WorldWideScience

Sample records for edge flaps sensoring

  1. Deformable trailing edge flaps for modern megawatt wind turbine controllers using strain gauge sensors

    DEFF Research Database (Denmark)

    Andersen, Peter Bjørn; Henriksen, Lars Christian; Gaunaa, Mac

    2010-01-01

    . By enabling the trailing edge to move independently and quickly along the spanwise position of the blade, local small flutuations in the aerodynamic forces can be alleviated by deformation of the airfoil flap. Strain gauges are used as input for the flap controller, and the effect of placing strain gauges......The present work contains a deformable trailing edge flap controller integrated in a numerically simulated modern, variablespeed, pitch-regulated megawatt (MW)-size wind turbine. The aeroservoelastic multi-body code HAWC2 acts as a component in the control loop design. At the core of the proposed...... edge flaps on a wind turbine blade rather than a conclusive control design with traditional issues like stability and robustness fully investigated. Recent works have shown that the fatigue load reduction by use of trailing edge flaps may be greater than for traditional pitch control methods...

  2. Advanced load alleviation for wind turbines using adaptive trailing edge flaps: Sensoring and control

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Peter Bjoern

    2010-02-15

    The purpose of wind turbines and their predecessors the windmill, is to convert the energy in the wind to usable energy forms. Whereas windmills of the past focused on the conversion of wind power to torque for grinding, pumping and winching, modern wind turbines convert the wind energy into electric power. They do so through incorporation of generators, which convert mechanical torque into electricity. Wind turbines are designed to keep the overall cost per produced Kilo Watt hour as low as possible. One way of improving the performance and lifetime of the wind turbine is through active flow control. Active control is often considered costly but if the lifespan of the components can be increased it could be justifiable. This thesis covers various aspects of 'smart control' such as control theory, sensoring, optimization, experiments and numerical modeling. (author)

  3. Flap Edge Noise Reduction Fins

    Science.gov (United States)

    Khorrami, Mehdi R. (Inventor); Choudhan, Meelan M. (Inventor)

    2015-01-01

    A flap of the type that is movably connected to an aircraft wing to provide control of an aircraft in flight includes opposite ends, wherein at least a first opposite end includes a plurality of substantially rigid, laterally extending protrusions that are spaced apart to form a plurality of fluidly interconnected passageways. The passageways have openings adjacent to upper and lower sides of the flap, and the passageways include a plurality of bends such that high pressure fluid flows from a high pressure region to a low pressure region to provide a boundary condition that inhibits noise resulting from airflow around the end of the flap.

  4. Experimental Study of Wake / Flap Interaction Noise and the Reduction of Flap Side Edge Noise

    Science.gov (United States)

    Hutcheson, Florence V.; Stead, Daniel J.; Plassman, Gerald E.

    2016-01-01

    The effects of the interaction of a wake with a half-span flap on radiated noise are examined. The incident wake is generated by bars of various widths and lengths or by a simplified landing gear model. Single microphone and phased array measurements are used to isolate the effects of the wake interaction on the noise radiating from the flap side edge and flap cove regions. The effects on noise of the wake generator's geometry and relative placement with respect to the flap are assessed. Placement of the wake generators upstream of the flap side edge is shown to lead to the reduction of flap side edge noise by introducing a velocity deficit and likely altering the instabilities in the flap side edge vortex system. Significant reduction in flap side edge noise is achieved with a bar positioned directly upstream of the flap side edge. The noise reduction benefit is seen to improve with increased bar width, length and proximity to the flap edge. Positioning of the landing gear model upstream of the flap side edge also leads to decreased flap side edge noise. In addition, flap cove noise levels are significantly lower than when the landing gear is positioned upstream of the flap mid-span. The impact of the local flow velocity on the noise radiating directly from the landing gear is discussed. The effects of the landing gear side-braces on flap side edge, flap cove and landing gear noise are shown.

  5. Model predictive control of trailing edge flaps on a wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Castaignet, D.B.

    2011-11-15

    Trailing edge flaps on wind turbine blades have been investigated for several years. Aero-servoelastic simulations carried out with different simulation tools, trailing edge flaps configurations and controller designs proved that trailing edge flaps are a suitable solution for reducing some of the wind turbine fatigue and extreme loads. This potential was confirmed with wind tunnel tests made on blade sections with trailing edge flaps and on a scaled two-bladed wind turbine in a wind tunnel. The work presented in this thesis includes a full-scale test run on a Vestas V27 wind turbine equipped with three trailing edge flaps on one blade, located on DTU's Risoe Campus in Roskilde, Denmark. This thesis is divided into three parts: the controller design, results from simulations, and results from the experiments. The trailing edge flaps controller designed for this project is based on a frequency-weighted model predictive control, tuned in order to target only the flapwise blade root loads at the frequencies contributing the most to blade root fatigue damage (the 1P, 2P and 3P frequencies), and to avoid unnecessary wear and tear of the actuators at high frequencies. A disturbance model consisting in periodic disturbances at the rotor speed harmonic frequencies and a quasi-steady input disturbance is aggregated to an analytical model of a spinning blade with trailing edge flaps. Simulations on a multi-megawatt wind turbine show the potential of the trailing edge flaps to reduce the flapwise blade root fatigue loads by 23%, but also the main shaft and the tower fatigue loads by up to 32%. Extreme loads during normal production also benefit from the trailing edge flaps. At last, the same controller was run on the Vestas V27 wind turbine located at the Risoe Campus of the Technical University of Denmark, in Roskilde, Denmark. One blade of the turbine was equipped with three independent trailing edge flaps. In spite of the failure of several sensors and actuators, the

  6. Modeling of Airfoil Trailing Edge Flap with Immersed Boundary Method

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2011-01-01

    The present work considers incompressible flow over a 2D airfoil with a deformable trailing edge. The aerodynamic characteristics of an airfoil with a trailing edge flap is numerically investigated using computational fluid dynamics. A novel hybrid immersed boundary (IB) technique is applied...... to simulate the moving part of the trailing edge. Over the main fixed part of the airfoil the Navier-Stokes (NS) equations are solved using a standard body-fitted finite volume technique whereas the moving trailing edge flap is simulated with the immersed boundary method on a curvilinear mesh. The obtained...... results show that the hybrid approach is an efficient and accurate method for solving turbulent flows past airfoils with a trailing edge flap and flow control using trailing edge flap is an efficient way to regulate the aerodynamic loading on airfoils....

  7. Characterization of Flap Edge Noise Radiation from a High-Fidelity Airframe Model

    Science.gov (United States)

    Humphreys, William M., Jr.; Khorrami, Mehdi R.; Lockard, David P.; Neuhart, Dan H.; Bahr, Christopher J.

    2015-01-01

    The results of an experimental study of the noise generated by a baseline high-fidelity airframe model are presented. The test campaign was conducted in the open-jet test section of the NASA Langley 14- by 22-foot Subsonic Tunnel on an 18%-scale, semi-span Gulfstream airframe model incorporating a trailing edge flap and main landing gear. Unsteady surface pressure measurements were obtained from a series of sensors positioned along the two flap edges, and far field acoustic measurements were obtained using a 97-microphone phased array that viewed the pressure side of the airframe. The DAMAS array deconvolution method was employed to determine the locations and strengths of relevant noise sources in the vicinity of the flap edges and the landing gear. A Coherent Output Power (COP) spectral method was used to couple the unsteady surface pressures measured along the flap edges with the phased array output. The results indicate that outboard flap edge noise is dominated by the flap bulb seal cavity with very strong COP coherence over an approximate model-scale frequency range of 1 to 5 kHz observed between the array output and those unsteady pressure sensors nearest the aft end of the cavity. An examination of experimental COP spectra for the inboard flap proved inconclusive, most likely due to a combination of coherence loss caused by decorrelation of acoustic waves propagating through the thick wind tunnel shear layer and contamination of the spectra by tunnel background noise at lower frequencies. Directivity measurements obtained from integration of DAMAS pressure-squared values over defined geometric zones around the model show that the baseline flap and landing gear are only moderately directional as a function of polar emission angle.

  8. Elastically Deformable Side-Edge Link for Trailing-Edge Flap Aeroacoustic Noise Reduction

    Science.gov (United States)

    Khorrami, Mehdi R. (Inventor); Lockard, David P. (Inventor); Moore, James B. (Inventor); Su, Ji (Inventor); Turner, Travis L. (Inventor); Lin, John C. (Inventor); Taminger, Karen M. (Inventor); Kahng, Seun K. (Inventor); Verden, Scott A. (Inventor)

    2014-01-01

    A system is provided for reducing aeroacoustic noise generated by an aircraft having wings equipped with trailing-edge flaps. The system includes a plurality of elastically deformable structures. Each structure is coupled to and along one of the side edges of one of the trailing-edge flaps, and is coupled to a portion of one of the wings that is adjacent to the one of the side edges. The structures elastically deform when the trailing-edge flaps are deployed away from the wings.

  9. Flap Side Edge Liners for Airframe Noise Reduction

    Science.gov (United States)

    Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

    2014-01-01

    One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

  10. Detached Eddy Simulation of Flap Side-Edge Flow

    Science.gov (United States)

    Balakrishnan, Shankar K.; Shariff, Karim R.

    2016-01-01

    Detached Eddy Simulation (DES) of flap side-edge flow was performed with a wing and half-span flap configuration used in previous experimental and numerical studies. The focus of the study is the unsteady flow features responsible for the production of far-field noise. The simulation was performed at a Reynolds number (based on the main wing chord) of 3.7 million. Reynolds Averaged Navier-Stokes (RANS) simulations were performed as a precursor to the DES. The results of these precursor simulations match previous experimental and RANS results closely. Although the present DES simulations have not reached statistical stationary yet, some unsteady features of the developing flap side-edge flowfield are presented. In the final paper it is expected that statistically stationary results will be presented including comparisons of surface pressure spectra with experimental data.

  11. A morphing trailing edge flap system for wind turbine blades

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Barlas, Athanasios; Løgstrup Andersen, Tom

    2015-01-01

    system has been further developed in corporation with the industrial partners Hydratech Industries (DK) and Rehau (DE). A new trailing edge flap design with spanwise voids (channels) and with a chord of 15cm suitable for a 1m chord blade section was developed. It was then manufactured by extrusion...

  12. Identification of Flap Motion Parameters for Vibration Reduction in Helicopter Rotors with Multiple Active Trailing Edge Flaps

    Directory of Open Access Journals (Sweden)

    Uğbreve;ur Dalli

    2011-01-01

    Full Text Available An active control method utilizing the multiple trailing edge flap configuration for rotorcraft vibration suppression and blade loads control is presented. A comprehensive model for rotor blade with active trailing edge flaps is used to calculate the vibration characteristics, natural frequencies and mode shapes of any complex composite helicopter rotor blade. A computer program is developed to calculate the system response, rotor blade root forces and moments under aerodynamic forcing conditions. Rotor blade system response is calculated using the proposed solution method and the developed program depending on any structural and aerodynamic properties of rotor blades, structural properties of trailing edge flaps and properties of trailing edge flap actuator inputs. Rotor blade loads are determined first on a nominal rotor blade without multiple active trailing edge flaps and then the effects of the active flap motions on the existing rotor blade loads are investigated. Multiple active trailing edge flaps are controlled by using open loop controllers to identify the effects of the actuator signal output properties such as frequency, amplitude and phase on the system response. Effects of using multiple trailing edge flaps on controlling rotor blade vibrations are investigated and some design criteria are determined for the design of trailing edge flap controller that will provide actuator signal outputs to minimize the rotor blade root loads. It is calculated that using the developed active trailing edge rotor blade model, helicopter rotor blade vibrations can be reduced up to 36% of the nominal rotor blade vibrations.

  13. An Elongated Leading Edge Facilitates Rotation Flap Closure: In Vivo Demonstration.

    Science.gov (United States)

    Lichon, Vanessa; Barbosa, Naiara; Gomez, Doug; Goldman, Glenn

    2016-01-01

    Variation in the design of a rotation flap may affect wound closure tension. Lengthening the leading edge of a rotation flap has been a method of reducing the tension of closure in the primary motion. An in vitro study negating this tenant has been published. The authors set out to design an in vivo experiment to determine if lengthening the leading edge of a rotation flap has the effect of reducing closure tension in the primary motion of the repair. An animal study approved by Institutional Animal Care and Use Committee was undertaken in a pig model. A tension-measuring apparatus was designed using Teflon-coated wires and digital tensiometers. Rotation flaps of a standard design and with elongated leading edges were incised on the flanks of pigs under general anesthesia. Flap closure tensions were measured at points along the leading edge of the flap and in the secondary motion. Elongating the leading edge of a flap led to a statistically significant reduction in closure tension in the primary motion of the flap and at the flap tip. The secondary motion closure tensions were essentially unaffected. The authors confirm that elongating the leading edge of a standard rotation flap will reduce closure tension in the primary flap motion.

  14. Frequency-Weighted Model Predictive Control of Trailing Edge Flaps on a Wind Turbine Blade

    DEFF Research Database (Denmark)

    Castaignet, Damien; Couchman, Ian; Poulsen, Niels Kjølstad

    2013-01-01

    flapwise blade root moment and trailing edge flap deflection. Frequency-weighted MPC is chosen for its ability to handle constraints on the trailing edge flaps deflection, and to target at loads with given frequencies only. The controller is first tested in servo-aeroelastic simulations, before being......This paper presents the load reduction achieved with trailing edge flaps during a full-scale test on a Vestas V27 wind turbine. The trailing edge flap controller is a frequency-weighted linear model predictive control (MPC) where the quadratic cost consists of costs on the zero-phase filtered...

  15. Identification of Flap Motion Parameters for Vibration Reduction in Helicopter Rotors with Multiple Active Trailing Edge Flaps

    OpenAIRE

    Dalli, Uğbreve;ur; Yüksel, Şcedilefaatdin

    2011-01-01

    An active control method utilizing the multiple trailing edge flap configuration for rotorcraft vibration suppression and blade loads control is presented. A comprehensive model for rotor blade with active trailing edge flaps is used to calculate the vibration characteristics, natural frequencies and mode shapes of any complex composite helicopter rotor blade. A computer program is developed to calculate the system response, rotor blade root forces and moments under aerodynamic forcing condit...

  16. Model Predictive Control of Trailing Edge Flaps on a wind turbine blade

    DEFF Research Database (Denmark)

    Castaignet, Damien; Poulsen, Niels Kjølstad; Buhl, Thomas

    2011-01-01

    Trailing Edge Flaps on wind turbine blades have been studied in order to achieve fatigue load reduction on the turbine components. We show in this paper how Model Predictive Control can be used to do frequency weighted control of the trailing edge flaps in order to reduce fatigue damage on the bl...

  17. Primary control of a Mach scale swashplateless rotor using brushless DC motor actuated trailing edge flaps

    Science.gov (United States)

    Saxena, Anand

    The focus of this research was to demonstrate a four blade rotor trim in forward flight using integrated trailing edge flaps instead of using a swashplate controls. A compact brushless DC motor was evaluated as an on-blade actuator, with the possibility of achieving large trailing edge flap amplitudes. A control strategy to actuate the trailing edge flap at desired frequency and amplitude was developed and large trailing edge flap amplitudes from the motor (instead of rotational motion) were obtained. Once the actuator was tested on the bench-top, a lightweight mechanism was designed to incorporate the motor in the blade and actuate the trailing edge flaps. A six feet diameter, four bladed composite rotor with motor-flap system integrated into the NACA 0012 airfoil section was fabricated. Systematic testing was carried out for a range of load conditions, first in the vacuum chamber followed by hover tests. Large trailing edge flap deflections were observed during the hover testing, and a peak to peak trailing edge flap amplitude of 18 degree was achieved at 2000 rotor RPM with hover tip Mach number of 0.628. A closed loop controller was designed to demonstrate trailing edge flap mean position and the peak to peak amplitude control. Further, a soft pitch link was designed and fabricated, to replace the stiff pitch link and thereby reduce the torsional stiffness of the blade to 2/rev. This soft pitch link allowed for blade root pitch motion in response to the trailing edge flap inputs. Blade pitch response due to both steady as well as sinusoidal flap deflections were demonstrated. Finally, tests were performed in Glenn L. Martin wind tunnel using a model rotor rig to assess the performance of motor-flap system in forward flight. A swashplateless trim using brushless DC motor actuated trailing edge flaps was achieved for a rotor operating at 1200 RPM and an advance ratio of 0.28. Also, preliminary exploration was carried out to test the scalability of the motor

  18. Model predictive control of trailing edge flaps on a wind turbine blade

    DEFF Research Database (Denmark)

    Castaignet, Damien Bruno

    of the wind turbine fatigue and extreme loads. This potential was confirmed with wind tunnel tests made on blade sections with trailing edge flaps and on a scaled two-bladed wind turbine in a wind tunnel. The work presented in this thesis includes a full-scale test run on a Vestas V27 wind turbine equipped...... fatigue loads by 23%, but also the main shaft and the tower fatigue loads by up to 32%. Extreme loads during normal production also benefit from the trailing edge flaps. At last, the same controller was run on the Vestas V27 wind turbine located at the Risø Campus of the Technical University of Denmark......Trailing edge flaps on wind turbine blades have been investigated for several years. Aero-servoelastic simulations carried out with different simulation tools, trailing edge flaps configurations and controller designs proved that trailing edge flaps are a suitable solution for reducing some...

  19. Aerodynamic optimization and mechanism design of flexible variable camber trailing-edge flap

    Directory of Open Access Journals (Sweden)

    Weishuang LU

    2017-06-01

    Full Text Available Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft. In order to improve flight efficiency during takeoff, cruise and landing states, the flexible variable camber trailing-edge flap is introduced, capable of changing its shape smoothly from 50% flap chord to the rear of the flap. Using a numerical simulation method for the case of the GA (W-2 airfoil, the multi-objective optimization of the overlap, gap, deflection angle, and bending angle of the flap under takeoff and landing configurations is studied. The optimization results show that under takeoff configuration, the variable camber trailing-edge flap can increase lift coefficient by about 8% and lift-to-drag ratio by about 7% compared with the traditional flap at a takeoff angle of 8°. Under landing configuration, the flap can improve the lift coefficient at a stall angle of attack about 1.3%. Under cruise state, the flap helps to improve the lift-to-drag ratio over a wide range of lift coefficients, and the maximum increment is about 30%. Finally, a corrugated structure–eccentric beam combination bending mechanism is introduced in this paper to bend the flap by rotating the eccentric beam.

  20. Investigation of the maximum load alleviation potential using trailing edge flaps controlled by inflow data

    DEFF Research Database (Denmark)

    Fischer, Andreas; Aagaard Madsen, Helge

    2014-01-01

    The maximum fatigue load reduction potential when using trailing edge flaps on mega-watt wind turbines was explored. For this purpose an ideal feed forward control algorithm using the relative velocity and angle of attack at the blade to control the loads was implemented. The algorithm was applied...... to time series from computations with the aeroelastic code HAWC2 and to measured time series. The fatigue loads could be reduced by 36% in the computations if the in flow sensor was at the same position as the blade load. The decrease of the load reduction potential when the sensor was at a distance from...... the blade load location was investigated. When the algorithm was applied to measured time series a load reduction of 23% was achieved which is still promissing, but significantly lower than the value achieved in computations....

  1. Optimal placement of trailing-edge flaps for helicopter vibration reduction using response surface methods

    Science.gov (United States)

    Viswamurthy, S. R.; Ganguli, Ranjan

    2007-03-01

    This study aims to determine optimal locations of dual trailing-edge flaps to achieve minimum hub vibration levels in a helicopter, while incurring low penalty in terms of required trailing-edge flap control power. An aeroelastic analysis based on finite elements in space and time is used in conjunction with an optimal control algorithm to determine the flap time history for vibration minimization. The reduced hub vibration levels and required flap control power (due to flap motion) are the two objectives considered in this study and the flap locations along the blade are the design variables. It is found that second order polynomial response surfaces based on the central composite design of the theory of design of experiments describe both objectives adequately. Numerical studies for a four-bladed hingeless rotor show that both objectives are more sensitive to outboard flap location compared to the inboard flap location by an order of magnitude. Optimization results show a disjoint Pareto surface between the two objectives. Two interesting design points are obtained. The first design gives 77 percent vibration reduction from baseline conditions (no flap motion) with a 7 percent increase in flap power compared to the initial design. The second design yields 70 percent reduction in hub vibration with a 27 percent reduction in flap power from the initial design.

  2. Load alleviation potential of the Controllable Rubber Trailing Edge Flap (CRTEF) in the INDUFLAP project

    DEFF Research Database (Denmark)

    Barlas, Thanasis K.; Bergami, Leonardo; Hansen, Morten Hartvig

    The load alleviation potential of the Controllable Rubber Trailing Edge Flap (CRTEF) is verified on a full Design Load Base (DLB) setup using the aeroelastic code HAWC2, and by investigating a flap configuration for the NREL 5MW Reference Wind Turbine (RWT) model. The performance of the CRTEF...

  3. Development of a Wind Turbine Test Rig and Rotor for Trailing Edge Flap Investigation: Static Flap Angles Case

    International Nuclear Information System (INIS)

    Abdelrahman, Ahmed; Johnson, David A

    2014-01-01

    One of the strategies used to improve performance and increase the life-span of wind turbines is active flow control. It involves the modification of the aerodynamic characteristics of a wind turbine blade by means of moveable aerodynamic control surfaces. Trailing edge flaps are relatively small moveable control surfaces placed at the trailing edge of a blade's airfoil that modify the lift of a blade or airfoil section. An instrumented wind turbine test rig and rotor were specifically developed to enable a wide-range of experiments to investigate the potential of trailing edge flaps as an active control technique. A modular blade based on the S833 airfoil was designed to allow accurate instrumentation and customizable settings. The blade is 1.7 meters long, had a constant 178mm chord and a 6° pitch. The modular aerodynamic parts were 3D printed using plastic PC-ABS material. The blade design point was within the range of wind velocities in the available large test facility. The wind facility is a large open jet wind tunnel with a maximum velocity of 11m/s in the test area. The capability of the developed system was demonstrated through an initial study of the effect of stationary trailing edge flaps on blade load and performance. The investigation focused on measuring the changes in flapwise bending moment and power production for different trailing edge flap spanwise locations and deflection angles. The relationship between the load reduction and deflection angle was linear as expected from theory and the highest reduction was caused by the flap furthest from the rotor center. Overall, the experimental setup proved to be effective in measuring small changes in flapwise bending moment within the wind turbine blade and will provide insight when (active) flap control is targeted

  4. Aeroelastic Stability of a 2D Airfoil Section equipped with a Trailing Edge Flap

    DEFF Research Database (Denmark)

    Bergami, Leonardo

    Recent studies conclude that important reduction of the fatigue loads encountered by a wind turbine blade can be achieved using a deformable trailing edge control system. The focus of the current work is to determine the effect of this flap-like system on the aeroelastic stability of a 2D airfoil...... section. A simulation tool is implemented to predict the flow speed at which a flap equipped section may become unstable, either due to flutter or divergence. First, the stability limits of the airfoil without flap are determined, and, in the second part of the work, a deformable trailing edge flap...... is applied. Stability is investigated for the uncontrolled flap, and for three different control algorithms. The three controls are tuned for fatigue load alleviation and they are based on, respectively, measurement of the heave displacement and velocity, measurement of the local angle of attack, measurement...

  5. Structural and mechanism design of an active trailing-edge flap blade

    DEFF Research Database (Denmark)

    Lee, Jae Hwan; Natarajan, Balakumaran; Eun, Won Jong

    2013-01-01

    , as the blade is able to withstand increased centrifugal force. The cross-section of the active blade is designed first. A stress/strain recovery analysis is then conducted to verify its structural integrity. A one-dimensional beam analysis is also carried out to assist with the construction of the fan diagram...... of the rotor through modification of unsteady aerodynamic loads. Piezoelectric actuators installed inside the blade manipulate the motion of the trailing edge flap. The proposed blade rotates at higher speed and additional structures are included to support the actuators and the flap. This improves the design....... To select the actuator and design the flap actuation region, the flap hinge moment is estimated via a CFD analysis. To obtain the desired flap deflection of ±4°, three actuators are required. The design of the flap actuation region is validated using a test bed with a skin hinge. However, because the skin...

  6. A simple concept for covering pressure sores: wound edge-based propeller perforator flap.

    Science.gov (United States)

    Kelahmetoglu, Osman; Van Landuyt, Koenraad; Yagmur, Caglayan; Sommeling, Casper E; Keles, Musa K; Tayfur, Volkan; Simsek, Tekin; Demirtas, Yener; Guneren, Ethem

    2017-12-01

    We present a new surgical modification to allow propeller perforator flaps to cover pressure sores at various locations. We used a propeller perforator flap concept based on the detection of newly formed perforator vessels located 1 cm from the wound margin and stimulated by the chronic inflammation process. Between January 2009 and January 2017, 33 wound edge-based propeller perforator flaps were used to cover pressure sores at various locations in 28 patients. In four cases more than one flap was used on the same patient. The patients comprised 18 males and 10 females with a mean age of 41·25 (range, 16-70) years. All patients underwent follow-up for 0-12 months. The mean follow-up duration was 5·03 months. Venous congestion was observed in three flaps that were rotated by 180° (9·1%). However, there was a significant difference between flaps rotated by 90° and 180° according to the complication rate (P = 0·034). Out of 33 flaps, 29 flaps healed uneventfully. Patients were able to sit and lie on their flaps three weeks after surgery. In our study, we were able to obtain satisfying final results using these novel flaps. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  7. Modulation of leading edge vorticity and aerodynamic forces in flexible flapping wings.

    Science.gov (United States)

    Zhao, Liang; Deng, Xinyan; Sane, Sanjay P

    2011-09-01

    In diverse biological flight systems, the leading edge vortex has been implicated as a flow feature of key importance in the generation of flight forces. Unlike fixed wings, flapping wings can translate at higher angles of attack without stalling because their leading edge vorticity is more stable than the corresponding fixed wing case. Hence, the leading edge vorticity has often been suggested as the primary determinant of the high forces generated by flapping wings. To test this hypothesis, it is necessary to modulate the size and strength of the leading edge vorticity independently of the gross kinematics while simultaneously monitoring the forces generated by the wing. In a recent study, we observed that forces generated by wings with flexible trailing margins showed a direct dependence on the flexural stiffness of the wing. Based on that study, we hypothesized that trailing edge flexion directly influences leading edge vorticity, and thereby the magnitude of aerodynamic forces on the flexible flapping wings. To test this hypothesis, we visualized the flows on wings of varying flexural stiffness using a custom 2D digital particle image velocimetry system, while simultaneously monitoring the magnitude of the aerodynamic forces. Our data show that as flexion decreases, the magnitude of the leading edge vorticity increases and enhances aerodynamic forces, thus confirming that the leading edge vortex is indeed a key feature for aerodynamic force generation in flapping flight. The data shown here thus support the hypothesis that camber influences instantaneous aerodynamic forces through modulation of the leading edge vorticity.

  8. Adaptive trailing edge flaps for active load alleviation in a smart rotor configuration

    Energy Technology Data Exchange (ETDEWEB)

    Bergami, L.

    2013-08-15

    The work investigates the development of an active smart rotor concept from an aero-servo-elastic perspective. An active smart rotor is a wind turbine rotor that, through a combination of sensors, control units and actuators, is able to alleviate the fluctuating part of the aerodynamic loads it has to withstand. The investigation focuses on a specific actuator type: the Adaptive Trailing Edge Flap (ATEF), which introduces a continuous deformation of the aft part of the airfoil camber-line. An aerodynamic model that accounts for the steady and unsteady effects of the flap deflection on a 2D airfoil section is developed, and, considering both attached and separated flow conditions, is validated by comparison against Computational Fluid Dynamic solutions and a panel code method. The aerodynamic model is integrated in the BEM-based aeroelastic simulation code HAWC2, thus providing a tool able to simulate the response of a wind turbine equipped with ATEF. A load analysis of the NREL 5 MW reference turbine in its baseline configuration reveals that the highest contribution to the blade flapwise fatigue damage originates from normal operation above rated wind speed, and from loads characterized by frequencies below 1 Hz. The analysis also reports that periodic load variations on the turbine blade account for nearly 11 % of the blade flapwise lifetime fatigue damage, while the rest is ascribed to load variations from disturbances of stochastic nature. The study proposes a smart rotor configuration with flaps laid out on the outer 20 % of the blade span, from 77 % to 97% of the blade length. The configuration is first tested with a simplified cyclic control approach, which gives a preliminary indication of the load alleviation potential, and also reveals the possibility to enhance the rotor energy capture below rated conditions by using the flaps. Two model based control algorithms are developed to actively alleviate the fatigue loads on the smart rotor with ATEF. The first

  9. Towards an industrial manufactured morphing trailing edge flap system for wind turbines

    OpenAIRE

    Aagaard Madsen , Helge; Løgstrup Andersen, Tom; Bergami, Leonardo; Jørgensen, Johnny Egtved; Candela Garolera, Anna; Holbøll, Joachim; Schettler, T.; Michels, P.; Schoebel, M.; Heisterberg, M.; Christensen, M.B.

    2014-01-01

    A flap actuation system, the Controllable Rubber Trailing Edge Flap (CRTEF), for distributed load control on a wind turbine blade has been developed in the period from 2006 to 2010 at DTU. The function of the system and its capability to change the lift on a blade section was measured during a wind tunnel experiment in 2009 with promising results. This led in 2011 to initiation of a new research project INDUFLAP with the main aim to transfer the flap technology to industry as concerns manufac...

  10. PIV study of flow around unsteady airfoil with dynamic trailing-edge flap deflection

    Energy Technology Data Exchange (ETDEWEB)

    Gerontakos, P.; Lee, T. [McGill University, Department of Mechanical Engineering, Montreal, Quebec (Canada)

    2008-12-15

    The flow around an oscillating NACA 0015 airfoil with prescheduled trailing-edge flap motion control was investigated by using particle image velocimetry (PIV). Aerodynamic load coefficients, obtained via surface pressure measurements, were also acquired to supplement the PIV results. The results demonstrate that upward flap deflections led to an improved negative peak pitching moment coefficient C{sub m,peak}, mainly as a consequence of the increased suction pressure on the lower surface of the flap. The behavior of the leading-edge vortex (LEV) was largely unaffected. Its strength was, however, reduced slightly compared to that of the uncontrolled airfoil. No trailing-edge vortex was observed. For downward flap deflection, the strength of the LEV was found to be slightly increased. A favorable increase in C{sub l,max}, as a consequence of downward flap-induced positive camber effects, accompanied by a detrimental increase in the nose-down C{sub m,peak}, due to the large pressure increase on the lower surface of the flap, was also observed. (orig.)

  11. Smart rotor modeling aero-servo-elastic modeling of a smart rotor with adaptive trailing edge flaps

    CERN Document Server

    Bergami, Leonardo

    2014-01-01

    A smart rotor is a wind turbine rotor that, through a combination of sensors, control units and actuators actively reduces the variation of the aerodynamic loads it has to withstand. Smart rotors feature?promising load alleviation potential and might provide the technological breakthrough required by the next generation of large wind turbine rotors.The book presents the aero-servo-elastic model of a smart rotor with Adaptive Trailing Edge Flaps for active load alleviation and provides an insight on the rotor aerodynamic, structural and control modeling. A novel model for the unsteady aerodynam

  12. Hybrid immersed boundary method for airfoils with a trailing-edge flap

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Behrens, Tim; Shen, Wen Zhong

    2013-01-01

    In this paper, a hybrid immersed boundary technique has been developed for simulating turbulent flows past airfoils with moving trailing-edge flaps. Over the main fixed part of the airfoil, the equations are solved using a standard body-fitted finite volume technique, whereas the moving trailing......-edge flap is simulated using the immersed boundary method on a curvilinear mesh. An existing in-house-developed flow solver is employed to solve the incompressible Reynolds-Averaged Navier-Stokes equations together with the k-ω turbulence model. To achieve consistent wall boundary conditions at the immersed...... boundaries the k-ωturbulence model is modified and adapted to the local conditions associated with the immersed boundary method. The obtained results show that the hybrid approach is an efficient and accurate method for solving turbulent flows past airfoils with a trailing-edge flap and that flow control...

  13. Structural and mechanism design of an active trailing-edge flap blade

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hwan [Samsung Techwin R and D Center, Seongnam (Korea, Republic of); Natarajan, Balakumaran; Eun, Won Jong; Shin, Sang Joon [Seoul National University, Seoul (Korea, Republic of); R, Viswamurthy S. [National Aerospace Laboratories, Bangalore (India); Park, Jae Sang [Agency for Defense Development, Daejeon (Korea, Republic of); Kim, Tae Song [Technical University of Denmark, Risoe Campus, Roskilde (Denmark)

    2013-09-15

    A conventional rotor control system restricted at 1/rev frequency component is unable to vary the hub vibratory loads and the aero acoustic noise, which exist in high frequency components. Various active rotor control methodologies have been examined in the literature to alleviate the problem of excessive hub vibratory loads and noise. The active control device manipulates the blade pitch angle with arbitrary higher harmonic frequencies individually. In this paper, an active trailing-edge flap blade, which is one of the active control methods, is developed to reduce vibratory loads and noise of the rotor through modification of unsteady aerodynamic loads. Piezoelectric actuators installed inside the blade manipulate the motion of the trailing edge flap. The proposed blade rotates at higher speed and additional structures are included to support the actuators and the flap. This improves the design, as the blade is able to withstand increased centrifugal force. The cross-section of the active blade is designed first. A stress/strain recovery analysis is then conducted to verify its structural integrity. A one-dimensional beam analysis is also carried out to assist with the construction of the fan diagram. To select the actuator and design the flap actuation region, the flap hinge moment is estimated via a CFD analysis. To obtain the desired flap deflection of ±4 .deg. , three actuators are required. The design of the flap actuation region is validated using a test bed with a skin hinge. However, because the skin hinge induces additional flap hinge moment, it does not provide sufficient deflection angle. Therefore, the flap hinge is replaced by a pin-type hinge, and the results are evaluated.

  14. Aeroelastic Optimization of a 10 MW Wind Turbine Blade with Active Trailing Edge Flaps

    DEFF Research Database (Denmark)

    Barlas, Athanasios; Tibaldi, Carlo; Zahle, Frederik

    2016-01-01

    This article presents the aeroelastic optimization of a 10MW wind turbine ‘smart blade’ equipped with active trailing edge flaps. The multi-disciplinary wind turbine analysis and optimization tool HawtOpt2 is utilized, which is based on the open-source framework Open-MDAO. The tool interfaces...... to several state-of-the art simulation codes, allowing for a wide variety of problem formulations and combinations of models. A simultaneous aerodynamic and structural optimization of a 10 MW wind turbine rotor is carried out with respect to material layups and outer shape. Active trailing edge flaps...

  15. Atmospheric Full Scale Testing of a Morphing Trailing Edge Flap System for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Barlas, Athanasios; Aagaard Madsen, Helge

    2015-01-01

    at the Risø Campus of DTU Wind Energy in Denmark. The design and instrumentation of the wing section and the AFS are described. The general description and objectives of the rotating test rig at the Risø campus of DTU are presented, along with an overview of sensors on the setup and the test cases. The post-processing...... of data is discussed and results of steady, flap step and azimuth control flap cases are presented....

  16. Structural design optimization of a morphing trailing edge flap for wind turbine blades

    DEFF Research Database (Denmark)

    Barlas, Athanasios; Lin, Yu-Huan; Aagaard Madsen, Helge

    A flap actuation system, the Controllable Rubber Trailing Edge Flap (CRTEF), for distributed load control on a wind turbine blade had been developed in the period from 2006 to 2013 at DTU (http://www.induflap.dk/). The purpose of the presented work is to optimize the structural design of the flex......A flap actuation system, the Controllable Rubber Trailing Edge Flap (CRTEF), for distributed load control on a wind turbine blade had been developed in the period from 2006 to 2013 at DTU (http://www.induflap.dk/). The purpose of the presented work is to optimize the structural design...... of the flexible part of the CRTEF based on a realistic blade section geometry in order to meet the required objectives and constraints. The objectives include the deflection requirements and the energy efficiency, while the constraints include the bending stiffness of the structure, the local shape deformations......, critical material strength, and manufacturing limitations. A model with arches forming concave on the flap surface and enclosing the voids to be pressurized results in the bending movement of the flap when pressure is applied on the voids to straighten the arches. The model is designed using SolidWorks...

  17. Testing of a new morphing trailing edge flap system on a novel outdoor rotating test rig

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Barlas, Athanasios; Løgstrup Andersen, Tom

    2015-01-01

    The morphing trailing edge system or flap system, CRTEF, has been developed over the last 10 years at DTU Wind Energy. After a promising wind tunnel test of the system in 2009 the INDUFLAP project has been carried out from 2011-2014 to transfer the technology from laboratory to industrial...... manufacturing and application. To narrow the gap between wind tunnel testing and full scale prototype testing we developed the rotating test rig. The overall objectives with the rotating test rig are: 1) to test the flap system in a realistic rotating environment with a realistic g-loading; 2) to measure...... the flap performance in real turbulent inflow and 3) to test the flap system in a realistic size and Reynolds number when comparing with full scale applications.. The rotating test rig consists of a 2.2m blade section attached to a 10m boom and mounted on a 100kW turbine platform. It was installed in June...

  18. Aeroservoelastic stability of a 2D airfoil section equipped with a trailing edge flap

    Energy Technology Data Exchange (ETDEWEB)

    Bergami, Leonardo

    2008-11-15

    Recent studies conclude that important reduction of the fatigue loads encountered by a wind turbine blade can be achieved using a deformable trailing edge control system. The focus of the current work is to determine the effect of this flap-like system on the aeroelastic stability of a 2D airfoil section. A simulation tool is implemented to predict the flow speed at which a flap equipped section may become unstable, either due to flutter or divergence. First, the stability limits of the airfoil without flap are determined, and, in the second part of the work, a deformable trailing edge flap is applied. Stability is investigated for the uncontrolled flap, and for three different control algorithms. The three controls are tuned for fatigue load alleviation and they are based on, respectively, measurement of the heave displacement and velocity, measurement of the local angle of attack, measurement of the pressure difference between the two sides of the airfoil. The stability of the aeroservoelastic system in a defined equilibrium state, and for a given flow speed, is then determined by solving an eigenvalue problem. Results show that the trailing edge control system modifies significantly the stability limits of the section. In the investigated case, increased flutter limits are reported when the elastic flap is left without control, whereas, by applying any of the control algorithms, the flutter velocity is reduced. Nevertheless, only in the heave control case the flutter limit becomes critically close to normal operation flow speeds. Furthermore, a marked dependence of the stability limits on the control gain is also observed and, by tuning the gain parameters, flutter and divergence can be suppressed for flow speed even above the flutter velocity encountered with uncontrolled flap. (author)

  19. Numerical Investigation of Flow Control Feasibility with a Trailing Edge Flap

    International Nuclear Information System (INIS)

    Zhu, W J; Shen, W Z; Sørensen, J N

    2014-01-01

    This paper concerns a numerical study of employing an adaptive trailing edge flap to control the lift of an airfoil subject to unsteady inflow conditions. The periodically varying inflow is generated by two oscillating airfoils, which are located upstream of the controlled airfoil. To establish the control system, a standard PID controller is implemented in a finite volume based incompressible flow solver. An immersed boundary method is applied to treat the problem of simulating a deformable airfoil trailing edge. The flow field is solved using a 2D Reynolds averaged Navier-Stokes finite volume solver. In order to more accurately simulate wall bounded flows around the immersed boundary, a modified boundary condition is introduced in the k- ω turbulence model. As an example, turbulent flow over a NACA 64418 airfoil with a deformable trailing edge is investigated. Results from numerical simulations are convincing and may give some highlights for practical implementations of trailing edge flap to a wind turbine rotor blade

  20. Performance of active edge pixel sensors

    Science.gov (United States)

    Bomben, M.; Ducourthial, A.; Bagolini, A.; Boscardin, M.; Bosisio, L.; Calderini, G.; D'Eramo, L.; Giacomini, G.; Marchiori, G.; Zorzi, N.; Rummler, A.; Weingarten, J.

    2017-05-01

    To cope with the High Luminosity LHC harsh conditions, the ATLAS inner tracker has to be upgraded to meet requirements in terms of radiation hardness, pile up and geometrical acceptance. The active edge technology allows to reduce the insensitive area at the border of the sensor thanks to an ion etched trench which avoids the crystal damage produced by the standard mechanical dicing process. Thin planar n-on-p pixel sensors with active edge have been designed and produced by LPNHE and FBK foundry. Two detector module prototypes, consisting of pixel sensors connected to FE-I4B readout chips, have been tested with beams at CERN and DESY. In this paper the performance of these modules are reported. In particular the lateral extension of the detection volume, beyond the pixel region, is investigated and the results show high hit efficiency also at the detector edge, even in presence of guard rings.

  1. Aerodynamic improvement of a delta wing in combination with leading edge flaps

    Directory of Open Access Journals (Sweden)

    Tadateru Ishide

    2017-11-01

    Full Text Available Recently, various studies of micro air vehicle (MAV and unmanned air vehicle (UAV have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing in low Reynold’s number region to develop an applicative these air vehicle. As an attractive tool in delta wing, leading edge flap (LEF is employed to directly modify the strength and structure of vortices originating from the separation point along the leading edge. Various configurations of LEF such as drooping apex flap and upward deflected flap are used in combination to enhance the aerodynamic characteristics in the delta wing. The fluid force measurement by six component load cell and particle image velocimetry (PIV analysis are performed as the experimental method. The relations between the aerodynamic superiority and the vortex behavior around the models are demonstrated.

  2. 2D numerical comparison of trailing edge flaps - UpWind WP1B3

    Energy Technology Data Exchange (ETDEWEB)

    Buhl, T.; Andersen, Peter B. (Risoe National Lab., DTU (DK)); Barlas, T.K. (DUWIND, Delft Technical Univ. (NL))

    2007-11-15

    This report covers the investigations and comparisons of trailing edge flaps carried out by Delft and Risoe. The work is a part of the W1B3 work package of the UpWind EU-project. This report covers only 2D test cases with simple control of the trailing edge flap with the objective of keeping CL constant. The 5MW UpWind reference turbine is used for the calculations. The section in 75% radius is investigated for three different cases; (1) a wind step from 10m/s to 11m/s, (2) a wind 'gust' from 10 m/s to 14m/s in 1 second and followed by 10m/s, (3) finally a turbulent wind series is simulated, and the performance of the flaps is investigated. The two different codes from Delft and Risoe are compared in the mentioned cases. (au)

  3. Investigation of the load reduction potential of two trailing edge flap controls using CFD

    DEFF Research Database (Denmark)

    Heinz, Joachim Christian; Sørensen, Niels N.; Zahle, Frederik

    2011-01-01

    ) and subjected to a turbulent inflow signal. The employed airfoil model corresponds to a successfully tested prototype airfoil where piezoelectric actuators were used for the flapping. In the present investigation two possible control methods for the flap are compared in their ability to reduce the fluctuating......In this work, a 2D aero‐servo‐elastic model of an airfoil section with 3 degrees of freedom (DOF) based on the 2D CFD solver EllipSys2D to calculate the aerodynamic forces is utilized to calculate the load reduction potential of an airfoil equipped with an adaptive trailing edge flap (ATEF...... normal forces on the airfoil due to a 4 s turbulent inflow signal and the best location of the measurement point for the respective control input is determined. While Control 1 uses the measurements of a Pitot tube mounted in front of the leading edge (LE) as input, Control 2 uses the pressure difference...

