30% geometric scale, full-span, sting-mounted model with the smart control surfaces on the starboard wing and conventional, hinged control surfaces on the port wing. Two LaRC-developed instrumentation systems were used during the test to externally measure the shapes of the smart control surface and quantify the effects of aerodynamic loading on the deflections: Videogrammetric Model Deformation (VMD) and Projection Moire Interferometry (PMI). VMD is an optical technique that uses single-camera photogrammetric tracking of discrete targets to determine deflections at specific points. PMI provides spatially continuous measurements of model deformation by computationally analyzing images of a grid projected onto the model surface. Both the VMD and PMI measurements served well to validate the use of on-board (internal) rotary potentiometers to measure the smart control surface deflection angles. Prior to the final

  19. Optimization of composite tiltrotor wings with extensions and winglets

    Science.gov (United States)

    Kambampati, Sandilya

    Tiltrotors suffer from an aeroelastic instability during forward flight called whirl flutter. Whirl flutter is caused by the whirling motion of the rotor, characterized by highly coupled wing-rotor-pylon modes of vibration. Whirl flutter is a major obstacle for tiltrotors in achieving high-speed flight. The conventional approach to assure adequate whirl flutter stability margins for tiltrotors is to design the wings with high torsional stiffness, typically using 23% thickness-to-chord ratio wings. However, the large aerodynamic drag associated with these high thickness-to-chord ratio wings decreases aerodynamic efficiency and increases fuel consumption. Wingtip devices such as wing extensions and winglets have the potential to increase the whirl flutter characteristics and the aerodynamic efficiency of a tiltrotor. However, wing-tip devices can add more weight to the aircraft. In this study, multi-objective parametric and optimization methodologies for tiltrotor aircraft with wing extensions and winglets are investigated. The objectives are to maximize aircraft aerodynamic efficiency while minimizing weight penalty due to extensions and winglets, subject to whirl flutter constraints. An aeroelastic model that predicts the whirl flutter speed and a wing structural model that computes strength and weight of a composite wing are developed. An existing aerodynamic model (that predicts the aerodynamic efficiency) is merged with the developed structural and aeroelastic models for the purpose of conducting parametric and optimization studies. The variables of interest are the wing thickness and structural properties, and extension and winglet planform variables. The Bell XV-15 tiltrotor aircraft the chosen as the parent aircraft for this study. Parametric studies reveal that a wing extension of span 25% of the inboard wing increases the whirl flutter speed by 10% and also increases the aircraft aerodynamic efficiency by 8%. Structurally tapering the wing of a tiltrotor

  20. Folding in and out: passive morphing in flapping wings.

    Science.gov (United States)

    Stowers, Amanda K; Lentink, David

    2015-03-25

    We present a new mechanism for passive wing morphing of flapping wings inspired by bat and bird wing morphology. The mechanism consists of an unactuated hand wing connected to the arm wing with a wrist joint. Flapping motion generates centrifugal accelerations in the hand wing, forcing it to unfold passively. Using a robotic model in hover, we made kinematic measurements of unfolding kinematics as functions of the non-dimensional wingspan fold ratio (2-2.5) and flapping frequency (5-17 Hz) using stereo high-speed cameras. We find that the wings unfold passively within one to two flaps and remain unfolded with only small amplitude oscillations. To better understand the passive dynamics, we constructed a computer model of the unfolding process based on rigid body dynamics, contact models, and aerodynamic correlations. This model predicts the measured passive unfolding within about one flap and shows that unfolding is driven by centrifugal acceleration induced by flapping. The simulations also predict that relative unfolding time only weakly depends on flapping frequency and can be reduced to less than half a wingbeat by increasing flapping amplitude. Subsequent dimensional analysis shows that the time required to unfold passively is of the same order of magnitude as the flapping period. This suggests that centrifugal acceleration can drive passive unfolding within approximately one wingbeat in small and large wings. Finally, we show experimentally that passive unfolding wings can withstand impact with a branch, by first folding and then unfolding passively. This mechanism enables flapping robots to squeeze through clutter without sophisticated control. Passive unfolding also provides a new avenue in morphing wing design that makes future flapping morphing wings possibly more energy efficient and light-weight. Simultaneously these results point to possible inertia driven, and therefore metabolically efficient, control strategies in bats and birds to morph or recover