  4. Aerodynamic forces and flow structures of the leading edge vortex on a flapping wing considering ground effect

    International Nuclear Information System (INIS)

    Truong, Tien Van; Yoon, Kwang Joon; Byun, Doyoung; Kim, Min Jun; Park, Hoon Cheol

    2013-01-01

    The aim of this work is to provide an insight into the aerodynamic performance of the beetle during takeoff, which has been estimated in previous investigations. We employed a scaled-up electromechanical model flapping wing to measure the aerodynamic forces and the three-dimensional flow structures on the flapping wing. The ground effect on the unsteady forces and flow structures were also characterized. The dynamically scaled wing model could replicate the general stroke pattern of the beetle's hind wing kinematics during takeoff flight. Two wing kinematic models have been studied to examine the influences of wing kinematics on unsteady aerodynamic forces. In the first model, the angle of attack is asymmetric and varies during the translational motion, which is the flapping motion of the beetle's hind wing. In the second model, the angle of attack is constant during the translational motion. The instantaneous aerodynamic forces were measured for four strokes during the beetle's takeoff by the force sensor attached at the wing base. Flow visualization provided a general picture of the evolution of the three-dimensional leading edge vortex (LEV) on the beetle hind wing model. The LEV is stable during each stroke, and increases radically from the root to the tip, forming a leading-edge spiral vortex. The force measurement results show that the vertical force generated by the hind wing is large enough to lift the beetle. For the beetle hind wing kinematics, the total vertical force production increases 18.4% and 8.6% for the first and second strokes, respectively, due to the ground effect. However, for the model with a constant angle of attack during translation, the vertical force is reduced during the first stroke. During the third and fourth strokes, the ground effect is negligible for both wing kinematic patterns. This finding suggests that the beetle's flapping mechanism induces a ground effect that can efficiently lift its body from the ground during takeoff

  5. Superconducting Metallic Glass Transition-Edge-Sensors

    Science.gov (United States)

    Hays, Charles C. (Inventor)

    2013-01-01

    A superconducting metallic glass transition-edge sensor (MGTES) and a method for fabricating the MGTES are provided. A single-layer superconducting amorphous metal alloy is deposited on a substrate. The single-layer superconducting amorphous metal alloy is an absorber for the MGTES and is electrically connected to a circuit configured for readout and biasing to sense electromagnetic radiation.

  6. Pneumatic artificial muscles for trailing edge flap actuation: a feasibility study

    Science.gov (United States)

    Woods, Benjamin K. S.; Kothera, Curt S.; Sirohi, Jayant; Wereley, Norman M.

    2011-10-01

    In this study a novel aircraft trailing edge flap actuation system was developed and tested. Pneumatic artificial muscles (PAMs) were used as the driving elements of this system to demonstrate their feasibility and utility as an alternative aerospace actuation technology. A prototype flap/actuator system was integrated into a model wing section and tested on the bench-top under simulated airloads for flight at 100 m s-1 (M = 0.3) and in an open-jet wind tunnel at free stream velocities ranging up to 45 m s-1 (M = 0.13). Testing was performed for actuator pressures ranging from 0.069 to 0.62 MPa (10-90 psi) and actuation frequencies from 0.1 to 31 Hz. Results show that the PAM-driven trailing edge flap system can generate substantial and sustainable dynamic deflections, thereby proving the feasibility of using pneumatic artificial muscle actuators in a trailing edge flap system. Key issues limiting system performance are identified, that should be resolved in future research.

  7. Pneumatic artificial muscles for trailing edge flap actuation: a feasibility study

    International Nuclear Information System (INIS)

    Woods, Benjamin K S; Wereley, Norman M; Kothera, Curt S; Sirohi, Jayant

    2011-01-01

    In this study a novel aircraft trailing edge flap actuation system was developed and tested. Pneumatic artificial muscles (PAMs) were used as the driving elements of this system to demonstrate their feasibility and utility as an alternative aerospace actuation technology. A prototype flap/actuator system was integrated into a model wing section and tested on the bench-top under simulated airloads for flight at 100 m s −1 (M = 0.3) and in an open-jet wind tunnel at free stream velocities ranging up to 45 m s −1 (M = 0.13). Testing was performed for actuator pressures ranging from 0.069 to 0.62 MPa (10–90 psi) and actuation frequencies from 0.1 to 31 Hz. Results show that the PAM-driven trailing edge flap system can generate substantial and sustainable dynamic deflections, thereby proving the feasibility of using pneumatic artificial muscle actuators in a trailing edge flap system. Key issues limiting system performance are identified, that should be resolved in future research

  8. On the Connection Between Flap Side-Edge Noise and Tip Vortex Dynamics

    Science.gov (United States)

    Casalino, D.; Hazir, A.; Fares, E.; Duda, B.; Khorrami, M. R.

    2015-01-01

    The goal of the present work is to investigate how the dynamics of the vortical flow about the flap side edge of an aircraft determine the acoustic radiation. A validated lattice- Boltzmann CFD solution of the unsteady flow about a detailed business jet configuration in approach conditions is used for the present analysis. Evidence of the connection between the noise generated by several segments of the inboard flap tip and the aerodynamic forces acting on the same segments is given, proving that the noise generation mechanism has a spatially coherent and acoustically compact character on the scale of the flap chord, and that the edge-scattering effects are of secondary importance. Subsequently, evidence of the connection between the kinematics of the tip vortex system and the aerodynamic force is provided. The kinematics of the dual vortex system are investigated via a core detection technique. Emphasis is placed on the mutual induction effects between the two main vortices rolling up from the pressure and suction sides of the flap edge. A simple heuristic formula that relates the far-field noise spectrum and the cross-spectrum of the unsteady vortical positions is developed.

  9. Approach for Structurally Clearing an Adaptive Compliant Trailing Edge Flap for Flight

    Science.gov (United States)

    Miller, Eric J.; Lokos, William A.; Cruz, Josue; Crampton, Glen; Stephens, Craig A.; Kota, Sridhar; Ervin, Gregory; Flick, Pete

    2015-01-01

    The Adaptive Compliant Trailing Edge (ACTE) flap was flown on the National Aeronautics and Space Administration (NASA) Gulfstream GIII testbed at the NASA Armstrong Flight Research Center. This smoothly curving flap replaced the existing Fowler flaps creating a seamless control surface. This compliant structure, developed by FlexSys Inc. in partnership with the Air Force Research Laboratory, supported NASA objectives for airframe structural noise reduction, aerodynamic efficiency, and wing weight reduction through gust load alleviation. A thorough structures airworthiness approach was developed to move this project safely to flight. A combination of industry and NASA standard practice require various structural analyses, ground testing, and health monitoring techniques for showing an airworthy structure. This paper provides an overview of compliant structures design, the structural ground testing leading up to flight, and the flight envelope expansion and monitoring strategy. Flight data will be presented, and lessons learned along the way will be highlighted.

  10. Adaptive Trailing Edge Flaps for Active Load Alleviation in a Smart Rotor Configuration

    DEFF Research Database (Denmark)

    Bergami, Leonardo

    to withstand. The investigation focuses on a specific actuator type: the Adaptive Trailing Edge Flap (ATEF), which introduces a continuous deformation of the aft part of the airfoil camber-line. An aerodynamic model that accounts for the steady and unsteady effects of the flap deflection on a 2D airfoil...... section is developed, and, considering both attached and separated flow conditions, is validated by comparison against Computational Fluid Dynamic solutions and a panel code method. The aerodynamic model is integrated in the BEM-based aeroelastic simulation code HAWC2, thus providing a tool able...... with flaps laid out on the outer 20 % of the blade span, from 77 % to 97% of the blade length. The configuration is first tested with a simplified cyclic control approach, which gives a preliminary indication of the load alleviation potential, and also reveals the possibility to enhance the rotor energy...

  11. Extreme load alleviation using industrial implementation of active trailing edge flaps in a full design load basis

    OpenAIRE

    Barlas, Athanasios; Pettas, Vasilis; Gertz, Drew Patrick; Aagaard Madsen , Helge

    2016-01-01

    The application of active trailing edge flaps in an industrial oriented implementation is evaluated in terms of capability of alleviating design extreme loads. A flap system with basic control functionality is implemented and tested in a realistic full Design Load Basis (DLB) for the DTU 10MW Reference Wind Turbine (RWT) model and for an upscaled rotor version in DTU's aeroelastic code HAWC2. The flap system implementation shows considerable potential in reducing extreme loads in components o...

  12. An investigation of unsteady 3-D effects on trailing edge flaps

    Directory of Open Access Journals (Sweden)

    E. Jost

    2017-05-01

    Full Text Available The present study investigates the impact of unsteady 3-D aerodynamic effects on a wind turbine blade with trailing edge flap by means of computational fluid dynamics (CFD. Harmonic oscillations are simulated on the DTU 10 MW rotor with a morphing flap of 10 % chord extent ranging from 70 to 80 % blade radius. The deflection frequency is varied in the range between 1 and 6 p. To quantify 3-D effects, rotor simulations are compared to 2-D airfoil computations and the 2-D theory by Theodorsen. It was found that the deflection of the flap on the 3-D rotor causes a complex wake development and induction which influences the loads over large parts of the blade. In particular, the rotor near wake with its trailing and shed vortex structures revealed a great impact. Trailing vorticity, a 3-D phenomenon, is caused by the gradient of bound circulation along the blade span. Shed vorticity originates from the temporal bound circulation gradient and is thus also apparent in 2-D. Both lead to an amplitude reduction and shed vorticity additionally to a hysteresis of the lift response with regard to the deflection signal in the flap section. A greater amplitude reduction and a less pronounced hysteresis is observed on the 3-D rotor compared to the 2-D airfoil case. Blade sections neighboring the flap experience, however, an opposing impact and hence partly compensate for the negative effect of trailing vortices in the flap section with respect to integral loads. Comparisons to steady flap deflections at the 3-D rotor revealed the high influence of dynamic inflow effects.

  13. Extreme load alleviation using industrial implementation of active trailing edge flaps in a full design load basis

    DEFF Research Database (Denmark)

    Barlas, Athanasios; Pettas, Vasilis; Gertz, Drew Patrick

    2016-01-01

    The application of active trailing edge flaps in an industrial oriented implementation is evaluated in terms of capability of alleviating design extreme loads. A flap system with basic control functionality is implemented and tested in a realistic full Design Load Basis (DLB) for the DTU 10MW...

  14. Active load reduction by means of trailing edge flaps on a wind turbine blade

    DEFF Research Database (Denmark)

    Couchman, Ian; Castaignet, Damien; Poulsen, Niels Kjølstad

    2014-01-01

    This paper presents the blade fatigue load reduction achieved with a trailing edge flap during a full scale test on a Vestas V27 wind turbine. A frequency-weighted linear model predictive control (MPC) is tuned to decrease flapwise blade root fatigue loads at the frequencies where most of the blade...... damage occurs, i.e. the 1P and 2P frequencies (respectively 1 and 2 events per revolution). Frequency-weighted MPC is chosen for its ability to handle constraints on the trailing edge flap deflection and to optimise its actuation in order to decrease wear and tear of the actuator. The controller...... was first tested in aero-servo-elastic simulations, before being implemented on a Vestas V27 wind turbine. Consistent load reduction is achieved during the full-scale test. An average of 14% flapwise blade root fatigue load reduction is measured....

  15. 2D numerical comparison of trailing edge flaps - UpWind WP1B3

    DEFF Research Database (Denmark)

    Buhl, Thomas; Andersen, Peter Bjørn; Barlas, T.K.

    This report covers the investigations and comparisons of trailing edge flaps carried out by Delft and Risø. The work is a part of the W1B3 work package of the UpWind EU-project. This report covers only 2D test cases with simple control of the trailing edge flap with the objective of keeping CL...... constant. The 5MW UpWind reference turbine is used for the calculations. The section in 75% radius is investigated for three different cases; 1) a wind step from 10m/s to 11m/s, 2) a wind “gust” from 10 m/s to 14m/s in 1 second and followed by 10m/s, 3) finally a turbulent wind series is simulated...

  16. Simulation of Moving Trailing Edge Flaps on a Wind Turbine Blade using a Navier-Stokes based Immersed Boundary Method

    DEFF Research Database (Denmark)

    Behrens, Tim

    . Simulations demonstrated the feasibility and robustness of the approach. The hybrid immersed boundary approach proved to be able to handle 3D airfoil sections with span-wise flap gaps. The flow around and in the wake of a deflected flap at a Reynolds number of 1.63mio was investigated for steady inflow......As the rotor diameter of wind turbines increases, turbine blades with distributed aerodynamic control surfaces promise significant load reductions. Therefore, they are coming into focus in relation to research in academia and industry. Trailing edge flaps are of particular interest in terms...... conditions. A control for two span-wise independent flaps was implemented and first load reductions could be achieved. The hybrid method has demonstrated to be a versatile tool in the research of moving trailing edge flaps. The results shall serve as the basis for future investigations of the unsteady flow...

  17. The Multipoint Global Shape Optimization of Flying Configuration with Movable Leading Edges Flaps

    Directory of Open Access Journals (Sweden)

    Adriana NASTASE

    2012-12-01

    Full Text Available The aerodynamical global optimized (GO shape of flying configuration (FC, at two cruising Mach numbers, can be realized by morphing. Movable leading edge flaps are used for this purpose. The equations of the surfaces of the wing, of the fuselage and of the flaps in stretched position are approximated in form of superpositions of homogeneous polynomes in two variables with free coefficients. These coefficients together with the similarity parameters of the planform of the FC are the free parameters of the global optimization. Two enlarged variational problems with free boundaries occur. The first one consists in the determination of the GO shape of the wing-fuselageFC, with the flaps in retracted position, which must be of minimum drag, at higher cruising Mach number. The second enlarged variational problem consists in the determination of the GO shape of the flaps in stretched position in such a manner that the entire FC shall be of minimum drag at the second lower Mach number. The iterative optimum-optimorum (OO theory of the author is used for the solving of these both enlarged variational problems. The inviscid GO shape of the FC is used only in the first step of iteration and the own developed hybrid solutions for the compressible Navier-Stokes partial-differential equations (PDEs are used for the determination of the friction drag coefficient and up the second step of iteration of OO theory.

  18. ATEFlap aerodynamic model, a dynamic stall model including the effects of trailing edge flap deflection

    Energy Technology Data Exchange (ETDEWEB)

    Bergami, L.; Gaunaa, M.

    2012-02-15

    The report presents the ATEFlap aerodynamic model, which computes the unsteady lift, drag and moment on a 2D airfoil section equipped with Adaptive Trailing Edge Flap. The model captures the unsteady response related to the effects of the vorticity shed into the wake, and the dynamics of flow separation a thin-airfoil potential flow model is merged with a dynamic stall model of the Beddoes-Leishmann type. The inputs required by the model are steady data for lift, drag, and moment coefficients as function of angle of attack and flap deflection. Further steady data used by the Beddoes- Leishmann dynamic stall model are computed in an external preprocessor application, which gives the user the possibility to verify, and eventually correct, the steady data passed to the aerodynamic model. The ATEFlap aerodynamic model is integrated in the aeroelastic simulation tool HAWC2, thus al- lowing to simulate the response of a wind turbine with trailing edge flaps on the rotor. The algorithms used by the preprocessor, and by aerodynamic model are presented, and modifications to previous implementations of the aerodynamic model are briefly discussed. The performance and the validity of the model are verified by comparing the dynamic response computed by the ATEFlap with solutions from CFD simulations. (Author)

  19. Thermal physics of transition edge sensor arrays

    International Nuclear Information System (INIS)

    Hoevers, H.F.C.

    2006-01-01

    Thermal transport in transition edge sensor (TES)-based microcalorimeter arrays is reviewed. The fundamentals of thermal conductance in Si 3 N 4 membranes are discussed and the magnitude of the electron-phonon coupling and Kapitza coupling in practical devices is summarized. Next, the thermal transport in high-stopping power and low-heat capacity absorbers, required for arrays of TES microcalorimeters, is discussed in combination with a performance analysis of detectors with mushroom-absorbers. Finally, the phenomenology of unexplained excess noise, observed in both Mo- and Ti-based TESs, is briefly summarized and related with the coupling of the TES to the heat bath

  20. Predicted Aerodynamic Characteristics of a NACA 0015 Airfoil Having a 25% Integral-Type Trailing Edge Flap

    Science.gov (United States)

    Hassan, Ahmed

    1999-01-01

    Using the two-dimensional ARC2D Navier-Stokes flow solver analyses were conducted to predict the sectional aerodynamic characteristics of the flapped NACA-0015 airfoil section. To facilitate the analyses and the generation of the computational grids, the airfoil with the deflected trailing edge flap was treated as a single element airfoil with no allowance for a gap between the flap's leading edge and the base of the forward portion of the airfoil. Generation of the O-type computational grids was accomplished using the HYGRID hyperbolic grid generation program. Results were obtained for a wide range of Mach numbers, angles of attack and flap deflections. The predicted sectional lift, drag and pitching moment values for the airfoil were then cast in tabular format (C81) to be used in lifting-line helicopter rotor aerodynamic performance calculations. Similar were also generated for the flap. Mathematical expressions providing the variation of the sectional lift and pitching moment coefficients for the airfoil and for the flap as a function of flap chord length and flap deflection angle were derived within the context of thin airfoil theory. The airfoil's sectional drag coefficient were derived using the ARC2D drag predictions for equivalent two dimensional flow conditions.

  1. A 3-D Computational Study of a Variable Camber Continuous Trailing Edge Flap (VCCTEF) Spanwise Segment

    Science.gov (United States)

    Kaul, Upender K.; Nguyen, Nhan T.

    2015-01-01

    Results of a computational study carried out to explore the effects of various elastomer configurations joining spanwise contiguous Variable Camber Continuous Trailing Edge Flap (VCCTEF) segments are reported here. This research is carried out as a proof-of-concept study that will seek to push the flight envelope in cruise with drag optimization as the objective. The cruise conditions can be well off design such as caused by environmental conditions, maneuvering, etc. To handle these off-design conditions, flap deflection is used so when the flap is deflected in a given direction, the aircraft angle of attack changes accordingly to maintain a given lift. The angle of attack is also a design parameter along with the flap deflection. In a previous 2D study,1 the effect of camber was investigated and the results revealed some insight into the relative merit of various camber settings of the VCCTEF. The present state of the art has not advanced sufficiently to do a full 3-D viscous analysis of the whole NASA Generic Transport Model (GTM) wing with VCCTEF deployed with elastomers. Therefore, this study seeks to explore the local effects of three contiguous flap segments on lift and drag of a model devised here to determine possible trades among various flap deflections to achieve desired lift and drag results. Although this approach is an approximation, it provides new insights into the "local" effects of the relative deflections of the contiguous spanwise flap systems and various elastomer segment configurations. The present study is a natural extension of the 2-D study to assess these local 3-D effects. Design cruise condition at 36,000 feet at free stream Mach number of 0.797 and a mean aerodynamic chord (MAC) based Reynolds number of 30.734x10(exp 6) is simulated for an angle of attack (AoA) range of 0 to 6 deg. In the previous 2-D study, the calculations revealed that the parabolic arc camber (1x2x3) and circular arc camber (VCCTEF222) offered the best L

  2. Dynamics of a pneumatic artificial muscle actuation system driving a trailing edge flap

    Science.gov (United States)

    Woods, Benjamin K. S.; Kothera, Curt S.; Wang, Gang; Wereley, Norman M.

    2014-09-01

    This study presents a time domain dynamic model of an antagonistic pneumatic artificial muscle (PAM) driven trailing edge flap (TEF) system for next generation active helicopter rotors. Active rotor concepts are currently being widely researched in the rotorcraft community as a means to provide a significant leap forward in performance through primary aircraft control, vibration mitigation and noise reduction. Recent work has shown PAMs to be a promising candidate for active rotor actuation due to their combination of high force, large stroke, light weight, and suitable bandwidth. When arranged into biologically inspired agonist/antagonist muscle pairs they can produce bidirectional torques for effectively driving a TEF. However, there are no analytical dynamic models in the literature that can accurately capture the behavior of such systems across the broad range of frequencies required for this demanding application. This work combines mechanical, pneumatic, and aerodynamic component models into a global flap system model developed for the Bell 407 rotor system. This model can accurately predict pressure, force, and flap angle response to pneumatic control valve inputs over a range of operating frequencies from 7 to 35 Hz (1/rev to 5/rev for the Bell 407) and operating pressures from 30 to 90 psi.

  3. Dynamics of a pneumatic artificial muscle actuation system driving a trailing edge flap

    International Nuclear Information System (INIS)

    Woods, Benjamin K S; Kothera, Curt S; Wang, Gang; Wereley, Norman M

    2014-01-01

    This study presents a time domain dynamic model of an antagonistic pneumatic artificial muscle (PAM) driven trailing edge flap (TEF) system for next generation active helicopter rotors. Active rotor concepts are currently being widely researched in the rotorcraft community as a means to provide a significant leap forward in performance through primary aircraft control, vibration mitigation and noise reduction. Recent work has shown PAMs to be a promising candidate for active rotor actuation due to their combination of high force, large stroke, light weight, and suitable bandwidth. When arranged into biologically inspired agonist/antagonist muscle pairs they can produce bidirectional torques for effectively driving a TEF. However, there are no analytical dynamic models in the literature that can accurately capture the behavior of such systems across the broad range of frequencies required for this demanding application. This work combines mechanical, pneumatic, and aerodynamic component models into a global flap system model developed for the Bell 407 rotor system. This model can accurately predict pressure, force, and flap angle response to pneumatic control valve inputs over a range of operating frequencies from 7 to 35 Hz (1/rev to 5/rev for the Bell 407) and operating pressures from 30 to 90 psi. (paper)

  4. A smart rotor configuration with linear quadratic control of adaptive trailing edge flaps for active load alleviation

    DEFF Research Database (Denmark)

    Bergami, Leonardo; Poulsen, Niels Kjølstad

    2015-01-01

    The paper proposes a smart rotor configuration where adaptive trailing edge flaps (ATEFs) are employed for active alleviation of the aerodynamic loads on the blades of the NREL 5 MW reference turbine. The flaps extend for 20% of the blade length and are controlled by a linear quadratic (LQ....... The effects of active flap control are assessed with aeroelastic simulations of the turbine in normal operation conditions, as prescribed by the International Electrotechnical Commission standard. The turbine lifetime fatigue damage equivalent loads provide a convenient summary of the results achieved...

  5. Flight test operations using an F-106B research airplane modified with a wing leading-edge vortex flap

    Science.gov (United States)

    Dicarlo, Daniel J.; Brown, Philip W.; Hallissy, James B.

    1992-01-01

    Flight tests of an F-106B aircraft equipped with a leading-edge vortex flap, which represented the culmination of a research effort to examine the effectiveness of the flap, were conducted at the NASA Langley Research Center. The purpose of the flight tests was to establish a data base on the use of a wing leading-edge vortex flap as a means to validate the design and analysis methods associated with the development of such a vortical flow-control concept. The overall experiment included: refinements of the design codes for vortex flaps; numerous wind tunnel entries to aid in verifying design codes and determining basic aerodynamic characteristics; design and fabrication of the flaps, structural modifications to the wing tip and leading edges of the test aircraft; development and installation of an aircraft research instrumentation system, including wing and flap surface pressure measurements and selected structural loads measurements; ground-based simulation to assess flying qualities; and finally, flight testing. This paper reviews the operational aspects associated with the flight experiment, which includes a description of modifications to the research airplane, the overall flight test procedures, and problems encountered. Selected research results are also presented to illustrate the accomplishments of the research effort.

  6. Transition edge sensor series array bolometer

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, J, E-mail: joern.beyer@ptb.d [Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, D-10587 Berlin (Germany)

    2010-10-15

    A transition edge sensor series array (TES-SA) is an array of identical TESs that are connected in series by low-inductance superconducting wiring. The array elements are equally and well thermally coupled to the absorber and respond to changes in the absorber temperature in synchronization. The TES-SA total resistance increases compared to a single TES while the shape of the superconducting transition is preserved. We are developing a TES-SA with a large number, hundreds to thousands, of array elements with the goal of enabling the readout of a TES-based bolometer operated at 4.2 K with a semiconductor-based amplifier located at room temperature. The noise and dynamic performance of a TES-SA bolometer based on a niobium/aluminum bilayer is analyzed. It is shown that stable readout of the bolometer with a low-noise transimpedance amplifier is feasible.

  7. Vortex dynamics in superconducting transition edge sensors

    Science.gov (United States)

    Ezaki, S.; Maehata, K.; Iyomoto, N.; Asano, T.; Shinozaki, B.

    2018-02-01

    The temperature dependence of the electrical resistance (R-T) and the current-voltage (I-V) characteristics has been measured and analyzed in a 40 nm thick Ti thin film, which is used as a transition edge sensor (TES). The analyses of the I-V characteristics with the vortex-antivortex pair dissociation model indicate the possible existence of the Berezinskii-Kosterlitz-Thouless (BKT) transition in two-dimensional superconducting Ti thin films. We investigated the noise due to the vortices' flow in TESs. The values of the current noise spectral density in the TESs were estimated by employing the vortex dynamics caused by the BKT transition in the Ti thin films. The estimated values of the current noise spectral density induced by the vortices' flow were in respectable agreement with the values of excess noise experimentally observed in the TESs with Ti/Au bilayer.

  8. Transition edge sensor series array bolometer

    International Nuclear Information System (INIS)

    Beyer, J

    2010-01-01

    A transition edge sensor series array (TES-SA) is an array of identical TESs that are connected in series by low-inductance superconducting wiring. The array elements are equally and well thermally coupled to the absorber and respond to changes in the absorber temperature in synchronization. The TES-SA total resistance increases compared to a single TES while the shape of the superconducting transition is preserved. We are developing a TES-SA with a large number, hundreds to thousands, of array elements with the goal of enabling the readout of a TES-based bolometer operated at 4.2 K with a semiconductor-based amplifier located at room temperature. The noise and dynamic performance of a TES-SA bolometer based on a niobium/aluminum bilayer is analyzed. It is shown that stable readout of the bolometer with a low-noise transimpedance amplifier is feasible.

  9. Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

    Science.gov (United States)

    Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

    2014-01-01

    This is the presentation to follow conference paper of the same name. The adaptive compliant trailing edge (ACTE) flap experiment safety of flight requires that the flap to wing interface loads be sensed and monitored in real time to ensure that the wing structural load limits are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces will be monitored and each contains four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty one applied test load cases were developed using the predicted in-flight loads for the ACTE experiment.

  10. Smart Rotor Modeling: Aero-Servo-Elastic Modeling of a Smart Rotor with Adaptive Trailing Edge Flaps

    DEFF Research Database (Denmark)

    Bergami, Leonardo

    the trailing edge flap deflection to actively reduce the fatigue loads on the structure. The performance of the smart rotor configuration and its control algorithms are finally quantified by aero-servo-elastic simulations of the smart rotor turbine operating in a standard turbulent wind field.......This book presents the formulation of an aero-servo-elastic model for a wind turbine rotor equipped with Adaptive Trailing Edge Flaps (ATEF), a smart rotor configuration. As the name suggests, an aero-servo-elastic model consists of three main components: an aerodynamic model, a structural model......, and a control model. The book first presents an engineering type of aerodynamic model that accounts for the dynamic effects of flap deflection. The aerodynamic model is implemented in a Blade Element Momentum framework, and coupled with a multi-body structural model in the aero-servoelastic simulation code HAWC...

  11. Position-sensitive transition-edge sensors

    International Nuclear Information System (INIS)

    Iyomoto, N.; Bandler, S.R.; Brekosky, R.P.; Chervenak, J.A.; Figueroa-Feliciano, E.; Finkbeiner, F.M.; Kelley, R.L.; Kilbourne, C.A.; Lindeman, M.A.; Murphy, K.; Porter, F.S.; Saab, T.; Sadleir, J.E.; Talley, D.J.

    2006-01-01

    We report the latest results from our development of Position-Sensitive Transition-edge sensors (PoSTs), which are one-dimensional imaging spectrometers. In PoSTs with segmented Au absorbers, we obtained 8eV energy resolution on K Kα lines, which is consistent to the baseline energy resolution and the design values, on all of the nine pixels, by choosing the best combination of the thermal conductance in absorbers and in links that connects the absorbers. The pulse decay time of 193μs is fast enough for our purpose. In a PoST with a continuous Bi/Cu absorber, by dividing the events into 63 effective pixels, we obtained energy resolutions of 16eV at the center 'pixel', which is comparable to the baseline energy resolution, and 33eV at the outer 'pixel'. The degradation of the energy resolution in the outer 'pixel' is due to position dependence, which we can cancel out by dividing the events into smaller 'pixels' when we have sufficient X-ray events

  12. A Model Based Control methodology combining Blade Pitch and Adaptive Trailing Edge Flaps in a common framework

    DEFF Research Database (Denmark)

    Henriksen, Lars Christian; Bergami, Leonardo; Andersen, Peter Bjørn

    2013-01-01

    This work investigates how adaptive trailing edge flaps and classical blade pitch can work in concert using a model-based state space control formulation. The trade-off between load reduction and actuator activity is decided by setting different weights in the objective function used by the model...

  13. A Model Based Control methodology combining Blade Pitch and Adaptive Trailing Edge Flaps in a common framework

    DEFF Research Database (Denmark)

    This work investigates how adaptive trailing edge flaps and classical blade pitch can work in concert using a model-based state space control formulation. The trade-off between load reduction and actuator activity is decided by setting different weights in the objective function used by the model...

  14. Development of a piezoelectric actuator for trailing-edge flap control of rotor blades

    Science.gov (United States)

    Straub, Friedrich K.; Ngo, Hieu T.; Anand, V.; Domzalski, David B.

    1999-06-01

    Piezoelectric actuator technology has now reached a level where macro-positioning applications in the context of smart structures can be considered. One application with high payoffs is vibration reduction, noise reduction, and performance improvements in helicopters. Integration of piezoelectric actuators in the rotor blade is attractive, since it attacks the problem at the source. The present paper covers the development of a piezoelectric actuator for trailing edge flap control on a 34-foot diameter helicopter main rotor. The design of an actuator using bi-axial stack columns, and its bench, shake, and spin testing are described. A series of enhancements lead to an improved version that, together with use of latest stack technology, meets the requirements. Next steps in this DARPA sponsored program are development of the actuator and full scale rotor system for wind tunnel testing in the NASA Ames 40 X 80 foot wind tunnel and flight testing on the MD Explorer.

  15. Continuous Trailing-Edge Flaps for Primary Flight Control of a Helicopter Main Rotor

    Science.gov (United States)

    Thornburgh, Robert P.; Kreshock, Andrew R.; Wilbur, Matthew L.; Sekula, Martin K.; Shen, Jinwei

    2014-01-01

    The use of continuous trailing-edge flaps (CTEFs) for primary flight control of a helicopter main rotor is studied. A practical, optimized bimorph design with Macro-Fiber Composite actuators is developed for CTEF control, and a coupled structures and computational fluid dynamics methodology is used to study the fundamental behavior of an airfoil with CTEFs. These results are used within a comprehensive rotorcraft analysis model to study the control authority requirements of the CTEFs when utilized for primary flight control of a utility class helicopter. A study of the effect of blade root pitch index (RPI) on CTEF control authority is conducted, and the impact of structural and aerodynamic model complexity on the comprehensive analysis results is presented. The results show that primary flight control using CTEFs is promising; however, a more viable option may include the control of blade RPI, as well.

  16. Computational study of the Risoe-B1-18 airfoil with a hinged flap providing variable trailing edge geometry

    Energy Technology Data Exchange (ETDEWEB)

    Troldborg, N.

    2005-03-01

    A comprehensive computational study, in both steady and unsteady flow conditions, has been carried out to investigate the aerodynamic characteristics of the Risoe-B1-18 airfoil equipped with variable trailing edge geometry as produced by a hinged flap. The function of such flaps should be to decrease fatigue-inducing oscillations on the blades. The computations were conducted using a 2D incompressible RANS solver with a k-w turbulence model under the assumption of a fully developed turbulent flow. The investigations were conducted at a Reynolds number of Re = 1.6 - 10{sup 6}. Calculations conducted on the baseline airfoil showed excellent agreement with measurements on the same airfoil with the same specified conditions. Furthermore, a more widespread comparison with an advanced potential theory code is presented. The influence of various key parameters, such as flap shape, flap size and oscillating frequencies, was investigated so that an optimum design can be suggested for application with wind turbine blades. It is concluded that a moderately curved flap with flap chord to airfoil curve ratio between 0.05 and 0.10 would be an optimum choice. (author)

  17. Microcalorimetry and the transition-edge sensor

    Science.gov (United States)

    Lindeman, Mark Anton

    2000-10-01

    Many scientific and industrial applications call for quantum-efficient high-energy-resolution microcalorimeters for the measurement of x rays. The applications driving the development of these detectors involve the measurement of faint sources of x rays in which few photons reach the detector. Interesting astrophysical applications for these microcalorimeters include the measurement of composition and temperatures of stellar atmospheres and diffuse interstellar plasmas. Other applications of microcalorimeter technology include x-ray fluorescence (XRF) measurements of industrial or scientific samples. We are attempting to develop microcalorimeters with energy resolutions of several eV because many sources (such as celestial plasmas) contain combinations of elements producing emission lines spaced only a few eV apart. Our microcalorimeters consist of a metal-film absorber (250mum x 250mum x 3mum of copper) coupled to a superconducting transition-edge-sensor (TES) thermometer. This microcalorimeter demonstrated an energy resolution of 42 eV (FWHM) at 6 keV, excellent linearity, and showed no evidence of position dependent response. The response of our microcalorimeters depends both on the temperature of the microcalorimeter and on the electrical current conducted through the TES thermometer. We present a microcalorimeter model that extends previous microcalorimeter theory to include additional current dependent effects. The model makes predictions about the effects of various forms of noise. In addition, the model helps us to understand what measurements are useful for characterizing TES microcalorimeters. While the energy resolution we obtained was quite good (twice as good as conventional semiconductor-based x-ray detectors), the obtained resolution was not as good as expected, due to excess noise from fluctuations in the TES thermometer. The energy resolution of future TES microcalorimeters can be improved by redesigning the calorimeters to minimize the noise due

  18. Microcalorimetry and the transition-edge sensor

    International Nuclear Information System (INIS)

    Lindeman, M A

    2000-01-01

    Many scientific and industrial applications call for quantum-efficient high-energy-resolution microcalorimeters for the measurement of x rays. The applications driving the development of these detectors involve the measurement of faint sources of x rays in which few photons reach the detector. Interesting astrophysical applications for these microcalorimeters include the measurement of composition and temperatures of stellar atmospheres and diffuse interstellar plasmas. Other applications of microcalorimeter technology include x-ray fluorescence (XRF) measurements of industrial or scientific samples. We are attempting to develop microcalorimeters with energy resolutions of several eV because many sources (such as celestial plasmas) contain combinations of elements producing emission lines spaced only a few eV apart. Our microcalorimeters consist of a metal-film absorber (250 (micro)m x 250(micro)m x 3 (micro)m of copper) coupled to a superconducting transition-edge-sensor (TES) thermometer. This microcalorimeter demonstrated an energy resolution of 42 eV (FWHM) at 6 keV, excellent linearity, and showed no evidence of position dependent response. The response of our microcalorimeters depends both on the temperature of the microcalorimeter and on the electrical current conducted through the TES thermometer. We present a microcalorimeter model that extends previous microcalorimeter theory to include additional current dependent effects. The model makes predictions about the effects of various forms of noise. In addition, the model helps us to understand what measurements are useful for characterizing TES microcalorimeters. While the energy resolution we obtained was quite good (twice as good as conventional semiconductor-based x-ray detectors), the obtained resolution was not as good as expected, due to excess noise from fluctuations in the TES thermometer. The energy resolution of future TES microcalorimeters can be improved by redesigning the calorimeters to

  19. Aerodynamic response of an airfoil section undergoing pitch motion and trailing edge flap deflection: a comparison of simulation methods

    DEFF Research Database (Denmark)

    Bergami, Leonardo; Riziotis, Vasilis A.; Gaunaa, Mac

    2015-01-01

    The study presents and compares aerodynamic simulations for an airfoil section with an adaptive trailing edge flap, which deflects following a smooth deformation shape. The simulations are carried out with three substantially different methods: a Reynolds-averaged Navier–Stokes solver, a viscous–inviscid...... to separated conditions and accounting for the effects of flap deflection; the steady results from the Navier–Stokes solver and the viscous–inviscid interaction method are used as input data for the simpler dynamic stall model. The paper characterizes then the dynamics of the unsteady forces and moments...

  20. Sizing and control of trailing edge flaps on a smart rotor for maximum power generation in low fatigue wind regimes

    DEFF Research Database (Denmark)

    Smit, Jeroen; Bernhammer, Lars O.; Navalkar, Sachin T.

    2016-01-01

    to fatigue damage have been identified. In these regions, the turbine energy output can be increased by deflecting the trailing edge (TE) flap in order to track the maximum power coefficient as a function of local, instantaneous speed ratios. For this purpose, the TE flap configuration for maximum power...... generation has been using blade element momentum theory. As a first step, the operation in non-uniform wind field conditions was analysed. Firstly, the deterministic fluctuation in local tip speed ratio due to wind shear was evaluated. The second effect is associated with time delays in adapting the rotor...

  1. Longitudinal Proximity Effect Superconducting Transition-Edge Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — Superconducting Transition-Edge Sensors (TESs) hold the highest energy resolving power of any nondispersive spectrometer.   They are used for imaging spectroscopy...

  2. Full-scale test of trailing edge flaps on a Vestas V27 wind turbine: active load reduction and system identification

    DEFF Research Database (Denmark)

    Castaignet, Damien; Barlas, Thanasis K.; Buhl, Thomas

    2014-01-01

    model, from trailing edge flap angle to flapwise blade root moment, was derived and compared with the linear analytical model used in the model predictive control design model. Flex5 simulations run with the same model predictive control showed a good correlation between the simulations......A full-scale test was performed on a Vestas V27 wind turbine equipped with one active 70 cm long trailing edge flap on one of its 13 m long blades. Active load reduction could be observed in spite of the limited spanwise coverage of the single active trailing edge flap. A frequency-weighted model...

  3. Characteristics of Ir/Au transition edge sensor

    International Nuclear Information System (INIS)

    Kunieda, Yuichi; Ohno, Masashi; Nakazawa, Masaharu; Takahashi, Hiroyuki; Fukuda, Daiji; Ohkubo, Masataka

    2004-01-01

    A new type of microcalorimeter has been developed using a transition edge sensor (TES) and an electro-thermal feedback (ETF) method to achieve higher energy resolution and higher count rate. We are developing a superconducting Ir-based transition edge sensor (TES) microcalorimeters. To improve thermal conductivity and achieve higher energy resolution with an Ir-TES, we fabricated an Ir/Au bilayer TES by depositing gold on Ir and investigated the influence of intermediate between superconducting and normal states at the transition edge for signal responses by microscopic observation in the Ir/Au-TES. (T. Tanaka)

  4. Development of Variable Camber Continuous Trailing Edge Flap for Performance Adaptive Aeroelastic Wing

    Science.gov (United States)

    Nguyen, Nhan; Kaul, Upender; Lebofsky, Sonia; Ting, Eric; Chaparro, Daniel; Urnes, James

    2015-01-01

    This paper summarizes the recent development of an adaptive aeroelastic wing shaping control technology called variable camber continuous trailing edge flap (VCCTEF). As wing flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. The initial VCCTEF concept was developed in 2010 by NASA under a NASA Innovation Fund study entitled "Elastically Shaped Future Air Vehicle Concept," which showed that highly flexible wing aerodynamic surfaces can be elastically shaped in-flight by active control of wing twist and bending deflection in order to optimize the spanwise lift distribution for drag reduction. A collaboration between NASA and Boeing Research & Technology was subsequently funded by NASA from 2012 to 2014 to further develop the VCCTEF concept. This paper summarizes some of the key research areas conducted by NASA during the collaboration with Boeing Research and Technology. These research areas include VCCTEF design concepts, aerodynamic analysis of VCCTEF camber shapes, aerodynamic optimization of lift distribution for drag minimization, wind tunnel test results for cruise and high-lift configurations, flutter analysis and suppression control of flexible wing aircraft, and multi-objective flight control for adaptive aeroelastic wing shaping control.

  5. Low-Speed Wind-Tunnel Investigation of Blowing Boundary-Layer Control on Leading- and Trailing-Edge Flaps of a Large-Scale, Low-Aspect-Ratio, 45 Swept-wing Airplane Configuration

    Science.gov (United States)

    Maki, Ralph L.

    1959-01-01

    Blowing boundary-layer control was applied to the leading- and trailing-edge flaps of a 45 deg sweptback-wing complete model in a full-scale low-speed wind-tunnel study. The principal purpose of the study was to determine the effects of leading-edge flap deflection and boundary-layer control on maximum lift and longitudinal stability. Leading-edge flap deflection alone was sufficient to maintain static longitudinal stability without trailing-edge flaps. However, leading-edge flap blowing was required to maintain longitudinal stability by delaying leading-edge flow separation when trailing-edge flaps were deflected either with or without blowing. Partial-span leading-edge flaps deflected 60 deg with moderate blowing gave the major increase in maximum lift, although higher deflection and additional blowing gave some further increase. Inboard of 0.4 semispan leading-edge flap deflection could be reduced to 40 deg and/or blowing could be omitted with only small loss in maximum lift. Trailing-edge flap lift increments were increased by boundary-layer control for deflections greater than 45 deg. Maximum lift was not increased with deflected trailing-edge flaps with blowing.

  6. The full-scale process and design changes for elimination of insulation edge separations and voids in tang flap area

    Science.gov (United States)

    Danforth, Richard A.

    1991-01-01

    Qualification of the full-scale process and design changes for elimination of redesigned solid rocket motor tang nitrile butadiene rubber insulation edge separations and voids was performed from 24 March to 3 December 1990. The objectives of this test were: to qualify design and process changes on flight hardware using a tie ply between the redesigned solid rocket motor steel case and the nitrile butadiene rubber insulation over the tang capture features; to qualify the use of methyl ethyl ketone in the tang flap region to reduce voids; and to determine if holes in the separator film reduce voids in the tang flap region. The tie ply is intended to aid insulation flow during the insulation cure process, and thus reduce or eliminate edge unbonds. Methyl ethyl ketone is intended to reduce voids in the tang flap area by providing better tacking characteristics. The perforated film was intended to provide possible vertical breathe paths to reduce voids in the tang area. Tang tie ply testing consisted of 270 deg of the tang circumference using a new layup method and 90 deg of the tang circumference using the current layup methods. Tie ply process success was defined as a reduction of insulation unbonds. Lack of any insulation edge unbonds on the tang area where the new process was used, and the presence of 17 unbonds with the current process, proves the test to be a success. Successful completion of this test has qualified the new processes.

  7. Numerical modeling of the vortex breakdown phenomenon on a delta wing with trailing-edge jet-flap

    International Nuclear Information System (INIS)

    Kyriakou, Marilena; Missirlis, Dimitrios; Yakinthos, Kyros

    2010-01-01

    The flow development over delta wings is highly complicated since the interaction of the angle of attack with the delta-wing geometry leads to the appearance of a pair of well-organized counter-rotating leading-edge vortical structures. For relatively moderate angles of attack, these vortices remain robust and contribute to the enhancement of the overall lift performance. However, at higher angles of attack the vortices develop instabilities leading to the well-known vortex breakdown phenomenon, resulting in a deterioration of the aerodynamic properties. Thus, delaying vortex breakdown at higher angles of attack, is important and for this reason various techniques have been developed to control the breakdown mechanism. Such a technique is the use of trailing-edge jet-flaps. In the present work, an attempt to model the vortex breakdown together with its control, above a delta wing at high angles of attack, for cases with and without a trailing-edge jet-flap, is presented. To model the turbulent stresses, the low-Reynolds-number stress-omega model was used. The computational results were in good agreement with the available experimental data regarding the prediction of the onset of vortex breakdown and showed that the use of jet-flaps can lead to a significant delay of the breakdown process.

  8. Applicability of linearized-theory attached-flow methods to design and analysis of flap systems at low speeds for thin swept wings with sharp leading edges

    Science.gov (United States)

    Carlson, Harry W.; Darden, Christine M.

    1987-01-01

    Low-speed experimental force and data on a series of thin swept wings with sharp leading edges and leading and trailing-edge flaps are compared with predictions made using a linearized-theory method which includes estimates of vortex forces. These comparisons were made to assess the effectiveness of linearized-theory methods for use in the design and analysis of flap systems in subsonic flow. Results demonstrate that linearized-theory, attached-flow methods (with approximate representation of vortex forces) can form the basis of a rational system for flap design and analysis. Even attached-flow methods that do not take vortex forces into account can be used for the selection of optimized flap-system geometry, but design-point performance levels tend to be underestimated unless vortex forces are included. Illustrative examples of the use of these methods in the design of efficient low-speed flap systems are included.