  1. Three-dimensional winged nanocone optical antennas.

    Science.gov (United States)

    Huttunen, Mikko J; Lindfors, Klas; Andriano, Domenico; Mäkitalo, Jouni; Bautista, Godofredo; Lippitz, Markus; Kauranen, Martti

    2014-06-15

    We introduce 3D optical antennas based on winged nanocones. The antennas support particle plasmon oscillations with current distributions that facilitate transformation of transverse far-field radiation to strong longitudinal local fields near the cone apices. We characterize the optical responses of the antennas by their extinction spectra and by second-harmonic generation microscopy with cylindrical vector beams. The results demonstrate a new 3D polarization-controllable optical antenna for applications in apertureless near-field microscopy, spectroscopy, and plasmonic sensing.

  2. Identifying hazards associated with lava deltas

    Science.gov (United States)

    Poland, Michael P.; Orr, Tim R.

    2014-01-01

    Lava deltas, formed where lava enters the ocean and builds a shelf of new land extending from the coastline, represent a significant local hazard, especially on populated ocean island volcanoes. Such structures are unstable and prone to collapse—events that are often accompanied by small explosions that can deposit boulders and cobbles hundreds of meters inland. Explosions that coincide with collapses of the East Lae ‘Apuki lava delta at Kīlauea Volcano, Hawai‘i, during 2005–2007 followed an evolutionary progression mirroring that of the delta itself. A collapse that occurred when the lava–ocean entry was active was associated with a blast of lithic blocks and dispersal of spatter and fine, glassy tephra. Shortly after delta growth ceased, a collapse exposed hot rock to cold ocean water, resulting in an explosion composed entirely of lithic blocks and lapilli. Further collapse of the delta after several months of inactivity, by which time it had cooled significantly, resulted in no recognizable explosion deposit. Seaward displacement and subsidence of the coastline immediately inland of the delta was measured by both satellite and ground-based sensors and occurred at rates of several centimeters per month even after the lava–ocean entry had ceased. The anomalous deformation ended only after complete collapse of the delta. Monitoring of ground deformation may therefore provide an indication of the potential for delta collapse, while the hazard associated with collapse can be inferred from the level of activity, or the time since the last activity, on the delta.

  3. Inactivation of the Deg protease family in the cyanobacterium Synechocystis sp. PCC 6803 has impact on the outer cell layers.

    Science.gov (United States)

    Cheregi, Otilia; Miranda, Hélder; Gröbner, Gerhard; Funk, Christiane

    2015-11-01

    The serine type Deg/HtrA proteases are distributed in a wide range of organisms from Escherichia coli to humans. The cyanobacterium Synechocystis sp. PCC 6803 possesses three Deg protease orthologues: HtrA, HhoA and HhoB. Previously we compared Synechocystis 6803 wild type cells exposed to mild or severe stress conditions with a mutant lacking all three Deg proteases and demonstrated that stress had strong impact on the proteomes and metabolomes. To identify the biochemical processes, which this protease family is involved in, here we compared Synechocystis sp. PCC 6803 wild type cells with a mutant lacking all three Deg proteases grown under normal growth conditions (30°C and 40 μmol photons m(-2) s(-1)). Deletion of the Deg proteases lead to the down-regulation of proteins related to the biosynthesis of outer cell layers (e.g. the GDP mannose 4,6-dehydratase) and affected protein secretion. During the late growth phase of the culture Deg proteases were found to be secreted to the extracellular medium of the Synechocystis sp. PCC 6803 wild type strain. While cyanobacterial Deg proteases seem to act mainly in the periplasmic space, deletion of the three proteases influences the proteome and metabolome of the whole cell. Impairments in the outer cell layers of the triple mutant might explain the higher sensitivity toward light and oxidative stress, which was observed earlier by Barker and coworkers. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Variable Geometry Aircraft Wing Supported by Struts And/Or Trusses

    Science.gov (United States)

    Melton, John E. (Inventor); Dudley, Michael R. (Inventor)

    2016-01-01

    The present invention provides an aircraft having variable airframe geometry for accommodating efficient flight. The aircraft includes an elongated fuselage, an oblique wing pivotally connected with said fuselage, a wing pivoting mechanism connected with said oblique wing and said fuselage, and a brace operably connected between said oblique wing and said fuselage. The present invention also provides an aircraft having an elongated fuselage, an oblique wing pivotally connected with said fuselage, a wing pivoting mechanism connected with said oblique wing and said fuselage, a propulsion system pivotally connected with said oblique wing, and a brace operably connected between said propulsion system and said fuselage.

  5. Morphing Wing Design with an Innovative Three-Dimensional Warping Actuation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced wing configurations where traditional control surfaces are replaced by dynamically controlled distribution of wing twist and/or camber can provide...

  6. Global Local Structural Optimization of Transportation Aircraft Wings

    NARCIS (Netherlands)

    Ciampa, P.D.; Nagel, B.; Van Tooren, M.J.L.

    2010-01-01

    The study presents a multilevel optimization methodology for the preliminary structural design of transportation aircraft wings. A global level is defined by taking into account the primary wing structural components (i.e., ribs, spars and skin) which are explicitly modeled by shell layered finite e

  7. Inertial Force Coupling to Nonlinear Aeroelasticity of Flexible Wing Aircraft

    Science.gov (United States)

    Nguyen, Nhan T.; Ting, Eric

    2016-01-01

    This paper investigates the inertial force effect on nonlinear aeroelasticity of flexible wing aircraft. The geometric are nonlinearity due to rotational and tension stiffening. The effect of large bending deflection will also be investigated. Flutter analysis will be conducted for a truss-braced wing aircraft concept with tension stiffening and inertial force coupling.

  8. Ray analysis of a class of hybrid cylindrical aircraft wings

    OpenAIRE

    Jha, RM; Bokhari, SA; Sudhakan, V; Mahapatra, PR

    1988-01-01

    A new approach to the modelling of aircraft wings, based on the combination of hybrid quadric (parabolic and circular) cylinders, has been presented for electromagnetic applications. Closed-form expressions have been obtained for ray parameters required in the high-frequency mutual coupling computation of antenna pairs located arbitrarily on an aircraft wing.

  9. Influence of anisotropic piezoelectric actuators on wing aerodynamic forces

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Changing the shape of an airfoil to enhance overall aircraft performance has always been a goal of aircraft designers. Using smart material to reshape the wing can improve aerodynamic performance. The influence of anisotropic effects of piezoelectric actuators on the aerodynamic characteristics of a simplified HALE wing model was investigated. Test verification was conducted.

  10. Energy-based Aeroelastic Analysis and Optimisation of Morphing Wings

    NARCIS (Netherlands)

    De Breuker, R.

    2011-01-01

    Morphing aircraft can change their shape radically when confronted with a variety of conflicting flight conditions throughout their mission. For instance the F-14 Tomcat fighter aircraft, known from the movie Top Gun, was able to sweep its wings from a straight wing configuration to a highly swept v

  11. Influence of anisotropic piezoelectric actuators on wing aerodynamic forces

    Institute of Scientific and Technical Information of China (English)

    GUAN De; LI Min; LI Wei; WANG MingChun

    2008-01-01

    Changing the shape of an airfoil to enhance overall aircraft performance has always been s goal of aircraft designers.Using smart material to reshape the wing can improve aerodynamic performance.The influence of anisotropic effects of piezo-electric actuators on the aerodynamic characteristics of a simplified HALE wing model was investigated.Test verification was conducted.