  9. Computational study of the Risø-B1-18 airfoil with a hinged flap providing variable trailing edge geometry

    DEFF Research Database (Denmark)

    Troldborg, Niels

    2005-01-01

    A comprehensive computational study, in both steady and unsteady flow conditions, has been carried out to investigate the aerodynamic characteristics of the Risø-B1.18 airfoil equipped with variable trailing edge geometry as produced by a hinged flap. The function of such flaps should...... on the baseline airfoil showed excellent agreement with measurements on the same airfoil with the same specified conditions. Furthermore, a more widespread comparison with an advanced potential theory code is presented. The influence of various key parameters, such as flap shape, flap size and oscillating...... frequencies, was investigated so that an optimum design can be suggested for application with wind turbine blades. It is concluded that a moderately curved flap with flap chord to airfoil curve ratio between 0.05 and 0.10 would be an optimum choice....

  10. Planar slim-edge pixel sensors for the ATLAS upgrades

    International Nuclear Information System (INIS)

    Altenheiner, S; Goessling, C; Jentzsch, J; Klingenberg, R; Lapsien, T; Rummler, A; Troska, G; Wittig, T; Muenstermann, D

    2012-01-01

    The ATLAS detector at CERN is a general-purpose experiment at the Large Hadron Collider (LHC). The ATLAS Pixel Detector is the innermost tracking detector of ATLAS and requires a sufficient level of hermeticity to achieve superb track reconstruction performance. The current planar n-type pixel sensors feature a pixel matrix of n + -implantations which is (on the opposite p-side) surrounded by so-called guard rings to reduce the high voltage stepwise towards the cutting edge and an additional safety margin. Because of the inactive region around the active area, the sensor modules have been shingled on top of each other's edge which limits the thermal performance and adds complexity in the present detector. The first upgrade phase of the ATLAS pixel detector will consist of the insertable b-layer (IBL), an additional b-layer which will be inserted into the present detector in 2013. Several changes in the sensor design with respect to the existing detector had to be applied to comply with the IBL's specifications and are described in detail. A key issue for the ATLAS upgrades is a flat arrangement of the sensors. To maintain the required level of hermeticity in the detector, the inactive sensor edges have to be reduced to minimize the dead space between the adjacent detector modules. Unirradiated and irradiated sensors with the IBL design have been operated in test beams to study the efficiency performance in the sensor edge region and it was found that the inactive edge width could be reduced from 1100 μm to less than 250 μm.

  11. Results from bonding of the SALT primary mirror edge sensors

    Science.gov (United States)

    Strydom, Ockert J.; Love, Jonathan; Gajjar, Hitesh

    2016-07-01

    The Southern African Large Telescope has till recently operated without active closed loop control of its Primary Mirror. The reason for this was that there were no suitable edge sensor system available on the market. Recently a system became available and SALT form Fogale Nanotech. The system consist of a sensor, cables and control electronics. The system was still under development and SALT was responsible for the integration of the sensors before deployment on the Telescope. Several issues still had to be addressed. One of these issues was the integration of the sensors at an appropriate production rate. The sensors was supplied as flexible pc boards with different types making up the transmitters and receivers. These flexible boards were bonded to ClearCeram Z L-Brackets before the appropriate connectors were installed. This paper describes the process used to integrate and test the sensors.

  12. 16 CFR 1211.12 - Requirements for edge sensors.

    Science.gov (United States)

    2010-01-01

    ... Section 1211.12 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... that the axis is perpendicular to the plane of the door. For an edge sensor intended to be used on a... direction perpendicular to the plane of the door. See figure 6. (2) With respect to the test of paragraph (a...

  13. Characteristics of Ti films for transition-edge sensor microcalorimeters

    International Nuclear Information System (INIS)

    Ukibe, M.; Koyanagi, M.; Ohkubo, M.; Pressler, H.; Kobayashi, N.

    1999-01-01

    We are developing X-ray microcalorimeters using superconducting transition-edge sensors (TESs), which can be operated at relatively high base temperatures of a 3 He cryostat. For this purpose, we have selected Ti films to be used as TESs. The Ti films were deposited on different substrates by RF-sputtering. It was found that the superconducting properties of the Ti films depended on Ar pressure, film thickness, and substrate surface roughness

  14. Characteristics of Ti films for transition-edge sensor microcalorimeters

    CERN Document Server

    Ukibe, M; Ohkubo, M; Pressler, H; Kobayashi, N

    1999-01-01

    We are developing X-ray microcalorimeters using superconducting transition-edge sensors (TESs), which can be operated at relatively high base temperatures of a sup 3 He cryostat. For this purpose, we have selected Ti films to be used as TESs. The Ti films were deposited on different substrates by RF-sputtering. It was found that the superconducting properties of the Ti films depended on Ar pressure, film thickness, and substrate surface roughness.

  15. Towards an industrial manufactured morphing trailing edge flap system for wind turbines

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Løgstrup Andersen, Tom; Bergami, Leonardo

    2014-01-01

    tunnel experiment in 2009 with promising results. This led in 2011 to initiation of a new research project INDUFLAP with the main aim to transfer the flap technology to industry as concerns manufacturing and testing. Three industrial partners are participating in the project. Rehau (DE) and Dansk Gummi...

  16. Aeroelastic Analysis of a Flexible Wing Wind Tunnel Model with Variable Camber Continuous Trailing Edge Flap Design

    Science.gov (United States)

    Nguyen, Nhan; Ting, Eric; Lebofsky, Sonia

    2015-01-01

    This paper presents data analysis of a flexible wing wind tunnel model with a variable camber continuous trailing edge flap (VCCTEF) design for drag minimization tested at the University of Washington Aeronautical Laboratory (UWAL). The wind tunnel test was designed to explore the relative merit of the VCCTEF concept for improved cruise efficiency through the use of low-cost aeroelastic model test techniques. The flexible wing model is a 10%-scale model of a typical transport wing and is constructed of woven fabric composites and foam core. The wing structural stiffness in bending is tailored to be half of the stiffness of a Boeing 757-era transport wing while the torsional stiffness is about the same. This stiffness reduction results in a wing tip deflection of about 10% of the wing semi-span. The VCCTEF is a multi-segment flap design having three chordwise camber segments and five spanwise flap sections for a total of 15 individual flap elements. The three chordwise camber segments can be positioned appropriately to create a desired trailing edge camber. Elastomeric material is used to cover the gaps in between the spanwise flap sections, thereby creating a continuous trailing edge. Wind tunnel data analysis conducted previously shows that the VCCTEF can achieve a drag reduction of up to 6.31% and an improvement in the lift-to-drag ratio (L=D) of up to 4.85%. A method for estimating the bending and torsional stiffnesses of the flexible wingUWAL wind tunnel model from static load test data is presented. The resulting estimation indicates that the stiffness of the flexible wing is significantly stiffer in torsion than in bending by as much as 9 to 1. The lift prediction for the flexible wing is computed by a coupled aerodynamic-structural model. The coupled model is developed by coupling a conceptual aerodynamic tool Vorlax with a finite-element model of the flexible wing via an automated geometry deformation tool. Based on the comparison of the lift curve slope

  17. Potential load reductions on megawatt turbines exposed to wakes using individual-pitch wake compensator and trailing-edge flaps

    DEFF Research Database (Denmark)

    Markou, Helen; Andersen, Peter Bjørn; Larsen, Gunner Chr.

    2011-01-01

    that typically focus on either load or power prediction. As a consequence, the wake affected inflow field generated by the DWM formulation opens for control strategies for the individual turbine. Two different control approaches for load reduction on the individual turbines are implemented in the multi-body aero-servo-elastic...... tool HAWC2, developed at Risø-DTU in Denmark, and their potential load reduction capabilities compared: (1) full-blade ‘individual-pitch controllers’ acting as wake compensators and (2) controllers using trailing-edge flaps. Information on the wake inflow conditions, induced by upstream turbines...... for the loading conditions of the individual turbines in the farm. The dynamic wake meandering model (DWM) is believed to capture the essential physics of the wake problem, and thus, both load and production aspects can be predicted, which is contrary to the traditional engineering wake prediction methods...

  18. DC and AC biasing of a transition edge sensor microcalorimeter

    International Nuclear Information System (INIS)

    Cunningham, M.F.; Ullom, J.N.; Miyazaki, T.; Drury, O.; Loshak, A.; Berg, M.L. van den; Labov, S.E.

    2002-01-01

    We are developing AC-biased transition edge sensor (TES) microcalorimeters for use in large arrays with frequency-domain multiplexing. Using DC bias, we have achieved a resolution of 17 eV FWHM at 2.6 keV with a decay time of 90 μs and an effective detector diameter of 300 μm. We have successfully measured thermal pulses with a TES microcalorimeter operated with an AC bias. We present here preliminary results from a single pixel detector operated under DC and AC bias conditions

  19. Operation of transition-edge sensors with excess thermal noise

    International Nuclear Information System (INIS)

    Maasilta, I J; Kinnunen, K M; Nuottajaervi, A K; Leppaeniemi, J; Luukanen, A

    2006-01-01

    The superconducting transition-edge sensor (TES) is currently one of the most attractive choices for ultra-high resolution calorimetry in the keV x-ray band, and is being considered for future ESA and NASA missions. We have performed a study on the noise characteristics of Au/Ti bilayer TESs, at operating temperatures around ∼100 mK, with the SQUID readout at 1.5 K. Experimental results indicate that without modifications the back-action noise from the SQUID chip degrades the noise characteristics significantly. We present a simple and effective solution to the problem: by installing an extra shunt resistor which absorbs the excess radiation from the SQUID input, we have reduced the excess thermal (photon) noise power down by approximately a factor of five, allowing high resolution operation of the sensors

  20. Determination of the Tc distribution for 1000 Transition Edge Sensors

    International Nuclear Information System (INIS)

    Brink, P.L.; Saab, T.; Miller, A.J.; Cabrera, B.; Castle, J.P.; Chang, C.; Young, B.A.; Akerib, D.S.; Discroll, D.; Kamat, S.; Perera, T.A.; Schnee, R.W.; Wang, G.; Emes, J.H.; Gaitskell, R.J.; Mandic, V.; Meunier, P.; Rau, W.; Sadoulet, B.; Seitz, D.N.

    2002-01-01

    The ZIP detectors deployed in the CDMS II experiment utilize phonon sensors comprising W Transition Edge Sensors (TESs). In order to ensure uniform collection of the athermal phonon signal the TESs are dispersed uniformly on one side of a 1 cm thick, 3 inch diameter, disk. Each quadrant contains 1036 TESs connected in parallel to one series-array SQUID amplifier. The initial superconducting transition temperatures of these TESs tend to be too high for our requirements, and substantial gradients make the operation of the detectors difficult. Hence our implementation of Fe-56 ion implantation, as reported at the previous LTD meeting, to reduce in a controlled manner the transition temperature. However, the successful implementation of this ion-implantation scheme requires accurate knowledge of the initial transition temperature of each TES in a given quadrant. We report on our approaches and techniques employed to address the issue of determining the initial Tc distribution

  1. Wind tunnel test on airfoil Riso-B1-18 with an Active Trailing Edge Flap

    DEFF Research Database (Denmark)

    Bak, Christian; Gaunaa, Mac; Andersen, Peter Bjørn

    2010-01-01

    A wind tunnel test of the wind turbine airfoil Risø-B1-18 equipped with an Active Trailing Edge Flap (ATEF) was carried out. The ATEF was 9% of the total chord, made of piezo electric actuators attached to the trailing edge of a non-deformable airfoil and actuated using an (electric) amplifier....... The airfoil was tested at Re = 1.66 × 106. Steady state and dynamic tests were carried out with prescribed deflections of the ATEF. The steady state tests showed that deflecting the ATEF towards the pressure side (positive ) translated the lift curve to higher lift values and deflecting the ATEF towards...... the suction side (negative ) translated the lift curve to lower lift values. Testing the airfoil for a step change of the ATEF from = -3.0 to +1.8 showed that the obtainable cl was 0.10 to 0.13 in the linear part of the lift curve. Modeling the step response with an indicial function formulation showed...

  2. Edge-TCT measurements on irradiated HV CMOS sensors

    CERN Document Server

    Weisser, Constantin

    2014-01-01

    Passive $100 \\times 100 \\,\\mu$m test diodes in an unirradiated and an irradiated HV2FEI4v3 HV-CMOS silicon sensor were analysed using the edge TCT technique. To integrate the sensor into the setup a PCB was designed to extract the signals, a cooling mechanism was constructed and the system housed in a shielding box. The observed signal had fast and slow contributions, that were interpreted as drift and diffusion. The former peaked in a region, that was interpreted as the depletion region, while the latter peaked further in the bulk material. Raising the bias voltage increased the depth of the former region, while pushing the latter region further into the bulk. The irradiated sample lost signal strength mainly in its slow part compared to the unirradiated sample, while its quick signal remained largely unaffected. As only the signal interpreted as drift is fast enough to be useful in LHC operation the investigated sensors could be considered radiation hard for this purpose. This gives further promise to ...

  3. Numerical Investigation of Flow Control Feasibility with a Trailing Edge Flap

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2014-01-01

    the control system, a standard PID controller is implemented in a finite volume based incompressible flow solver. An immersed boundary method is applied to treat the problem of simulating a deformable airfoil trailing edge. The flow field is solved using a 2D Reynolds averaged Navier-Stokes finite volume...... solver. In order to more accurately simulate wall bounded flows around the immersed boundary, a modified boundary condition is introduced in the k- ω turbulence model. As an example, turbulent flow over a NACA 64418 airfoil with a deformable trailing edge is investigated. Results from numerical...

  4. The effect of aspect ratio on the leading-edge vortex over an insect-like flapping wing.

    Science.gov (United States)

    Phillips, Nathan; Knowles, Kevin; Bomphrey, Richard J

    2015-10-09

    Insect wing shapes are diverse and a renowned source of inspiration for the new generation of autonomous flapping vehicles, yet the aerodynamic consequences of varying geometry is not well understood. One of the most defining and aerodynamically significant measures of wing shape is the aspect ratio, defined as the ratio of wing length (R) to mean wing chord (c). We investigated the impact of aspect ratio, AR, on the induced flow field around a flapping wing using a robotic device. Rigid rectangular wings ranging from AR = 1.5 to 7.5 were flapped with insect-like kinematics in air with a constant Reynolds number (Re) of 1400, and a dimensionless stroke amplitude of 6.5c (number of chords traversed by the wingtip). Pseudo-volumetric, ensemble-averaged, flow fields around the wings were captured using particle image velocimetry at 11 instances throughout simulated downstrokes. Results confirmed the presence of a high-lift, separated flow field with a leading-edge vortex (LEV), and revealed that the conical, primary LEV grows in size and strength with increasing AR. In each case, the LEV had an arch-shaped axis with its outboard end originating from a focus-sink singularity on the wing surface near the tip. LEV detachment was observed for AR > 1.5 around mid-stroke at ~70% span, and initiated sooner over higher aspect ratio wings. At AR > 3 the larger, stronger vortex persisted under the wing surface well into the next half-stroke leading to a reduction in lift. Circulatory lift attributable to the LEV increased with AR up to AR = 6. Higher aspect ratios generated proportionally less lift distally because of LEV breakdown, and also less lift closer to the wing root due to the previous LEV's continuing presence under the wing. In nature, insect wings go no higher than AR ~ 5, likely in part due to architectural and physiological constraints but also because of the reducing aerodynamic benefits of high AR wings.

  5. The Magnetically-Tuned Transition-Edge Sensor

    Science.gov (United States)

    Sadleir, John E.; Lee, Sang-Jun; Smith, Stephen J.; Busch, Sarah E.; Bandler, Simon R.; Adams, Joseph S.; Eckart, Megan E.; Chevenak, James A.; Kelley, Richard L.; Kilbourne, Caroline A.; hide

    2014-01-01

    We present the first measurements on the proposed magnetically-tuned superconducting transition-edge sensor (MTES) and compare the modified resistive transition with the theoretical prediction. A TES's resistive transition is customarily characterized in terms of the unit less device parameters alpha and beta corresponding to the resistive response to changes in temperature and current respectively. We present a new relationship between measured IV quantities and the parameters alpha and beta and use these relations to confirm we have stably biased a TES with negative beta parameter with magnetic tuning. Motivated by access to this new unexplored parameter space, we investigate the conditions for bias stability of a TES taking into account both self and externally applied magnetic fields.

  6. Fabrication of Ultrasensitive Transition Edge Sensor Bolometric Detectors for HIRMES

    Science.gov (United States)

    Brown, Ari-David; Brekosky, Regis; Franz, David; Hsieh, Wen-Ting; Kutyrev, Alexander; Mikula, Vilem; Miller, Timothy; Moseley, S. Harvey; Oxborrow, Joseph; Rostem, Karwan; hide

    2017-01-01

    The high resolution mid-infrared spectrometer (HIRMES) is a high resolving power (R approx. 100,000) instrument operating in the 25-122 micron spectral range and will fly on board the Stratospheric Observatory for Far-Infrared Astronomy (SOFIA) in 2019. Central ot HIRMES are its two transition edge sensor (TES) bolometric cameras, an 8x16 detector high resolution array and a 64x16 detector low resolution array. Both types of detectors consist of MoAu TES fabricated on leg-isolated Si membranes. Whereas the high resolution detectors, with noise equivalent power (NEP) approx. 2 aW/square root of (Hz), are fabricated on 0.45 micron Si substrates, the low resolution detectors, with NEP approx. 10 aW/square root of (Hz), are fabricated on 1.40 micron Si. Here we discuss the similarities and difference in the fabrication methodologies used to realize the two types of detectors.

  7. Single-photon light detection with transition-edge sensors

    International Nuclear Information System (INIS)

    Rajteri, M.; Taralli, E.; Portesi, C.; Monticone, E.

    2008-01-01

    Transition-Edge Sensors (TESs) are micro calorimeters that measure the energy of incident single-photons by the resistance increase of a superconducting film biased within the superconducting-to-normal transition. TES are able to detect single photons from x-ray to IR with an intrinsic energy resolution and photon-number discrimination capability. Metrological, astronomical and quantum communication applications are the fields where these properties can be particularly important. In this work, we report about characterization of different TESs based on Ti films. Single-photons have been detected from 200 nm to 800 nm working at T c ∼ 100 m K. Using a pulsed laser at 690 nm we have demonstrated the capability to resolve up to five photons.

  8. Analytical expressions for transition edge sensor excess noise models

    International Nuclear Information System (INIS)

    Brandt, Daniel; Fraser, George W.

    2010-01-01

    Transition edge sensors (TESs) are high-sensitivity thermometers used in cryogenic microcalorimeters which exploit the steep gradient in resistivity with temperature during the superconducting phase transition. Practical TES devices tend to exhibit a white noise of uncertain origin, arising inside the device. We discuss two candidate models for this excess noise, phase slip shot noise (PSSN) and percolation noise. We extend the existing PSSN model to include a magnetic field dependence and derive a basic analytical model for percolation noise. We compare the predicted functional forms of the noise current vs. resistivity curves of both models with experimental data and provide a set of equations for both models to facilitate future experimental efforts to clearly identify the source of excess noise.

  9. Development of X-ray microcalorimeters using transition edge sensors

    International Nuclear Information System (INIS)

    Ukibe, M; Hirayama, F.; Tanaka, K.; Koyanagi, M.; Ohkubo, M.; Kobayashi, N.; Morooka, T.; Chinone, K.

    2000-01-01

    We are developing X-ray microcalorimeters using superconducting transition edge sensors (TESs), which can be operated at relatively high temperatures in a 3 He cryostat, and DC-SQUID current amplifiers to realize an X-ray spectroscopy with a high energy resolution and a high counting rate. The TESs are proximity bilayers of Ti and Au on SiN x membranes with 500-1000 nm thicknesses. The typical TES has a T c value of 0.4 K and a ΔT c value of 2 mK. Two types of DC-SQUID amplifiers were developed; the single stage with 200-series SQUIDs and the double stage with an input SQUID and 50-series SQUIDs. The X-ray detection experiment is in progress. (author)

  10. Antenna-coupled bolometer arrays using transition-edge sensors

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Michael J. [Department of Physics, University of California, Berkeley, California 94720 (United States)]. E-mail: mmyers@cosmology.berkeley.edu; Ade, Peter [School of Physics and Astronomy, Cardiff University, Cardiff, Wales (United Kingdom); Arnold, Kam [Department of Physics, University of California, Berkeley, California 94720 (United States); Engargiola, Greg [Department of Astronomy, University of California, Berkeley, California 94720 (United States); Holzapfel, Bill [Department of Physics, University of California, Berkeley, California 94720 (United States); Lee, Adrian T. [Department of Physics, University of California, Berkeley, California 94720 (United States); O' Brient, Roger [Department of Physics, University of California, Berkeley, California 94720 (United States); Richards, Paul L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Smith, Andy [Northrop Grumman, Redondo Beach, California 90278 (United States); Spieler, Helmuth [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tran, Huan T. [Department of Physics, University of California, Berkeley, California 94720 (United States)

    2006-04-15

    We are developing antenna-coupled Transition-Edge Sensor (TES) bolometer arrays for use in measurements of the CMB polarization. TES bolometers have many well-known advantages over conventional bolometers, such as increased speed, linearity, and the existence of readout multiplexers. Antenna-coupled bolometers use an on-chip planar antenna to couple light into the bolometer. The antenna directivity and polarization sensitivity, along with the potential for on-chip band defining filters and channelizing circuits, allow a significant increase in focal plane integration. This eliminates the bulky horns, quasioptical filters, dichroics, and polarizers which might otherwise be needed in a conventional bolometric system. This simplification will ease the construction of receivers with larger numbers of pixels. We report on the fabrication and optical testing of single antenna-coupled bolometer pixels with integrated band defining filters. We will also discuss current progress on fabrication of a bolometer array based on this design.

  11. X-ray imaging characterization of active edge silicon pixel sensors

    International Nuclear Information System (INIS)

    Ponchut, C; Ruat, M; Kalliopuska, J

    2014-01-01

    The aim of this work was the experimental characterization of edge effects in active-edge silicon pixel sensors, in the frame of X-ray pixel detectors developments for synchrotron experiments. We produced a set of active edge pixel sensors with 300 to 500 μm thickness, edge widths ranging from 100 μm to 150 μm, and n or p pixel contact types. The sensors with 256 × 256 pixels and 55 × 55 μm 2 pixel pitch were then bump-bonded to Timepix readout chips for X-ray imaging measurements. The reduced edge widths makes the edge pixels more sensitive to the electrical field distribution at the sensor boundaries. We characterized this effect by mapping the spatial response of the sensor edges with a finely focused X-ray synchrotron beam. One of the samples showed a distortion-free response on all four edges, whereas others showed variable degrees of distortions extending at maximum to 300 micron from the sensor edge. An application of active edge pixel sensors to coherent diffraction imaging with synchrotron beams is described

  12. SQUID readout multiplexers for transition-edge sensor arrays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Adrian T. [Physics Department, University of California, Berkeley, CA 94720 (United States) and Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)]. E-mail: atl@physics.berkeley.edu

    2006-04-15

    Two classes of SQUID multiplexer are being developed for large arrays of cryogenic sensors, distinguished by their operation in either the time domain or frequency domain. Several systems optimized for use with Transition-Edge Sensors (TES) are reaching a high level of maturity, and will be deployed on funded astrophysics experiments in the next several years. A useful technical figure of merit is the product of the number of detectors multplexed multipled by the bandwidth of the detectors, which can be termed the 'total signal bandwidth' of a multiplexer system. This figure of merit is comparable within a factor of two for the mature systems. Several new concepts for increasing the total bandwidth are being developed in the broad class of frequency domain multiplexers. Another notable area of progress is in the level of integration of muliplexer and detector array. The time domain system for SCUBA-II is a sophisticated bump-bonded sandwich structure, and the Jena/MPI group is integrating detectors and a time domain multiplexer on one substrate. Finally, the Kinetic Inductance Detectors (KID)/HEMT (non-SQUID) detector/multiplexer system, will be discussed briefly.

  13. Investigation of the theoretical load alleviation potential using trailing edge flaps controlled by inflow data

    DEFF Research Database (Denmark)

    Fischer, Andreas; Aagaard Madsen, Helge

    2016-01-01

    the rotational frequency. The highest fatigue load reduction was achieved when the inflow sensor was placed at the outer parts of the blade. In the best case, the reduction of the local fatigue loads induced by the blade sectional normal force was 60%. The control method gave the highest fatigue load reductions...... effects seem to be negligible. Copyright © 2015 John Wiley & Sons, Ltd....

  14. Probing active-edge silicon sensors using a high precision telescope

    NARCIS (Netherlands)

    Akiba, K.; Artuso, M.; van Beveren, V.; van Beuzekom, M.; Boterenbrood, H.; Buytaert, J.; Collins, P.; Dumps, R.; van der Heijden, B.; Hombach, C.; Hynds, D.; Hsu, D.; John, M.; Koffeman, E.; Leflat, A.; Li, Y.; Longstaff, I.; Morton, A.; PérezTrigo, E.; Plackett, R.; Reid, M.M.; Rodríguez Perez, P.; Schindler, H.; Tsopelas, P.; Vázquez Sierra, C.; Wysokiński, M.

    2015-01-01

    The performance of prototype active-edge VTT sensors bump-bonded to the Timepix ASIC is presented. Non-irradiated sensors of thicknesses 100-200 μm and pixel-to-edge distances of 50 μm and 100 μm were probed with a beam of charged hadrons with sub-pixel precision using the Timepix telescope

  15. Successful closure of treatment-naïve, flat edge (Type II, full-thickness macular hole using inverted internal limiting membrane flap technique

    Directory of Open Access Journals (Sweden)

    Hussain N

    2016-10-01

    Full Text Available Nazimul Hussain,1 Anjli Hussain2 1Department of Ophthalmology, Al Zahra Hospital, 2Al Zahra Medical Center, Dubai, United Arab Emirates Objective: The objective of this study was to present the outcome of the internal limiting membrane (ILM peeling flap technique for a treatment-naïve, flat edge (Type II, full-thickness macular hole (MH. Methods: A 52-year-old man presented with complaints of decreased vision and seeing black spot. He was diagnosed to have a flat edge, full-thickness MH, which was confirmed by optical coherence tomography (OCT. He underwent 23G vitrectomy with brilliant blue G-assisted inverted ILM peeling with an inverted flap over the hole followed by fluid gas exchange. Results: Postoperative follow-up until 3 months showed successful closure of the MH, which was confirmed by OCT. The best-corrected visual acuity improved from baseline 6/60 to 6/12 at the final follow-up. Conclusion: Using the inverted ILM flap technique, a treatment-naïve, flat edge (Type II, full thickness MH achieved successful anatomical and functional outcomes. Keywords: macular hole, inverted ILM, optical coherence tomography

  16. Probing active-edge silicon sensors using a high precision telescope

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, K. [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Artuso, M. [Syracuse University, Syracuse, NY (United States); Beveren, V. van; Beuzekom, M. van; Boterenbrood, H. [Nikhef, Amsterdam (Netherlands); Buytaert, J.; Collins, P.; Dumps, R. [CERN, the European Organisation for Nuclear Research, Geneva (Switzerland); Heijden, B. van der [Nikhef, Amsterdam (Netherlands); Hombach, C. [University of Manchester, Manchester, Lancashire (United Kingdom); Hynds, D. [Glasgow University, Glasgow, Lanarkshire (United Kingdom); Hsu, D. [Syracuse University, Syracuse, NY (United States); John, M. [University of Oxford, Oxfordshire (United Kingdom); Koffeman, E. [Nikhef, Amsterdam (Netherlands); Leflat, A. [Lomonosov Moscow State University, Moscow (Russian Federation); Li, Y. [Tsinghua University, Beijing (China); Longstaff, I.; Morton, A. [Glasgow University, Glasgow, Lanarkshire (United Kingdom); Pérez Trigo, E. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Plackett, R. [Diamond Light Source Ltd., Didcot, Oxfordshire (United Kingdom); and others

    2015-03-21

    The performance of prototype active-edge VTT sensors bump-bonded to the Timepix ASIC is presented. Non-irradiated sensors of thicknesses 100–200 μm and pixel-to-edge distances of 50 μm and 100 μm were probed with a beam of charged hadrons with sub-pixel precision using the Timepix telescope assembled at the SPS at CERN. The sensors are shown to be highly efficient up to a few micrometers from the physical edge of the sensor. The distortion of the electric field lines at the edge of the sensors is studied by reconstructing the streamlines of the electric field using two-pixel clusters. These results are supported by TCAD simulations. The reconstructed streamlines are used to study the field distortion as a function of the bias voltage and to apply corrections to the cluster positions at the edge.

  17. Transition-edge sensor imaging arrays for astrophysics applications

    Science.gov (United States)

    Burney, Jennifer Anne

    Many interesting objects in our universe currently elude observation in the optical band: they are too faint or they vary rapidly and thus any structure in their radiation is lost over the period of an exposure. Conventional photon detectors cannot simultaneously provide energy resolution and time-stamping of individual photons at fast rates. Superconducting detectors have recently made the possibility of simultaneous photon counting, imaging, and energy resolution a reality. Our research group has pioneered the use of one such detector, the Transition-Edge Sensor (TES). TES physics is simple and elegant. A thin superconducting film, biased at its critical temperature, can act as a particle detector: an incident particle deposits energy and drives the film into its superconducting-normal transition. By inductively coupling the detector to a SQUID amplifier circuit, this resistance change can be read out as a current pulse, and its energy deduced by integrating over the pulse. TESs can be used to accurately time-stamp (to 0.1 [mu]s) and energy-resolve (0.15 eV at 1.6 eV) near-IR/visible/near-UV photons at rates of 30~kHz. The first astronomical observations using fiber-coupled detectors were made at the Stanford Student Observatory 0.6~m telescope in 1999. Further observations of the Crab Pulsar from the 107" telescope at the University of Texas McDonald Observatory showed rapid phase variations over the near-IR/visible/near-UV band. These preliminary observations provided a glimpse into a new realm of observations of pulsars, binary systems, and accreting black holes promised by TES arrays. This thesis describes the development, characterization, and preliminary use of the first camera system based on Transition-Edge Sensors. While single-device operation is relatively well-understood, the operation of a full imaging array poses significant challenges. This thesis addresses all aspects related to the creation and characterization of this cryogenic imaging

  18. Edge pixel response studies of edgeless silicon sensor technology for pixellated imaging detectors

    Science.gov (United States)

    Maneuski, D.; Bates, R.; Blue, A.; Buttar, C.; Doonan, K.; Eklund, L.; Gimenez, E. N.; Hynds, D.; Kachkanov, S.; Kalliopuska, J.; McMullen, T.; O'Shea, V.; Tartoni, N.; Plackett, R.; Vahanen, S.; Wraight, K.

    2015-03-01

    Silicon sensor technologies with reduced dead area at the sensor's perimeter are under development at a number of institutes. Several fabrication methods for sensors which are sensitive close to the physical edge of the device are under investigation utilising techniques such as active-edges, passivated edges and current-terminating rings. Such technologies offer the goal of a seamlessly tiled detection surface with minimum dead space between the individual modules. In order to quantify the performance of different geometries and different bulk and implant types, characterisation of several sensors fabricated using active-edge technology were performed at the B16 beam line of the Diamond Light Source. The sensors were fabricated by VTT and bump-bonded to Timepix ROICs. They were 100 and 200 μ m thick sensors, with the last pixel-to-edge distance of either 50 or 100 μ m. The sensors were fabricated as either n-on-n or n-on-p type devices. Using 15 keV monochromatic X-rays with a beam spot of 2.5 μ m, the performance at the outer edge and corners pixels of the sensors was evaluated at three bias voltages. The results indicate a significant change in the charge collection properties between the edge and 5th (up to 275 μ m) from edge pixel for the 200 μ m thick n-on-n sensor. The edge pixel performance of the 100 μ m thick n-on-p sensors is affected only for the last two pixels (up to 110 μ m) subject to biasing conditions. Imaging characteristics of all sensor types investigated are stable over time and the non-uniformities can be minimised by flat-field corrections. The results from the synchrotron tests combined with lab measurements are presented along with an explanation of the observed effects.

  19. AERO2S - SUBSONIC AERODYNAMIC ANALYSIS OF WINGS WITH LEADING- AND TRAILING-EDGE FLAPS IN COMBINATION WITH CANARD OR HORIZONTAL TAIL SURFACES (IBM PC VERSION)

    Science.gov (United States)

    Carlson, H. W.

    1994-01-01

    This code was developed to aid design engineers in the selection and evaluation of aerodynamically efficient wing-canard and wing-horizontal-tail configurations that may employ simple hinged-flap systems. Rapid estimates of the longitudinal aerodynamic characteristics of conceptual airplane lifting surface arrangements are provided. The method is particularly well suited to configurations which, because of high speed flight requirements, must employ thin wings with highly swept leading edges. The code is applicable to wings with either sharp or rounded leading edges. The code provides theoretical pressure distributions over the wing, the canard or horizontal tail, and the deflected flap surfaces as well as estimates of the wing lift, drag, and pitching moments which account for attainable leading edge thrust and leading edge separation vortex forces. The wing planform information is specified by a series of leading edge and trailing edge breakpoints for a right hand wing panel. Up to 21 pairs of coordinates may be used to describe both the leading edge and the trailing edge. The code has been written to accommodate 2000 right hand panel elements, but can easily be modified to accommodate a larger or smaller number of elements depending on the capacity of the target computer platform. The code provides solutions for wing surfaces composed of all possible combinations of leading edge and trailing edge flap settings provided by the original deflection multipliers and by the flap deflection multipliers. Up to 25 pairs of leading edge and trailing edge flap deflection schedules may thus be treated simultaneously. The code also provides for an improved accounting of hinge-line singularities in determination of wing forces and moments. To determine lifting surface perturbation velocity distributions, the code provides for a maximum of 70 iterations. The program is constructed so that successive runs may be made with a given code entry. To make additional runs, it is

  20. AERO2S - SUBSONIC AERODYNAMIC ANALYSIS OF WINGS WITH LEADING- AND TRAILING-EDGE FLAPS IN COMBINATION WITH CANARD OR HORIZONTAL TAIL SURFACES (CDC VERSION)

    Science.gov (United States)

    Darden, C. M.

    1994-01-01

    This code was developed to aid design engineers in the selection and evaluation of aerodynamically efficient wing-canard and wing-horizontal-tail configurations that may employ simple hinged-flap systems. Rapid estimates of the longitudinal aerodynamic characteristics of conceptual airplane lifting surface arrangements are provided. The method is particularly well suited to configurations which, because of high speed flight requirements, must employ thin wings with highly swept leading edges. The code is applicable to wings with either sharp or rounded leading edges. The code provides theoretical pressure distributions over the wing, the canard or horizontal tail, and the deflected flap surfaces as well as estimates of the wing lift, drag, and pitching moments which account for attainable leading edge thrust and leading edge separation vortex forces. The wing planform information is specified by a series of leading edge and trailing edge breakpoints for a right hand wing panel. Up to 21 pairs of coordinates may be used to describe both the leading edge and the trailing edge. The code has been written to accommodate 2000 right hand panel elements, but can easily be modified to accommodate a larger or smaller number of elements depending on the capacity of the target computer platform. The code provides solutions for wing surfaces composed of all possible combinations of leading edge and trailing edge flap settings provided by the original deflection multipliers and by the flap deflection multipliers. Up to 25 pairs of leading edge and trailing edge flap deflection schedules may thus be treated simultaneously. The code also provides for an improved accounting of hinge-line singularities in determination of wing forces and moments. To determine lifting surface perturbation velocity distributions, the code provides for a maximum of 70 iterations. The program is constructed so that successive runs may be made with a given code entry. To make additional runs, it is

  1. AlMn Transition Edge Sensors for Advanced ACTPol

    Science.gov (United States)

    Li, Dale; Austermann, Jason E.; Beall, James A.; Tucker, Daniel T.; Duff, Shannon M.; Gallardo, Patricio A.; Henderson, Shawn W.; Hilton, Gene C.; Ho, Shuay-Pwu; Hubmayr, Johannes; hide

    2016-01-01

    Advanced ACTPol (Adv ACT) will use an array of multichroic polarization sensitive AIMn transition edge sensor (TES) bolometers read out through time-division multiplexing. Aluminum doped with a low concentration of manganese can be deposited to a bulk film thickness for a more reliable superconducting critical temperature uniformity compared to thin bilayers. To build the TES, the AlMn alloy is deposited, over Nb wiring, to a specific thickness to set the TES normal resistance. The doping concentration of manganese coarsely defines the TES critical temperature, while a fine tuning is achieved by heating the deposited film to a specific temperature. The TES island is connected to the thermal bath via four silicon-nitride membranes, where their geometry defines the thermal conductance to the temperature of the bath. Lastly, the TES heat capacity is increased by addition of PdAu electrically connected to the AlMn film. Designs and performance characteristics of these AlMn TESs are presented for use in AdvACT.

  2. AlMn Transition Edge Sensors for Advanced ACTPol

    Science.gov (United States)

    Li, Dale; Austermann, Jason E.; Beall, James A.; Becker, Daniel T.; Duff, Shannon M.; Gallardo, Patricio A.; Henderson, Shawn W.; Hilton, Gene C.; Ho, Shuay-Pwu; Hubmayr, Johannes; Koopman, Brian J.; McMahon, Jeffrey J.; Nati, Federico; Niemack, Michael D.; Pappas, Christine G.; Salatino, Maria; Schmitt, Benjamin L.; Simon, Sara M.; Staggs, Suzanne T.; Van Lanen, Jeff; Ward, Jonathan T.; Wollack, Edward J.

    2016-07-01

    Advanced ACTPol (AdvACT) will use an array of multichroic polarization-sensitive AlMn transition edge sensor (TES) bolometers read out through time-division multiplexing. Aluminum doped with a low concentration of manganese can be deposited to a bulk film thickness for a more reliable superconducting critical temperature uniformity compared to thin bilayers. To build the TES, the AlMn alloy is deposited, over Nb wiring, to a specific thickness to set the TES normal resistance. The doping concentration of manganese coarsely defines the TES critical temperature, while a fine tuning is achieved by heating the deposited film to a specific temperature. The TES island is connected to the thermal bath via four silicon-nitride membranes, where their geometry defines the thermal conductance to the temperature of the bath. Lastly, the TES heat capacity is increased by addition of PdAu electrically connected to the AlMn film. Designs and performance characteristics of these AlMn TESs are presented for use in AdvACT.

  3. Optical response of Al/Ti bilayer transition edge sensors

    International Nuclear Information System (INIS)

    Zhang Qing-Ya; Liu Jian-She; Dong Wen-Hui; He Gen-Fang; Li Tie-Fu; Chen Wei; Wang Tian-Shun; Zhou Xing-Xiang

    2014-01-01

    We report the optical response characteristics of Al/Ti bilayer transition edge sensors (TESs), which are mainly comprised of Al/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3 He sorption refrigerator and the device's response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time (τ eff ) of the devices at different biases and discussed the dependence of τ eff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τ eff = 3.9 μs, which indicates a high temperature sensitivity (α = T/R · dR/dT = 326). The results also showed that the TES exhibits good linearity under optical pulses of variable widths. (interdisciplinary physics and related areas of science and technology)

  4. High-fidelity linear time-invariant model of a smart rotor with adaptive trailing edge flaps

    DEFF Research Database (Denmark)

    Bergami, Leonardo; Hansen, Morten Hartvig

    2017-01-01

    aero-servo-elastic model support the design, systematic tuning and model synthesis of smart rotor control systems. As an example application, the gains of an individual flap controller are tuned using the Ziegler-Nichols method for the full-order poles. The flap controller is based on feedback...

  5. Low Thermal Conductance Transition Edge Sensor (TES) for SPICA

    International Nuclear Information System (INIS)

    Khosropanah, P.; Dirks, B.; Kuur, J. van der; Ridder, M.; Bruijn, M.; Popescu, M.; Hoevers, H.; Gao, J. R.; Morozov, D.; Mauskopf, P.

    2009-01-01

    We fabricated and characterized low thermal conductance transition edge sensors (TES) for SAFARI instrument on SPICA. The device is based on a superconducting Ti/Au bilayer deposited on suspended SiN membrane. The critical temperature of the device is 113 mK. The low thermal conductance is realized by using long and narrow SiN supporting legs. All measurements were performed having the device in a light-tight box, which to a great extent eliminates the loading of the background radiation. We measured the current-voltage (IV) characteristics of the device in different bath temperatures and determine the thermal conductance (G) to be equal to 320 fW/K. This value corresponds to a noise equivalent power (NEP) of 3x10 -19 W/√(Hz). The current noise and complex impedance is also measured at different bias points at 55 mK bath temperature. The measured electrical (dark) NEP is 1x10 -18 W/√(Hz), which is about a factor of 3 higher than what we expect from the thermal conductance that comes out of the IV curves. Despite using a light-tight box, the photon noise might still be the source of this excess noise. We also measured the complex impedance of the same device at several bias points. Fitting a simple first order thermal-electrical model to the measured data, we find an effective time constant of about 2.7 ms and a thermal capacity of 13 fJ/K in the middle of the transition.

  6. Transition edge sensors for bolometric applications: responsivity and saturation

    International Nuclear Information System (INIS)

    Goldie, D. J.; Audley, M. D.; Glowacka, D. M.; Tsaneva, V. N.; Withington, S.

    2008-01-01

    Microstrip-coupled transition edge sensors (TESs) combined with waveguide-horn technology produce sensitive bolometric detectors with well-defined, single-mode beam patterns and excellent polarization characteristics. These devices are now being deployed for astronomical observations. In bolometric applications, where power levels are monitored, the critical parameter that characterizes the detection is the power-to-current responsivity s I (ω), where ω is the postdetection angular frequency. In real applications, such as on a ground-based telescope, the signal of interest is superimposed on a background such as the thermal emission from the atmosphere. The power emitted by the atmosphere changes slowly in time and these changes may change the responsivity of the detector. A detailed understanding of how s I (ω) changes as a function of applied power levels and how the TES response saturates is vital for accurate calibration of astronomical data. In this paper we describe measurements of the changes in the current flowing through a TES as a function of the circuit bias and the applied power. From these measurements we calculate the efficiency of the coupling of power into the TES from a closely thermally coupled microstrip termination resistor and we determine the zero frequency responsivity s I (0) as a function of both the circuit bias and power. The variation of the responsivity is compared with predictions of a small-signal model: for the case when the loop gain L I is high, when simplifying approximations to the full solution to the electrothermal equations apply; and using the electrothermal parameters of the TES, determined by impedance measurements, as inputs to the full model solution. We find good agreement between theory and measurement in both cases in the relevant regimes

  7. Ship Sensor Observations for Life on the Edge 2005 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly measurements made by selected ship sensors on the R/V Seward Johnson during the "Life on the Edge 2005" expedition sponsored by the National Oceanic and...

  8. Ship Sensor Observations for Life on the Edge 2004 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly measurements made by selected ship sensors on the R/V Seward Johnson during the "Life on the Edge 2004" expedition sponsored by the National Oceanic and...

  9. Oriented Edge-Based Feature Descriptor for Multi-Sensor Image Alignment and Enhancement

    Directory of Open Access Journals (Sweden)

    Myung-Ho Ju

    2013-10-01

    Full Text Available In this paper, we present an efficient image alignment and enhancement method for multi-sensor images. The shape of the object captured in a multi-sensor images can be determined by comparing variability of contrast using corresponding edges across multi-sensor image. Using this cue, we construct a robust feature descriptor based on the magnitudes of the oriented edges. Our proposed method enables fast image alignment by identifying matching features in multi-sensor images. We enhance the aligned multi-sensor images through the fusion of the salient regions from each image. The results of stitching the multi-sensor images and their enhancement demonstrate that our proposed method can align and enhance multi-sensor images more efficiently than previous methods.

  10. Functional characterization of planar sensors with active edges using laser and X-ray beam scans

    International Nuclear Information System (INIS)

    Povoli, M.; Bagolini, A.; Boscardin, M.; Dalla Betta, G.-F.; Giacomini, G.; Hasi, J.; Oh, A.; Zorzi, N.

    2013-01-01

    We report on the functional characterization of planar sensors with active edges fabricated at Fondazione Bruno Kessler (FBK), Trento, Italy. The measurements here reported were performed by means of laser and X-ray beam scans mainly focusing on the signal efficiency of the edge region of the devices. Results are very encouraging and show very good sensitivity up to few microns away from the device physical edge

  11. Functional characterization of planar sensors with active edges using laser and X-ray beam scans

    Energy Technology Data Exchange (ETDEWEB)

    Povoli, M., E-mail: povoli@disi.unitn.it [Dipartimento di Ingegneria e Scienza dell' Informazione, Università di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento),Via Sommarive, 14, I-38123 Povo di Trento (Italy); Bagolini, A.; Boscardin, M. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Dalla Betta, G.-F. [Dipartimento di Ingegneria e Scienza dell' Informazione, Università di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento),Via Sommarive, 14, I-38123 Povo di Trento (Italy); Giacomini, G. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Hasi, J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025-7015 (United States); Oh, A. [The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Zorzi, N. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy)

    2013-08-01

    We report on the functional characterization of planar sensors with active edges fabricated at Fondazione Bruno Kessler (FBK), Trento, Italy. The measurements here reported were performed by means of laser and X-ray beam scans mainly focusing on the signal efficiency of the edge region of the devices. Results are very encouraging and show very good sensitivity up to few microns away from the device physical edge.

  12. First experimental results on active and slim-edge silicon sensors for XFEL

    International Nuclear Information System (INIS)

    Pancheri, L.; Benkechcache, M. E. A.; Betta, G.-F. Dalla; Xu, H.; Verzellesi, G.; Ronchin, S.; Boscardin, M.; Ratti, L.; Grassi, M.; Lodola, L.; Malcovati, P.; Vacchi, C.; Manghisoni, M.; Re, V.; Traversi, G.; Batignani, G.; Bettarini, S.; Casarosa, G.; Giorgi, M.; Forti, F.

    2016-01-01

    This work presents the first characterization results obtained on a pilot fabrication run of planar sensors, tailored for X-ray imaging applications at FELs, developed in the framework of INFN project PixFEL. Active and slim-edge p-on-n sensors are fabricated on n-type high-resistivity silicon with 450 μm thickness, bonded to a support wafer. Both diodes and pixelated sensors with a pitch of 110 μm are included in the design. Edge structures with different number of guard rings are designed to comply with the large bias voltage required by the application after accumulating an ionizing radiation dose as large as 1GGy. Preliminary results from the electrical characterization of the produced sensors, providing a first assessment of the proposed approach, are discussed. A functional characterization of the sensors with a pulsed infrared laser is also presented, demonstrating the validity of slim-edge configurations.

  13. Blowing Flap Experiment: PIV Measurements

    Science.gov (United States)

    Hutcheson, Florence V.; Stead, Daniel J.; Bremmer, David M.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the flap vortex system. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  14. SALT segmented primary mirror: laboratory test results for FOGALE inductive edge sensors

    Science.gov (United States)

    Menzies, John; Gajjar, Hitesh; Buous, Sébastien; Buckley, David; Gillingham, Peter

    2010-07-01

    At the Southern African Large Telescope (SALT), in collaboration with FOGALE Nanotech, we have been testing the recently-developed new generation inductive edge sensors. The Fogale inductive sensor is one technology being evaluated as a possible replacement for the now defunct capacitance-based edge sensing system. We present the results of exhaustive environmental testing of two variants of the inductive sensor. In addition to the environmental testing including RH and temperature cycles, the sensor was tested for sensitivity to dust and metals. We also consider long-term sensor stability, as well as that of the electronics and of the glue used to bond the sensor to its supporting structure. A prototype design for an adjustable mount is presented which will allow for in-plane gap and shear variations present in the primary mirror configuration without adversely disturbing the figure of the individual mirror segments or the measurement accuracy.

  15. Unexpected Nonlinear Effects in Superconducting Transition-Edge Sensors

    Science.gov (United States)

    Sadleir, John

    2016-01-01

    When a normal metal transitions into the superconducting state the DC resistance drops from a finite value to zero over some finite transition width in temperature, current, and magnetic field. Superconducting transition-edge sensors (TESs) operate within this transition region and uses resistive changes to measure deposited thermal energy. This resistive transition is not perfectly smooth and a wide range of TES designs and materials show sub-structure in the resistive transition (as seen in smooth nonmonotonic behavior, jump discontinuities, and hysteresis in the devices current-voltage relation and derivatives of the resistance with respect to temperature, bias current, and magnetic field). TES technology has advanced to the point where for many applications this structure is the limiting factor in performance and optimization consists of finding operating points away from these structures. For example, operating at or near this structure can lead to nonlinearity in the detectors response and gain scale, limit the spectral range of the detector by limiting the usable resistive range, and degrade energy resolution. The origin of much of this substructure is unknown. This presentation investigates a number of possible sources in turn. First we model the TES as a superconducting weak-link and solve for the characteristic differential equations current and voltage time dependence. We find:(1) measured DC biased current-voltage relationship is the time-average of a much higher frequency limit cycle solution.(2) We calculate the fundamental frequency and estimate the power radiated from the TES treating the bias leads as an antennae.(3) The solution for a set of circuit parameters becomes multivalued leading to current transitions between levels.(4)The circuit parameters can change the measure resistance and mask the true critical current. As a consequence the TES resistance surface is not just a function of temperature, current, and magnetic field but is also a

  16. Edge-TCT for the investigation of radiation damaged silicon strip sensors

    Energy Technology Data Exchange (ETDEWEB)

    Feindt, Finn

    2017-02-15

    The edge Transient Current Technique (TCT) is a method for the investigation of silicon sensors. This method requires infrared light from a sub-ns pulsed laser to be focused to a μm-size spot and scanned across the polished cut edge of a sensor. Electron-hole pairs are generated along the light beam in the sensor. These charge carriers drift in the electric field and induce transient currents on the sensor electrodes. The current transients are analyzed as a function of the applied voltage, temperature, absorbed dose and position of the laser-light focus, in order to determine the the drift velocities, electric field and the charge collection in the strip sensor. In the scope of this work, a new edge-TCT setup is commissioned, a procedure for the polishing of the cut edge is implemented and a method to position the focus of the laser light with respect to the sensor is developed. First edge-TCT measurements are performed on non-irradiated, 285 μm thick n-type strip sensors, and the pulse shape and charge collection is studied under different conditions. Furthermore, the prompt current of the transients is extracted, which is the first step towards the determination of the electric field. A new method to measure the attenuation of light in silicon is tested on a non-irradiated sensor and on sensors irradiated with up to a 1 MeV neutron equivalent fluence of 1.14 x 10{sup 15} cm{sup -2}, using laser light with a wavelength of 1052 nm.

  17. Edge-TCT for the investigation of radiation damaged silicon strip sensors

    International Nuclear Information System (INIS)

    Feindt, Finn

    2017-02-01

    The edge Transient Current Technique (TCT) is a method for the investigation of silicon sensors. This method requires infrared light from a sub-ns pulsed laser to be focused to a μm-size spot and scanned across the polished cut edge of a sensor. Electron-hole pairs are generated along the light beam in the sensor. These charge carriers drift in the electric field and induce transient currents on the sensor electrodes. The current transients are analyzed as a function of the applied voltage, temperature, absorbed dose and position of the laser-light focus, in order to determine the the drift velocities, electric field and the charge collection in the strip sensor. In the scope of this work, a new edge-TCT setup is commissioned, a procedure for the polishing of the cut edge is implemented and a method to position the focus of the laser light with respect to the sensor is developed. First edge-TCT measurements are performed on non-irradiated, 285 μm thick n-type strip sensors, and the pulse shape and charge collection is studied under different conditions. Furthermore, the prompt current of the transients is extracted, which is the first step towards the determination of the electric field. A new method to measure the attenuation of light in silicon is tested on a non-irradiated sensor and on sensors irradiated with up to a 1 MeV neutron equivalent fluence of 1.14 x 10"1"5 cm"-"2, using laser light with a wavelength of 1052 nm.

  18. Superconducting transition edge sensors and methods for design and manufacture thereof

    Science.gov (United States)

    Sadleir, John E. (Inventor)

    2013-01-01

    Methods for forming sensors using transition edge sensors (TES) and sensors therefrom are described. The method includes forming a plurality of sensor arrays includes at least one TES device. The TES device includes a TES device body, a first superconducting lead contacting a first portion of the TES device body, and a second superconducting lead contacting of a second portion of the TES device body, where the first and second superconducting leads separated on the TES device body by a lead spacing. The lead spacing can be selected to be different for at least two of the plurality of sensor arrays. The method also includes determining a transition temperature for each of the plurality of sensor arrays and generating a signal responsive to detecting a change in the electrical characteristics of one of the plurality of sensor arrays meeting a transition temperature criterion.

  19. Advanced Load Alleviation for Wind Turbines using Adaptive Trailing Edge Flaps: Sensoring and Control

    DEFF Research Database (Denmark)

    Andersen, Peter Bjørn

    The purpose of wind turbines and their predecessors the windmill, is to convert the energy in the wind to usable energy forms. Whereas windmills of the past focused on the conversion of wind power to torque for grinding, pumping and winching, modern wind turbines convert the wind energy...... into electric power. They do so through incorporation of generators, which convert mechanical torque into electricity. Wind turbines are designed to keep the overall cost per produced Kilo Watt hour as low as possible. One way of improving the performance and lifetime of the wind turbine is through active flow...

  20. Thin n-in-p planar pixel sensors and active edge sensors for the ATLAS upgrade at HL-LHC

    International Nuclear Information System (INIS)

    Terzo, S; Macchiolo, A; Nisius, R; Paschen, B

    2014-01-01

    Silicon pixel modules employing n-in-p planar sensors with an active thickness of 200 μm, produced at CiS, and 100-200 μm thin active/slim edge sensor devices, produced at VTT in Finland have been interconnected to ATLAS FE-I3 and FE-I4 read-out chips. The thin sensors are designed for high energy physics collider experiments to ensure radiation hardness at high fluences. Moreover, the active edge technology of the VTT production maximizes the sensitive region of the assembly, allowing for a reduced overlap of the modules in the pixel layer close to the beam pipe. The CiS production includes also four chip sensors according to the module geometry planned for the outer layers of the upgraded ATLAS pixel detector to be operated at the HL-LHC. The modules have been characterized using radioactive sources in the laboratory and with high precision measurements at beam tests to investigate the hit efficiency and charge collection properties at different bias voltages and particle incidence angles. The performance of the different sensor thicknesses and edge designs are compared before and after irradiation up to a fluence of 1.4 × 10 16 n eq /cm 2

  1. Review of superconducting transition-edge sensors for x-ray and gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    Ullom, Joel N; Bennett, Douglas A

    2015-01-01

    We present a review of emerging x-ray and gamma-ray spectrometers based on arrays of superconducting transition-edge sensors (TESs). Special attention will be given to recent progress in TES applications and in understanding TES physics. (paper)

  2. Measurement of quasiparticle transport in aluminum films using tungsten transition-edge sensors

    International Nuclear Information System (INIS)

    Yen, J. J.; Shank, B.; Cabrera, B.; Moffatt, R.; Redl, P.; Young, B. A.; Tortorici, E. C.; Brink, P. L.; Cherry, M.; Tomada, A.; Kreikebaum, J. M.

    2014-01-01

    We report on experimental studies of phonon sensors which utilize quasiparticle diffusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach. These studies allow the design of phonon sensors with improved performance.

  3. An edge-TCT setup for the investigation of radiation damaged silicon sensors

    Energy Technology Data Exchange (ETDEWEB)

    Feindt, Finn; Scharf, Christian; Garutti, Erika; Klanner, Robert [Institute for Experimental Physics, Hamburg University, Luruper Chaussee 149, D-22761 Hamburg (Germany)

    2016-07-01

    The aim of this work is to measure the electric field, drift velocity and charge collection of electrons and holes in radiation-damaged silicon strip sensors. For this purpose the edge Transient Current Technique (TCT) is employed. In contrast to conventional TCT, this method requires light from a sub-ns pulsed, infrared laser to be focused to a μm-size spot and scanned across the polished edge of a strip sensor. Thus electron-hole pairs are generated at a known depth in the sensor. Electrons and holes drift in the electric field and induce transient currents on the sensor electrodes. The current wave forms are analyzed as a function of the applied voltage and the position of the laser focus in order to determine the electric field, the drift velocities and the charge collection. In this talk the setup and the procedure for polishing the sensor edge are described, and first results, regarding the measurement of the laser light focus are presented.

  4. Flap testing on the rotating test rig in the INDUFLAP project

    DEFF Research Database (Denmark)

    Barlas, Athanasios; Aagaard Madsen, Helge; Enevoldsen, Karen

    Tests of a prototype Controllable Rubber Trailing Edge Flap (CRTEF) are performed on the rotating test rig at the Risø campus of DTU. The general description and objectives are presented, along with an overview of sensors on the setup and the test cases. The post-processing of data is discussed...

  5. Slim edge studies, design and quality control of planar ATLAS IBL pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Tobias

    2013-05-08

    One of the four large experiments at the LHC at CERN is the ATLAS detector, a multi purpose detector. Its pixel detector, composed of three layers, is the innermost part of the tracker. As it is closest to the interaction point, it represents a basic part of the track reconstruction. Besides the requested high resolution one main requirement is the radiation hardness. In the coming years the radiation damage will cause deteriorations of the detector performance. With the planned increase of the luminosity, especially after the upgrade to the High Luminosity LHC, this radiation damage will be even intensified. This circumstance necessitates a new pixel detector featuring improved radiation hard sensors and read-out chips. The present shutdown of the LHC is already utilized to insert an additional b-layer (IBL) into the existing ATLAS pixel detector. The current n-in-n pixel sensor design had to be adapted to the new read-out chip and the module specifications. The new stave geometry requests a reduction of the inactive sensor edge. In a prototype wafer production all modifications have been implemented. The sensor quality control was supervised which led to the decision of the final sensor thickness. In order to evaluate the performance of the sensor chip assemblies with an innovative slim edge design, they have been operated in test beam setups before and after irradiation. Furthermore, the quality control of the planar IBL sensor wafer production was supervised from the stage of wafer delivery to that before the flip chip process to ensure a sufficient amount of functional sensors for the module production.

  6. PIV Measurements on a Blowing Flap

    Science.gov (United States)

    Hutcheson, Florence V.; Stead, Daniel J.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several blowing flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main-element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the vortex system or accelerated the merging of the side vortex to the flap top surface. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  7. First results from Position-Sensitive quantum calorimeters using Mo/Au Transition-Edge Sensors

    International Nuclear Information System (INIS)

    Figueroa-Feliciano, Enectali; Chervenak, Jay; Finkbeiner, Fred M.; Li, Mary; Lindeman, Mark A.; Stahle, Caroline K.; Stahle, Carl M.

    2002-01-01

    We report the first results from a high-energy-resolution imaging spectrometer called a Position-Sensitive Transition-Edge Sensor (PoST). A PoST is a quantum calorimeter consisting of two Transition Edge Sensors (TESs) on the ends of a long absorber to do one dimensional imaging spectroscopy. Comparing rise time and energy information, the position of the event in the PoST is determined. Energy is inferred from the sum of the two pulses. We have fabricated 7- and 15-pixel PoSTs using Mo-Au TESs and Au absorbers. We have achieved 32 eV FWHM energy resolution at 1.5 keV with a 7-pixel PoST calorimeter

  8. Frequency-domain readout multiplexing of transition-edge sensor arrays

    Energy Technology Data Exchange (ETDEWEB)

    Lanting, T.M. [Physics Department, University of California, Berkeley, CA 94720 (United States)]. E-mail: tlanting@berkeley.edu; Arnold, K. [Physics Department, University of California, Berkeley, CA 94720 (United States); Cho, Hsiao-Mei [Physics Department, University of California, Berkeley, CA 94720 (United States); Clarke, John [Physics Department, University of California, Berkeley, CA 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Dobbs, Matt [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Holzapfel, William [Physics Department, University of California, Berkeley, CA 94720 (United States); Lee, Adrian T. [Physics Department, University of California, Berkeley, CA 94720 (United States); Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Lueker, M. [Physics Department, University of California, Berkeley, CA 94720 (United States); Richards, P.L. [Physics Department, University of California, Berkeley, CA 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Smith, A.D. [Northrop-Grumman, Redondo Beach, CA 94278 (United States); Spieler, H.G. [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2006-04-15

    We have demonstrated frequency-domain readout multiplexing of eight channels for superconducting transition-edge sensor bolometer arrays. The multiplexed readout noise is 6.5 pA/{radical}Hz, well below the bolometer dark noise of 15-20 pA/{radical}Hz. We measure an upper limit on crosstalk of 0.004 between channels adjacent in frequency which meets our design requirement of 0.01. We have observed vibration insensitivity in our frequency-domain multiplexed transition-edge sensors, making this system very attractive for telescope and satellite observations. We also discuss extensions to our multiplexed readout. In particular, we are developing a SQUID flux-locked loop that is entirely cold and collaborating on digital multiplexer technology in order to scale up the number of multiplexed channels.

  9. Semantic Edge Based Disparity Estimation Using Adaptive Dynamic Programming for Binocular Sensors.

    Science.gov (United States)

    Zhu, Dongchen; Li, Jiamao; Wang, Xianshun; Peng, Jingquan; Shi, Wenjun; Zhang, Xiaolin

    2018-04-03

    Disparity calculation is crucial for binocular sensor ranging. The disparity estimation based on edges is an important branch in the research of sparse stereo matching and plays an important role in visual navigation. In this paper, we propose a robust sparse stereo matching method based on the semantic edges. Some simple matching costs are used first, and then a novel adaptive dynamic programming algorithm is proposed to obtain optimal solutions. This algorithm makes use of the disparity or semantic consistency constraint between the stereo images to adaptively search parameters, which can improve the robustness of our method. The proposed method is compared quantitatively and qualitatively with the traditional dynamic programming method, some dense stereo matching methods, and the advanced edge-based method respectively. Experiments show that our method can provide superior performance on the above comparison.

  10. Coupled Vortex-Lattice Flight Dynamic Model with Aeroelastic Finite-Element Model of Flexible Wing Transport Aircraft with Variable Camber Continuous Trailing Edge Flap for Drag Reduction

    Science.gov (United States)

    Nguyen, Nhan; Ting, Eric; Nguyen, Daniel; Dao, Tung; Trinh, Khanh

    2013-01-01

    This paper presents a coupled vortex-lattice flight dynamic model with an aeroelastic finite-element model to predict dynamic characteristics of a flexible wing transport aircraft. The aircraft model is based on NASA Generic Transport Model (GTM) with representative mass and stiffness properties to achieve a wing tip deflection about twice that of a conventional transport aircraft (10% versus 5%). This flexible wing transport aircraft is referred to as an Elastically Shaped Aircraft Concept (ESAC) which is equipped with a Variable Camber Continuous Trailing Edge Flap (VCCTEF) system for active wing shaping control for drag reduction. A vortex-lattice aerodynamic model of the ESAC is developed and is coupled with an aeroelastic finite-element model via an automated geometry modeler. This coupled model is used to compute static and dynamic aeroelastic solutions. The deflection information from the finite-element model and the vortex-lattice model is used to compute unsteady contributions to the aerodynamic force and moment coefficients. A coupled aeroelastic-longitudinal flight dynamic model is developed by coupling the finite-element model with the rigid-body flight dynamic model of the GTM.

  11. Suppression of excess noise in Transition-Edge Sensors using magnetic field and geometry

    International Nuclear Information System (INIS)

    Ullom, J.N.; Doriese, W.B.; Hilton, G.C.; Beall, J.A.; Deiker, S.; Irwin, K.D.; Reintsema, C.D.; Vale, L.R.; Xu, Y.

    2004-01-01

    We report recent progress at NIST on Mo/Cu Transition-Edge Sensors (TESs). While the signal-band noise of our sensors agrees with theory, we observe excess high-frequency noise. We describe this noise and demonstrate that it can be strongly suppressed by a magnetic field perpendicular to the plane of the sensor. Both the excess noise and α=(T/R)(dR/dT) depend strongly on field so our results show that accurate comparisons between devices are only possible when the field is well known or constant. We also present results showing the noise performance of TES designs incorporating parallel and perpendicular normal metal bars, an array of normal metal islands, and in wedge-shaped devices. We demonstrate significant reduction of high-frequency noise with the perpendicular bar devices at the cost of reduced α. Both the bars and the magnetic field are useful noise reduction techniques for bolometers

  12. Ship Sensor Observations for Life on the Edge 2003: Exploring Deep Ocean Habitats - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly measurements made by selected ship sensors on the R/V Seward Johnson during the "Life on the Edge 2003: Exploring Deep Ocean Habitats" expedition sponsored by...

  13. Spatial asymmetry in tactile sensor skin deformation aids perception of edge orientation during haptic exploration.

    Science.gov (United States)

    Ponce Wong, Ruben D; Hellman, Randall B; Santos, Veronica J

    2014-01-01

    Upper-limb amputees rely primarily on visual feedback when using their prostheses to interact with others or objects in their environment. A constant reliance upon visual feedback can be mentally exhausting and does not suffice for many activities when line-of-sight is unavailable. Upper-limb amputees could greatly benefit from the ability to perceive edges, one of the most salient features of 3D shape, through touch alone. We present an approach for estimating edge orientation with respect to an artificial fingertip through haptic exploration using a multimodal tactile sensor on a robot hand. Key parameters from the tactile signals for each of four exploratory procedures were used as inputs to a support vector regression model. Edge orientation angles ranging from -90 to 90 degrees were estimated with an 85-input model having an R (2) of 0.99 and RMS error of 5.08 degrees. Electrode impedance signals provided the most useful inputs by encoding spatially asymmetric skin deformation across the entire fingertip. Interestingly, sensor regions that were not in direct contact with the stimulus provided particularly useful information. Methods described here could pave the way for semi-autonomous capabilities in prosthetic or robotic hands during haptic exploration, especially when visual feedback is unavailable.

  14. Unsteady lift and thrust of a 2D flapping thin airfoil in the presence of additional leading edge vortices

    Science.gov (United States)

    Alaminos-Quesada, Javier; Fernandez-Feria, Ramon

    2017-11-01

    The effect of leading-edge vortices (LEVs) on the lift, thrust and moment of a two-dimensional heaving and pitching foil is analyzed from the unsteady, linear potential theory. General expressions taking into account the effect of unsteady point vortices interacting with the oscillatory trailing wake are first derived. Then, simplified expressions for the initial stages of the growing LEV on each half-stroke are used to obtain analytical closed expressions for the main contribution of these vortices to the lift, thrust and moment. It is found that, within the linear potential framework and the Brown-Michael model, the LEV contributes to the aerodynamic forces and moment only for combined pitching and heaving motions of the foil, being a relevant contribution for sufficiently large values of the product of the reduced frequency and the amplitude of the heaving and/or pitching motions. The results are compared with available experimental data and numerical simulations. Supported by the Ministerio de Economia y Competitividad of Spain Grants No. DPI2013-40479-P and DPI2016-76151-C2-1-R.

  15. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

    Hansen, H. I.; Thoft-Christensen, Palle

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap...... is the streamlined part of the edge of the girder. Additional aerodynamic derivatives are shown for the flaps and it is shown how methods already developed can be used to estimate the flutter wind velocity for a bridge section with flaps. As an example, the flutter wind velocity is calculated for different flap...... configurations for a bridge section model by using aerodynamic derivatives for a flat plate. The example shows that different flap configurations can either increase or decrease the flutter wind velocity. for optimal flap configurations flutter will not occur....

  16. Pixel Sensors with slim edges and small pitches for the CMS upgrades for HL-LHC

    CERN Document Server

    AUTHOR|(CDS)2084134; Bolla, Gino; Rivera, Ryan Allen; Uplegger, Lorenzo; Zoi, Irene

    2016-01-01

    Planar n-in-n silicon detectors with small pitches and slim edges are being investigated for the innermost layers of tracking devices for the foreseen upgrades of the LHC. Sensor prototypes compatible with the CMS readout, fabricated by Sintef, were tested in the laboratory and with a 120~GeV/c proton beam at the Fermilab test beam facility before and after irradiation with up to 2x10$^{15}$ n$_{eq}/$cm$^2$ fluence. Preliminary results of the data analysis are presented.

  17. Percolation model of excess electrical noise in transition-edge sensors

    International Nuclear Information System (INIS)

    Lindeman, M.A.; Anderson, M.B.; Bandler, S.R.; Bilgri, N.; Chervenak, J.; Gwynne Crowder, S.; Fallows, S.; Figueroa-Feliciano, E.; Finkbeiner, F.; Iyomoto, N.; Kelley, R.; Kilbourne, C.A.; Lai, T.; Man, J.; McCammon, D.; Nelms, K.L.; Porter, F.S.; Rocks, L.E.; Saab, T.; Sadleir, J.; Vidugiris, G.

    2006-01-01

    We present a geometrical model to describe excess electrical noise in transition-edge sensors (TESs). In this model, a network of fluctuating resistors represents the complex dynamics inside a TES. The fluctuations can cause several resistors in series to become superconducting. Such events short out part of the TES and generate noise because much of the current percolates through low resistance paths. The model predicts that excess white noise increases with decreasing TES bias resistance (R/R N ) and that perpendicular zebra stripes reduce noise and alpha of the TES by reducing percolation

  18. Pixel sensors with slim edges and small pitches for the CMS upgrades for HL-LHC

    Energy Technology Data Exchange (ETDEWEB)

    Vernieri, Caterina, E-mail: cvernier@fnal.gov [Fermilab, Batavia, IL 60510 (United States); Bolla, Gino; Rivera, Ryan; Uplegger, Lorenzo [Fermilab, Batavia, IL 60510 (United States); Zoi, Irene [Fermilab, Batavia, IL 60510 (United States); University of Florence, Firenze, 50121 (Italy)

    2017-02-11

    Planar n-in-n silicon detectors with small pitches and slim edges are being investigated for the innermost layers of tracking devices for the foreseen upgrades of the LHC experiments. Sensor prototypes compatible with the CMS readout, fabricated by Sintef, were tested in the laboratory and with a 120 GeV/c proton beam at the Fermilab test beam facility before and after irradiation with up to 2×10{sup 15} n{sub eq}/cm{sup 2} fluence. Preliminary results of the data analysis are presented.

  19. Impedance measurements on a fast transition-edge sensor for optical and near-infrared range

    International Nuclear Information System (INIS)

    Taralli, E; Portesi, C; Lolli, L; Monticone, E; Rajteri, M; Novikov, I; Beyer, J

    2010-01-01

    Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 μm x 20 μm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C, thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.

  20. Thermal properties of calorimeters with Ti/Au transition-edge sensors on silicon nitride membranes

    International Nuclear Information System (INIS)

    Ukibe, M.; Tanaka, K.; Koyanagi, M.; Morooka, T.; Pressler, H.; Ohkubo, M.; Kobayashi, N.

    2000-01-01

    We are developing X-ray microcalorimeters employing superconducting-transition-edge sensors (TESs) for relatively high operation-temperatures of an 3 He cryostat. The TESs are proximity bilayers of Ti and Au. An important thermal parameters, the thermal conductance G, of the microcalorimeters on SiN x membranes was evaluated by a simple method using R-T curves at different bias currents. It has been shown that the G value can be controlled by altering the membrane thickness and size

  1. Development of active edge pixel sensors and four-side buttable modules using vertical integration technologies

    CERN Document Server

    INSPIRE-00219560; Moser, H.-G.; Nisius, R.; Richter, R.H.; Terzo, S.; Weigell, P.

    2014-01-01

    We present an R&D activity focused on the development of novel modules for the upgrade of the ATLAS pixel system at the High Luminosity LHC (HL-LHC). The modules consist of n-in-p pixel sensors, 100 or 200 $\\mu$m thick, produced at VTT (Finland) with an active edge technology, which considerably reduces the dead area at the periphery of the device. The sensors are interconnected with solder bump-bonding to the ATLAS FE-I3 and FE-I4 read-out chips, and characterized with radioactive sources and beam tests at the CERN-SPS and DESY. The results of these measurements will be discussed for devices before and after irradiation up to a fluence of $5\\times 10^{15}$ \

  2. Molybdenum-gold proximity bilayers as transition edge sensors for microcalorimeters and bolometers

    International Nuclear Information System (INIS)

    Chen, T.C.; Bier, A.; DiCamillo, B.; Finkbeiner, F. M.

    1999-01-01

    Mo/Au proximity bilayers as transition edge sensors (TESs) are promising candidates for low-temperature thermometry. The transition temperature of the bilayers can be easily tuned between 50 and 600 mK, yielding sensors which can be used in a variety of calorimetric and bolometric applications. With phase transition widths of less than 1 mK, Mo/Au TESs show very high temperature sensitivity (d(logR)/d(logT)∼2500). Also, Mo/Au TESs show improved thermal and chemical stability compared to most other bilayer configurations. Fabrication issues and detector performance of Mo/Au TESs on Si 3 N 4 membranes are discussed. (author)

  3. X-ray metrology of an array of active edge pixel sensors for use at synchrotron light sources

    Science.gov (United States)

    Plackett, R.; Arndt, K.; Bortoletto, D.; Horswell, I.; Lockwood, G.; Shipsey, I.; Tartoni, N.; Williams, S.

    2018-01-01

    We report on the production and testing of an array of active edge silicon sensors as a prototype of a large array. Four Medipix3RX.1 chips were bump bonded to four single chip sized Advacam active edge n-on-n sensors. These detectors were then mounted into a 2 by 2 array and tested on B16 at Diamond Light Source with an x-ray beam spot of 2um. The results from these tests, compared with optical metrology demonstrate that this type of sensor is sensitive to the physical edge of the silicon, with only a modest loss of efficiency in the final two rows of pixels. We present the efficiency maps recorded with the microfocus beam and a sample powder diffraction measurement. These results give confidence that this sensor technology can be used effectively in larger arrays of detectors at synchrotron light sources.

  4. Simplified two-fluid current–voltage relation for superconductor transition-edge sensors

    International Nuclear Information System (INIS)

    Wang, Tian-Shun; Chen, Jun-Kang; Zhang, Qing-Ya; Li, Tie-Fu; Liu, Jian-She; Chen, Wei; Zhou, Xingxiang

    2013-01-01

    We propose a simplified current–voltage (IV) relation for the analysis and simulation of superconductor transition-edge sensor (TES) circuits. Compared to the conventional approach based on the effective TES resistance, our expression describes the device behavior more thoroughly covering the superconducting, transitional, and normal-state for TES currents in both directions. We show how to use our IV relation to perform small-signal analysis and derive the device's temperature and current sensitivities based on its physical parameters. We further demonstrate that we can use our IV relation to greatly simplify TES device modeling and make SPICE simulation of TES circuits easily accessible. We present some interesting results as examples of valuable simulations enabled by our IV relation. -- Highlights: •We propose an IV relation for superconductor transition-edge sensors (TES). •We derive the dependence of the sensitivity of TES on its physical parameters. •We use our IV relation for SPICE modeling of TES device. •We present simulation results using device model based on our IV relation

  5. Simplified two-fluid current–voltage relation for superconductor transition-edge sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tian-Shun; Chen, Jun-Kang [Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei City, Anhui Province 230026 (China); Zhang, Qing-Ya; Li, Tie-Fu; Liu, Jian-She [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China); Chen, Wei, E-mail: weichen@tsinghua.edu.cn [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China); Zhou, Xingxiang, E-mail: xizhou@ustc.edu.cn [Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei City, Anhui Province 230026 (China)

    2013-11-21

    We propose a simplified current–voltage (IV) relation for the analysis and simulation of superconductor transition-edge sensor (TES) circuits. Compared to the conventional approach based on the effective TES resistance, our expression describes the device behavior more thoroughly covering the superconducting, transitional, and normal-state for TES currents in both directions. We show how to use our IV relation to perform small-signal analysis and derive the device's temperature and current sensitivities based on its physical parameters. We further demonstrate that we can use our IV relation to greatly simplify TES device modeling and make SPICE simulation of TES circuits easily accessible. We present some interesting results as examples of valuable simulations enabled by our IV relation. -- Highlights: •We propose an IV relation for superconductor transition-edge sensors (TES). •We derive the dependence of the sensitivity of TES on its physical parameters. •We use our IV relation for SPICE modeling of TES device. •We present simulation results using device model based on our IV relation.

  6. High-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array

    Science.gov (United States)

    Guss, Paul; Rabin, Michael; Croce, Mark; Hoteling, Nathan; Schwellenbach, David; Kruschwitz, Craig; Mocko, Veronika; Mukhopadhyay, Sanjoy

    2017-09-01

    We demonstrate very high-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor (TES) array. The readout circuit consists of superconducting microwave resonators coupled to radio frequency superconducting-quantum-interference devices (RF-SQUIDs) and transduces changes in input current to changes in phase of a microwave signal. We used a flux-ramp modulation to linearize the response and avoid low-frequency noise. The result is a very high-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array. We performed and validated a small-scale demonstration and test of all the components of our concept system, which encompassed microcalorimetry, microwave multiplexing, RF-SQUIDs, and software-defined radio (SDR). We shall display data we acquired in the first simultaneous combination of all key innovations in a 4-pixel demonstration, including microcalorimetry, microwave multiplexing, RF-SQUIDs, and SDR. We present the energy spectrum of a gadolinium-153 (153Gd) source we measured using our 4-pixel TES array and the RF-SQUID multiplexer. For each pixel, one can observe the two 97.4 and 103.2 keV photopeaks. We measured the 153Gd photon source with an achieved energy resolution of 70 eV, full width half maximum (FWHM) at 100 keV, and an equivalent readout system noise of 90 pA/pHz at the TES. This demonstration establishes a path for the readout of cryogenic x-ray and gamma ray sensor arrays with more elements and spectral resolving powers. We believe this project has improved capabilities and substantively advanced the science useful for missions such as nuclear forensics, emergency response, and treaty verification through the explored TES developments.

  7. Flight Investigation of the Low-Speed Characteristics of a 45 deg Swept-Wing Fighter-Type Airplane with Blowing Boundary-Layer Control Applied to the Leading- and Trailing-Edge Flaps

    Science.gov (United States)

    Quigley, Hervey C.; Anderson, Seth B.; Innis, Robert C.

    1960-01-01

    A flight investigation has been conducted to study how pilots use the high lift available with blowing-type boundary-layer control applied to the leading- and trailing-edge flaps of a 45 deg. swept-wing airplane. The study includes documentation of the low-speed handling qualities as well as the pilots' evaluations of the landing-approach characteristics. All the pilots who flew the airplane considered it more comfortable to fly at low speeds than any other F-100 configuration they had flown. The major improvements noted were the reduced stall speed, the improved longitudinal stability at high lift, and the reduction in low-speed buffet. The study has shown the minimum comfortable landing-approach speeds are between 120.5 and 126.5 knots compared to 134 for the airplane with a slatted leading edge and the same trailing-edge flap. The limiting factors in the pilots' choices of landing-approach speeds were the limits of ability to control flight-path angle, lack of visibility, trim change with thrust, low static directional stability, and sluggish longitudinal control. Several of these factors were found to be associated with the high angles of attack, between 13 deg. and 15 deg., required for the low approach speeds. The angle of attack for maximum lift coefficient was 28 deg.

  8. Development of active edge pixel sensors and four-side buttable modules using vertical integration technologies

    Energy Technology Data Exchange (ETDEWEB)

    Macchiolo, A., E-mail: Anna.Macchiolo@mpp.mpg.de [Max-Planck-Institut for Physics, Föhringer Ring 6, D-80805 Munich (Germany); Andricek, L. [Semiconductor Laboratory of the Max-Planck-Society, Otto Hahn Ring 6, D-81739 Munich (Germany); Moser, H.-G.; Nisius, R. [Max-Planck-Institut for Physics, Föhringer Ring 6, D-80805 Munich (Germany); Richter, R.H. [Semiconductor Laboratory of the Max-Planck-Society, Otto Hahn Ring 6, D-81739 Munich (Germany); Terzo, S.; Weigell, P. [Max-Planck-Institut for Physics, Föhringer Ring 6, D-80805 Munich (Germany)

    2014-11-21

    We present an R and D activity focused on the development of novel modules for the upgrade of the ATLAS pixel system at the High Luminosity LHC (HL-LHC). The modules consist of n-in-p pixel sensors, 100 or 200 μm thick, produced at VTT (Finland) with an active edge technology, which considerably reduces the dead area at the periphery of the device. The sensors are interconnected with solder bump-bonding to the ATLAS FE-I3 and FE-I4 read-out chips, and characterised with radioactive sources and beam tests at the CERN-SPS and DESY. The results of these measurements will be discussed for devices before and after irradiation up to a fluence of 5×10{sub 15}n{sub eq}/cm{sup 2}. We will also report on the R and D activity to obtain Inter Chip Vias (ICVs) on the ATLAS read-out chip in collaboration with the Fraunhofer Institute EMFT. This step is meant to prove the feasibility of the signal transport to the newly created readout pads on the backside of the chips allowing for four side buttable devices without the presently used cantilever for wire bonding. The read-out chips with ICVs will be interconnected to thin pixel sensors, 75 μm and 150 μm thick, with the Solid Liquid Interdiffusion (SLID) technology, which is an alternative to the standard solder bump-bonding.

  9. Optimization of Advanced ACTPol Transition Edge Sensor Bolometer Operation Using R(T,I) Transition Measurements

    Science.gov (United States)

    Salatino, Maria

    2017-06-01

    In the current submm and mm cosmology experiments the focal planes are populated by kilopixel transition edge sensors (TESes). Varying incoming power load requires frequent rebiasing of the TESes through standard current-voltage (IV) acquisition. The time required to perform IVs on such large arrays and the resulting transient heating of the bath reduces the sky observation time. We explore a bias step method that significantly reduces the time required for the rebiasing process. This exploits the detectors' responses to the injection of a small square wave signal on top of the dc bias current and knowledge of the shape of the detector transition R(T,I). This method has been tested on two detector arrays of the Atacama Cosmology Telescope (ACT). In this paper, we focus on the first step of the method, the estimate of the TES %Rn.

  10. Optimization of Transition Edge Sensor Arrays for Cosmic Microwave Background Observations With the South Pole Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Junjia; Ade, P. A. R.; Anderson, A. J.; Avva, J.; Ahmed, Z.; Arnold, K.; Austermann, J. E.; Bender, A. N.; Benson, B. A.; Bleem, L. E.; Byrum, K.; Carlstrom, J. E.; Carter, F. W.; Chang, C. L.; Cho, H. M.; Cliche, J. F.; Cukierman, A.; Czaplewski, D.; Divan, R.; de Haan, T.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Gilbert, A.; Gannon, R.; Guyser, R.; Halverson, N. W.; Harrington, N. L.; Hattori, K.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Hubmayr, J.; Huang, N.; Irwin, K. D.; Jeong, O.; Khaire, T.; Kubik, D.; Kuo, C. L.; Lee, A. T.; Leitch, E. M.; Meyer, S. S.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Shariff, J. A.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J.; Stan, L.; Stark, A. A.; Story, K.; Suzuki, A.; Tang, Q. Y.; Thakur, R. B.; Thompson, K. L.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Wu, W. L. K.; Yefremenko, V.; Yoon, K. W.

    2017-06-01

    In this paper, we describe the optimization of transition-edge-sensor (TES) detector arrays for the third-generation camera for the South PoleTelescope. The camera, which contains similar to 16 000 detectors, will make high-angular-resolution maps of the temperature and polarization of the cosmic microwave background. Our key results are scatter in the transition temperature of Ti/Au TESs is reduced by fabricating the TESs on a thin Ti(5 nm)/Au(5 nm) buffer layer and the thermal conductivity of the legs that support our detector islands is dominated by the SiOx dielectric in the microstrip transmission lines that run along the legs.

  11. Phonon-mediated superconducting transition-edge sensor X-ray detectors for use in astronomy

    Science.gov (United States)

    Leman, Steven W.; Martinez-Galarce, Dennis S.; Brink, Paul L.; Cabrera, Blas; Castle, Joseph P.; Morse, Kathleen; Stern, Robert A.; Tomada, Astrid

    2004-09-01

    Superconducting Transition-Edge Sensors (TESs) are generating a great deal of interest in the areas of x-ray astrophysics and space science, particularly to develop them as large-array, imaging x-ray spectrometers. We are developing a novel concept that is based on position-sensitive macro-pixels placing TESs on the backside of a silicon or germanium absorber. Each x-ray absorbed will be position (X/δX and Y/δY ~ 100) and energy (E/δE ~ 1000) resolved via four distributed TES readouts. In the future, combining such macropixels with advances in multiplexing could lead to 30 by 30 arrays of close-packed macro-pixels equivalent to imaging instruments of 10 megapixels or more. We report on our progress to date and discuss its application to a plausible solar satellite mission and plans for future development.

  12. An investigation of excess noise in transition-edge sensors on a solid silicon substrate

    International Nuclear Information System (INIS)

    Crowder, S.G.; Lindeman, M.A.; Anderson, M.B.; Bandler, S.R.; Bilgri, N.; Bruijn, M.P.; Chervenak, J.; Figueroa-Feliciano, E.; Finkbeiner, F.; Germeau, A.; Hoevers, H.F.C.; Iyomoto, N.; Kelly, R.; Kilbourne, C.A.; Lai, T.; Man, J.; McCammon, D.; Nelms, K.L.; Porter, F.S.; Rocks, L.; Saab, T.; Sadleir, J.; Vidugiris, G.

    2006-01-01

    Transition-edge sensors (TESs) exhibit two major types of excess noise above the expected and unavoidable thermodynamic fluctuation noise (TFN) to the heat sink and Johnson noise. High-resistance TESs such as those made by the Netherlands Institute for Space Research (SRON) show excess noise consistent with internal TFN (ITFN) caused by random energy transport within the TES itself while low resistance TESs show an excess voltage noise of unknown origin seemingly unrelated to temperature fluctuations. Running a high-resistance TES on a high thermal conductivity substrate should suppress ITFN and allow detection of any excess voltage noise. We tested two TESs on a solid silicon substrate fabricated by SRON of a relatively high normal state resistance of ∼200 mΩ. After determining a linear model of the TES response to noise for the devices, we found little excess TFN and little excess voltage noise for bias currents of up to ∼20 μA

  13. Fabrication of Transition Edge Sensor Microcalorimeters for X-Ray Focal Planes

    Science.gov (United States)

    Chervenak, James A.; Adams, Joseph S.; Audley, Heather; Bandler, Simon R.; Betancourt-Martinez, Gabriele; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline; Lee, Sang Jun; hide

    2015-01-01

    Requirements for focal planes for x-ray astrophysics vary widely depending on the needs of the science application such as photon count rate, energy band, resolving power, and angular resolution. Transition edge sensor x-ray calorimeters can encounter limitations when optimized for these specific applications. Balancing specifications leads to choices in, for example, pixel size, thermal sinking arrangement, and absorber thickness and material. For the broadest specifications, instruments can benefit from multiple pixel types in the same array or focal plane. Here we describe a variety of focal plane architectures that anticipate science requirements of x-ray instruments for heliophysics and astrophysics. We describe the fabrication procedures that enable each array and explore limitations for the specifications of such arrays, including arrays with multiple pixel types on the same array.

  14. Optimizing Transition Edge Sensors for High-Resolution X-ray Spectroscopy

    International Nuclear Information System (INIS)

    Saab, Tarek; Bandler, Simon R.; Boyce, Kevin; Chervenak, James A.; Figueroa-Feliciano, Enectali; Iyomoto, Naoko; Kelley, Richard L.; Kilbourne, Caroline A.; Porter, Frederick S.; Sadleir, John E.

    2006-01-01

    Transition Edge Sensors (TES) have found applications as astronomical detectors ranging from the microwave to the gamma ray energy bands. Each energy band, however, imposes a different set of requirements on the TES such as energy and timing resolution, focal plane coverage, and the mechanisms by which the signal is coupled to the detector. This paper focuses on the development of TESs optimized for the 0.1-10 keV energy range at the NASA Goddard Space Flight Center. Such detectors are suitable candidates for some of the upcoming X-ray observatories such as NeXT and Constellation-X. Ongoing efforts at producing, characterizing, and modeling such devices, as well as the latest results, are discussed

  15. Characterization and reduction of noise in Mo/Au transition edge sensors

    International Nuclear Information System (INIS)

    Lindeman, Mark A.; Bandler, Simon; Brekosky, Regis P.; Chervenak, James A.; Figueroa-Feliciano, Enectali; Finkbeiner, Fred M.; Saab, Tarek; Stahle, Caroline K.