  12. Significance of wing morphometry in distinguishing some of the ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... the photos, Scale factor values were shown on the ruler. Wing pho- tos were ... Analysis of wing Landmark data (in TPS format). At the end of the .... not clearly separated, and most groups were mixed. (Figure 9, Table 7).

  13. Wing flexibility effects in clap-and-fling

    NARCIS (Netherlands)

    Percin, M.; Hu, Y.; Van Oudheusden, B.W.; Remes, B.; Scarano, F.

    2011-01-01

    The work explores the use of time-resolved tomographic PIV measurements to study a flapping-wing model, the related vortex generation mechanisms and the effect of wing flexibility on the clap-and-fling movement in particular. An experimental setup is designed and realized in a water t

  14. The function of PS integrins in Drosophila wing morphogenesis.

    Science.gov (United States)

    Wilcox, M; DiAntonio, A; Leptin, M

    1989-12-01

    Integrins are found on many cell types during the development of most organisms. In Drosophila their functions can be analysed genetically. An analysis of lethal mutations in a PS integrin gene showed that the integrins were required for muscle attachment and for certain cell sheet migrations during embryogenesis. In this paper we use viable mutations in integrin component genes to look at integrin function in the later stages of development of one adult structure, the wing. We show that two known viable mutations, one which has its primary effect on the fly's escape response, the other on wing morphogenesis, are mutations in the beta and PS2alpha subunits, respectively, of the PS integrins. The mutation non-jumper (mys(mj42)) in the beta subunit leads to wasting of the thoracic jump muscles. Flies in which the dosage of this allele is reduced (and no wildtype copy is present) show defects also in wing morphogenesis. The two surfaces of the wing fail to connect properly, resulting in 'blistering' of the wing and the formation of extra crossveins. The mutation in the gene for the PS2alpha integrin subunit, inflated, also leads to a failure in wing surface apposition and consequent wing blistering. When the two mutations are combined, the mutant phenotype is greatly enhanced. Thus, one of the roles of the PS integrins in late Drosophila development is to ensure the correct apposition and patterning of the wing epithelia.

  15. Anisotropism of the Non-Smooth Surface of Butterfly Wing

    Institute of Scientific and Technical Information of China (English)

    Gang Sun; Yan Fang; Qian Cong; Lu-quan Ren

    2009-01-01

    Twenty-nine species of butterflies were collected for observation and determination of the wing surfaces using a Scanning Electron Microscope (SEM). Butterfly wing surface displays structural anisotropism in micro-, submicro- and nano-scales. The scales on butterfly wing surface arrange like overlapping roof tiles. There are submicrometric vertical gibbosities, horizontal links, and nano-protuberances on the scales. First-incline-then-drip method and first-drip-then-incline method were used to measure the Sliding Angle (SA) of droplet on butterfly wing surface by an optical Contact Angle (CA) measuring system.Relatively smaller sliding angles indicate that the butterfly wing surface has fine self-cleaning property. Significantly different SAs in various directions indicate the anisotropic self-cleaning property of butterfly wing surface. The SAs on the butterfly wing surface without scales are remarkably larger than those with scales, which proves the crucial role of scales in determining the self-cleaning property. Butterfly wing surface is a template for design and fabrication of biomimetic materials and self-cleaning substrates. This work may offer insights into how to design directional self-cleaning coatings and anisotropic wetting surface.

  16. Unsteady Aerodynamics of Flapping Wing of a Bird

    Directory of Open Access Journals (Sweden)