    2004-01-01

    We measured noise in a variety of Mo/Au transition-edge sensor (TES) X-ray calorimeters. We investigated the relationship between the noise, bias, and the superconducting phase transition in the TESs. Our square TES calorimeters have achieved very good energy resolutions (2.4 eV at 1.5 keV) but their resolutions have been limited by broadband white excess noise generated by the TES when it is biased in the phase transition. We have recently fabricated Mo/Cu TESs with interdigitated normal metal bars deposited on top of the bilayer. The new TES calorimeters have demonstrated little or no excess noise in the phase transition. These results point the way to development of TES calorimeters with higher energy resolution

  16. Transition-edge sensor arrays for UV-optical-IR astrophysics

    International Nuclear Information System (INIS)

    Burney, J.; Bay, T.J.; Barral, J.; Brink, P.L.; Cabrera, B.; Castle, J.P.; Miller, A.J.; Nam, S.; Rosenberg, D.; Romani, R.W.; Tomada, A.

    2006-01-01

    Our research group has developed and characterized transition-edge sensor (TES) arrays for near IR-optical-near UV astrophysical observations. These detectors have a time-stamp accuracy of 0.3μs and an energy resolution of 0.16eV for 2.33eV photons at very high rates (30kHz). We have installed a 6x6 array of these TESs in an adiabatic demagnetization refrigerator equipped with windows for direct imaging. We discuss new instrumentation progress and current data in all aspects related to successful operation of this camera system, including: detector and array performance, position dependence and cross-talk, low-temperature and readout electronics, quantum and system efficiency, IR filtering, and focus and imaging

  17. Microstructure Analysis of Bismuth Absorbers for Transition-Edge Sensor X-ray Microcalorimeters

    Science.gov (United States)

    Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

    2018-03-01

    Given its large X-ray stopping power and low specific heat capacity, bismuth (Bi) is a promising absorber material for X-ray microcalorimeters and has been used with transition-edge sensors (TESs) in the past. However, distinct X-ray spectral features have been observed in TESs with Bi absorbers deposited with different techniques. Evaporated Bi absorbers are widely reported to have non-Gaussian low-energy tails, while electroplated ones do not show this feature. In this study, we fabricated Bi absorbers with these two methods and performed microstructure analysis using scanning electron microscopy and X-ray diffraction microscopy. The two types of material showed the same crystallographic structure, but the grain size of the electroplated Bi was about 40 times larger than that of the evaporated Bi. This distinction in grain size is likely to be the cause of their different spectral responses.

  18. Non-linear effects in transition edge sensors for X-ray detection

    International Nuclear Information System (INIS)

    Bandler, S.R.; Figueroa-Feliciano, E.; Iyomoto, N.; Kelley, R.L.; Kilbourne, C.A.; Murphy, K.D.; Porter, F.S.; Saab, T.; Sadleir, J.

    2006-01-01

    In a microcalorimeter that uses a transition-edge sensor to detect energy depositions, the small signal energy resolution improves with decreasing heat capacity. This improvement remains true up to the point where non-linear and saturation effects become significant. This happens when the energy deposition causes a significant change in the sensor resistance. Not only does the signal size become a non-linear function of the energy deposited, but also the noise becomes non-stationary over the duration of the pulse. Algorithms have been developed that can calculate the optimal performance given this non-linear behavior that typically requires significant processing and calibration work-both of which are impractical for space missions. We have investigated the relative importance of the various non-linear effects, with the hope that a computationally simple transformation can overcome the largest of the non-linear and non-stationary effects, producing a highly linear 'gain' for pulse-height versus energy, and close to the best energy resolution at all energies when using a Wiener filter

  19. Simulations of a rotor with active deformable trailing edge flaps in half-wake inflow: Comparison of EllipSys 3D with HAWC2

    DEFF Research Database (Denmark)

    Barlas, Thanasis K.; Zahle, Frederik; Sørensen, Niels N.

    2012-01-01

    Various research projects have focused on active aerodynamic load control of wind turbines using control devices on the blades, for example flaps. The aerodynamic load predictions of utilized aeroelastic codes have not yet been fully validated with full rotor CFD or experimental results. In this ...... a controller based on a Pitot tube velocity feedback measured at flap mid-span. Good agreement is found between EllipSys3D and HAWC2 in the prediction of the dynamic blade loads, considering the high complexity of the flow case....

  20. Comparing Transition-Edge Sensor Response Times in a Modified Contact Scheme with Different Support Beams

    Science.gov (United States)

    Beyer, A. D.; Kenyon, M. E.; Bumble, B.; Runyan, M. C.; Echternach, P. E.; Holmes, W. A.; Bock, J. J.; Bradford, C. M.

    2013-01-01

    We present measurements of the thermal conductance, G, and effective time constants, tau, of three transition-edge sensors (TESs) populated in arrays operated from 80-87mK with T(sub C) approximately 120mK. Our TES arrays include several variations of thermal architecture enabling determination of the architecture that demonstrates the minimum noise equivalent power (NEP), the lowest tau and the trade-offs among designs. The three TESs we report here have identical Mo/Cu bilayer thermistors and wiring structures, while the thermal architectures are: 1) a TES with straight support beams of 1mm length, 2) a TES with meander support beams of total length 2mm and with 2 phononfilter blocks per beam, and 3) a TES with meander support beams of total length 2mm and with 6 phonon-filter blocks per beam. Our wiring scheme aims to lower the thermistor normal state resistance R(sub N) and increase the sharpness of the transition alpha=dlogR/dlogT at the transition temperature T(sub C). We find an upper limit of given by (25+/-10), and G values of 200fW/K for 1), 15fW/K for 2), and 10fW/K for 3). The value of alpha can be improved by slightly increasing the length of our thermistors.

  1. Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

    Science.gov (United States)

    Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline; hide

    2007-01-01

    Arrays of superconducting transition-edge sensors (TES) can provide high spatial and energy resolution necessary for x-ray astronomy. High quantum efficiency and uniformity of response can be achieved with a suitable absorber material, in which absorber x-ray stopping power, heat capacity, and thermal conductivity are relevant parameters. Here we compare these parameters for bismuth and gold. We have fabricated electroplated gold, electroplated gold/electroplated bismuth, and evaporated gold/evaporated bismuth 8x8 absorber arrays and find that a correlation exists between the residual resistance ratio (RRR) and thin film microstructure. This finding indicates that we can tailor absorber material conductivity via microstructure alteration, so as to permit absorber thermalization on timescales suitable for high energy resolution x-ray microcalorimetry. We show that by incorporating absorbers possessing large grain size, including electroplated gold and electroplated gold/electroplated bismuth, into our current Mo/Au TES, devices with tunable heat capacity and energy resolution of 2.3 eV (gold) and 2.1 eV (gold/bismuth) FWHM at 6 keV have been fabricated.

  2. Towards Development of Microcalorimeter Arrays of Mo/Au Transition-Edge Sensors with Bismuth Absorbers

    Science.gov (United States)

    Tralshawala, Nilesh; Brekosky, Regis; Figueroa-Feliciano, Enectali; Li, Mary; Stahle, Carl; Stahle, Caroline

    2000-01-01

    We report on our progress towards the development of arrays of X-ray microcalorimeters as candidates for the high resolution x-ray spectrometer on the Constellation-X mission. The microcalorimeter arrays (30 x 30) with appropriate pixel sizes (0.25 mm. x 0.25 mm) and high packing fractions (greater than 96%) are being developed. Each individual pixel has a 10 micron thick Bi X-ray absorber that is shaped like a mushroom to increase the packing fraction, and a Mo/Au proximity effect superconducting transition edge sensor (TES). These are deposited on a 0.25 or 0.5 micron thick silicon nitride membrane with slits to provide a controllable weak thermal link to the sink temperature. Studies are underway to model, test and optimize the TES pixel uniformity, critical current, heat capacity and the membrane thermal conductance in the array structure. Fabrication issues and procedures, and results of our efforts based on these optimizations will be provided.

  3. Multi-Absorber Transition-Edge Sensors for X-Ray Astronomy Applications

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Bandler, S. R.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; hide

    2012-01-01

    We are developing multi-absorber Transition-Edge Sensors (TESs) for applications in x-ray astronomy. These position-sensitive devices consist of multiple x-ray absorbers each with a different thermal coupling to a single readout TES. Heat diffusion between the absorbers and the TES gives rise to a characteristic pulse shape corresponding to each absorber element and enables position discrimination. The development of these detectors is motivated by a desire to maximize focal plane arrays with the fewest number of readout channels. In this contribution we report on the first results from devices consisting of nine) 65 X 65 sq. microns Au x-ray absorbers) 5 microns thick. These are coupled to a single 35 X 35 sq. microns Mo/Au bilayer TES. These devices have demonstrated full-width-half-maximum (FWHM) energy resolution of 2.1 eV at 1.5 keV) 2.5 eV at 5.9 keV and 3.3 eV at 8 keV. This is coupled with position discrimination from pulse shape over the same energy range. We use a finite-element model to reproduce the measured pulse shapes and investigate the detector non-linearity with energy) which impacts on the devices position sensitivity and energy resolution.

  4. Small Pitch Transition-Edge Sensors with Broadband High Spectral Resolution for Solar Physics

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Eckart, M. E.; Smith, Adams; Bailey, C. N.; Bandler, S. R.; Chevenak, J. A.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; hide

    2012-01-01

    We are developing small pitch transition-edge sensor (TES) X-ray detectors optimized for solar astronomy. These devices are fabricated on thick Si substrates with embedded Cu heat-sink layer. We use 35 x 35 square micrometers Mo/Au TESs with 4.5 micrometer thick Au absorbers. We have tested devices with different geometric absorber stem contact areas with the TES and surrounding substrate area. This allows us to investigate the loss of athermal phonons to the substrate. Results show a correlation between thc stem contact area and a broadening in the spectral line shape indicative of athermal phonon loss. When the contact area is minimized we have obtained exceptional broadband spectral resolution of 1.28 plus or minus 0.03 eV at an energy of 1.5 keV, 1.58 plus or minus 0.07 eV at 5.9 keV and 1.96 plus or minus 0.08 eV at 8 keV. The linearity in the measured gain scale is understood in the context of the longitudinal proximity effect from the electrical bias leads resulting in transition characteristics that are strongly dependent upon TES size.

  5. Complex Impedance of Fast Optical Transition Edge Sensors up to 30 MHz

    Science.gov (United States)

    Hattori, K.; Kobayashi, R.; Numata, T.; Inoue, S.; Fukuda, D.

    2018-03-01

    Optical transition edge sensors (TESs) are characterized by a very fast response, of the order of μs, which is 10^3 times faster than TESs for X-ray and gamma-ray. To extract important parameters associated with the optical TES, complex impedances at high frequencies (> 1 MHz) need to be measured, where the parasitic impedance in the circuit and reflections of electrical signals due to discontinuities in the characteristic impedance of the readout circuits become significant. This prevents the measurements of the current sensitivity β , which can be extracted from the complex impedance. In usual setups, it is hard to build a circuit model taking into account the parasitic impedances and reflections. In this study, we present an alternative method to estimate a transfer function without investigating the details of the entire circuit. Based on this method, the complex impedance up to 30 MHz was measured. The parameters were extracted from the impedance and were compared with other measurements. Using these parameters, we calculated the theoretical limit on an energy resolution and compared it with the measured energy resolution. In this paper, the reasons for the deviation of the measured value from theoretically predicted values will be discussed.

  6. Characterization and fabrication of Ti/Pd bilayers for transition-edge sensors

    International Nuclear Information System (INIS)

    Monticone, E; Taralli, E; Portesi, C; Fretto, M; Rocci, R; Cerri, R; Rajteri, M

    2009-01-01

    Transition-edge sensor (TES) microcalorimeters are extensively used as single photon detectors from infrared to x-ray. Their good energy resolution and photon number resolving capability at visible and near-infrared wavelengths make them powerful tools for quantum information and quantum computation. In this work we report details on the fabrication of Ti/Pd TESs deposited by e-beam evaporation on silicon nitride substrates. By the proximity effect between Ti and Pd, the Ti critical temperature was tuned down to 100 mK, usual working temperature for these devices. Sharp transition of two-three mK and reproducible Tc were obtained. The Pd material can be a valid alternative to widely used Au proximity material thanks to its stronger influence on the Ti layer, that allows to obtain the same temperature reduction with thinner layers. Thermal and electrical characteristics of Ti/Au and Ti/Pd bilayers are compared in view of single photon detection.

  7. SQUID multiplexing using baseband feedback for space application of transition-edge sensor microcalorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Takei, Y; Yamasaki, N Y; Hirakoso, W; Kimura, S; Mitsuda, K, E-mail: takei@astro.isas.jaxa.j [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, 229-8510 (Japan)

    2009-11-15

    A microcalorimeter array based on a transition-edge sensor (TES) thermometer is a promising imaging spectrometer for use in future x-ray astronomy missions. A TES microcalorimeter achieves {approx}<5 eV energy resolution and an array of >100 pixels also provides a moderate imaging capability. For a large format array, signal multiplexing at the low temperature stage is mandatory in order to reduce heat loads from cold stage preamplifiers and through wirings. We are developing frequency division multiplexing (FDM). In FDM, each TES is ac-biased with a different carrier frequency. Signals from several pixels are summed and then read out by one dc SQUID (superconducting quantum interference device). The maximum number of multiplexed pixels is limited by the bandwidth of a SQUID in a flux-locked loop. Assuming 1 m cable length between the room temperature and the cold stage, the bandwidth is only <1 MHz with a standard flux-locked loop, due to the delay and phase shift of wirings. We report our development of baseband feedback, a new feedback scheme that overcomes the bandwidth limitation. In baseband feedback, the signal ({approx}<10 kHz) from the TES is sent back to the SQUID after the phase of carrier frequency ({approx}1 MHz) has been adjusted. We demonstrated open-loop gain of 8 for 10 kHz signal at 5 MHz carrier frequency, which indicates the possibility of {approx}40-pixel multiplexing of the TES signal.

  8. Energy-Aware Computation Offloading of IoT Sensors in Cloudlet-Based Mobile Edge Computing.

    Science.gov (United States)

    Ma, Xiao; Lin, Chuang; Zhang, Han; Liu, Jianwei

    2018-06-15

    Mobile edge computing is proposed as a promising computing paradigm to relieve the excessive burden of data centers and mobile networks, which is induced by the rapid growth of Internet of Things (IoT). This work introduces the cloud-assisted multi-cloudlet framework to provision scalable services in cloudlet-based mobile edge computing. Due to the constrained computation resources of cloudlets and limited communication resources of wireless access points (APs), IoT sensors with identical computation offloading decisions interact with each other. To optimize the processing delay and energy consumption of computation tasks, theoretic analysis of the computation offloading decision problem of IoT sensors is presented in this paper. In more detail, the computation offloading decision problem of IoT sensors is formulated as a computation offloading game and the condition of Nash equilibrium is derived by introducing the tool of a potential game. By exploiting the finite improvement property of the game, the Computation Offloading Decision (COD) algorithm is designed to provide decentralized computation offloading strategies for IoT sensors. Simulation results demonstrate that the COD algorithm can significantly reduce the system cost compared with the random-selection algorithm and the cloud-first algorithm. Furthermore, the COD algorithm can scale well with increasing IoT sensors.

  9. An analytical model for pulse shape and electrothermal stability in two-body transition-edge sensor microcalorimeters

    International Nuclear Information System (INIS)

    Bennett, D. A.; Horansky, R. D.; Schmidt, D. R.; Swetz, D. S.; Vale, L. R.; Ullom, J. N.; Hoover, A. S.; Hoteling, N. J.; Rabin, M. W.

    2010-01-01

    High-resolution superconducting gamma-ray sensors show potential for the more accurate analysis of nuclear material. These devices are part of a larger class of microcalorimeters and bolometers based on transition edge sensors (TESs) that have two distinct thermal bodies. We derive the time domain behavior of the current and temperature for compound TES devices in the small signal limit and demonstrate the utility of these equations for device design and characterization. In particular, we use the model to fit pulses from our gamma-ray microcalorimeters and demonstrate how critical damping and electrothermal stability can be predicted.

  10. How cutting-edge technologies impact the design of electrochemical (bio)sensors for environmental analysis. A review.

    Science.gov (United States)

    Arduini, Fabiana; Cinti, Stefano; Scognamiglio, Viviana; Moscone, Danila; Palleschi, Giuseppe

    2017-03-22

    Through the years, scientists have developed cutting-edge technologies to make (bio)sensors more convenient for environmental analytical purposes. Technological advancements in the fields of material science, rational design, microfluidics, and sensor printing, have radically shaped biosensor technology, which is even more evident in the continuous development of sensing systems for the monitoring of hazardous chemicals. These efforts will be crucial in solving some of the problems constraining biosensors to reach real environmental applications, such as continuous analyses in field by means of multi-analyte portable devices. This review (with 203 refs.) covers the progress between 2010 and 2015 in the field of technologies enabling biosensor applications in environmental analysis, including i) printing technology, ii) nanomaterial technology, iii) nanomotors, iv) biomimetic design, and (v) microfluidics. Next section describes futuristic cutting-edge technologies that are gaining momentum in recent years, which furnish highly innovative aspects to biosensing devices. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Ultra-low-noise transition edge sensors for the SAFARI L-band on SPICA

    Science.gov (United States)

    Goldie, D. J.; Gao, J. R.; Glowacka, D. M.; Griffin, D. K.; Hijmering, R.; Khosropanah, P.; Jackson, B. D.; Mauskopf, P. D.; Morozov, D.; Murphy, J. A.; Ridder, M.; Trappe, N.; O'Sullivan, C.; Withington, S.

    2012-09-01

    The Far-Infrared Fourier transform spectrometer instrument SAFARI-SPICA which will operate with cooled optics in a low-background space environment requires ultra-sensitive detector arrays with high optical coupling efficiencies over extremely wide bandwidths. In earlier papers we described the design, fabrication and performance of ultra-low-noise Transition Edge Sensors (TESs) operated close to 100mk having dark Noise Equivalent Powers (NEPs) of order 4 × 10-19W/√Hz close to the phonon noise limit and an improvement of two orders of magnitude over TESs for ground-based applications. Here we describe the design, fabrication and testing of 388-element arrays of MoAu TESs integrated with far-infrared absorbers and optical coupling structures in a geometry appropriate for the SAFARI L-band (110 - 210 μm). The measured performance shows intrinsic response time τ ~ 11ms and saturation powers of order 10 fW, and a dark noise equivalent powers of order 7 × 10-19W/√Hz. The 100 × 100μm2 MoAu TESs have transition temperatures of order 110mK and are coupled to 320×320μm2 thin-film β-phase Ta absorbers to provide impedance matching to the incoming fields. We describe results of dark tests (i.e without optical power) to determine intrinsic pixel characteristics and their uniformity, and measurements of the optical performance of representative pixels operated with flat back-shorts coupled to pyramidal horn arrays. The measured and modeled optical efficiency is dominated by the 95Ω sheet resistance of the Ta absorbers, indicating a clear route to achieve the required performance in these ultra-sensitive detectors.

  12. An optimized knife-edge method for on-orbit MTF estimation of optical sensors using powell parameter fitting

    Science.gov (United States)

    Han, Lu; Gao, Kun; Gong, Chen; Zhu, Zhenyu; Guo, Yue

    2017-08-01

    On-orbit Modulation Transfer Function (MTF) is an important indicator to evaluate the performance of the optical remote sensors in a satellite. There are many methods to estimate MTF, such as pinhole method, slit method and so on. Among them, knife-edge method is quite efficient, easy-to-use and recommended in ISO12233 standard for the wholefrequency MTF curve acquisition. However, the accuracy of the algorithm is affected by Edge Spread Function (ESF) fitting accuracy significantly, which limits the range of application. So in this paper, an optimized knife-edge method using Powell algorithm is proposed to improve the ESF fitting precision. Fermi function model is the most popular ESF fitting model, yet it is vulnerable to the initial values of the parameters. Considering the characteristics of simple and fast convergence, Powell algorithm is applied to fit the accurate parameters adaptively with the insensitivity to the initial parameters. Numerical simulation results reveal the accuracy and robustness of the optimized algorithm under different SNR, edge direction and leaning angles conditions. Experimental results using images of the camera in ZY-3 satellite show that this method is more accurate than the standard knife-edge method of ISO12233 in MTF estimation.

  13. Distributed transition-edge sensors for linearized position response in a phonon-mediated X-ray imaging spectrometer

    Science.gov (United States)

    Cabrera, Blas; Brink, Paul L.; Leman, Steven W.; Castle, Joseph P.; Tomada, Astrid; Young, Betty A.; Martínez-Galarce, Dennis S.; Stern, Robert A.; Deiker, Steve; Irwin, Kent D.

    2004-03-01

    For future solar X-ray satellite missions, we are developing a phonon-mediated macro-pixel composed of a Ge crystal absorber with four superconducting transition-edge sensors (TES) distributed on the backside. The X-rays are absorbed on the opposite side and the energy is converted into phonons, which are absorbed into the four TES sensors. By connecting together parallel elements into four channels, fractional total energy absorbed between two of the sensors provides x-position information and the other two provide y-position information. We determine the optimal distribution for the TES sub-elements to obtain linear position information while minimizing the degradation of energy resolution.

  14. Experimental and numerical study of an autonomous flap

    NARCIS (Netherlands)

    Bernhammer, L.O.; Navalkar, S.T.; Sodja, J.; De Breuker, R.; Karpel, M.

    2015-01-01

    This paper presents the experimental and numerical study of an autonomous load alleviation concept using trailing edge flaps. The flaps are autonomous units, which for instance can be used for gust load alleviation. The unit is self-powered and self-actuated through trailing edge tabs which are

  15. Design and TCAD simulation of planar p-on-n active-edge pixel sensors for the next generation of FELs

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Betta, G.-F., E-mail: gianfranco.dallabetta@unitn.it [Università di Trento, Dipartimento di Ingegneria Industriale, I-38123 Trento (Italy); TIFPA INFN, I-38123 Trento (Italy); Batignani, G. [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Benkechkache, M.A. [TIFPA INFN, I-38123 Trento (Italy); University Constantine 1, Department of Electronics in the Science and Technology Faculty, I-25017 Constantine (Algeria); Bettarini, S.; Casarosa, G. [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Comotti, D. [Università di Pavia, Dipartimento di Ingegneria Industriale e dell' Informazione, I-27100 Pavia (Italy); INFN Sezione di Pavia, I-27100 Pavia (Italy); Fabris, L. [INFN Sezione di Pavia, I-27100 Pavia (Italy); Università di Bergamo, Dipartimento di Ingegneria e Scienze Applicate, I-24044 Dalmine (Italy); Forti, F. [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Grassi, M. [Università di Pavia, Dipartimento di Ingegneria Industriale e dell' Informazione, I-27100 Pavia (Italy); INFN Sezione di Pavia, I-27100 Pavia (Italy); Latreche, S. [University Constantine 1, Department of Electronics in the Science and Technology Faculty, I-25017 Constantine (Algeria); Lodola, L.; Malcovati, P. [Università di Pavia, Dipartimento di Ingegneria Industriale e dell' Informazione, I-27100 Pavia (Italy); INFN Sezione di Pavia, I-27100 Pavia (Italy); Manghisoni, M. [INFN Sezione di Pavia, I-27100 Pavia (Italy); Università di Bergamo, Dipartimento di Ingegneria e Scienze Applicate, I-24044 Dalmine (Italy); and others

    2016-07-11

    We report on the design and TCAD simulations of planar p-on-n sensors with active edge aimed at a four-side buttable X-ray detector module for future FEL applications. Edge terminations with different number of guard rings were designed to find the best trade-off between breakdown voltage and border gap size. The methodology of the sensor design, the optimization of the most relevant parameters to maximize the breakdown voltage and the final layout are described.

  16. Design and TCAD simulation of planar p-on-n active-edge pixel sensors for the next generation of FELs

    International Nuclear Information System (INIS)

    Dalla Betta, G.-F.; Batignani, G.; Benkechkache, M.A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Fabris, L.; Forti, F.; Grassi, M.; Latreche, S.; Lodola, L.; Malcovati, P.; Manghisoni, M.

    2016-01-01

    We report on the design and TCAD simulations of planar p-on-n sensors with active edge aimed at a four-side buttable X-ray detector module for future FEL applications. Edge terminations with different number of guard rings were designed to find the best trade-off between breakdown voltage and border gap size. The methodology of the sensor design, the optimization of the most relevant parameters to maximize the breakdown voltage and the final layout are described.

  17. Exotic wakes of flapping fins

    DEFF Research Database (Denmark)

    Schnipper, Teis

    We present, in 8 chapters, experiments on and numerical simulations of bodies flapping in a fluid. Focus is predominantly on a rigid foil, a model fish, that performs prescribed pitching oscillations where the foil rotates around its leading edge. In a flowing soap film is measured, with unpreced......We present, in 8 chapters, experiments on and numerical simulations of bodies flapping in a fluid. Focus is predominantly on a rigid foil, a model fish, that performs prescribed pitching oscillations where the foil rotates around its leading edge. In a flowing soap film is measured......-speed and the strength ratio of the vortices formed at the foil’s leading and trailing edge. The simulated vortex particles and measured thickness variations in the soap film show similar behaviour which indicates that the soap film provides a good approximation the flow of a two-dimensional incompressible and Newtonian...

  18. Modified cup flap for volar oblique fingertip amputations

    Directory of Open Access Journals (Sweden)

    Ahmadli, A.

    2016-02-01

    Full Text Available We describe a modified volar “V-Y cup” flap for volar fingertip defects that do not exceed more than half of the distal phalanx for better aesthetic and functional outcome. In seven cases out of eight, the flap was elevated with a subdermal pedicle, whereas in one case, the flap was elevated as an island on the bilateral neurovascular bundle. The fingertips have been evaluated for sensibility using standard tests, hook nail deformity and patient satisfaction. Seven flaps have survived completely. The flap with skeletonized bilateral digital neurovascular bundle has shown signs of venous insufficiency on the 5 postoperative day with consecutive necrosis. Suturing the distal edges of the flap in a “cupping” fashion provided a normal pulp contour. The modified flap can be used for defects as mentioned above. Subdermally dissected pedicle-based flap is safe and easy to elevate. The aesthetic and functional outcomes have been reported to be satisfactory.

  19. High-resolution gamma-ray spectroscopy with a microwave-multiplexed transition-edge sensor array

    Energy Technology Data Exchange (ETDEWEB)

    Noroozian, Omid [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, Colorado 80309 (United States); Mates, John A. B.; Bennett, Douglas A.; Brevik, Justus A.; Fowler, Joseph W.; Gao, Jiansong; Hilton, Gene C.; Horansky, Robert D.; Irwin, Kent D.; Schmidt, Daniel R.; Vale, Leila R.; Ullom, Joel N. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Kang, Zhao [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)

    2013-11-11

    We demonstrate very high resolution photon spectroscopy with a microwave-multiplexed two-pixel transition-edge sensor (TES) array. We measured a {sup 153}Gd photon source and achieved an energy resolution of 63 eV full-width-at-half-maximum at 97 keV and an equivalent readout system noise of 86 pA/√(Hz) at the TES. The readout circuit consists of superconducting microwave resonators coupled to radio-frequency superconducting-quantum-interference-devices and transduces changes in input current to changes in phase of a microwave signal. We use flux-ramp modulation to linearize the response and evade low-frequency noise. This demonstration establishes one path for the readout of cryogenic X-ray and gamma-ray sensor arrays with more than 10{sup 3} elements and spectral resolving powers R=λ/Δλ>10{sup 3}.

  20. Development of phonon-mediated transition-edge-sensor x-ray detectors for use in astronomy

    Science.gov (United States)

    Leman, Steven W.

    Low temperature detectors have grown in popularity over the years for a variety of reasons. Reduced thermal noise and the associated reduction in statistical fluctuations improve signal to noise. Novel material properties at low temperature such as superconductivity can be exploited. And let us not forget easier access to cryogenic techniques, for example industry made and sold refrigerators eliminating the need for graduate students to make their own. In this thesis I discuss development of a novel phonon-mediated distributed transition-edge-sensor x-ray detector which would be useful for astrophysical studies such as magnetic recombination in the solar corona, the warm-hot intergalactic medium and surveys of clusters and groups of galaxies. The detector uses a large semiconductor absorber and Transition-Edge-Sensors (TESs) to readout the absorbed energy. Calorimetry is performed on individual photons and a partitioning of the energy between various TESs allows for position determination. Hence time varying astronomical sources can be spectroscopically studied and imaged. I will conclude with a discussion of the detector's performance and propose a next generation detector which could make significant improvements on the design discussed in this thesis.

  1. Flexible wings in flapping flight

    Science.gov (United States)

    Moret, Lionel; Thiria, Benjamin; Zhang, Jun

    2007-11-01

    We study the effect of passive pitching and flexible deflection of wings on the forward flapping flight. The wings are flapped vertically in water and are allowed to move freely horizontally. The forward speed is chosen by the flapping wing itself by balance of drag and thrust. We show, that by allowing the wing to passively pitch or by adding a flexible extension at its trailing edge, the forward speed is significantly increased. Detailed measurements of wing deflection and passive pitching, together with flow visualization, are used to explain our observations. The advantage of having a wing with finite rigidity/flexibility is discussed as we compare the current results with our biological inspirations such as birds and fish.

  2. Power performance optimization and loads alleviation with active flaps using individual flap control

    DEFF Research Database (Denmark)

    Pettas, Vasilis; Barlas, Athanasios; Gertz, Drew Patrick

    2016-01-01

    the sensor inputs. The AEP is increased due to the upscaling but also further due to the flap system while the fatigue loads in components of interest (blade, tower, nacelle and main bearing) are reduced close to the level of the original turbine. The aim of this study is to demonstrate a simple....... In an industrial-oriented manner the baseline rotor is upscaled by 5% and the ATEFs are implemented in the outer 30% of the blades. The flap system is kept simple and robust with a single flap section and control with wind speed, rotor azimuth, root bending moments and angle of attack in flap's mid-section being...

  3. Navier-Stokes Computations of a Wing-Flap Model With Blowing Normal to the Flap Surface

    Science.gov (United States)

    Boyd, D. Douglas, Jr.

    2005-01-01

    A computational study of a generic wing with a half span flap shows the mean flow effects of several blown flap configurations. The effort compares and contrasts the thin-layer, Reynolds averaged, Navier-Stokes solutions of a baseline wing-flap configuration with configurations that have blowing normal to the flap surface through small slits near the flap side edge. Vorticity contours reveal a dual vortex structure at the flap side edge for all cases. The dual vortex merges into a single vortex at approximately the mid-flap chord location. Upper surface blowing reduces the strength of the merged vortex and moves the vortex away from the upper edge. Lower surface blowing thickens the lower shear layer and weakens the merged vortex, but not as much as upper surface blowing. Side surface blowing forces the lower surface vortex farther outboard of the flap edge by effectively increasing the aerodynamic span of the flap. It is seen that there is no global aerodynamic penalty or benefit from the particular blowing configurations examined.

  4. Active-Optical Sensors Using Red NDVI Compared to Red Edge NDVI for Prediction of Corn Grain Yield in North Dakota, U.S.A.

    Science.gov (United States)

    Sharma, Lakesh K; Bu, Honggang; Denton, Anne; Franzen, David W

    2015-11-02

    Active-optical sensor readings from an N non-limiting area standard established within a farm field are used to predict yield in the standard. Lower yield predictions from sensor readings obtained from other parts of the field outside of the N non-limiting standard area indicate a need for supplemental N. Active-optical sensor algorithms for predicting corn (Zea mays, L.) yield to direct in-season nitrogen (N) fertilization in corn utilize red NDVI (normalized differential vegetative index). Use of red edge NDVI might improve corn yield prediction at later growth stages when corn leaves cover the inter-row space resulting in "saturation" of red NDVI readings. The purpose of this study was to determine whether the use of red edge NDVI in two active-optical sensors (GreenSeeker™ and Holland Scientific Crop Circle™) improved corn yield prediction. Nitrogen rate experiments were established at 15 sites in North Dakota (ND). Sensor readings were conducted at V6 and V12 corn. Red NDVI and red edge NDVI were similar in the relationship of readings with yield at V6. At V12, the red edge NDVI was superior to the red NDVI in most comparisons, indicating that it would be most useful in developing late-season N application algorithms.

  5. Active-Optical Sensors Using Red NDVI Compared to Red Edge NDVI for Prediction of Corn Grain Yield in North Dakota, U.S.A.

    Science.gov (United States)

    Sharma, Lakesh K.; Bu, Honggang; Denton, Anne; Franzen, David W.

    2015-01-01

    Active-optical sensor readings from an N non-limiting area standard established within a farm field are used to predict yield in the standard. Lower yield predictions from sensor readings obtained from other parts of the field outside of the N non-limiting standard area indicate a need for supplemental N. Active-optical sensor algorithms for predicting corn (Zea mays, L.) yield to direct in-season nitrogen (N) fertilization in corn utilize red NDVI (normalized differential vegetative index). Use of red edge NDVI might improve corn yield prediction at later growth stages when corn leaves cover the inter-row space resulting in “saturation” of red NDVI readings. The purpose of this study was to determine whether the use of red edge NDVI in two active-optical sensors (GreenSeeker™ and Holland Scientific Crop Circle™) improved corn yield prediction. Nitrogen rate experiments were established at 15 sites in North Dakota (ND). Sensor readings were conducted at V6 and V12 corn. Red NDVI and red edge NDVI were similar in the relationship of readings with yield at V6. At V12, the red edge NDVI was superior to the red NDVI in most comparisons, indicating that it would be most useful in developing late-season N application algorithms. PMID:26540057

  6. The CRESST-III iStick veto. Stable operation of multiple transition edge sensors in one readout circuit

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, Johannes [Max-Planck-Institut f. Physik (Werner-Heisenberg-Institut) (Germany); Ludwig-Maximilians-Universitaet Muenchen (Germany); Collaboration: CRESST-Collaboration

    2016-07-01

    To enable complete rejection of holder-related events in the upcoming CRESST-III dark matter search experiment, the scintillating target crystals are held by calcium tungstate sticks (iSticks) instrumented with tungsten transition edge sensors (TESs). Since the iStick signals are used exclusively for vetoing, it is sufficient to register if an event happened in any stick, without knowing which one. This allows the operation of all iSticks in a single readout circuit, requiring just one SQUID magnetometer. The talk describes the effect of bias current heating and corresponding hysteresis phenomena known in single-TES circuits, and the resulting conditions for stability in multiple-TES circuits. The fundamentally different behaviour of parallel and series circuits and resulting design choices are explored.

  7. Performance of horn-coupled transition edge sensors for L- and S-band optical detection on the SAFARI instrument

    Science.gov (United States)

    Goldie, D. J.; Glowacka, D. M.; Withington, S.; Chen, Jiajun; Ade, P. A. R.; Morozov, D.; Sudiwala, R.; Trappe, N. A.; Quaranta, O.

    2016-07-01

    We describe the geometry, architecture, dark- and optical performance of ultra-low-noise transition edge sensors as THz detectors for the SAFARI instrument. The TESs are fabricated from superconducting Mo/Au bilayers coupled to impedance-matched superconducting β-phase Ta thin-film absorbers. The detectors have phonon-limited dark noise equivalent powers of order 0.5 - 1.0 aW/ √ Hz and saturation powers of order 20 - 40 fW. The low temperature test configuration incorporating micro-machined backshorts is also described, and construction and typical performance characteristics for the optical load are shown. We report preliminary measurements of the optical performance of these TESs for two SAFARI bands; L-band at 110 - 210 μm and S-band 34 - 60 μm .

  8. Design and Optimization of Multi-Pixel Transition-Edge Sensors for X-Ray Astronomy Applications

    Science.gov (United States)

    Smith, Stephen J.; Adams, Joseph S.; Bandler, Simon R.; Chervenak, James A.; Datesman, Aaron Michael; Eckart, Megan E.; Ewin, Audrey J.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; hide

    2017-01-01

    Multi-pixel transition-edge sensors (TESs), commonly referred to as 'hydras', are a type of position sensitive micro-calorimeter that enables very large format arrays to be designed without commensurate increase in the number of readout channels and associated wiring. In the hydra design, a single TES is coupled to discrete absorbers via varied thermal links. The links act as low pass thermal filters that are tuned to give a different characteristic pulse shape for x-ray photons absorbed in each of the hydra sub pixels. In this contribution we report on the experimental results from hydras consisting of up to 20 pixels per TES. We discuss the design trade-offs between energy resolution, position discrimination and number of pixels and investigate future design optimizations specifically targeted at meeting the readout technology considered for Lynx.

  9. Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

    Science.gov (United States)

    Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

    2017-11-01

    Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth, and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. We show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.

  10. Reconstruction of pressure sores with perforator-based propeller flaps.

    Science.gov (United States)

    Jakubietz, Rafael G; Jakubietz, Danni F; Zahn, Robert; Schmidt, Karsten; Meffert, Rainer H; Jakubietz, Michael G

    2011-03-01

    Perforator flaps have been successfully used for reconstruction of pressure sores. Although V-Y advancement flaps approximate debrided wound edges, perforator-based propeller flaps allow rotation of healthy tissue into the defect. Perforator-based propeller flaps were planned in 13 patients. Seven pressure sores were over the sacrum, five over the ischial tuberosity, and one on the tip of the scapula. Three patients were paraplegic, six were bedridden, and five were ambulatory. In three patients, no perforators were found. In 10 patients, propeller flaps were transferred. In two patients, total flap necrosis occurred, which was reconstructed with local advancement flaps. In two cases, a wound dehiscence occurred and had to be revised. One hematoma required evacuation. No further complications were noted. No recurrence at the flap site occurred. Local perforator flaps allow closure of pressure sores without harvesting muscle. The propeller version has the added benefit of transferring tissue from a distant site, avoiding reapproximation of original wound edges. Twisting of the pedicle may cause torsion and venous obstruction. This can be avoided by dissecting a pedicle of at least 3 cm. Propeller flaps are a safe option for soft tissue reconstruction of pressure sores. © Thieme Medical Publishers.

  11. Progress in the Development of Mo-Au Transition-Edge Sensors for X-Ray Spectroscopy

    Science.gov (United States)

    Stahle, Caroline K.; Brekosky, Regis P.; Figueroa-Feliciano, Enectali; Finkbeiner, Fred M.; Gygax, John D.; Li, Mary J.; Lindeman, Mark A..; Porter, F. Scott; Tralshawalaa, Nilesh

    2000-01-01

    X-ray microcalorimeters using transition-edge sensors (TES) show great promise for use in astronomical x-ray spectroscopy. We have obtained very high energy resolution (2.8 electronvolts at 1.5 kiloelectronvolts and 3.7 electronvolts at 3.3 kiloelectronvolts) in a large, isolated TES pixel using a Mo/Au proximity-effect bilayer on a silicon nitride membrane. We will discuss the performance and our characterization of that device. In order to be truly suitable for use behind an x-ray telescope, however, such devices need to be arrayed with a pixel size and focal-plane coverage commensurate with the telescope focal length and spatial resolution. Since this requires fitting the TES and its thermal link, a critical component of each calorimeter pixel, into a far more compact geometry than has previously been investigated, we must study the fundamental scaling laws in pixel optimization. We have designed a photolithography mask that will allow us to probe the range in thermal conductance that can be obtained by perforating the nitride membrane in a narrow perimeter around the sensor. This mask will also show the effects of reducing the TES area. Though we have not yet tested devices of the compact designs, we will present our progress in several of the key processing steps and discuss the parameter space of our intended investigations.

  12. Electromagnetic Design of Feedhorn-Coupled Transition-Edge Sensors for Cosmic Microwave Background Polarimetery

    Science.gov (United States)

    Chuss, David T.

    2011-01-01

    Observations of the cosmic microwave background (CMB) provide a powerful tool for probing the evolution of the early universe. Specifically, precision measurement of the polarization of the CMB enables a direct test for cosmic inflation. A key technological element on the path to the measurement of this faint signal is the capability to produce large format arrays of background-limited detectors. We describe the electromagnetic design of feedhorn-coupled, TES-based sensors. Each linear orthogonal polarization from the feed horn is coupled to a superconducting microstrip line via a symmetric planar orthomode transducer (OMT). The symmetric OMT design allows for highly-symmetric beams with low cross-polarization over a wide bandwidth. In addition, this architecture enables a single microstrip filter to define the passband for each polarization. Care has been taken in the design to eliminate stray coupling paths to the absorbers. These detectors will be fielded in the Cosmology Large Angular Scale Surveyor (CLASS).

  13. Quasiparticle Diffusion in Al Films Coupled to Tungsten Transition Edge Sensors

    Science.gov (United States)

    Yen, J. J.; Young, B. A.; Cabrera, B.; Brink, P. L.; Cherry, M.; Moffatt, R.; Pyle, M.; Redl, P.; Tomada, A.; Tortorici, E. C.

    2014-08-01

    We report recent results obtained from several W/Al test devices on Si wafers fabricated specifically to better understand energy collection in phonon sensors used for the Cryogenic Dark Matter Search (CDMS) experiment. The devices under study consist of three different lengths of 250 m-wide by 300 nm-thick Al absorber films, coupled to 250 m x 250 m (40 nm thick) W-TESs at each end of the Al film. An Fe source was used to excite a NaCl reflector producing 2.6 keV Cl X-rays that were absorbed in our test device after passing through a collimator. The impinging X-rays broke Cooper pairs in the Al film, producing quasiparticles that we detected after they propagated into the W-TESs. We studied the diffusion of these quasiparticles in the Al, trapping effects in the Al film, and energy transmission at the Al/W interfaces.

  14. Active control of an edge-mode-based plasmon-induced absorption sensor.

    Science.gov (United States)

    Li, Yong; Su, Yi; Lin, Qi; Zhai, Xiang; Wang, Ling-Ling

    2018-04-01

    We investigate the formation and evolution of plasmon-induced absorption (PIA) effect in a three-dimensional graphene waveguide structure. The PIA window is formed by near-field coupling of the graphene edge mode, the extremely destructive interference between the radiative mode and sub-radiative mode of graphene nanoribbons. The resonance intensity has a significant dependence on the coupling distance between the graphene nanoribbons. At the same time, it is particularly sensitive to the refractive index of the environment, which is promising for sensing devices. In addition, the resonant wavelength can be actively controlled by changing the Fermi energy of graphene. Moreover, it can be seen that the group time delay of the PIA window reaches -0.28   ps , which is a good candidate for ultrafast light application. Finally, additional graphene nanoribbons can also form a double-channel PIA window. Our work may provide an excellent platform for controlling the optical transmission of highly integrated plasmonic components.

  15. Tuning SPT-3G Transition-Edge-Sensor Electrical Properties with a Four-Layer Ti-Au-Ti-Au Thin-Film Stack

    Science.gov (United States)

    Carter, F. W.; Ade, P. A. R.; Ahmed, Z.; Anderson, A. J.; Austermann, J. E.; Avva, J. S.; Thakur, R. Basu; Bender, A. N.; Benson, B. A.; Carlstrom, J. E.; Cecil, T.; Chang, C. L.; Cliche, J. F.; Cukierman, A.; Denison, E. V.; de Haan, T.; Ding, J.; Divan, R.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Foster, A.; Gannon, R. N.; Gilbert, A.; Groh, J. C.; Halverson, N. W.; Harke-Hosemann, A. H.; Harrington, N. L.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Huang, N.; Irwin, K. D.; Jeong, O. B.; Jonas, M.; Khaire, T.; Kofman, A. M.; Korman, M.; Kubik, D.; Kuhlmann, S.; Kuo, C. L.; Kutepova, V.; Lee, A. T.; Lowitz, A. E.; Meyer, S. S.; Michalik, D.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Noble, G. I.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Ruhl, J. E.; Saunders, L. J.; Sayre, J. T.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J. A.; Stan, L.; Stark, A. A.; Story, K. T.; Suzuki, A.; Tang, Q. Y.; Thompson, K. L.; Tucker, C.; Vale, L. R.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.; Young, M. R.

    2018-04-01

    We have developed superconducting Ti transition-edge sensors with Au protection layers on the top and bottom for the South Pole Telescope's third-generation receiver (a cosmic microwave background polarimeter, due to be upgraded this austral summer of 2017/2018). The base Au layer (deposited on a thin Ti glue layer) isolates the Ti from any substrate effects; the top Au layer protects the Ti from oxidation during processing and subsequent use of the sensors. We control the transition temperature and normal resistance of the sensors by varying the sensor width and the relative thicknesses of the Ti and Au layers. The transition temperature is roughly six times more sensitive to the thickness of the base Au layer than to that of the top Au layer. The normal resistance is inversely proportional to sensor width for any given film configuration. For widths greater than five micrometers, the critical temperature is independent of width.

  16. Optimization of morphing flaps based on fluid structure interaction modeling

    DEFF Research Database (Denmark)

    Barlas, Athanasios; Akay, Busra

    2018-01-01

    This article describes the design optimization of morphing trailing edge flaps for wind turbines with ‘smart blades’. A high fidelity Fluid Structure Interaction (FSI) simulation framework is utilized, comprised of 2D Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) models....... A coupled aero-structural simulation of a 10% chordwise length morphing trailing edge flap for a 4 MW wind turbine rotor is carried out and response surfaces are produced with respect to the flap internal geometry design parameters for the design conditions. Surrogate model based optimization is applied...

  17. Transition edge sensor-energy-dispersive spectrometer (TES-EDS) using a cryogen-free dilution refrigerator for material analysis

    International Nuclear Information System (INIS)

    Tanaka, Keiichi; Odawara, Akikazu; Nagata, Atsushi; Ikeda, Masanori; Baba, Yukari; Nakayama, Satoshi; Chinone, Kazuo

    2006-01-01

    A cryogen-free energy-dispersive spectrometer (EDS) using a transition edge sensor (TES) was developed for material analysis. This system can maintain a temperature at 130 mK within 30 μK, and has good energy resolution (19 eV for Mn-Kα) for long-time measurement with a drift in the DC level of less than 0.02 eV/min. This system utilizes a dilution refrigerator (φ 272 mmxheight 572 mm) and has a snout (370 mm long and φ25 mm) similar to that in a conventional EDS system. The dilution refrigerator is pre-cooled by a GM refrigerator. A flexible tube between the dilution refrigerator and GM refrigerator damps the mechanical vibration of the GM refrigerator. Two shields (4 and 80 K) thermally protect the Cu rod (φ8 mm) cooled to be 100 mK. Windows composed of polyimide+Al film allow X-ray detection above the C-Kα line. A TES (6 mmx6 mm) and array SQUID amplifier (1.5 mmx3 mm) are mounted on top of the Cu rod. For Mn-Kα, the pulse height is 5.5 μA and decay time (τ eff ) is 90 μs. The maximum count rate (1/20 τ eff ) is estimated at about 500 cps

  18. Fabrication of close-packed TES microcalorimeter arrays using superconducting molybdenum/gold transition-edge sensors

    Science.gov (United States)

    Finkbeiner, F. M.; Brekosky, R. P.; Chervenak, J. A.; Figueroa-Feliciano, E.; Li, M. J.; Lindeman, M. A.; Stahle, C. K.; Stahle, C. M.; Tralshawala, N.

    2002-02-01

    We present an overview of our efforts in fabricating Transition-Edge Sensor (TES) microcalorimeter arrays for use in astronomical x-ray spectroscopy. Two distinct types of array schemes are currently pursued: 5×5 single pixel TES array where each pixel is a TES microcalorimeter, and Position-Sensing TES (PoST) array. In the latter, a row of 7 or 15 thermally-linked absorber pixels is read out by two TES at its ends. Both schemes employ superconducting Mo/Au bilayers as the TES. The TES are placed on silicon nitride membranes for thermal isolation from the structural frame. The silicon nitride membranes are prepared by a Deep Reactive Ion Etch (DRIE) process into a silicon wafer. In order to achieve the concept of closely packed arrays without decreasing its structural and functional integrity, we have already developed the technology to fabricate arrays of cantilevered pixel-sized absorbers and slit membranes in silicon nitride films. Furthermore, we have started to investigate ultra-low resistance through-wafer micro-vias to bring the electrical contact out to the back of a wafer. .

  19. Development of High Frequency Transition-Edge-Sensor Polarimeters for Next Generation Cosmic Microwave Background Experiments and Galactic Foreground Measurements

    Science.gov (United States)

    Walker, Samantha; Sierra, Carlos E.; Austermann, Jason Edward; Beall, James; Becker, Dan; Dober, Bradley; Duff, Shannon; Hilton, Gene; Hubmayr, Johannes; Van Lanen, Jeffrey L.; McMahon, Jeff; Simon, Sara M.; Ullom, Joel; Vissers, Michael R.; NIST Quantum Sensors Group

    2018-06-01

    Observations of the cosmic microwave background (CMB) provide a powerful tool for probing the earliest moments of the universe and therefore have the potential to transform our understanding of cosmology. In particular, precision measurements of its polarization can reveal the existence of gravitational waves produced during cosmic inflation. However, these observations are complicated by the presence of astrophysical foregrounds, which may be separated by using broad frequency coverage, as the spectral energy distribution between foregrounds and the CMB is distinct. For this purpose, we are developing large-bandwidth, feedhorn-coupled transition-edge-sensor (TES) arrays that couple polarized light from waveguide to superconducting microstrip by use of a symmetric, planar orthomode transducer (OMT). In this work, we describe two types of pixels, an ultra-high frequency (UHF) design, which operates from 195 GHz-315 GHz, and an extended ultra-high frequency (UHF++) design, which operates from 195 GHz-420 GHz, being developed for next generation CMB experiments that will come online in the next decade, such as CCAT-prime and the Simons Observatory. We present the designs, simulation results, fabrication, and preliminary measurements of these prototype pixels.

  20. Ultra-Sensitive Transition-Edge Sensors (TESs) for Far-IR/Submm Space-Borne Spectroscopy

    Science.gov (United States)

    Kenyon, M.; Day, P. K.; Bradford, C. M.; Bock, J .J.; Leduc, H. G.

    2011-01-01

    We have built surface micromachined thin-film metallized Si(x)N(y) optical absorbers for transition-edge sensors (TESs) suitable for the Background - Limited far-IR/Submm Spectrograph (BLISS). BLISS is a broadband (38 micrometers - 433 micrometers), grating spectrometer consisting of five wavebands each with a modest resolution of R (is) approx. 1000. Because BLISS requires the effective noise equivalent power (NEP) of the TES to be below 10 (exp 19) W/Hz(exp 1/2), our TESs consist of four long (1000 micrometers), narrow (0.4 micrometers ), and thin (0.25 micrometers ) Si(x) N(y) support beams that reduce the thermal conductance G between the substrate and the optical absorber. To reduce the heat capacity of the absorber and make the response time tau fast enough for BLISS, our absorbers are patterned into a mesh geometry with a fill factor of less than 10%. We use a bilayer of Ti/Au to make the effective impedance of the absorber match the impedance of the incoming radiation for each band. Measurements of the response time of the metallized absorbers to heat pulses show that their heat capacity exceeds the predictions of the Debye model. Our results are suggestive that the surface of the low pressure chemical vapor deposition (LPCVD) Si(x)N(y) used in the absorbers' construction is the source of microstates that dominate the heat capacity.

  1. Ultra-Sensitive Transition-Edge Sensors for the Background Limited Infrared/Sub-mm Spectrograph (BLISS)

    Science.gov (United States)

    Beyer, A. D.; Kenyon, M. E.; Echternach, P. M.; Chui, T.; Eom, B.-H.; Day, P. K.; Bock, J. J.; Holmes, W.A.; Bradford, C. M.

    2011-01-01

    We report progress in fabricating ultra-sensitive superconducting transition-edge sensors (TESs) for BLISS. BLISS is a suite of grating spectrometers covering 35-433 micron with R approx. 700 cooled to 50 mK that is proposed to fly on the Japanese space telescope SPICA. The detector arrays for BLISS are TES bolometers readout with a time domain SQUID multiplexer. The required noise equivalent power (NEP) for BLISS is NEP = 10(exp -19) W/Hz(exp 1/2) with an ultimate goal of NEP= 5 x 10(exp -20) W/Hz(exp 1/2) to achieve background limited noise performance. The required and goal response times are tau = 150 ms and tau = 50ms respectively to achieve the NEP at the required and goal optical chop frequency 1-5 Hz. We measured prototype BLISS arrays and have achieved NEP = 6 x 10(exp -18) W/Hz(exp 1/2) and tau = 1.4 ms with a Ti TES (T(sub C) = 565 mK) and NEP approx. 2.5 x 10(exp -19) W/Hz(exp 1/2) and tau approximates 4.5 ms with an Ir TES (T(sub C) = 130 mK). Dark power for these tests is estimated at 1-5 fW.

  2. High-resolution X-ray emission spectroscopy with transition-edge sensors: present performance and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Uhlig, J.; Doriese, W. B.; Fowler, J. W.; Swetz, D. S.; Jaye, C.; Fischer, D. A.; Reintsema, C. D.; Bennett, D. A.; Vale, L. R.; Mandal, U.; O' Neil, G. C.; Miaja-Avila, L.; Joe, Y. I.; El Nahhas, A.; Fullagar, W.; Parnefjord Gustafsson, F.; Sundström, V.; Kurunthu, D.; Hilton, G. C.; Schmidt, D. R.; Ullom, J. N.

    2015-04-21

    X-ray emission spectroscopy (XES) is a powerful element-selective tool to analyze the oxidation states of atoms in complex compounds, determine their electronic configuration, and identify unknown compounds in challenging environments. Until now the low efficiency of wavelength-dispersive X-ray spectrometer technology has limited the use of XES, especially in combination with weaker laboratory X-ray sources. More efficient energy-dispersive detectors have either insufficient energy resolution because of the statistical limits described by Fano or too low counting rates to be of practical use. This paper updates an approach to high-resolution X-ray emission spectroscopy that uses a microcalorimeter detector array of superconducting transition-edge sensors (TESs). TES arrays are discussed and compared with conventional methods, and shown under which circumstances they are superior. It is also shown that a TES array can be integrated into a table-top time-resolved X-ray source and a soft X-ray synchrotron beamline to perform emission spectroscopy with good chemical sensitivity over a very wide range of energies.

  3. Pedicled perforator flaps

    DEFF Research Database (Denmark)

    Demirtas, Yener; Ozturk, Nuray; Kelahmetoglu, Osman

    2009-01-01

    Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap...... to reconstruct the defect. The perforators are marked with a hand-held Doppler probe and multiple flaps are designed. The appropriate flap is elevated after identifying the perforator(s). Dissection of the perforator(s) or complete incision of the flap margins are not mandatory if the flap is mobilized...... adequately to cover the defect. Defects measuring 3 x 3 cm up to 20 x 20 cm at diverse locations were successfully reconstructed in 20 of 21 patients with 26 flaps. Pedicled perforator flaps offer us reliable and satisfactory results of reconstruction at different anatomic territories of the body. It sounds...

  4. A novel sensor for two-degree-of-freedom motion measurement of linear nanopositioning stage using knife edge displacement sensing technique

    Science.gov (United States)

    Zolfaghari, Abolfazl; Jeon, Seongkyul; Stepanick, Christopher K.; Lee, ChaBum

    2017-06-01

    This paper presents a novel method for measuring two-degree-of-freedom (DOF) motion of flexure-based nanopositioning systems based on optical knife-edge sensing (OKES) technology, which utilizes the interference of two superimposed waves: a geometrical wave from the primary source of light and a boundary diffraction wave from the secondary source. This technique allows for two-DOF motion measurement of the linear and pitch motions of nanopositioning systems. Two capacitive sensors (CSs) are used for a baseline comparison with the proposed sensor by simultaneously measuring the motions of the nanopositioning system. The experimental results show that the proposed sensor closely agrees with the fundamental linear motion of the CS. However, the two-DOF OKES technology was shown to be approximately three times more sensitive to the pitch motion than the CS. The discrepancy in the two sensor outputs is discussed in terms of measuring principle, linearity, bandwidth, control effectiveness, and resolution.

  5. Photoactivated Mixed In-Plane and Edge-Enriched p-Type MoS2 Flake-Based NO2 Sensor Working at Room Temperature.

    Science.gov (United States)

    Agrawal, Abhay V; Kumar, Rahul; Venkatesan, Swaminathan; Zakhidov, Alex; Yang, Guang; Bao, Jiming; Kumar, Mahesh; Kumar, Mukesh

    2018-05-25

    Toxic gases are produced during the burning of fossil fuels. Room temperature (RT) fast detection of toxic gases is still challenging. Recently, MoS 2 transition metal dichalcogenides have sparked great attention in the research community due to their performance in gas sensing applications. However, MoS 2 based gas sensors still suffer from long response and recovery times, especially at RT. Considering this challenge, here, we report photoactivated highly reversible and fast detection of NO 2 sensors at room temperature (RT) by using mixed in-plane and edge-enriched p-MoS 2 flakes (mixed MoS 2 ). The sensor showed fast response with good sensitivity of ∼10.36% for 10 ppm of NO 2 at RT without complete recovery. However, complete recovery was obtained with better sensor performance under UV light illumination at RT. The UV assisted NO 2 sensing showed improved performance in terms of fast response and recovery kinetics with enhanced sensitivity to 10 ppm NO 2 concentration. The sensor performance is also investigated under thermal energy, and a better sensor performance with reduced sensitivity and high selectivity toward NO 2 was observed. A detailed gas sensing mechanism based on the density functional theory (DFT) calculations for favorable NO 2 adsorption sites on in-plane and edge-enriched MoS 2 flakes is proposed. This study revealed the role of favorable adsorption sites in MoS 2 flakes for the enhanced interaction of target gases and developed a highly sensitive, reversible, and fast gas sensor for next-generation toxic gases at room temperature.

  6. X-ray microanalysis with transition edge sensors. The future of material analysis with scanning electron microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Hollerith, C.

    2006-07-05

    In current experiments and technical applications the demand for new and advanced concepts for the detection of radiation and particle is increasing. Low temperature detectors such as Transition Edge Sensors (TES) have been developed as ultrahigh-resolution radiation and particle detectors offering advantages in manifold applications. They were designed primarily for astrophysical experiments such as the dark matter search. In material analysis they have been introduced to revolutionize mass spectroscopy of biological molecules and Energy Dispersive X-ray Spectroscopy (EDS). EDS is the determination of the elemental constitution of samples in scanning electron microscopes (SEMs) with characteristic X-ray radiation excited by the electron beam. The use of TES detectors improves the EDS analysis of small volumes such as particles or thin layers. This is especially important for the semiconductor industry because of the continual shrinking of device size. Current structure sizes of 65 nm are already demanding new approaches in analytic methodology. In this thesis the introduction and improvement of a fully automated TES detector system in the industrial environment of a semiconductor failure analysis lab is described. This system, marketed under the trade name of 'Polaris' by the manufacturer, is based on a mechanical pulse tube cooler in combination with an adiabatic demagnetization refrigerator (ADR) for cooling the TES detector to its operating temperature. Several large improvements had to be made to the system during the total system integration. The energy resolution could be improved significantly thus enabling a better peak separation and the measurement of chemical shifts. Due to the small area of TES detectors compared with conventional EDS detectors the efficiency of the system proved to be too low for everyday use. A polycapillary X-ray lens was added to the system in order to solve this problem. The application of the lens, however, brought its

  7. Water Tunnel Studies of Dynamic Wing Flap Effects

    Science.gov (United States)

    2016-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited WATER TUNNEL...Master’s Thesis 4. TITLE AND SUBTITLE WATER TUNNEL STUDIES OF DYNAMIC WING FLAP EFFECTS 5. FUNDING NUMBERS 6. AUTHOR(S) Edgar E. González 7. PERFORMING...ABSTRACT (maximum 200 words ) The flow features developing over a two-element NACA 0012 airfoil, with the rear portion serving as a trailing edge flap

  8. Optimisation of a novel trailing edge concept for a high lift device

    CSIR Research Space (South Africa)

    Botha, JDM

    2015-01-01

    Full Text Available This study aimed to observe the effect of a novel concept (referred to as the flap extension) implemented on the leading edge of the flap of a three element high lift device. The high lift device, consisting of a flap, main element and slat...

  9. Structural health monitoring method for wind turbine trailing edge: Crack growth detection using Fibre Bragg Grating sensor embedded in composite materials

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    In this article a novel method to assess a crack growing/damage event in composite material using Fibre Bragg Grating (FBG) sensors embedded in a host material and its application into a composite material structure, Wind Turbine Trailing Edge, is presented. A Structure-Material-FBG model......, such as compression fields ahead the crack or non-uniform strain fields, and then identify the presence of such damage in the structure. Experimental tests were conducted to fully characterize this concept and support the model. Double Cantilever Beams (DCB), made with two glass fibre beams glued with structural...

  10. Longitudinal Stability and Control Characteristics as Determined by the Rocket-model Technique for an Inline, Cruciform, Canard Missile Configuration with a Low-aspect-ratio Wing Having Trailing-edge Flap Controls for a Mach Number Range of 0.7 to 1.

    Science.gov (United States)

    Baber, Hal T , Jr; Moul, Martin T

    1955-01-01

    Two full-scale models of an inline, cruciform, canard missile configuration having a low-aspect-ratio wing equipped with flap-type controls were flight tested in order to determine the missile's longitudinal aerodynamic characteristics. Stability derivatives and control and drag characteristics are presented for a range of Mach number from 0.7 to 1.8. Nonlinear lift and moment curves were noted for the angle - of-attack range of this test (0 deg to 8 deg). The aerodynamic-center location for angles of attack near 50 remained nearly constant for supersonic speeds at 13.5 percent of the mean aerodynamic chord; whereas for angles of attack near 0 deg, there was a rapid forward movement of the aerodynamic center as the Mach number increased. At a control deflection of 0 deg, the missile's response to the longitudinal control was in an essentially fixed space plane which was not coincident with the pitch plane as a result of the missile rolling. As a consequence, stability characteristics were determined from the resultant of pitch and yaw motions. The damping-in-pitch derivatives for the two angle -of-attack ranges of the test are in close agreement and varied only slightly with Mach number. The horn-balanced trailing-edge flap was effective in producing angle of attack over the Mach number range.

  11. Longitudinal Stability and Control Characteristics as Determined by the Rocket-Model Technique for an Inline, Cruciform, Canard Missile Configuration with a Low-Aspect-Ratio Wing Having Trailing-Edge Flap Controls for a Mach Number Range of 0.7 to 1.8

    Science.gov (United States)

    Baber, H. T., Jr.; Moul, M. T.

    1955-01-01

    Two full-scale models of an inline, cruciform, canard missile configuration having a low-aspect-ratio wing equipped with flap-type controls were flight tested in order to determine the missile's longitudinal aerodynamic characteristics. Stability derivatives and control and drag characteristics are presented for a range of Mach number from 0.7 to 1.8. Nonlinear lift and moment curves were noted for the angle-of-attack range of this test (0 deg to 8 deg ). The aerodynamic-center location for angles of attack near 5 deg remained nearly constant for supersonic speeds at 13.5 percent of the mean aerodynamic chord; whereas for angles of attack near O deg, there was a rapid forward movement of the aerodynamic center as the Mach number increased. At a control deflection of O deg, the missile's response to the longitudinal control was in an essentially fixed space plane which was not coincident with the pitch plane as a result of the missile rolling. As a consequence, stability characteristics were determined from the resultant of pitch and yaw motions. The damping-in-pitch derivatives for the two angle-of-attack ranges of the test are in close agreement and varied only slightly with Mach number. The horn-balanced trailing-edge flap was effective in producing angle of attack over the Mach number range.

  12. Propeller TAP flap

    DEFF Research Database (Denmark)

    Thomsen, Jørn Bo; Bille, Camilla; Wamberg, Peter

    2013-01-01

    major complications needing additional surgery. One flap was lost due to a vascular problem. Breast reconstruction can be performed by a propeller TAP flap without cutting the descending branch of the thoracodorsal vessels. However, the authors would recommend that a small cuff of muscle is left around...

  13. A Long-Period Grating Sensor for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Glavind, Lars

    This PhD project concerns the applied research for providing a novel sensor for measurements on wind turbine blades, based on Long-Period Gratings. The idea is based on the utilization of a special asymmetrical optical fibre with Long-Period Gratings for directional sensitive bend sensing...... blade material, where a suitable process and recoating material were investigated. The sensor was implemented and tested on a full scale wind turbine blade placed on a test rig. This first prototype has demonstrated the capability of the sensor for wind turbine blade monitoring, particular...... the possibility to distinguish between the flap- and edge-wise bend directions on the wind turbine blade, providing a selective sensor. The sensor has proven to be very robust and suitable for this application....

  14. Effect of chordwise deformation on unsteady aerodynamic mechanisms in hovering flapping flight

    NARCIS (Netherlands)

    Noyon, T.A.; Tay, W.B.; Van Oudheusden, B.W.; Bijl, H.

    2014-01-01

    A three-dimensional simulation of hovering flapping wings was performed using an immersed boundary method. This was done to investigate the effects of chordwise wing deformation on three important unsteady aerodynamic mechanisms found in flapping flight, namely Leading Edge Vortex (LEV) shedding,

  15. 3D active edge silicon sensors: Device processing, yield and QA for the ATLAS-IBL production

    Energy Technology Data Exchange (ETDEWEB)

    Da Vià, Cinzia; Boscardil, Maurizio; Dalla Betta, GianFranco; Darbo, Giovanni; Fleta, Celeste; Gemme, Claudia; Giacomini, Gabriele; Grenier, Philippe; Grinstein, Sebastian; Hansen, Thor-Erik; Hasi, Jasmine; Kenney, Christopher; Kok, Angela; La Rosa, Alessandro; Micelli, Andrea; Parker, Sherwood; Pellegrini, Giulio; Pohl, David-Leon; Povoli, Marco; Vianello, Elisa; Zorzi, Nicola; Watts, S. J.

    2013-01-01

    3D silicon sensors, where plasma micromachining is used to etch deep narrow apertures in the silicon substrate to form electrodes of PIN junctions, were successfully manufactured in facilities in Europe and USA. In 2011 the technology underwent a qualification process to establish its maturity for a medium scale production for the construction of a pixel layer for vertex detection, the Insertable B-Layer (IBL) at the CERN-LHC ATLAS experiment. The IBL collaboration, following that recommendation from the review panel, decided to complete the production of planar and 3D sensors and endorsed the proposal to build enough modules for a mixed IBL sensor scenario where 25% of 3D modules populate the forward and backward part of each stave. The production of planar sensors will also allow coverage of 100% of the IBL, in case that option was required. This paper will describe the processing strategy which allowed successful 3D sensor production, some of the Quality Assurance (QA) tests performed during the pre-production phase and the production yield to date.

  16. 3D active edge silicon sensors: Device processing, yield and QA for the ATLAS-IBL production

    Energy Technology Data Exchange (ETDEWEB)

    Da Vià, Cinzia, E-mail: cinzia.da.via@cern.ch [School of Physics and Astronomy, The University of Manchester, Oxford Road, M13 9PL Manchester (United Kingdom); Boscardil, Maurizio [Fondazione Bruno Kessler, FBK-CMM, Via Sommarive 18, I-38123 Trento (Italy); Dalla Betta, GianFranco [DISI, Università degli Studi di Trento and INFN, Via Sommarive 14, I-38123 Trento (Italy); Darbo, Giovanni [INFN Sezione di Genova, Via Dodecaneso 33, I-14146 Genova (Italy); Fleta, Celeste [Centro Nacional de Microelectronica, CNM-IMB (CSIC), Barcelona E-08193 (Spain); Gemme, Claudia [INFN Sezione di Genova, Via Dodecaneso 33, I-14146 Genova (Italy); Giacomini, Gabriele [Fondazione Bruno Kessler, FBK-CMM, Via Sommarive 18, I-38123 Trento (Italy); Grenier, Philippe [SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Grinstein, Sebastian [Institut de Fisica d' Altes Energies (IFAE) and ICREA, Universitat Autonoma de Barcelona (UAB) E-08193, Bellaterra, Barcelona (Spain); Hansen, Thor-Erik [SINTEF MiNaLab, Blindern, N-0314 Oslo (Norway); Hasi, Jasmine; Kenney, Christopher [SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Kok, Angela [SINTEF MiNaLab, Blindern, N-0314 Oslo (Norway); La Rosa, Alessandro [CERN CH 1211, Geneva 23 (Switzerland); Micelli, Andrea [Tne University of Udine and INFN, via del Cotonificio 108, 33100 Udine (Italy); Parker, Sherwood [University of Hawaii, c/o Lawrence Berkeley Laboratory, Berkeley, CA 94720 (United States); Pellegrini, Giulio [Centro Nacional de Microelectronica, CNM-IMB (CSIC), Barcelona E-08193 (Spain); Pohl, David-Leon [Physikalisches Institut der Universität Bonn, Nußallee 12 D-53115, Bonn, Federal Republic of Germany (Germany); Povoli, Marco [DISI, Università degli Studi di Trento and INFN, Via Sommarive 14, I-38123 Trento (Italy); and others

    2013-01-21

    3D silicon sensors, where plasma micromachining is used to etch deep narrow apertures in the silicon substrate to form electrodes of PIN junctions, were successfully manufactured in facilities in Europe and USA. In 2011 the technology underwent a qualification process to establish its maturity for a medium scale production for the construction of a pixel layer for vertex detection, the Insertable B-Layer (IBL) at the CERN-LHC ATLAS experiment. The IBL collaboration, following that recommendation from the review panel, decided to complete the production of planar and 3D sensors and endorsed the proposal to build enough modules for a mixed IBL sensor scenario where 25% of 3D modules populate the forward and backward part of each stave. The production of planar sensors will also allow coverage of 100% of the IBL, in case that option was required. This paper will describe the processing strategy which allowed successful 3D sensor production, some of the Quality Assurance (QA) tests performed during the pre-production phase and the production yield to date.

  17. [Saphenous perforator flap].

    Science.gov (United States)

    Winkel, R; Tajsic, N; Husum, H; Schlageter, M; Hanebuth, G; Hoffmann, R

    2013-04-01

    Replacement of full thickness soft tissue defects in the lower leg and ankle, appropriate to the defect and following the course of blood vessels feeding the skin of a distally hinged fasciocutaneous flap most reliably based on the individual anatomy of distal perforators of the posterior tibial artery. Full thickness soft tissue defects, up to 12 cm in length and up to 8 cm in width. Sufficient vascularization of the foot required, in osteomyelitis, and when joints, fractures, implants and tendons are exposed and when a split skin graft, a local flap, a suralis perforator flap or a free flap is not indicated. For patients, in whom a 1-2 h operation is not possible; necessity of angioplasty; decollement or scars around the distal perforators of the posterior tibial artery; local infection or necrosis of soft tissues and/or bone, which cannot be totally excised. Radical debridement; flap dissection without tourniquet; microdissection; design of the flap on the skin: pivot point ~ 10 cm (6-14 cm) proximal of the tip of the medial malleolus; base ~ 5 cm in width, between the course of the saphenous nerve and of the great saphenous vein and the Achilles tendon; adipofascial pedicle up to 15 cm in length sited over the septum between soleus and flexor digitorum muscles, following the course of the saphenous nerve, with a central skin stripe, which expands into a proximal skin island; skin island is outlined similar to the defect, but larger by 1 to 2 cm, surrounded by an adipofascial border: adjustment of the planning as well as of the elevation of these flaps according to the individual position and the caliber of perforators requires in each case the search for a perforator at the estimated pivot point. Delay of transposition, if the division of more than one perforator proximal to the pivot point obviously diminishes circulation. No "tunnelling "of the pedicle; defects of skin due to the elevation of the flap are replaced by split and meshed skin grafts or temporary

  18. Regional estimation of savanna grass nitrogen using the red-edge band of the RapidEye sensor

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available recent high resolution spaceborne multispectral sensor (i.e. RapidEye) in the Kruger National Park (KNP) and its surrounding areas, South Africa. The RapidEyesensor contains five spectral bands in the visible-to-near infrared (VNIR), including a red...

  19. Update on scribe–cleave–passivate (SCP) slim edge technology for silicon sensors: Automated processing and radiation resistance

    Energy Technology Data Exchange (ETDEWEB)

    Fadeyev, V., E-mail: fadeyev@ucsc.edu [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States); Ely, S.; Galloway, Z.; Ngo, J.; Parker, C.; Sadrozinski, H.F.-W. [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States); Christophersen, M.; Phlips, B.F. [U.S. Naval Research Laboratory, Code 7654, 4555 Overlook Avenue, Southwest Washington, DC 20375 (United States); Pellegrini, G.; Rafi, J.M.; Quirion, D. [Instituto de Microelectrónica de Barcelona, IMB-CNM-CSIC, Bellaterra, Barcelona (Spain); Dalla Betta, G.-F. [INFN and University of Trento, Via Sommarive, 14, 38123 Povo di Trento (Italy); Boscardin, M. [Fondazione Bruno Kessler, Via Sommarive, 18, 38123 Povo di Trento (Italy); Casse, G. [Department of Physics, University of Liverpool, O. Lodge Laboratory, Oxford Street, Liverpool L69 7ZE (United Kingdom); Gorelov, I.; Hoeferkamp, M.; Metcalfe, J.; Seidel, S. [Department of Physics and Astronomy, University of New Mexico, MSC 07 4220, 1919 Lomas Boulevard NE, Albuquerque, NM 87131 (United States); Gaubas, E.; Ceponis, T. [Institute of Applied Research, Vilnius University, Sauletekio 9, LT-10222 Vilnius (Lithuania); and others

    2014-11-21

    We pursue scribe–cleave–passivate (SCP) technology for making “slim edge” sensors. The goal is to reduce the inactive region at the periphery of the devices while maintaining their performance. In this paper we report on two aspects of the current efforts. The first one involves fabrication options for mass production. We describe the automated cleaving tests and a simplified version of SCP post-processing of n-type devices. Another aspect is the radiation resistance of the passivation. We report on the radiation tests of n- and p-type devices with protons and neutrons.

  20. In-vivo quantitative evaluation of perfusion zones and perfusion gradient in the deep inferior epigastric artery perforator flap

    Science.gov (United States)

    Saint-Cyr, Michel; Lakhiani, Chrisovalantis; Cheng, Angela; Mangum, Michael; Liang, Jinyang; Teotia, Sumeet; Livingston, Edward H.; Zuzak, Karel J.

    2013-03-01

    The selection of well-vascularized tissue during DIEP flap harvest remains controversial. While several studies have elucidated cross-midline perfusion, further characterization of perfusion to the ipsilateral hemiabdomen is necessary for minimizing rates of fat necrosis or partial fat necrosis in bilateral DIEP flaps. Eighteen patients (29 flaps) underwent DIEP flap harvest using a prospectively designed protocol. Perforators were marked and imaged with a novel system for quantitatively measuring tissue oxygenation, the Digital Light Hyperspectral Imager. Images were then analyzed to determine if perforator selection influenced ipsilateral flap perfusion. Flaps based on a single lateral row perforator (SLRP) were found to have a higher level of hemoglobin oxygenation in Zone I (mean %HbO2 = 76.1) compared to single medial row perforator (SMRP) flaps (%HbO2 = 71.6). Perfusion of Zone III relative to Zone I was similar between SLRP and SMRP flaps (97.4% vs. 97.9%, respectively). These differences were not statistically significant (p>0.05). Perfusion to the lateral edge of the flap was slightly greater for SLRP flaps compared SMRP flaps (92.1% vs. 89.5%, respectively). SMRP flaps had superior perfusion travelling inferiorly compared to SLRP flaps (88.8% vs. 83.9%, respectively). Overall, it was observed that flaps were better perfused in the lateral direction than inferiorly. Significant differences in perfusion gradients directed inferiorly or laterally were observed, and perforator selection influenced perfusion in the most distal or inferior aspects of the flap. This suggests broader clinical implications for flap design that merit further investigation.

  1. RANS Simulations of Aerodynamic Performance of NACA 0015 Flapped Airfoil

    Directory of Open Access Journals (Sweden)

    Sohaib Obeid

    2017-01-01

    Full Text Available An analysis of 2D subsonic flow over an NACA 0015 airfoil with a 30% trailing edge flap at a constant Reynolds number of 106 for various incidence angles and a range of flap deflections is presented. The steady-state governing equations of continuity and momentum conservation are solved combined with the realizable k-ε turbulence model using the ANSYS-Fluent code (Version 13.7, ANSYS, Inc., Canonsburg, PA, USA. The primary objective of the study is to provide a comprehensive understanding of flow characteristics around the NACA 0015 airfoil as a function of the angle of attack and flap deflection at Re = 106 using the realizable k-ε turbulence model. The results are validated through comparison of the predictions with the free field experimental measurements. Consistent with the experimental observations, the numerical results show that increased flap deflections increase the maximum lift coefficient, move the zero-lift angle of attack (AoA to a more negative value, decrease the stall AoA, while the slope of the lift curve remains unchanged and the curve just shifts upwards. In addition, the numerical simulations provide limits for lift increment Δ C l and Cl, max values to be 1.1 and 2.2, respectively, obtained at a flap deflection of 50°. This investigation demonstrates that the realizable k-ε turbulence model is capable of predicting flow features over an airfoil with and without flap deflections with reasonable accuracy.

  2. Sensors

    CERN Document Server

    Pigorsch, Enrico

    1997-01-01

    This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...

  3. Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)

    1999-10-01

    A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)

  4. The Versatile Modiolus Perforator Flap

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Thomsen, Jorn Bo

    2016-01-01

    BACKGROUND: Perforator flaps are well established, and their usefulness as freestyle island flaps is recognized. The whereabouts of vascular perforators and classification of perforator flaps in the face are a debated subject, despite several anatomical studies showing similar consistency. In our...... experience using freestyle facial perforator flaps, we have located areas where perforators are consistently found. This study is focused on a particular perforator lateral to the angle of the mouth; the modiolus and the versatile modiolus perforator flap. METHODS: A cohort case series of 14 modiolus...... perforator flap reconstructions in 14 patients and a color Doppler ultrasonography localization of the modiolus perforator in 10 volunteers. RESULTS: All 14 flaps were successfully used to reconstruct the defects involved, and the location of the perforator was at the level of the modiolus as predicted...

  5. Experimental Investigation of the Aerodynamic Ground Effect of a Tailless Lambda-Shaped UCAV with Wing Flaps

    National Research Council Canada - National Science Library

    Mostaccio, Jason T

    2006-01-01

    .... The following study extends the existing database by analyzing the inherent aerodynamic behavior that is produced by employing trailing edge flap deflections while flying in-ground-effect (IGE...

  6. Aerodynamic characteristics of NACA 4412 airfoil section with flap in extreme ground effect

    Directory of Open Access Journals (Sweden)

    Alex E. Ockfen

    2009-09-01

    Full Text Available Wing-in-Ground vehicles and aerodynamically assisted boats take advantage of increased lift and reduced drag of wing sections in the ground proximity. At relatively low speeds or heavy payloads of these craft, a flap at the wing trailing-edge can be applied to boost the aerodynamic lift. The influence of a flap on the two-dimensional NACA 4412 airfoil in viscous ground-effect flow is numerically investigated in this study. The computational method consists of a steady-state, incompressible, finite volume method utilizing the Spalart-Allmaras turbulence model. Grid generation and solution of the Navier-Stokes equations are completed using computer program Fluent. The code is validated against published experimental and numerical results of unbounded flow with a flap, as well as ground-effect motion without a flap. Aerodynamic forces are calculated, and the effects of angle of attack, Reynolds number, ground height, and flap deflection are presented for a split and plain flap. Changes in the flow introduced with the flap addition are also discussed. Overall, the use of a flap on wings with small attack angles is found to be beneficial for small flap deflections up to 5% of the chord, where the contribution of lift augmentation exceeds the drag increase, yielding an augmented lift-to-drag ratio.

  7. Multi-parameter Nonlinear Gain Correction of X-ray Transition Edge Sensors for the X-ray Integral Field Unit

    Science.gov (United States)

    Cucchetti, E.; Eckart, M. E.; Peille, P.; Porter, F. S.; Pajot, F.; Pointecouteau, E.

    2018-04-01

    With its array of 3840 Transition Edge Sensors (TESs), the Athena X-ray Integral Field Unit (X-IFU) will provide spatially resolved high-resolution spectroscopy (2.5 eV up to 7 keV) from 0.2 to 12 keV, with an absolute energy scale accuracy of 0.4 eV. Slight changes in the TES operating environment can cause significant variations in its energy response function, which may result in systematic errors in the absolute energy scale. We plan to monitor such changes at pixel level via onboard X-ray calibration sources and correct the energy scale accordingly using a linear or quadratic interpolation of gain curves obtained during ground calibration. However, this may not be sufficient to meet the 0.4 eV accuracy required for the X-IFU. In this contribution, we introduce a new two-parameter gain correction technique, based on both the pulse-height estimate of a fiducial line and the baseline value of the pixels. Using gain functions that simulate ground calibration data, we show that this technique can accurately correct deviations in detector gain due to changes in TES operating conditions such as heat sink temperature, bias voltage, thermal radiation loading and linear amplifier gain. We also address potential optimisations of the onboard calibration source and compare the performance of this new technique with those previously used.

  8. Adiabatic Demagnetization Refrigerator Field Mapping and Shielding Models for a 70 mK Superconducting Transition Edge Sensor Array and Associated Electronics

    Science.gov (United States)

    Ladner, D. R.; Martinez-Galarce, D. S.; McCammon, D.

    2006-04-01

    An X-ray detection instrument to be flown on a sounding rocket experiment (the Advanced Technology Solar Spectroscopic Imager - ATSSI) for solar physics observations is being developed by the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL). The detector is a novel class of microcalorimeter, a superconducting Transition-Edge Sensor (TES), that coupled with associated SQUID and feedback electronics requires high temperature stability at ~70 mK to resolve the energy of absorbed X-ray photons emitted from the solar corona. The cooling system incorporates an existing Adiabatic Demagnetization Refrigerator (ADR) developed at the University of Wisconsin (UW), which was previously flown to study the diffuse cosmic X-ray background. The Si thermistor detectors for that project required 130 K shielded JFET electronic components that are much less sensitive to the external field of the ADR solenoid than are the 1st (~70 mK) and 2nd (~2 K) SQUID stages used with TESs for solar observations. Modification of the Wisconsin ADR design, including TES focal plane and electronics re-positioning, therefore requires a tradeoff between the existing ADR solenoid nulling coil geometry and a low mass passive solenoid shield, while preserving the vibration isolation features of the existing design. We have developed models to accurately compute the magnetic field with and without shielding or nulling coils at critical locations to guide the re-design of the detector subsystem. The models and their application are described.

  9. Commercialization of Micro-fabrication of Antenna-Coupled Transition Edge Sensor Bolometer Detectors for Studies of the Cosmic Microwave Background

    Science.gov (United States)

    Suzuki, Aritoki; Bebek, Chris; Garcia-Sciveres, Maurice; Holland, Stephen; Kusaka, Akito; Lee, Adrian T.; Palaio, Nicholas; Roe, Natalie; Steinmetz, Leo

    2018-04-01

    We report on the development of commercially fabricated multichroic antenna-coupled transition edge sensor (TES) bolometer arrays for cosmic microwave background (CMB) polarimetry experiments. CMB polarimetry experiments have deployed instruments in stages. Stage II experiments deployed with O(1000) detectors and reported successful detection of B-mode (divergence-free) polarization pattern in the CMB. Stage III experiments have recently started observing with O(10,000) detectors with wider frequency coverage. A concept for a stage IV experiment, CMB-S4, is emerging to make a definitive measurement of CMB polarization from the ground with O(400,000) detectors. The orders of magnitude increase in detector count for CMB-S4 require a new approach in detector fabrication to increase fabrication throughput and reduce the cost. We report on collaborative efforts with two commercial micro-fabrication foundries to fabricate antenna-coupled TES bolometer detectors. The detector design is based on the sinuous antenna-coupled dichroic detector from the POLARBEAR-2 experiment. The TES bolometers showed the expected I-V response, and the RF performance agrees with the simulation. We will discuss the motivation, design consideration, fabrication processes, test results, and how industrial detector fabrication could be a path to fabricate hundreds of detector wafers for future CMB polarimetry experiments.

  10. Pitch, roll, and yaw moment generator for insect-like tailless flapping-wing MAV

    Science.gov (United States)

    Phan, Hoang Vu; Park, Hoon Cheol

    2016-04-01

    In this work, we proposed a control moment generator, which is called Trailing Edge Change (TEC) mechanism, for attitudes change in hovering insect-like tailless flapping-wing MAV. The control moment generator was installed to the flapping-wing mechanism to manipulate the wing kinematics by adjusting the wing roots location symmetrically or asymmetrically. As a result, the mean aerodynamic force center of each wing is relocated and control moments are generated. The three-dimensional wing kinematics captured by three synchronized high-speed cameras showed that the flapping-wing MAV can properly modify the wing kinematics. In addition, a series of experiments were performed using a multi-axis load cell to evaluate the forces and moments generation. The measurement demonstrated that the TEC mechanism produced reasonable amounts of pitch, roll and yaw moments by shifting position of the trailing edges at the wing roots of the flapping-wing MAV.

  11. Diaphragmatic hernia repair using a rectus abdominis muscle pedicle flap in three dogs.

    Science.gov (United States)

    Chantawong, P; Komin, K; Banlunara, W; Kalpravidh, M

    2013-01-01

    To report the clinical use of a pedicle flap from the rectus abdominis muscle to repair extensive diaphragmatic tears in dogs with diaphragmatic hernia. Three dogs with a combination of radial and circumferential diaphragmatic tears were studied. The circumferential tear was repaired by suturing the wound edge with the edge at the abdominal wall. A pedicle flap of the rectus abdominis muscle was used for repairing the radial tear. The dogs were examined radiographically for lung and diaphragm appearance and evidence of reherniation at 10 days, and at one, two, and four months after surgery, and fluoroscopically for paradoxical motion of the diaphragm at one and four months. The rectus abdominis muscle pedicle flap was successfully used in all three dogs. The animals recovered uneventfully without evidence of reherniation during the four follow-up months. Fluoroscopic examination revealed no paradoxical motion of the diaphragm. A rectus abdominis muscle pedicle flap can be used for repairing large diaphragmatic defects in dogs.

  12. The freestyle pedicle perforator flap

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Jackson, Ian T; Westvik, Tormod S

    2015-01-01

    BACKGROUND: Perforating vessels are a consistent anatomical finding and well described in the current literature. Any skin flap can be raised on a subcutaneous pedicle as long as it contains at least one supplying perforator. Perforator flaps have been interlinked with microsurgery and generally...... not widely performed by the general plastic surgeons. The aim of this paper is to present the simplicity of pedicled perforator flap reconstruction of moderate-sized defects of the extremities and torso. METHODS: We retrospectively reviewed the charts of 34 patients reconstructed using 34 freestyle pedicled...... perforator flaps for moderate-sized defects of the truncus and extremities. We registered indications, flap size and localization, success rate, and complications. Most importantly, we describe a simple approach to the design of freestyle pedicled perforator flaps and elaborate on technical aspects...

  13. A Comparative Study of Simulated and Measured Gear-Flap Flow Interaction

    Science.gov (United States)

    Khorrami, Mehdi R.; Mineck, Raymond E.; Yao, Chungsheng; Jenkins, Luther N.; Fares, Ehab

    2015-01-01

    The ability of two CFD solvers to accurately characterize the transient, complex, interacting flowfield asso-ciated with a realistic gear-flap configuration is assessed via comparison of simulated flow with experimental measurements. The simulated results, obtained with NASA's FUN3D and Exa's PowerFLOW® for a high-fidelity, 18% scale semi-span model of a Gulfstream aircraft in landing configuration (39 deg flap deflection, main landing gear on and off) are compared to two-dimensional and stereo particle image velocimetry measurements taken within the gear-flap flow interaction region during wind tunnel tests of the model. As part of the bench-marking process, direct comparisons of the mean and fluctuating velocity fields are presented in the form of planar contour plots and extracted line profiles at measurement planes in various orientations stationed in the main gear wake. The measurement planes in the vicinity of the flap side edge and downstream of the flap trailing edge are used to highlight the effects of gear presence on tip vortex development and the ability of the computational tools to accurately capture such effects. The present study indicates that both computed datasets contain enough detail to construct a relatively accurate depiction of gear-flap flow interaction. Such a finding increases confidence in using the simulated volumetric flow solutions to examine the behavior of pertinent aer-odynamic mechanisms within the gear-flap interaction zone.