    M. Agoes Moelyadi

    2013-04-01

    Full Text Available The unsteady flow behavior and time-dependent aerodynamic characteristics of the flapping motion of a bird’s wing were investigated using a computational method. During flapping, aerodynamic interactions between bird wing surfaces and surrounding flow may occur, generating local time-dependent flow changes in the flow field and aerodynamic load of birds. To study the effect of flapping speed on unsteady aerodynamic load, two kinds of computational simulations were carried out, namely a quasi-steady and an unsteady simulation. To mimic the movement of the down-stroke and the upstroke of a bird, the flapping path accorded to a sinus function, with the wing attitude changing in dihedral angle and time. The computations of time-dependent viscous flow were based on the solution of the Reynolds Averaged Navier-Stokes equations by applying the k-e turbulence model. In addition, the discretization for the computational domain around the model used multi-block structured grid to provide more accuracy in capturing viscous flow, especially in the vicinity of the wing and body surfaces, to obtain a proper wing-body geometry model. For this research, the seagull bird was chosen, which has high aspect ratio wings with pointed wing-tips and a high camber wing section. The results include mesh movement, velocity contours as well as aerodynamic coefficients of the flapping motion of the bird at various flapping frequencies.

  17. Stable structural color patterns displayed on transparent insect wings.

    Science.gov (United States)

    Shevtsova, Ekaterina; Hansson, Christer; Janzen, Daniel H; Kjærandsen, Jostein

    2011-01-11

    Color patterns play central roles in the behavior of insects, and are important traits for taxonomic studies. Here we report striking and stable structural color patterns--wing interference patterns (WIPs)--in the transparent wings of small Hymenoptera and Diptera, patterns that have been largely overlooked by biologists. These extremely thin wings reflect vivid color patterns caused by thin film interference. The visibility of these patterns is affected by the way the insects display their wings against various backgrounds with different light properties. The specific color sequence displayed lacks pure red and matches the color vision of most insects, strongly suggesting that the biological significance of WIPs lies in visual signaling. Taxon-specific color patterns are formed by uneven membrane thickness, pigmentation, venation, and hair placement. The optically refracted pattern is also stabilized by microstructures of the wing such as membrane corrugations and spherical cell structures that reinforce the pattern and make it essentially noniridescent over a large range of light incidences. WIPs can be applied to map the micromorphology of wings through direct observation and are useful in several fields of biology. We demonstrate their usefulness as identification patterns to solve cases of cryptic species complexes in tiny parasitic wasps, and indicate their potentials for research on the genetic control of wing development through direct links between the transregulatory wing landscape and interference patterns we observe in Drosophila model species. Some species display sexually dimorphic WIPs, suggesting sexual selection as one of the driving forces for their evolution.

  18. Closed-type wing for drones: positive and negative characteristics

    Directory of Open Access Journals (Sweden)

    Leonid I. Gretchihin

    2014-02-01

    Full Text Available The paper presents the aerodynamics of a wing of a closed oval ellipsoidal shape, designed with the use of the molecular-kinetic theory. The positive and negative characteristics of aircraft - drones with an oval wing are described. The theoretical calculations have been experimentally checked.

  19. Jet reorientation in active galactic nuclei : two winged radio galaxies

    NARCIS (Netherlands)

    Dennett-Thorpe, J; Scheuer, PAG; Laing, RA; Bridle, AH; Pooley, GG; Reich, W

    2002-01-01

    Winged, or X-shaped, radio sources form a small class of morphologically peculiar extragalactic sources. We present multifrequency radio observations of two such sources. We derive maximum ages since any re-injection of fresh particles of 34 and 17 Myr for the wings of 3C 223.1 and 3C 403 respective

  20. Flapping-wing mechanical butterfly on a wheel

    Science.gov (United States)

    Godoy-Diana, Ramiro; Thiria, Benjamin; Pradal, Daniel

    2009-11-01

    We examine the propulsive performance of a flapping-wing device turning on a ``merry-go-round'' type base. The two-wing flapper is attached to a mast that is ball-bearing mounted to a central shaft in such a way that the thrust force produced by the wings makes the flapper turn around this shaft. The oscillating lift force produced by the flapping wings is aligned with the mast to avoid vibration of the system. A turning contact allows to power the motor that drives the wings. We measure power consumption and cruising speed as a function of flapping frequency and amplitude as well as wing flexibility. The design of the wings permits to change independently their flexibility in the span-wise and chord-wise directions and PIV measurements in various planes let us examine the vorticity field around the device. A complete study of the effect of wing flexibility on the propulsive performance of the system will be presented at the conference.