  14. Keystone flaps in coloured skin: Flap technology for the masses?

    Directory of Open Access Journals (Sweden)

    Satish P Bhat

    2013-01-01

    Full Text Available Introduction: Viscoelastic properties of skin in coloured ethnic groups are less favourable compared to Caucasians for executing Keystone flaps. Keystone flaps have so far been evaluated and reported only in Caucasians. The potential of Keystone flaps in a coloured ethnic group is yet unknown. Aim: This article reviews the experience to reconstruct skin defects presenting in a coloured ethnic group, by using Keystone flaps, with a review of existing literature. Design: Uncontrolled case series. Materials and Methods: This retrospective review involves 55 consecutive Keystone flaps used from 2009 to 2012, for skin defects in various locations. Patient demographic data, medical history, co-morbidity, surgical indication, defect features, complications, and clinical outcomes are evaluated and presented. Results: In this population group with Fitzpatrick type 4 and 5 skin, the average patient age was 35.73. Though 60% of flaps (33/55 in the series involved specific risk factors, only two flaps failed. Though seven flaps had complications, sound healing was achieved by suitable intervention giving a success rate of 96.36%. Skin grafts were needed in only four cases. Conclusions: Keystone flaps achieve primary wound healing for a wide spectrum of defects with an acceptable success rate in a coloured skin population with unfavorable biophysical properties. By avoiding conventional local flaps and at times even microsurgical flaps, good aesthetic outcome is achieved without additional skin grafts or extensive operative time. All advantages seen in previous studies were verified. These benefits can be most appreciated in coloured populations, with limited resources and higher proportion of younger patients and unfavorable defects.

  15. Optimisation of a novel trailing edge concept for a high lift device

    CSIR Research Space (South Africa)

    Botha, JDM

    2014-09-01

    Full Text Available A novel concept (referred to as the flap extension) is implemented on the leading edge of the flap of a three element high lift device. The concept is optimised using two optimisation approaches based on Genetic Algorithm optimisations. A zero order...

  16. Transition-Edge Sensor Pixel Parameter Design of the Microcalorimeter Array for the X-Ray Integral Field Unit on Athena

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Bandler, S. R.; Betancourt-Martinez, G. L.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; hide

    2016-01-01

    The focal plane of the X-ray integral field unit (X-IFU) for ESA's Athena X-ray observatory will consist of approximately 4000 transition edge sensor (TES) x-ray microcalorimeters optimized for the energy range of 0.2 to 12 kiloelectronvolts. The instrument will provide unprecedented spectral resolution of approximately 2.5 electronvolts at energies of up to 7 kiloelectronvolts and will accommodate photon fluxes of 1 milliCrab (90 counts per second) for point source observations. The baseline configuration is a uniform large pixel array (LPA) of 4.28 arcseconds pixels that is read out using frequency domain multiplexing (FDM). However, an alternative configuration under study incorporates an 18 by × 18 small pixel array (SPA) of 2 arcseconds pixels in the central approximately 36 arcseconds region. This hybrid array configuration could be designed to accommodate higher fluxes of up to 10 milliCrabs (900 counts per second) or alternately for improved spectral performance (less than 1.5 electronvolts) at low count-rates. In this paper we report on the TES pixel designs that are being optimized to meet these proposed LPA and SPA configurations. In particular we describe details of how important TES parameters are chosen to meet the specific mission criteria such as energy resolution, count-rate and quantum efficiency, and highlight performance trade-offs between designs. The basis of the pixel parameter selection is discussed in the context of existing TES arrays that are being developed for solar and x-ray astronomy applications. We describe the latest results on DC biased diagnostic arrays as well as large format kilo-pixel arrays and discuss the technical challenges associated with integrating different array types on to a single detector die.

  17. Transition-edge sensor pixel parameter design of the microcalorimeter array for the x-ray integral field unit on Athena

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Bandler, S. R.; Betancourt-Martinez, G. L.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Miniussi, A. R.; Porter, F. S.; Sadleir, J. E.; Sakai, K.; Wakeham, N. A.; Wassell, E. J.; Yoon, W.; Bennett, D. A.; Doriese, W. B.; Fowler, J. W.; Hilton, G. C.; Morgan, K. M.; Pappas, C. G.; Reintsema, C. N.; Swetz, D. S.; Ullom, J. N.; Irwin, K. D.; Akamatsu, H.; Gottardi, L.; den Hartog, R.; Jackson, B. D.; van der Kuur, J.; Barret, D.; Peille, P.

    2016-07-01

    The focal plane of the X-ray integral field unit (X-IFU) for ESA's Athena X-ray observatory will consist of 4000 transition edge sensor (TES) x-ray microcalorimeters optimized for the energy range of 0.2 to 12 keV. The instrument will provide unprecedented spectral resolution of 2.5 eV at energies of up to 7 keV and will accommodate photon fluxes of 1 mCrab (90 cps) for point source observations. The baseline configuration is a uniform large pixel array (LPA) of 4.28" pixels that is read out using frequency domain multiplexing (FDM). However, an alternative configuration under study incorporates an 18 × 18 small pixel array (SPA) of 2" pixels in the central 36" region. This hybrid array configuration could be designed to accommodate higher fluxes of up to 10 mCrab (900 cps) or alternately for improved spectral performance (< 1.5 eV) at low count-rates. In this paper we report on the TES pixel designs that are being optimized to meet these proposed LPA and SPA configurations. In particular we describe details of how important TES parameters are chosen to meet the specific mission criteria such as energy resolution, count-rate and quantum efficiency, and highlight performance trade-offs between designs. The basis of the pixel parameter selection is discussed in the context of existing TES arrays that are being developed for solar and x-ray astronomy applications. We describe the latest results on DC biased diagnostic arrays as well as large format kilo-pixel arrays and discuss the technical challenges associated with integrating different array types on to a single detector die.

  18. Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-Millimetre Spectrograph (BLISS) for SPICA

    Science.gov (United States)

    Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M.; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

    2012-01-01

    We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda = 35-435 microns and with R = lambda/(delta)lambda approx. 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10(exp -20) W/Hz(1/2) and response time t or = 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(1/2) and tapprox.5ms for straight-beam TESs. In fact, we expected NEPapprox.1.5x10(exp -19)W/Hz(1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10(exp -19)W/Hz(1/2) in our single-pixel test system and NEP=(1.6+0.3)x10(exp -19)W/Hz(1/2) in our array test system.

  19. Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-mm Spectrograph (BLISS) for SPICA

    Science.gov (United States)

    Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M .; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

    2012-01-01

    We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda=35-435 micron and with R=lambda/delta lambda approximately equals 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10 (sup -20) W/Hz(exp 1/2) and response time tau = 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(sub 1/2) and Tau approximately equals 5ms for straight-beam TESs. In fact, we expected NEP approximately equals 1.5x10(exp -19)?W/Hz(sup 1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10 (sup -19)W/Hz(exp 1/2) in our single-pixel test system and NEP=(1.6+/-0.3)x10(sup -19)W/Hz(sup 1/2) in our array test system.

  20. [Clinical application of modified upper gluteal rhomboid fasciocutaneous flap in repairing sacrococcygeal pressure sores].

    Science.gov (United States)

    Jiang, Maohua; Yang, Xiaoliang; Wei, Bangmin; Li, Yinghao

    2012-03-01

    To investigate the method and effectiveness of repairing sacrococcygeal pressure sores with modified upper gluteal rhomboid fasciocutaneous flap. Between January 2004 and March 2011, 43 patients with sacrococcygeal pressure sores were treated. There were 25 males and 18 females with an average age of 63 years (range, 38-95 years). The disease duration was 3 months to 2 years and 6 months (mean, 8.5 months). The size of pressure sores ranged from 6 cm x 5 cm to 18 cm x 13 cm. According to the extent and lesion degree of pressure scores, 23 pressure sores were rated as degree III and 20 pressure sores as degree IV. The modified upper gluteal rhomboid flap was designed, one-side upper gluteal fasciocutaneous flaps were transplanted to repair sacrococcygeal pressure sores in 19 cases and two-side flaps in 24 cases. The size of one side flap ranged from 6.5 cm x 4.5 cm to 18.0 cm x 11.5 cm. Fluid under flap occurred in 1 case and edge necrosis of the flaps in 3 cases at 7 days after operation, which were cured after drainage and dressing change; the other flaps survived, and incisions healed by first intention. All patients were followed up 6 months to 3 years with an average of 11 months. Two patients relapsed at 5 months and 8 months, respectively; the other patients had no recurrence. The color of the flaps was normal, and the appearance and elasticity of the flaps were good. The modified upper gluteal rhomboid fasciocutaneous flap has the advantages of simple design and operation, less injury, and reliable effect in repairing sacrococcygeal pressure sores.

  1. Influence of hinge point on flexible flap aerodynamic performance

    International Nuclear Information System (INIS)

    Zhao, H Y; Ye, Z; Wu, P; Li, C

    2013-01-01

    Large scale wind turbines lead to increasing blade lengths and weights, which presents new challenges for blade design. This paper selects NREL S809 airfoil, uses the parameterized technology to realize the flexible trailing edge deformation, researches the static aerodynamic characteristics of wind turbine blade airfoil with flexible deformation, and the dynamic aerodynamic characteristics in the process of continuous deformation, analyses the influence of hinge point position on flexible flap aerodynamic performance, in order to further realize the flexible wind turbine blade design and provides some references for the active control scheme. The results show that compared with the original airfoil, proper trailing edge deformation can improve the lift coefficient, reduce the drag coefficient, and thereby more efficiently realize flow field active control. With hinge point moving forward, total aerodynamic performance of flexible flap improves. Positive swing angle can push the transition point backward, thus postpones the occurrence of the transition phenomenon

  2. Method and apparatus for controlling pitch and flap angles of a wind turbine

    Science.gov (United States)

    Deering, Kenneth J [Seattle, WA; Wohlwend, Keith P [Issaquah, WA

    2009-05-12

    A wind turbine with improved response to wind conditions is provided. Blade flap angle motion is accompanied by a change in pitch angle by an amount defining a pitch/flap coupling ratio. The coupling ratio is non-constant as a function of a flap angle and is preferably a substantially continuous, non-linear function of flap angle. The non-constant coupling ratio can be provided by mechanical systems such as a series of linkages or by configuring electronic or other control systems and/or angle sensors. A link with a movable proximal end advantageously is part of the mechanical system. The system can provide relatively large coupling ratios and relatively large rates of coupling ratio changes especially for near-feather pitches and low flap angles.

  3. A dynamic stall model for airfoils with deformable trailing edges

    DEFF Research Database (Denmark)

    Andersen, Peter Bjørn; Gaunaa, Mac; Bak, Christian

    2009-01-01

    , lead-lag, pitch, trailing-edge flapping. In the linear region, the model reduces to the inviscid model, which includes the aerodynamic effect of a thin airfoil with a deformable camberline in inviscid flow. Therefore, the proposed model can be considered a crossover between the work of Gaunaa......The present work contains an extension of the Beddoes-Leishman-type dynamic stall model. In this work, a deformable trailing-edge flap has been added to the dynamic stall model. The model predicts the unsteady aerodynamic forces and moments on an airfoil section undergoing arbitrary motion in heave...... for the attached flow region and Hansen et al. The model is compared qualitatively to wind tunnel measurements of a Riso/ B1-18 blade section equipped with deformable trailing-edge flap devices in the form of piezoelectric devices. Copyright © 2009 John Wiley & Sons, Ltd....

  4. Propeller Flaps: A Literature Review.

    Science.gov (United States)

    Sisti, Andrea; D'Aniello, Carlo; Fortezza, Leonardo; Tassinari, Juri; Cuomo, Roberto; Grimaldi, Luca; Nisi, Giuseppe

    2016-01-01

    Since their introduction in 1991, propeller flaps are increasingly used as a surgical approach to loss of substance. The aim of this study was to evaluate the indications and to verify the outcomes and the complication rates using this reconstructing technique through a literature review. A search on PubMed was performed using "propeller flap", "fasciocutaneous flap", "local flap" or "pedicled flap" as key words. We selected clinical studies using propeller flaps as a reconstructing technique. We found 119 studies from 1991 to 2015. Overall, 1,315 propeller flaps were reported in 1,242 patients. Most frequent indications included loss of substance following tumor excision, repair of trauma-induced injuries, burn scar contractures, pressure sores and chronic infections. Complications were observed in 281/1242 patients (22.6%) occurring more frequently in the lower limbs (31.8%). Partial flap necrosis and venous congestion were the most frequent complications. The complications' rate was significantly higher in infants (70 years old) but there was not a significant difference between the sexes. Trend of complication rate has not improved during the last years. Propeller flaps showed a great success rate with low morbidity, quick recovery, good aesthetic outcomes and reduced cost. The quality and volume of the transferred soft tissue, the scar orientation and the possibility of direct donor site closure should be considered in order to avoid complications. Indications for propeller flaps are small- or medium-sized defects located in a well-vascularized area with healthy surrounding tissues. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  5. Results of the AVATAR project for the validation of 2D aerodynamic models with experimental data of the DU95W180 airfoil with unsteady flap

    DEFF Research Database (Denmark)

    Ferreira, C.; Gonzalez, A.; Baldacchino, D.

    2016-01-01

    , for different angle of attack and flap settings, including unsteady oscillatory trailing-edge-flap motion, carried out within the framework of WP3: Models for Flow Devices and Flow Control, Task 3.1: CFD and Experimental Database. The aerodynamics codes are: AdaptFoil2D, Foil2W, FLOWer, MaPFlow, OpenFOAM, Q3UIC...

  6. White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

    Science.gov (United States)

    Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

    2014-06-01

    White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 104 ≤ Q ≤ 2 × 104 and the square root of spectral density of current noise referred to the SQUID input √SI = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers PMR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √SI is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of PMR) or the quantization noise due to the resolution of 300-K electronics (for large values of PMR). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit √SI ≤ 5 pA/√Hz, i.e., close to √SI of

  7. White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

    International Nuclear Information System (INIS)

    Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

    2014-01-01

    White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 10 4  ≤ Q ≤ 2 × 10 4 and the square root of spectral density of current noise referred to the SQUID input √S I  = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S 21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers P MR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √S I is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of P MR ) or the quantization noise due to the resolution of 300-K electronics (for large values of P MR ). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit

  8. Minimizing 1/f Noise in Magnetic Sensors with a MEMS Flux Concentrator

    National Research Council Canada - National Science Library

    Edelstein, A. S; Fischer, Greg; Pulskamp, Jeff; Pedersen, Michael; Bernard, William; Cheng, Shu F

    2004-01-01

    .... This shift is accomplished by modulating the magnetic field before it reaches the sensor. In our device, the magnetic sensor, a GMR sensor, is placed between flux concentrators that have been deposited on MEMS flaps...

  9. Sensor

    OpenAIRE

    Gleeson, Helen; Dierking, Ingo; Grieve, Bruce; Woodyatt, Christopher; Brimicombe, Paul

    2015-01-01

    An electrical temperature sensor (10) comprises a liquid crystalline material (12). First and second electrically conductive contacts (14), (16), having a spaced relationship there between, contact the liquid crystalline material (12). An electric property measuring device is electrically connected to the first and second contacts (14), (16) and is arranged to measure an electric property of the liquid crystalline material (12). The liquid crystalline material (12) has a transition temperatur...

  10. The Temporalis Muscle Flap in Maxillofacial Reconstruction

    International Nuclear Information System (INIS)

    ElSheikh, M; Zeitoun, I; ElMassry, M A K

    1991-01-01

    The temporalis muscle flap is a very versatile and valuable axial flap, which could be used in various reconstructive procedures in and around the oro-maxillofacial region. The surgical anatomy, vascular pattern and technique of elevation of the flap are described, together with our experience in different reconstructive situations. The advantages and disadvantages of the use of this flap are thoroughly discussed taking into consideration the potentiality of cancer recurrence under cover of the flap. (author)

  11. The Pedicled LICAP Flap Combined with a Free Abdominal Flap In Autologous Breast Reconstructions

    Directory of Open Access Journals (Sweden)

    Thomas Sjøberg, MD

    2018-01-01

    Conclusion:. In selected patients with insufficient abdominal flap tissue, a combination of a free abdominal flap and a pedicled LICAP flap is a valuable option to increase breast size and cosmetic outcome. Additional symmetrizing surgery might still be necessary.

  12. The effect of chordwise flexibility on flapping foil propulsion in quiescent fluid

    Science.gov (United States)

    Shinde, Sachin; Arakeri, Jaywant

    2010-11-01

    Motivated to understand the role of wing flexibility of flying creatures during hovering, we experimentally study the effect of chordwise flexibility on the flow generated in quiescent fluid by a sinusoidally pitching rigid symmetrical foil with a flexible flap attached at the trailing edge. This foil produces a narrow, coherent jet containing reverse Karman vortex street, and a corresponding thrust. The thrust and flow is similar to that produced by a hovering bird or insect, however the mechanism seems to be different from known hovering mechanisms. Novelty of the present hovering mechanism is that the thrust generation is due to the coordinated pushing action of rigid foil and flexible flap. We identify the flow and vortex generation mechanism. This foil produces jet flows over a range of flapping frequencies and amplitudes. In contrast, the foil without flap i.e. with rigid trailing edge produces a weak, divergent jet that meanders randomly. Appending a flexible flap to the foil suppresses jet-meandering and strengthens the jet. Flexibility of flap is crucial in determining the flow structure. This study is useful in designing MAVs and thrusters.

  13. Soap films burst like flapping flags.

    Science.gov (United States)

    Lhuissier, Henri; Villermaux, Emmanuel

    2009-07-31

    When punctured, a flat soap film bursts by opening a hole driven by liquid surface tension. The hole rim does not, however, remain smooth but soon develops indentations at the tip of which ligaments form, ultimately breaking and leaving the initially connex film into a mist of disjointed drops. We report on original observations showing that these indentations result from a flaglike instability between the film and the surrounding atmosphere inducing an oscillatory motion out of its plane. Just like a flag edge flaps in the wind, the film is successively accelerated on both sides perpendicularly to its plane, inducing film thickness modulations and centrifuging liquid ligaments that finally pinch off to form the observed spray. This effect exemplifies how the dynamics of fragile objects such as thin liquid films is sensitive to their embedding medium.

  14. Wake Measurement Downstream of a Hybrid Wing Body Model with Blown Flaps

    Science.gov (United States)

    Lin, John C.; Jones, Gregory S.; Allan, Brian G.; Westra, Bryan W.; Collins, Scott W.; Zeune, Cale H.

    2010-01-01

    Flow-field measurements were obtained in the wake of a full-span Hybrid Wing Body model with internally blown flaps. The test was performed at the NASA Langley 14 x 22 Foot Subsonic Tunnel at low speeds. Off-body measurements were obtained with a 7-hole probe rake survey system. Three model configurations were investigated. At 0deg angle of attack the surveys were completed with 0deg and 60deg flap deflections. At 10deg angle of attack the wake surveys were completed with a slat and a 60deg flap deflection. The 7-hole probe results further quantified two known swirling regions (downstream of the outboard flap edge and the inboard/outboard flap juncture) for the 60deg flap cases with blowing. Flowfield results and the general trends are very similar for the two blowing cases at nozzle pressure ratios of 1.37 and 1.56. High downwash velocities correlated with the enhanced lift for the 60deg flap cases with blowing. Jet-induced effects are the largest at the most inboard station for all (three) velocity components due in part to the larger inboard slot height. The experimental data are being used to improve computational tools for high-lift wings with integrated powered-lift technologies.

  15. Edge Matters

    DEFF Research Database (Denmark)

    Earon, Ofri

    2013-01-01

    of this container is to separate inside from outside and to protect and provide privacy, psychological as well as physical (Venturi, 1966). But, if dwelling phenomenon takes place both inside and outside the private house – why is the urban house an enclosed box? What is the differentiation between inside...... and outside the contemporary urban house? And what is the interplay between them? The research argues for re-thinking the edge zone between inside and outside the urban house. Therefore, although, residential buildings in the city are the objects of study, the focal point here is the edge zone along...... the building. The research explores and develops the architectural characteristics of correlations between the resident, the singular unit, the building and the given location at the edge zone. It approaches the edge zone of the urban house as a platform for dynamic interactions between these behaviours...

  16. Fascioperichondrial Flap with a Proximal Base Combined with Prominent Ear Surgery

    Directory of Open Access Journals (Sweden)

    Heval Selman Özkan

    2017-08-01

    Full Text Available Objective: In this article, we present a personalized surgical technique to relocate a fascioperichondrial flap with a proximal base as an additional measure to improve results and hide sharp edges which frequently occur following traditional otoplasty. Materials and Methods: Fascioperichondrial flap with a proximal base prepared from the dorsal side was transposed to the anterior helix and conchal excision side and secured with stitches to hide visible edges and reinforce Furnas sutures. Nine patients operated for prominent ear deformity using this modification were included in the study and follow-up period was at least 6 months. Conchal mastoid distances were calculated from the superior and middle third of the ears before and after the operation, also in follow-up controls to determine the efficiency of the method. Results: There were no suture extrusions, skin necrosis or infection. The mean difference for both the upper and middle third of the ears were considerably lower (p≤0.05 at the end of six month after the operation. There were no visible skin edges and discomfort described by the patients. Conclusion: Fascioperichondrial flap with a proximal base repositioning to conchal side is an easy procedure that can be applied simply as an adjunct to traditional techniques. Addition of this flap provides an additional tissue to reinforce suture repair and, the results seem to be more durable and strong. Another main advantage of this flap is eliminating the unnatural visible breakpoints in the conchal bowl.

  17. Dynamic Flaps Electronic Scan Antenna

    National Research Council Canada - National Science Library

    Gonzalez, Daniel

    2000-01-01

    A dynamic FLAPS(TM) electronic scan antenna was the focus of this research. The novelty S of this SBIR resides in the use of plasma as the main component of this dynamic X-Band phased S array antenna...

  18. [Aesthetic effect of wound repair with flaps].

    Science.gov (United States)

    Tan, Qian; Zhou, Hong-Reng; Wang, Shu-Qin; Zheng, Dong-Feng; Xu, Peng; Wu, Jie; Ge, Hua-Qiang; Lin, Yue; Yan, Xin

    2012-08-01

    To investigate the aesthetic effect of wound repair with flaps. One thousand nine hundred and ninety-six patients with 2082 wounds hospitalized from January 2004 to December 2011. These wounds included 503 deep burn wounds, 268 pressure sores, 392 soft tissue defects caused by trauma, 479 soft tissue defects due to resection of skin cancer and mole removal, 314 soft tissue defects caused by scar excision, and 126 other wounds. Wound area ranged from 1.5 cm x 1.0 cm to 30.0 cm x 22.0 cm. Sliding flaps, expanded flaps, pedicle flaps, and free flaps were used to repair the wounds in accordance with the principle and timing of wound repair with flaps. Five flaps showed venous congestion within 48 hours post-operation, 2 flaps of them improved after local massage. One flap survived after local heparin wet packing and venous bloodletting. One flap survived after emergency surgical embolectomy and bridging with saphenous vein graft. One flap showed partial necrosis and healed after skin grafting. The other flaps survived well. One thousand three hundred and twenty-one patients were followed up for 3 months to 2 years, and flaps of them were satisfactory in shape, color, and elasticity, similar to that of normal skin. Some patients underwent scar revision later with good results. Application of suitable flaps in wound repair will result in quick wound healing, good function recovery, and satisfactory aesthetic effect.

  19. Effect of flexibility on flapping wing characteristics under forward flight

    International Nuclear Information System (INIS)

    Zhu, Jianyang; Jiang, Lin; Zhou, Chaoying; Wang, Chao

    2014-01-01

    Through two-dimensional numerical simulation and by solving the unsteady incompressible Navier–Stokes (NS) equations, coupled with the structural dynamic equation for the motion of the wing, the effect of flexibility on flapping wing characteristics during forward flight is systematically studied. The flapping wing is considered as a cantilever, which performs the translational and rotational motion at its leading edge, and the other part is passively deformed by the aerodynamic force. The frequency ratio ω* and mass ratio m* are defined and used to characterize the flexibility of the flapping wing. It has been found that an optimal range of the frequency ratio exists in which the flexible wing possesses both a larger propulsive efficiency and lifting efficiency than their rigid counterpart. Also, the flexible wing with the smaller mass ratio may be of benefit to generate thrust, while the larger mass ratio may be of benefit to generate lift. In addition, a stronger leading edge vortex and reattachment vortex are observed around the appropriate flexibility wing’s surface, which therefore leads to better aerodynamic characteristics. (paper)

  20. Management of Vortices Trailing Flapped Wings via Separation Control

    Science.gov (United States)

    Greenblatt, David

    2005-01-01

    A pilot study was conducted on a flapped semi-span model to investigate the concept and viability of near-wake vortex management via separation control. Passive control was achieved by means of a simple fairing and active control was achieved via zero mass-flux blowing slots. Vortex sheet strength, estimated by integrating surface pressure ports, was used to predict vortex characteristics by means of inviscid rollup relations. Furthermore, vortices trailing the flaps were mapped using a seven-hole probe. Separation control was found to have a marked effect on vortex location, strength, tangential velocity, axial velocity and size over a wide range of angles of attack and control conditions. In general, the vortex trends were well predicted by the inviscid rollup relations. Manipulation of the separated flow near the flap edges exerted significant control over both outboard and inboard edge vortices while producing negligible lift excursions. Dynamic separation and attachment control was found to be an effective means for dynamically perturbing the vortex from arbitrarily long wavelengths down to wavelengths less than a typical wingspan. In summary, separation control has the potential for application to time-independent or time-dependent wake alleviation schemes, where the latter can be deployed to minimize adverse effects on ride-quality and dynamic structural loading.

  1. Free-style puzzle flap: the concept of recycling a perforator flap.

    Science.gov (United States)

    Feng, Kuan-Ming; Hsieh, Ching-Hua; Jeng, Seng-Feng

    2013-02-01

    Theoretically, a flap can be supplied by any perforator based on the angiosome theory. In this study, the technique of free-style perforator flap dissection was used to harvest a pedicled or free skin flap from a previous free flap for a second difficult reconstruction. The authors call this a free-style puzzle flap. For the past 3 years, the authors treated 13 patients in whom 12 pedicled free-style puzzle flaps were harvested from previous redundant free flaps and recycled to reconstruct soft-tissue defects at various anatomical locations. One free-style free puzzle flap was harvested from a previous anterolateral thigh flap for buccal cancer to reconstruct a foot defect. Total flap survival was attained in 12 of 13 flaps. One transferred flap failed completely. This patient had received postoperative radiotherapy after the initial cancer ablation and free anterolateral thigh flap reconstruction. Another free flap was used to close and reconstruct the wound. All the donor sites could be closed primarily. The free-style puzzle flap, harvested from a previous redundant free flap and used as a perforator flap to reconstruct a new defect, has proven to be versatile and reliable. When indicated, it is an alternative donor site for further reconstruction of soft-tissue defects.

  2. Correction of incomplete cleft palate by u-shaped flap palatoplasty ...

    African Journals Online (AJOL)

    After complete dissection of the nasal and palatal mucosa, palatal muscles were carefully dissected from the posterior edge of the bones of the hard palate, wherein the well-mobilised flap receded backward spontaneously and elongated the soft palate. After suturing the nasal mucosa in the midline, the dissected palatal ...

  3. Reconstruction of the pelvic floor and the vagina after total pelvic exenteration using the transverse musculocutaneous gracilis flap.

    Science.gov (United States)

    Kaartinen, Ilkka S; Vuento, Maarit H; Hyöty, Marja K; Kallio, Jukka; Kuokkanen, Hannu O

    2015-01-01

    Total pelvic exenteration (TPE) is a rare operation in which the pelvic contents are removed entirely. Several options for pelvic floor and vaginal reconstruction have been described including transverse rectus abdominis musculocutaneous (TRAM) or deep inferior epigastric perforator (DIEP) flaps. The transverse musculocutaneous gracilis (TMG) flap has been introduced for breast reconstruction as a free flap. We adopted the pedicled TMG flap for reconstructions after TPE. To the best of our knowledge, this is the first report of this method in the literature. Between November 2011 and February 2014, 12 patients underwent TPE and reconstruction with unilateral (six patients) or bilateral (six patients) pedicled TMG flaps. Five patients underwent vaginal reconstruction with bilateral TMG flaps. We describe the operative procedure and the outcome of the operation in these patients. The total mean operative times for TPE with or without vaginal reconstruction were 467 ± 12 and 386 ± 59 min, respectively. The TMG flaps had enough vascular tissue and mobility for reconstructing the TPE defects. There was distal edge necrosis in one out of 18 flaps, while the rest survived completely. During the follow-up, complete wound healing with no signs of weakening of the pelvic floor was observed in all cases. Soft-tissue reconstructions are needed to reduce complications associated with TPE, to secure the pelvic floor and to reconstruct the vagina in select patients. The TMG flap is a logical flap choice that does not lead to functional deficits, complicate the abdominal ostomies or weaken the abdominal wall. It reduces the length of operation compared to that of abdominal flaps. IV, therapeutic. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. Effects of irradiation of skin flaps

    International Nuclear Information System (INIS)

    Sumi, Y.; Ueda, M.; Oka, T.; Torii, S.

    1984-01-01

    The reaction of skin flaps to irradiation and the optimum postoperative time for irradiation was studied in the rat. Flaps showed different reactions depending on the time of irradiation. There was a correlation between the radiosensitivity and the vascularity of the flap. Those flaps in the marginal hypovascular stage of revascularization showed reactions similar to normal skin. However, severe adverse reactions were observed in the marginal hypervascular stage

  5. Aerothermal Assment Of The Expert Flap In The SCIROCCO Wind Tunnel

    Science.gov (United States)

    Walpot, L.; Di Clemente, M.; Vos, J.; Etchells, J.; Trifoni, E.; Thoemel, J.; Gavira, J.

    2011-05-01

    In the frame of the “In-Flight Test Measurement Techniques for Aerothermodynamics” activity of the EXPERT Program, the EXPERT Instrumented Open Flap Assembly experiment has the objective to verify the design/sensor integration and validate the CFD tools. Ground based measurements were made in Europe’s largest high enthalpy plasma facility, Scirocco in Italy. Two EXPERT flaps of the flight article, instrumented with 14 thermocouples, 5 pressure ports, a pyrometer and an IR camera mounted in the cavity instrumented flap will collect in-flight data. During the Scirocco experiment, an EXPERT flap model identical to the flight article was mounted at 45 deg on a holder including cavity and was subjected to a hot plasma flow at an enthalpy up to 11MJ/kg at a stagnation pressure of 7 bar. The test model sports the same pressure sensors as the flight article. Hypersonic state-of-the-art codes were then be used to perform code-to-code and wind tunnel-to-code comparisons, including thermal response of the flap as collected during the tests by the sensors and camera.

  6. Vascularized Fibula Flaps for Mandibular Reconstruction: An ...

    African Journals Online (AJOL)

    For decades, osseous vascularised flaps have been used for reconstruction of the mandible with the vascularised fibula flap (VFF) remaining the commonly used osseous free flap, reasons ranging from its adequate bone and pedicle length to its receptive dental implant placement quality. This report considers a modest use ...

  7. Polidocanol injection for chemical delay and its effect on the survival of rat dorsal skin flaps.

    Science.gov (United States)

    Menevşe, Gülsüm Tetik; TeomanTellioglu, Ali; Altuntas, Nurgül; Cömert, Ayhan; Tekdemir, Ibrahim

    2014-06-01

    Surgical delay is an invasive method requiring a two-stage surgical procedure. Hence, methods that may serve as an alternative to surgical delay have become the focus of interest of research studies. From a conceptual view, any technique that interrupts the blood flow along the edges of a proposed flap will render the flap ischemic and induce a delay phenomenon. Polidocanol (Aethoxysklerol(®)-Kreussler) was initially used as a local anesthetic. Nowadays, it has been used as a sclerosing agent to treat telangiectasias and varicose veins. The aim of this experimental study was to investigate the effects of polidocanol injected around the periphery of a random flap as a sclerosing agent on flap delay and survival in a random flap model. A preliminary histopathologic study was performed on two rats to evaluate the sclerosing effect and distribution of polidocanol injection. After the preliminary study, the main study was carried out with three groups: group 1: dorsal flap (n = 10); group 2: dorsal flap + surgical delay (n = 10), group 3: dorsal flap + chemical delay (n = 10). Tissue samples obtained from the flap and injection area revealed destruction of intradermal vessels. The area affected with sclerosis was limited to 0.1 cm beyond the injection site. Mean viable flap areas were 52.1 ± 4.38% (44.0-58.2) in group 1, 64.8 ± 8.92% (57.2-89.2) in group 2, and 71.8 ± 5.18% (64.0-84.0) in group 3. A statistically highly significant difference was found between the surgical delay and chemical delay groups versus the group without delay (p injection around the dorsal flap in the rat is a safe and easy method for nonsurgical delay. The results have shown a flap survival benefit that is superior to controls and equivalent to surgical delay. The clinical application of polidocanol, already in clinical practice for occlusal of telangiectasias, for surgical delay appears feasible. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons

  8. Efficient flapping flight of pterosaurs

    Science.gov (United States)

    Strang, Karl Axel

    In the late eighteenth century, humans discovered the first pterosaur fossil remains and have been fascinated by their existence ever since. Pterosaurs exploited their membrane wings in a sophisticated manner for flight control and propulsion, and were likely the most efficient and effective flyers ever to inhabit our planet. The flapping gait is a complex combination of motions that sustains and propels an animal in the air. Because pterosaurs were so large with wingspans up to eleven meters, if they could have sustained flapping flight, they would have had to achieve high propulsive efficiencies. Identifying the wing motions that contribute the most to propulsive efficiency is key to understanding pterosaur flight, and therefore to shedding light on flapping flight in general and the design of efficient ornithopters. This study is based on published results for a very well-preserved specimen of Coloborhynchus robustus, for which the joints are well-known and thoroughly described in the literature. Simplifying assumptions are made to estimate the characteristics that can not be inferred directly from the fossil remains. For a given animal, maximizing efficiency is equivalent to minimizing power at a given thrust and speed. We therefore aim at finding the flapping gait, that is the joint motions, that minimize the required flapping power. The power is computed from the aerodynamic forces created during a given wing motion. We develop an unsteady three-dimensional code based on the vortex-lattice method, which correlates well with published results for unsteady motions of rectangular wings. In the aerodynamic model, the rigid pterosaur wing is defined by the position of the bones. In the aeroelastic model, we add the flexibility of the bones and of the wing membrane. The nonlinear structural behavior of the membrane is reduced to a linear modal decomposition, assuming small deflections about the reference wing geometry. The reference wing geometry is computed for

  9. THORACO - ABDOMINAL FLAP FOR RESURFACING LARGE POST MASTECTOMY DEFECTS IN LOCALLY ADVANCED CA. BREAST

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao

    2015-02-01

    Full Text Available Covering of large wounds after mastectomy in locally advanced Ca breast with skin that can withstand radiotherapy is a challenge to the surgeon. Here this study we used a local advancement flap from the adjacent area called Thoraco - A bdominal F la p (TA flap for such giant defects. This is based on superficial and lumbar arteries and is thick to with stand consequent RT . MATERIALS AND METHODS: Of the total 107 cases of LABC 32 had post mastectomy defects of larger than 12 cm and could not be closed by simple approximation. Among the 32 cases 17 cases are covered by split thickness skin grafting. 15 cases are covered by TA flap. These cases are assessed for mean operating time, mean blood loss, post - operative stay, flap necrosis and viability of the f lap after radiotherapy. RESULTS: There is minimal extra time or blood loss in these cases . All the flaps healed well except for small edge necrosis in 4 cases. In all the patients we could start radiotherapy in the fourth week of surgery and all the flaps withstood RT well. After further evaluation probably this can be recommended as procedure for giant post mastectomy defects particularly for those who require RT early

  10. Bilateral simultaneous breast reconstruction with SGAP flaps.

    Science.gov (United States)

    Flores, Jaime I; Magarakis, Michael; Venkat, Raghunandan; Shridharani, Sachin M; Rosson, Gedge D

    2012-07-01

    Two work-horse approaches to postmastectomy breast reconstruction are the deep inferior epigastric perforator flap and the superior gluteal artery perforator (SGAP) flap [and its variation, the lateral septocutaneous superior gluteal artery perforator flap]. Our purpose was fourfold: 1) to analyze our experience with the SGAP flaps for simultaneous bilateral breast reconstruction; 2) to analyze our experience with lateral septocutaneous superior gluteal artery perforator flaps for that procedure; 3) to compare our results with those in the literature; and 4) to highlight the importance of preoperative three-dimensional computed tomographic angiography. A retrospective chart review was completed for 23 patients who underwent breast reconstruction between December 2005 and January 2010 via an SGAP flap (46 flaps). We reviewed flap weight, ischemia time, length of stay, overall flap survival, fat necrosis development, and emergency re-exploration. Mean weights were 571.2 ± 222.0 g (range 186-1,117 g) and 568.0 ± 237.5 g (range 209-1,115 g) for the left and right buttock flap, respectively. Mean ischemia time was 129.1 ± 15.7 and 177.7 ± 24.7 minutes for the first and second flap, respectively. Mean hospital stay was 5.3 ± 2.5 days. All flaps survived. Fat necrosis developed in five flaps (10.8%), and emergency re-exploration was required in three patients (three flaps). When harvesting abdominal tissue is a poor option, the SGAP flap is an efficacious procedure for patients desiring autologous breast reconstruction, and bilateral procedures can be performed simultaneously. Copyright © 2012 Wiley Periodicals, Inc.

  11. Image Sensor

    OpenAIRE

    Jerram, Paul; Stefanov, Konstantin

    2017-01-01

    An image sensor of the type for providing charge multiplication by impact ionisation has plurality of multiplication elements. Each element is arranged to receive charge from photosensitive elements of an image area and each element comprises a sequence of electrodes to move charge along a transport path. Each of the electrodes has an edge defining a boundary with a first electrode, a maximum width across the charge transport path and a leading edge that defines a boundary with a second elect...

  12. Reconstruction of Facial Defect Using Deltopectoral Flap.

    Science.gov (United States)

    Aldelaimi, Tahrir N; Khalil, Afrah A

    2015-11-01

    Reconstruction of the head and neck is a challenge for otolarygology surgeons, maxillofacial surgeons as well as plastic surgeons. Defects caused by the resection and/or trauma should be closed with flaps which match in color, texture and hair bearing characteristics with the face. Deltopectoral flap is a one such flap from chest and neck skin mainly used to cover the facial defects. This study report a patient presenting with tragic Road Traffic Accident (RTA) admitted to maxillofacial surgery department at Ramadi Teaching Hospital, Anbar province, Iraq. An incision, medially based, was done and deltopectoral fascio-cutaneous flap was used for surgical exposure and closure of defects after RTA. There was no major complication. Good aesthetic and functional results were achieved. Deltopectoral flap is an excellent alternative for the reconstruction of head and neck. Harvesting and application of the flap is rapid and safe. Only a single incision is sufficient for dissection and flap elevation.

  13. Innervated boomerang flap for finger pulp reconstruction.

    Science.gov (United States)

    Chen, Shao-Liang; Chiou, Tai-Fung

    2007-11-01

    The boomerang flap originates from the dorsolateral aspect of the proximal phalanx of an adjacent digit and is supplied by the retrograde blood flow through the vascular arcades between the dorsal and palmar digital arteries. To provide sensation of the boomerang flap for finger pulp reconstruction, the dorsal sensory branch of the proper digital nerve and the superficial sensory branch of the corresponding radial or ulnar nerve are included within the skin flap. After transfer of the flap to the injured site, epineural neurorrhaphies are done between the digital nerves of the pulp and the sensory branches of the flap. We used this sensory flap in five patients, with more than 1 year follow-up, and all patients achieved measurable two-points discrimination. The boomerang flap not only preserves the proper palmar digital artery but also provides an extended and innervated skin paddle. It seems to be an alternative choice for one-stage reconstruction of major pulp defect.

  14. Cost-effectiveness of monitoring free flaps.

    Science.gov (United States)

    Subramaniam, Shiva; Sharp, David; Jardim, Christopher; Batstone, Martin D

    2016-06-01

    Methods of free flap monitoring have become more sophisticated and expensive. This study aims to determine the cost of free flap monitoring and examine its cost effectiveness. We examined a group of patients who had had free flaps to the head and neck over a two-year period, and combined these results with costs obtained from business managers and staff. There were 132 free flaps with a success rate of 99%. The cost of monitoring was Aus $193/flap. Clinical monitoring during this time period cost Aus$25 476 and did not lead to the salvage of any free flaps. Cost equivalence is reached between monitoring and not monitoring only at a failure rate of 15.8%. This is to our knowledge the first study to calculate the cost of clinical monitoring of free flaps, and to examine its cost-effectiveness. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. All rights reserved.

  15. Development of planar detectors with active edge

    International Nuclear Information System (INIS)

    Povoli, M.; Bagolini, A.; Boscardin, M.; Dalla Betta, G.-F.; Giacomini, G.; Vianello, E.; Zorzi, N.

    2011-01-01

    We report on the first batch of planar active edge sensors fabricated at Fondazione Bruno Kessler (Trento, Italy) on the way to the development of full 3D detectors with active edges. The main design and technological aspects are reported, along with selected results from the electrical characterization of detectors and test structures.

  16. Development of planar detectors with active edge

    Energy Technology Data Exchange (ETDEWEB)

    Povoli, M., E-mail: povoli@disi.unitn.it [Dipartimento di Ingegneria e Scienza dell' Informazione, Universita di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento) (Italy); Bagolini, A.; Boscardin, M. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Dalla Betta, G.-F. [Dipartimento di Ingegneria e Scienza dell' Informazione, Universita di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento) (Italy); Giacomini, G.; Vianello, E.; Zorzi, N. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy)

    2011-12-01

    We report on the first batch of planar active edge sensors fabricated at Fondazione Bruno Kessler (Trento, Italy) on the way to the development of full 3D detectors with active edges. The main design and technological aspects are reported, along with selected results from the electrical characterization of detectors and test structures.

  17. Lift production through asymmetric flapping

    Science.gov (United States)

    Jalikop, Shreyas; Sreenivas, K. R.

    2009-11-01

    At present, there is a strong interest in developing Micro Air Vehicles (MAV) for applications like disaster management and aerial surveys. At these small length scales, the flight of insects and small birds suggests that unsteady aerodynamics of flapping wings can offer many advantages over fixed wing flight, such as hovering-flight, high maneuverability and high lift at large angles of attack. Various lift generating mechanims such as delayed stall, wake capture and wing rotation contribute towards our understanding of insect flight. We address the effect of asymmetric flapping of wings on lift production. By visualising the flow around a pair of rectangular wings flapping in a water tank and numerically computing the flow using a discrete vortex method, we demonstrate that net lift can be produced by introducing an asymmetry in the upstroke-to-downstroke velocity profile of the flapping wings. The competition between generation of upstroke and downstroke tip vortices appears to hold the key to understanding this lift generation mechanism.

  18. Numerical and experimental investigations on unsteady aerodynamics of flapping wings

    Science.gov (United States)

    Yu, Meilin

    The development of a dynamic unstructured grid high-order accurate spectral difference (SD) method for the three dimensional compressible Navier-Stokes (N-S) equations and its applications in flapping-wing aerodynamics are carried out in this work. Grid deformation is achieved via an algebraic blending strategy to save computational cost. The Geometric Conservation Law (GCL) is imposed to ensure that grid deformation will not contaminate the flow physics. A low Mach number preconditioning procedure is conducted in the developed solver to handle the bio-inspired flow. The capability of the low Mach number preconditioned SD solver is demonstrated by a series of two dimensional (2D) and three dimensional (3D) simulations of the unsteady vortex dominated flow. Several topics in the flapping wing aerodynamics are numerically and experimentally investigated in this work. These topics cover some of the cutting-edge issues in flapping wing aerodynamics, including the wake structure analysis, airfoil thickness and kinematics effects on the aerodynamic performances, vortex structure analysis around 3D flapping wings and the kinematics optimization. Wake structures behind a sinusoidally pitching NACA0012 airfoil are studied with both experimental and numerical approaches. The experiments are carried out with Particle Image Velocimetry (PIV) and two types of wake transition processes, namely the transition from a drag-indicative wake to a thrust-indicative wake and that from the symmetric wake to the asymmetric wake are distinguished. The numerical results from the developed SD solver agree well with the experimental results. It is numerically found that the deflective direction of the asymmetric wake is determined by the initial conditions, e.g. initial phase angle. As most insects use thin wings (i. e., wing thickness is only a few percent of the chord length) in flapping flight, the effects of airfoil thickness on thrust generation are numerically investigated by simulating

  19. Perforator anatomy of the ulnar forearm fasciocutaneous flap.

    Science.gov (United States)

    Mathy, Jon A; Moaveni, Zachary; Tan, Swee T

    2012-08-01

    The ulnar forearm fasciocutaneous flap (UFFF) is a favourable alternative to the radial forearm flap when thin and pliable tissue is required. The precise anatomy of the cutaneous perforators of UFFF has not been previously reported. The position of cutaneous perforators>0.5 mm was recorded while raising 52 consecutive free UFFFs in 51 patients at our Centre. Three (6%) UFFFs in two patients demonstrated direct cutaneous supply through a superficial ulnar artery, a known anatomic variance. There was no cutaneous perforator>0.5 mm in one flap. Among the remaining 48 dissections, an average of 3 (range, 1-6) cutaneous perforators were identified. Ninety-four percent of these forearms demonstrated at least one perforator>0.5 mm within 3 cm, and all had at least one perforator within 6 cm of the midpoint of the forearm. Proximal perforators were more likely to be musculo-cutaneous through the edge of flexor carpi ulnaris or flexor digitorum superficialis, while mid- to distal perforators were septo-cutaneous. UFFF skin paddle designed to overlie an area within 3 cm of the midpoint between the medial epicondyle and the pisiform is most likely to include at least one cutaneous perforator from the ulnar artery, without a need for intra-operative skin island adjustment. This novel anatomic finding and other practical generalisations are discussed to facilitate successful elevation of UFFF. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  20. Edge Detection,

    Science.gov (United States)

    1985-09-01

    PROJECT. T ASK0 Artificial Inteligence Laboratory AREA It WORK UNIT NUMBERS V 545 Technology Square ( Cambridge, HA 02139 I I* CONTOOL1LIN@4OFFICE NAME...ARD-A1t62 62 EDGE DETECTION(U) NASSACNUSETTS INST OF TECH CAMBRIDGE 1/1 ARTIFICIAL INTELLIGENCE LAB E C HILDRETH SEP 85 AI-M-8 N99SI4-8S-C-6595...used to carry out this analysis. cce~iO a N) ’.~" D LI’BL. P p ------------ Sj. t i MASSACHUSETTS INSTITUTE OF TECHNOLOGY i ARTIFICIAL INTELLIGENCE

  1. The DelFly design, aerodynamics, and artificial intelligence of a flapping wing robot

    CERN Document Server

    de Croon, G C H E; Remes, B D W; Ruijsink, R; De Wagter, C

    2016-01-01

    This book introduces the topics most relevant to autonomously flying flapping wing robots: flapping-wing design, aerodynamics, and artificial intelligence. Readers can explore these topics in the context of the "Delfly", a flapping wing robot designed at Delft University in The Netherlands. How are tiny fruit flies able to lift their weight, avoid obstacles and predators, and find food or shelter? The first step in emulating this is the creation of a micro flapping wing robot that flies by itself. The challenges are considerable: the design and aerodynamics of flapping wings are still active areas of scientific research, whilst artificial intelligence is subject to extreme limitations deriving from the few sensors and minimal processing onboard. This book conveys the essential insights that lie behind success such as the DelFly Micro and the DelFly Explorer. The DelFly Micro, with its 3.07 grams and 10 cm wing span, is still the smallest flapping wing MAV in the world carrying a camera, whilst the DelFly Expl...

  2. Revisit of Nasolabial flap in the reconstruction of defects involving ...

    African Journals Online (AJOL)

    Conclusion: Data from this study suggest that NL flap is a reliable option for reconstruction of the oral floor, in form as well as function, without esthetic compromise and has a major role even in this era of free flaps. Keywords: Floor of mouth defects, local flaps, nasolabail flap, oral cavity defects, reconstruction, regional flaps ...

  3. Flow structures around a flapping wing considering ground effect

    Science.gov (United States)

    Van Truong, Tien; Kim, Jihoon; Kim, Min Jun; Park, Hoon Cheol; Yoon, Kwang Joon; Byun, Doyoung

    2013-07-01

    Over the past several decades, there has been great interest in understanding the aerodynamics of flapping flight, namely the two flight modes of hovering and forward flight. However, there has been little focus on the aerodynamic characteristics during takeoff of insects. In a previous study we found that the Rhinoceros Beetle ( Trypoxylusdichotomus) takes off without jumping, which is uncommon for other insects. In this study we built a scaled-up electromechanical model of a flapping wing and investigated fluid flow around the beetle's wing model. In particular, the present dynamically scaled mechanical model has the wing kinematics pattern achieved from the real beetle's wing kinematics during takeoff. In addition, we could systematically change the three-dimensional inclined motion of the flapping model through each stroke. We used digital particle image velocimetry with high spatial resolution, and were able to qualitatively and quantitatively study the flow field around the wing at a Reynolds number of approximately 10,000. The present results provide insight into the aerodynamics and the evolution of vortical structures, as well as the ground effect experienced by a beetle's wing during takeoff. The main unsteady mechanisms of beetles have been identified and intensively analyzed as the stability of the leading edge vortex (LEV) during strokes, the delayed stall during upstroke, the rotational circulation in pronation periods, and wake capture in supination periods. Due to the ground effect, the LEV was enhanced during half downstroke, and the lift force could thus be increased to lift the beetle during takeoff. This is useful for researchers in developing a micro air vehicle that has a beetle-like flapping wing motion.

  4. Head and neck reconstruction with pedicled flaps in the free flap era.

    Science.gov (United States)

    Mahieu, R; Colletti, G; Bonomo, P; Parrinello, G; Iavarone, A; Dolivet, G; Livi, L; Deganello, A

    2016-12-01

    Nowadays, the transposition of microvascular free flaps is the most popular method for management of head and neck defects. However, not all patients are suitable candidates for free flap reconstruction. In addition, not every defect requires a free flap transfer to achieve good functional results. The aim of this study was to assess whether pedicled flap reconstruction of head and neck defects is inferior to microvascular free flap reconstruction in terms of complications, functionality and prognosis. The records of consecutive patients who underwent free flap or pedicled flap reconstruction after head and neck cancer ablation from 2006 to 2015, from a single surgeon, in the AOUC Hospital, Florence Italy were analysed. A total of 93 patients, the majority with oral cancer (n = 59), were included, of which 64 were pedicled flap reconstructions (69%). The results showed no significant differences in terms of functional outcome, flap necrosis and complications in each type of reconstruction. Multivariate regression analysis of flap necrosis and functional impairments showed no associated factors. Multivariate regression analysis of complicated flap healing showed that only comorbidities remained an explaining factor (p = 0.019). Survival analysis and proportional hazard regression analysis regarding cancer relapse or distant metastasis, showed no significant differences in prognosis of patients concerning both types of reconstruction. In this retrospective, non-randomised study cohort, pedicled flaps were not significantly inferior to free flaps for reconstruction of head and neck defects, considering functionality, complications and prognosis. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

  5. Performance of flapping airfoil propulsion with LBM method and DMD analysis

    Science.gov (United States)

    Li, Bing-Hua; Huang, Xian-Wen; Zheng, Yao; Xie, Fang-Fang; Wang, Jing; Zou, Jian-Feng

    2018-05-01

    In this work, the performance of flapping airfoil propulsion at low Reynolds number of Re = 100-400 is studied numerically with the lattice Boltzmann method (LBM). Combined with immersed boundary method (IBM), the LBM has been widely used to simulate moving boundary problems. The influences of the reduced frequency on the plunging and pitching airfoil are explored. It is found that the leading-edge vertex separation and inverted wake structures are two main coherent structures, which dominate the flapping airfoil propulsion. However, the two structures play different roles in the flow and the combination effects on the propulsion need to be clarified. To do so, we adopt the dynamic mode decomposition (DMD) algorithm to reveal the underlying physics. The DMD has been proven to be very suitable for analyzing the complex transient systems like the vortex structure of flapping flight.

  6. Living edge

    DEFF Research Database (Denmark)

    Earon, Ofri

    2014-01-01

    was originally introduced to enhance indoor qualities including light and view. Throughout the paper, it is argued that these ecological motives have grown to architectural and urban dimensions. The paper analyzes the characteristics and potentials of these dimensions and their interconnections. The paper...... on the ground level, but there is a lack of recognition in the significance of communicative characters as well at the higher part of the edge. The city’s planning approach is “Consider urban life before urban space. Consider urban space before buildings” This urban strategy neglects the possible architectural...... contribution to the street atmosphere and its effect on urban life. Bay balcony has been a common architectural element in Copenhagen’s residential buildings, since the end of the twenties. It is a domestic border with an architectural thickness combining window, door, windowsill and balcony. The bay balcony...

  7. Topology optimization of pressure adaptive honeycomb for a morphing flap

    Science.gov (United States)

    Vos, Roelof; Scheepstra, Jan; Barrett, Ron

    2011-03-01

    The paper begins with a brief historical overview of pressure adaptive materials and structures. By examining avian anatomy, it is seen that pressure-adaptive structures have been used successfully in the Natural world to hold structural positions for extended periods of time and yet allow for dynamic shape changes from one flight state to the next. More modern pneumatic actuators, including FAA certified autopilot servoactuators are frequently used by aircraft around the world. Pneumatic artificial muscles (PAM) show good promise as aircraft actuators, but follow the traditional model of load concentration and distribution commonly found in aircraft. A new system is proposed which leaves distributed loads distributed and manipulates structures through a distributed actuator. By using Pressure Adaptive Honeycomb (PAH), it is shown that large structural deformations in excess of 50% strains can be achieved while maintaining full structural integrity and enabling secondary flight control mechanisms like flaps. The successful implementation of pressure-adaptive honeycomb in the trailing edge of a wing section sparked the motivation for subsequent research into the optimal topology of the pressure adaptive honeycomb within the trailing edge of a morphing flap. As an input for the optimization two known shapes are required: a desired shape in cruise configuration and a desired shape in landing configuration. In addition, the boundary conditions and load cases (including aerodynamic loads and internal pressure loads) should be specified for each condition. Finally, a set of six design variables is specified relating to the honeycomb and upper skin topology of the morphing flap. A finite-element model of the pressure-adaptive honeycomb structure is developed specifically tailored to generate fast but reliable results for a given combination of external loading, input variables, and boundary conditions. Based on two bench tests it is shown that this model correlates well

  8. An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions

    NARCIS (Netherlands)

    Hummelink, S.L.; Verhulst, A.C.; Maal, T.J.J.; Hoogeveen, Y.L.; Schultze Kool, L.J.; Ulrich, D.J.O.

    2017-01-01

    BACKGROUND: Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available

  9. Influence of inflow angle on flexible flap aerodynamic performance

    International Nuclear Information System (INIS)

    Zhao, H Y; Ye, Z; Li, Z M; Li, C

    2013-01-01

    Large scale wind turbines have larger blade lengths and weights, which creates new challenges for blade design. This paper selects NREL S809 airfoil, and uses the parameterized technology to realize the flexible trailing edge deformation, researches the dynamic aerodynamic characteristics in the process of continuous flexible deformation, analyses the influence of inflow angle on flexible flap aerodynamic performance, in order to further realize the flexible wind turbine blade design and provides some references for the active control scheme. The results show that compared with the original airfoil, proper trailing edge deformation can improve the lift coefficient, reduce the drag coefficient, and thereby more efficiently realize flow field active control. With inflow angle increases, dynamic lift-drag coefficient hysteresis loop shape deviation occurs, even turns into different shapes. Appropriate swing angle can improve the flap lift coefficient, but may cause early separation of flow. To improve the overall performance of wind turbine blades, different angular control should be used at different cross sections, in order to achieve the best performance

  10. Dermatosurgery Rounds - The Island SKIN Infraorbital Flap

    Directory of Open Access Journals (Sweden)

    Georgi Tchernev

    2017-07-01

    Full Text Available The main objective in dermatologic surgery is complete excision of the tumour while achieving the best possible functional and cosmetic outcome. Also we must take into account age, sex, and tumour size and site. We should also consider the patient's expectations, the preservation of the different cosmetic units, and the final cosmetic outcome. Various reconstructive methods ranging from secondary healing to free flap applications are usedfor the reconstruction of perinasal or facial defects caused by trauma or tumour surgery. Herein, we describe the nasal infraorbital island skin flap for the reconstruction in a patient with basal cell carcinoma. No complications were observed in operation field. The infraorbital island skin flap which we describe for the perinasal area reconstruction is a safe, easily performed and versatile flap. The multidimensional use of this flap together with a relatively easy reconstruction plan and surgical procedure would be effective in flap choice.

  11. An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions.

    Science.gov (United States)

    Hummelink, S; Verhulst, Arico C; Maal, Thomas J J; Hoogeveen, Yvonne L; Schultze Kool, Leo J; Ulrich, Dietmar J O

    2017-07-01

    Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available nowadays, we can combine information to preoperatively plan the optimal flap volume to be harvested. In this proof-of-concept, we investigated whether projection of a virtual flap planning onto the patient's abdomen using a projection method could result in harvesting the correct flap volume. In six patients (n = 9 breasts), 3D stereophotogrammetry and CTA data were combined from which a virtual flap planning was created comprising perforator locations, blood vessel trajectory and flap size. All projected perforators were verified with Doppler ultrasound. Intraoperative flap measurements were collected to validate the determined flap delineation volume. The measured breast volume using 3D stereophotogrammetry was 578 ± 127 cc; on CTA images, 527 ± 106 cc flap volumes were planned. The nine harvested flaps weighed 533 ± 109 g resulting in a planned versus harvested flap mean difference of 5 ± 27 g (flap density 1.0 g/ml). In 41 out of 42 projected perforator locations, a Doppler signal was audible. This proof-of-concept shows in small numbers that flap volumes can be included into a virtual DIEP flap planning, and transferring the virtual planning to the patient through a projection method results in harvesting approximately the same volume during surgery. In our opinion, this innovative approach is the first step in consequently achieving symmetric breast volumes in DIEP flap breast reconstructions. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Root coverage with bridge flap

    Directory of Open Access Journals (Sweden)

    Pushpendra Kumar Verma

    2013-01-01

    Full Text Available Gingival recession in anterior teeth is a common concern due to esthetic reasons or root sensitivity. Gingival recession, especially in multiple anterior teeth, is of huge concern due to esthetic reasons. Various mucogingival surgeries are available for root coverage. This case report presents a new bridge flap technique, which allows the dentist not only to cover the previously denuded root surfaces but also to increase the zone of attached gingiva at a single step. In this case, a coronally advanced flap along with vestibular deepening technique was used as root coverage procedure for the treatment of multiple recession-type defect. Here, vestibular deepening technique is used to increase the width of the attached gingiva. The predictability of this procedure results in an esthetically healthy periodontium, along with gain in keratinized tissue and good patient′s acceptance.

  13. Medial canthal reconstruction with multiple local flaps

    Directory of Open Access Journals (Sweden)

    Akihiro Ogino

    2018-03-01

    Conclusion: This method is somewhat complicated compared to reconstruction with a single flap, but it is a combination of standard local flaps and is a simple reconstructive procedure. By adding additional resection, the suture line is consistent with the border of the facial unit, so postoperative scarring is inconspicuous. This technique is aesthetically useful because of the continuity of colour and texture resulting from the use of adjacent flaps.

  14. Pedicled Temporalis Muscle Flap for Craniofacial Reconstruction: A 35-Year Clinical Experience with 366 Flaps.

    Science.gov (United States)

    Spanio di Spilimbergo, Stefano; Nordera, Paolo; Mardini, Samir; Castiglione, Giusy; Chim, Harvey; Pinna, Vittore; Brunello, Massimo; Cusino, Claudio; Roberto, Squaquara; Baciliero, Ugo

    2017-02-01

    In the past 130 years, the temporalis muscle flap has been used for a variety of different indications. In this age of microsurgery and perforator flaps, the temporalis muscle flap still has many useful applications for craniofacial reconstruction. Three hundred sixty-six temporalis muscle flaps were performed in a single center between 1978 and 2012. The authors divided the cases into two series-before and after 1994-because, after 1994, they started to perform free flap reconstructions, and indications for reconstruction with a temporalis muscle flap were changed RESULTS:: In the series after 1994, flaps were most commonly used for reconstruction of defects in the maxilla, mandible, and oropharynx, in addition to facial reanimation and filling of orbital defects. Complications included total flap necrosis (1.6 percent) and partial flap necrosis (10.7 percent). The rate of material extrusion at the donor site decreased after porous polyethylene was uniformly used for reconstruction from 17.1 to 7.9 percent. The pedicled temporalis muscle flap continues to have many applications in craniofacial reconstruction. With increasing use of free flaps, the authors' indications for the pedicled temporalis muscle flap are now restricted to (1) orbital filling for congenital or acquired anophthalmia; (2) filling of unilateral maxillectomy defects; and (3) facial reanimation in selected cases of facial nerve palsy. Therapeutic, IV.

  15. Head and neck reconstruction with pedicled flaps in the free flap era

    NARCIS (Netherlands)

    Mahieu, R.; Colletti, G.; Bonomo, P.; Parrinello, G.; Iavarone, A.; Dolivet, G.; Livi, L.; Deganello, A.

    2016-01-01

    Nowadays, the transposition of microvascular free flaps is the most popular method for management of head and neck defects. However, not all patients are suitable candidates for free flap reconstruction. In addition, not every defect requires a free flap transfer to achieve good functional results.

  16. Refining the intrinsic chimera flap: a review.

    Science.gov (United States)

    Agarwal, Jayant P; Agarwal, Shailesh; Adler, Neta; Gottlieb, Lawrence J

    2009-10-01

    Reconstruction of complex tissue deficiencies in which each missing component is in a different spatial relationship to each other can be particularly challenging, especially in patients with limited recipient vessels. The chimera flap design is uniquely suited to reconstruct these deformities. Chimera flaps have been previously defined in many ways with 2 main categories: prefabricated or intrinsic. Herein we attempt to clarify the definition of a true intrinsic chimeric flap and provide examples of how these constructs provide a method for reconstruction of complex defects. The versatility of the intrinsic chimera flap and its procurement from 7 different vascular systems is described. A clarification of the definition of a true intrinsic chimera flap is described. In addition, construction of flaps from the lateral femoral circumflex, deep circumflex iliac, inferior gluteal, peroneal, subscapular, thoracodorsal, and radial arterial systems is described to showcase the versatility of these chimera flaps. A true intrinsic chimera flap must consist of more than a single tissue type. Each of the tissue components receives its blood flow from separate vascular branches or perforators that are connected to a single vascular source. These vascular branches must be of appropriate length to allow for insetting with 3-dimensional spatial freedom. There are a multitude of sites from which true intrinsic chimera flaps may be harvested.

  17. Optimal propulsive flapping in Stokes flows.

    Science.gov (United States)

    Was, Loïc; Lauga, Eric

    2014-03-01

    Swimming fish and flying insects use the flapping of fins and wings to generate thrust. In contrast, microscopic organisms typically deform their appendages in a wavelike fashion. Since a flapping motion with two degrees of freedom is able, in theory, to produce net forces from a time-periodic actuation at all Reynolds numbers, we compute in this paper the optimal flapping kinematics of a rigid spheroid in a Stokes flow. The hydrodynamics for the force generation and energetics of the flapping motion is solved exactly. We then compute analytically the gradient of a flapping efficiency in the space of all flapping gaits and employ it to derive numerically the optimal flapping kinematics as a function of the shape of the flapper and the amplitude of the motion. The kinematics of optimal flapping are observed to depend weakly on the flapper shape and are very similar to the figure-eight motion observed in the motion of insect wings. Our results suggest that flapping could be a exploited experimentally as a propulsion mechanism valid across the whole range of Reynolds numbers.

  18. Optimal propulsive flapping in Stokes flows

    International Nuclear Information System (INIS)

    Was, Loïc; Lauga, Eric

    2014-01-01

    Swimming fish and flying insects use the flapping of fins and wings to generate thrust. In contrast, microscopic organisms typically deform their appendages in a wavelike fashion. Since a flapping motion with two degrees of freedom is able, in theory, to produce net forces from a time-periodic actuation at all Reynolds numbers, we compute in this paper the optimal flapping kinematics of a rigid spheroid in a Stokes flow. The hydrodynamics for the force generation and energetics of the flapping motion is solved exactly. We then compute analytically the gradient of a flapping efficiency in the space of all flapping gaits and employ it to derive numerically the optimal flapping kinematics as a function of the shape of the flapper and the amplitude of the motion. The kinematics of optimal flapping are observed to depend weakly on the flapper shape and are very similar to the figure-eight motion observed in the motion of insect wings. Our results suggest that flapping could be a exploited experimentally as a propulsion mechanism valid across the whole range of Reynolds numbers. (paper)

  19. Haptic Edge Detection Through Shear

    Science.gov (United States)

    Platkiewicz, Jonathan; Lipson, Hod; Hayward, Vincent

    2016-03-01

    Most tactile sensors are based on the assumption that touch depends on measuring pressure. However, the pressure distribution at the surface of a tactile sensor cannot be acquired directly and must be inferred from the deformation field induced by the touched object in the sensor medium. Currently, there is no consensus as to which components of strain are most informative for tactile sensing. Here, we propose that shape-related tactile information is more suitably recovered from shear strain than normal strain. Based on a contact mechanics analysis, we demonstrate that the elastic behavior of a haptic probe provides a robust edge detection mechanism when shear strain is sensed. We used a jamming-based robot gripper as a tactile sensor to empirically validate that shear strain processing gives accurate edge information that is invariant to changes in pressure, as predicted by the contact mechanics study. This result has implications for the design of effective tactile sensors as well as for the understanding of the early somatosensory processing in mammals.

  20. Venous coupler use for free-flap breast reconstructions: specific analyses of TMG and DIEP flaps.

    Science.gov (United States)

    Bodin, Frédéric; Brunetti, Stefania; Dissaux, Caroline; Erik, A Sauleau; Facca, Sybille; Bruant-Rodier, Catherine; Liverneaux, Philippe

    2015-05-01

    The purpose of this report was to present the results of comparisons of anastomotic data and flap complications in the use of venous coupler in breast reconstruction with the transverse musculocutaneous gracilis (TMG) flap and the deep inferior epigastric perforator (DIEP) flap. Over a three-year period, 95 patients suffering from breast cancer were treated with mastectomy and breast reconstruction using free flaps. We performed 121 mechanical venous anastomoses for 105 flap procedures (80 DIEP and 25 TMG). The coupler size, anastomotic duration, number of anastomoses and postoperative complications were assessed for the entire series. The coupling device was perfectly suitable for all end-to-end anastomoses between the vein(s) of the flap and the internal mammary vein(s). No venous thrombosis occurred. The mean anastomotic time did not significantly differ between the DIEP (330 seconds) and TMG flap procedures (352 seconds) (P = 0.069). Additionally, there were no differences in coupling time observed following a comparison of seven coupler sizes (P = 0.066). The mean coupler size used during the TMG flap procedure was smaller than that used with the DIEP (2.4 mm versus 2.8 mm) (P TMG flap (28%) than with the DIEP flap (11%). The coupler size used was smaller for the TMG procedure and when double venous anastomosis was performed. Additionally, anastomotic time was not affected by the flap type or coupler size used or by anastomosis number. © 2014 Wiley Periodicals, Inc.

  1. Innovation in the planning of V-Y rotation advancement flaps: A template for flap design

    Directory of Open Access Journals (Sweden)

    Utku Can Dölen

    2018-01-01

    Full Text Available Local flaps exhibit excellent color matching that no other type of flap can compete with. Moreover, surgery using a local flap is easier and faster than surgery using a distant or free flap. However, local flaps can be much more difficult to design. We designed 2 templates to plan a V-Y rotation advancement flap. The template for a unilateral V-Y rotation advancement flap was used on the face (n=5, anterior tibia (n=1, posterior axilla (n=1, ischium (n=1, and trochanter (n=2. The template for a bilateral flap was used on the sacrum (n=8, arm (n=1, and anterior tibia (n=1. The causes of the defects were meningocele (n=3, a decubitus ulcer (n=5, pilonidal sinus (n=3, and skin tumor excision (n=10. The meningocele patients were younger than 8 days. The mean age of the adult patients was 50.4 years (range, 19–80 years. All the donor areas of the flaps were closed primarily. None of the patients experienced wound dehiscence or partial/total flap necrosis. The templates guided surgeons regarding the length and the placement of the incision for a V-Y rotation advancement flap according to the size of the wound. In addition, they could be used for the training of residents.

  2. Median forehead flap - beyond classic indication

    Directory of Open Access Journals (Sweden)

    Cristian R. Jecan

    2016-11-01

    Full Text Available Introduction. The paramedian forehead flap is one of the best options for reconstruction of the median upper two-thirds of the face due to its vascularity, color, texture match and ability to resurface all or part of the reconstructed area. The forehead flap is the gold standard for nasal soft tissue reconstruction and the flap of choice for larger cutaneous nasal defects having a robust pedicle and large amount of tissue. Materials and Methods. We are reporting a clinical series of cutaneous tumors involving the nose, medial canthus, upper and lower eyelid through a retrospective review of 6 patients who underwent surgical excision of the lesion and primary reconstruction using a paramedian forehead flap. Results. The forehead flap was used for total nose reconstruction, eyelids and medial canthal reconstruction. All flaps survived completely and no tumor recurrence was seen in any of the patients. Cosmetic and functional results were favorable. Conclusions. The forehead flap continues to be one of the best options for nose reconstruction and for closure of surgical defects of the nose larger than 2 cm. Even though is not a gold standard, median forehead flap can be an advantageous technique in periorbital defects reconstruction.

  3. A PIV Study of Baseline and Controlled Flow over the Highly Deflected Flap of a Generic Low Aspect Ratio Trapezoidal Wing

    Science.gov (United States)

    Tewes, Philipp; Genschow, Konstantin; Little, Jesse; Wygnanski, Israel

    2017-11-01

    A detailed flow survey using PIV was conducted over a highly-deflected flap (55°) of a low-aspect ratio trapezoidal wing. The wing section is a NACA 0012 with 45° sweep at both the leading and trailing edges, an aspect ratio of 1.5 and a taper ratio of 0.27. The main element is equipped with 7 equally spaced fluidic oscillators, covering the inner 60 % of the span, located near the flap hinge. Experiments were carried out at 0° and 8° incidence at a Reynolds number of 1.7 .106 for both baseline and active flow control (AFC) cases. Velocity ISO-surfaces, x-vorticity and streamlines are analyzed / discussed. A flap leading edge vortex governs the baseline flow field for 0°. This vortical structure interacts with the jets emitted by the actuators (Cμ = 1 %). Its development is hampered and the vortex is redirected toward the trailing edge resulting in a CL increase. At 8°, the dominant flap leading edge vortex could not be detected and is believed to have already merged with the tip vortex. AFC attached the flow over the flap and enhanced the lift by up to 20 % while maintaining longitudinal stability. The dominant flow features in the AFC cases are actuator-generated streamwise vortices which appear stronger at 8°. This work was supported by the Office of Naval Research under ONR Grant No. N00014-14-1-0387.

  4. Active Control of Separation From the Flap of a Supercritical Airfoil

    Science.gov (United States)

    Melton, LaTunia Pack; Yao, Chung-Sheng; Seifert, Avi

    2006-01-01

    Zero-mass-flux periodic excitation was applied at several regions on a simplified high-lift system to delay the occurrence of flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge flap and a 25% chord simply hinged trailing edge flap. Detailed flow features were measured in an attempt to identify optimal actuator placement. The measurements included steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization, and particle image velocimetry (PIV). The current paper describes the application of active separation control at several locations on the deflected trailing edge flap. High frequency (F(+) approximately equal to 10) and low frequency amplitude modulation (F(+) sub AM approximately equal to 1) of the high frequency excitation were used for control. It was noted that the same performance gains were obtained with amplitude modulation and required only 30% of the momentum input required by pure sine excitation.

  5. Versatality of Nasolabial Flap in Orofacial Reconstruction

    Directory of Open Access Journals (Sweden)

    Nandesh Shetty

    2015-01-01

    Materials and Methods: A total of 10 patients were selected based on the size of surgical defect. Nasolabial flap was used to reconstruct defects of small to moderate size in the oro-facial region and post-operative follow up was done. Results: All of the patients underwent inferiorly based Transposition Island flap for reconstruction of different oro-facial defects. Few complications like bulky size of the flap, slight donor site distortion (scar formation and intra-oral hair growth were seen in six patients. Two incidences of infection in the transferred flap were seen. Conclusion: It is a safe minor procedure done under general anesthesia with good reconstructive results over small or moderately sized maxillofacial defects. Proper attention to flap design, operative technique and post - operative management are useful in reducing the incidence of complications.

  6. Energy management - The delayed flap approach

    Science.gov (United States)

    Bull, J. S.

    1976-01-01

    Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

  7. Laser resurfacing of skin flaps: an experimental comparison

    Directory of Open Access Journals (Sweden)

    Srdan Babovic

    2011-05-01

    Full Text Available Objective. The influence of Coherent Ultrapulse, TruPulse and Erbium: YAG laser skin resurfacing on survival of the skin flaps when performed simultaneously was evaluated. Material and methods. We used twelve female Yucatan minipigs in the study. Skin flaps including paniculus carnosus were raised on the animals’ back. The flaps were sutured into the defect under tension. We designed 4 experimental groups: Control-Flaps only, Group 2-Flaps + 4 immediate TruPulse laser passes, Group 3-Flaps + 2 immediate Coherent UltraPulse laser passes, Group 4-Flaps – immediate 50J/cm2 total fluence with Erbium: YAG laser. Results. Flap survival in Control group was 98.8%. There was no flap in Group 2 with complete survival. Survival of the flaps in Group 2 (Tru-Pulse ranged from 75-90%, with average flap survival area of 85.2%. In Group 3 (UltraPulse all 24 flaps had some area of necrosis. Flap survival in Group 3 ranged from 75-95%, with an average of 85.6%. In Group 4 (Erbium: YAG flap survival area ranged from 70-95%, with all 24 flaps with some area of necrosis, with average flap survival area of 87.3%. There is a significant statistical difference in flap survival area between groups 2, 3 and 4 versus Control (p<0.001. Conclusion. The results of our study suggest that laser resurfacing of skin flaps sutured under tension in the same operative session is detrimental for skin flap survival. We also found no significant difference in flap survival area between TruPulse, Coherent UltraPulse and Erbium: YAG laser treated flaps.

  8. Wavefront aberrometry and refractive outcomes of flap amputation after LASIK

    NARCIS (Netherlands)

    Al Saady, Rana L.; van der Meulen, Ivanka J.; Nieuwendaal, Carla P.; Engelbrecht, Leonore A.; Mourits, Maarten P.; Lapid-Gortzak, Ruth

    2014-01-01

    Laser in situ keratomileusis flap amputation was performed in 3 eyes of 2 patients because of flap melt and surface irregularity. In the first patient, a 34-year-old man, flaps were excised after a photorefractive keratectomy retreatment procedure on a previous LASIK flap had been done, secondary to

  9. The Versatile Extended Thoracodorsal Artery Perforator Flap for Breast Reconstruction

    DEFF Research Database (Denmark)

    Jacobs, Jordan; Børsen-Koch, Mikkel; Gunnarsson, Gudjon L.

    2016-01-01

    complications occurred in 10 of 106 (10%) cases and included hematoma (1/108), venous congestion (2/108), and partial flap necrosis (7/108). The reconstructive goal was achieved in 103 of 106 (97%) flaps. CONCLUSIONS: The TAP flap is a pedicled, fasciocutaneous flap that can be used for total breast...

  10. Dorsal hand coverage with free serratus fascia flap

    DEFF Research Database (Denmark)

    Fotopoulos, Peter; Holmer, Per; Leicht, Pernille

    2003-01-01

    in the flap, leaving the long thoracic nerve intact on the serratus muscle. Coverage of the flap with split-thickness skin graft is done immediately. The free serratus fascia flap is an ideal flap for dorsal hand coverage when the extensor tendons are exposed, especially because of low donor-site morbidity....

  11. A Review Of Pectoralis Major Musculocutaneous Island Flap In ...

    African Journals Online (AJOL)

    Like microvascular free flaps, pectoralis major flaps can be transferred in a single stage and have largely replaced deltepectoral (Bakanjiam) flap in head and neck reconstruction. This retrospective study was carried out to highlight the usefulness of this flap in different situations. Ten patients, aged six to 55 years operated ...

  12. Total endoscopic free flap harvest of a serratus anterior fascia flap for microsurgical lower leg reconstruction

    Directory of Open Access Journals (Sweden)

    Erdmann, Alfons

    2014-04-01

    Full Text Available [english] Background: A tremendous number of free flaps have been developed in the past. As the surgical result depends not only on a successful flap transfer but also on the harvest, this paper details the procedures for undertaking the first total endoscopic harvest of a serratus fascia flap for free flap transplantation to the lower leg. Patient and methods: In September 2012 we performed the first total endoscopic serratus anterior fascia free flap harvest. The incision of 2.5 cm length was made 10 cm in front of anterior muscle border of the latissimus dorsi at level with the midthorax. After insertion of a flexible laparoscopic single port system we started CO gas insufflation. We used this setting to meticulously prepare a neo cavity between atissimus dorsi and M. serratus anterior. The vessels were dissected and the thoraco-dorsal nerve was separated. With a second auxiliary incision we used a clamp to support the raising of the fascia flap from the underlying muscle. Finally we clipped the vessels to the latissimus dorsi muscle and the flap vessels at the Arteria and Vena axillaris. The flap was extracted via the 2.5 cm incision.Results: We were able to perform a total endoscopic harvest of a serratus fascia flap for free flap reconstruction of soft tissues. With this new operative technique we were able to avoid a long skin incision, which in our view lowers the morbidity at the harvest area.Conclusion: We describe a new method for the total endoscopic harvest of the serratus fascia flap for free flap transfer. The flap was harvested within reasonable time and following surgery leaves the patient with minimal donor site morbidity compared to the open technique.

  13. Comparison of gluteal perforator flaps and gluteal fasciocutaneous rotation flaps for reconstruction of sacral pressure sores.

    Science.gov (United States)

    Chen, Yen-Chou; Huang, Eng-Yen; Lin, Pao-Yuan

    2014-03-01

    The gluteus maximus myocutaneous flap was considered the workhorse that reconstructed sacral pressure sores, but was gradually replaced by fasciocutaneous flap because of several disadvantages. With the advent of the perforator flap technique, gluteal perforator (GP) flap has gained popularity nowadays. The aim of this study was to compare the complications and outcomes between GP flaps and gluteal fasciocutaneous rotation (FR) flaps in the treatment of sacral pressure sores. Between April 2007 and June 2012, 63 patients underwent sacral pressure sore reconstructions, with a GP flap used in 31 cases and an FR flap used in 32 cases. Data collected on the patients included patient age, gender, co-morbidity for being bedridden and follow-up time. Surgical details collected included the defect size, operative time and estimated blood loss. Complications recorded included re-operation, dehiscence, flap necrosis, wound infection, sinus formation, donor-site morbidity and recurrence. The complications and clinical outcomes were compared between these two groups. We found that there was no significant difference in patient demographics, surgical complications and recurrence between these two groups. In gluteal FR flap group, all recurrent cases (five) were treated by reuse of previous flaps. Both methods are comparable, good and safe in treating sacral pressure sores. Gluteal FR flap can be performed without microsurgical dissection, and re-rotation is feasible in recurrent cases. The authors suggest using gluteal FR flaps in patients with a high risk of sore recurrence. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  14. A dynamic stall model for airfoils with deformable trailing edges

    DEFF Research Database (Denmark)

    Andersen, Peter Bjørn; Gaunaa, Mac; Bak, Dan Christian

    2007-01-01

    on an airfoil section undergoing arbitrary motion in heave, lead-lag, pitch, Trailing Edge (TE) flapping. In the linear region, the model reduces to the inviscid model of Gaunaa [4], which includes the aerodynamic effect of a thin airfoil with a deformable camberline in inviscid flow. Therefore, the proposed......The present work contains an extension of the Beddoes-Leishman (B-L) type dynamic stall model, as described by Hansen et al. [7]. In this work a Deformable Trailing Edge Geometry (DTEG) has been added to the dynamic stall model. The model predicts the unsteady aerodynamic forces and moments...

  15. Optimal pitching axis location of flapping wings for efficient hovering flight.

    Science.gov (United States)

    Wang, Q; Goosen, J F L; van Keulen, F

    2017-09-01

    Flapping wings can pitch passively about their pitching axes due to their flexibility, inertia, and aerodynamic loads. A shift in the pitching axis location can dynamically alter the aerodynamic loads, which in turn changes the passive pitching motion and the flight efficiency. Therefore, it is of great interest to investigate the optimal pitching axis for flapping wings to maximize the power efficiency during hovering flight. In this study, flapping wings are modeled as rigid plates with non-uniform mass distribution. The wing flexibility is represented by a linearly torsional spring at the wing root. A predictive quasi-steady aerodynamic model is used to evaluate the lift generated by such wings. Two extreme power consumption scenarios are modeled for hovering flight, i.e. the power consumed by a drive system with and without the capacity of kinetic energy recovery. For wings with different shapes, the optimal pitching axis location is found such that the cycle-averaged power consumption during hovering flight is minimized. Optimization results show that the optimal pitching axis is located between the leading edge and the mid-chord line, which shows close resemblance to insect wings. An optimal pitching axis can save up to 33% of power during hovering flight when compared to traditional wings used by most of flapping wing micro air vehicles (FWMAVs). Traditional wings typically use the straight leading edge as the pitching axis. With the optimized pitching axis, flapping wings show higher pitching amplitudes and start the pitching reversals in advance of the sweeping reversals. These phenomena lead to higher lift-to-drag ratios and, thus, explain the lower power consumption. In addition, the optimized pitching axis provides the drive system higher potential to recycle energy during the deceleration phases as compared to their counterparts. This observation underlines the particular importance of the wing pitching axis location for energy-efficient FWMAVs when

  16. Hydrodynamic schooling of flapping swimmers

    International Nuclear Information System (INIS)

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-01-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups

  17. Hydrodynamic schooling of flapping swimmers

    Science.gov (United States)

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

  18. Unsteady aerodynamics of a pitching-flapping-perturbed revolving wing at low Reynolds number

    Science.gov (United States)

    Chen, Long; Wu, Jianghao; Zhou, Chao; Hsu, Shih-Jung; Cheng, Bo

    2018-05-01

    Due to adverse viscous effects, revolving wings suffer universally from low efficiency at low Reynolds number (Re). By reciprocating wing revolving motion, natural flyers flying at low Re successfully exploit unsteady effects to augment force production and efficiency. Here we investigate the aerodynamics of an alternative, i.e., a revolving wing with concomitant unsteady pitching and vertical flapping perturbations (a pitching-flapping-perturbed revolving wing). The current work builds upon a previous study on flapping-perturbed revolving wings (FP-RWs) and focuses on combined effects of pitching-flapping perturbation on force generation and vortex behaviors. The results show that, compared with a FR-RW, pitching motion further (1) reduces the external driving torque for rotating at 0° angle of attack (α0) and (2) enhances lift and leads to a self-rotating equilibrium at α0 = 20°. The power loading of a revolving wing at α0 = 20° can be improved using pitching-flapping perturbations with large pitching amplitude but small Strouhal number. Additionally, an advanced pitching improves the reduction of external driving torque, whereas a delayed pitching weakens both the lift enhancement and the reduction of external driving torque. Further analysis shows that pitching effects can be mainly decomposed into the Leading-Edge-Vortex (LEV)-mediated pressure component and geometric projection component, together they determine the force performance. LEV circulation is found to be determined by the instantaneous effective angle of attack but could be affected asymmetrically between upstroke and downstroke depending on the nominal angle of attack. Pitching-flapping perturbation thus can potentially inspire novel mechanisms to improve the aerodynamic performance of rotary wing micro air vehicles.

  19. Particle image velocimetry investigation of flow over unsteady airfoil with trailing-edge strip

    Energy Technology Data Exchange (ETDEWEB)

    Gerontakos, P.; Lee, T. [McGill University, Montreal, QC (Canada)

    2008-04-15

    The flow over a flapped NACA 0012 airfoil, oscillated slightly through the static-stall angle, was investigated by using particle image velocimetry, and was supplemented by surface pressure and dynamic-load measurements. A significant increase in the dynamic lift force and nose-down pitching moment was observed. The most pronounced flow phenomenon was the formation and detachment of an energetic leading-edge vortex compared to the no-flapped airfoil. The details of the underlying physical mechanisms responsible for the various light-stall flow processes were provided via the instantaneous velocity and vorticity fields measurements. In contrast to the Gurney flap, the inverted trailing-edge strip led to an improved negative damping while a reduced lift force. The addition of an inverted strip always led to the appearance of a Karman-type vortex shedding street immediately downstream of the strip over the entire oscillation cycle. (orig.)

  20. Slim edges in double-sided silicon 3D detectors

    International Nuclear Information System (INIS)

    Povoli, M; Dalla Betta, G-F; Bagolini, A; Boscardin, M; Giacomini, G; Vianello, E; Zorzi, N

    2012-01-01

    Minimization of the insensitive edge area is one of the key requirements for silicon radiation detectors to be used in future silicon trackers. In 3D detectors this goal can be achieved with the active edge, at the expense of a high fabrication process complexity. In the framework of the ATLAS 3D sensor collaboration, we produced modified 3D silicon sensors with a double-sided technology. While this approach is not suitable to obtain active edges, because it does not use a support wafer, it allows for a new type of edge termination, the slim edge. In this paper we report on the development of the slim edge, from numerical simulations to design and testing, proving that it works effectively without increasing the fabrication complexity of silicon 3D detectors, and that it could be further optimized to reduce the insensitive edge region to less than 100 μm.

  1. Boomerang flap reconstruction for the breast.

    Science.gov (United States)

    Baumholtz, Michael A; Al-Shunnar, Buthainah M; Dabb, Richard W

    2002-07-01

    The boomerang-shaped latissimus dorsi musculocutaneous flap for breast reconstruction offers a stable platform for breast reconstruction. It allows for maximal aesthetic results with minimal complications. The authors describe a skin paddle to obtain a larger volume than either the traditional elliptical skin paddle or the extended latissimus flap. There are three specific advantages to the boomerang design: large volume, conical shape (often lacking in the traditional skin paddle), and an acceptable donor scar. Thirty-eight flaps were performed. No reconstruction interfered with patient's ongoing oncological regimen. The most common complication was seroma, which is consistent with other latissimus reconstructions.

  2. The transverse musculocutaneous gracilis flap for breast reconstruction: guidelines for flap and patient selection.

    Science.gov (United States)

    Schoeller, Thomas; Huemer, Georg M; Wechselberger, Gottfried

    2008-07-01

    The transverse musculocutaneous gracilis (TMG) flap has received little attention in the literature as a valuable alternative source of donor tissue in the setting of breast reconstruction. The authors give an in-depth review of their experience with breast reconstruction using the TMG flap. A retrospective review of 111 patients treated with a TMG flap for breast reconstruction in an immediate or a delayed setting between August of 2002 and July of 2007 was undertaken. Of these, 26 patients underwent bilateral reconstruction and 68 underwent unilateral reconstruction, and 17 patients underwent reconstruction unilaterally with a double TMG flap. Patient age ranged between 24 and 65 years (mean, 37 years). Twelve patients had to be taken back to the operating room because of flap-related problems and nine patients underwent successful revision microsurgically, resulting in three complete flap losses in a series of 111 patients with 154 transplanted TMG flaps. Partial flap loss was encountered in two patients, whereas fat tissue necrosis was managed conservatively in six patients. Donor-site morbidity was an advantage of this flap, with a concealed scar and minimal contour irregularities of the thigh, even in unilateral harvest. Complications included delayed wound healing (n = 10), hematoma (n = 5), and transient sensory deficit over the posterior thigh (n = 49). The TMG flap is more than an alternative to the deep inferior epigastric perforator (DIEP) flap in microsurgical breast reconstruction in selected patients. In certain indications, such as bilateral reconstructions, it possibly surpasses the DIEP flap because of a better concealed donor scar and easier harvest.

  3. Quasi-3d aerodynamic code for analyzing dynamic flap response

    DEFF Research Database (Denmark)

    Ramos García, Néstor

    A computational model for predicting the aerodynamic behavior of wind turbine airfoil profiles subjected to steady and unsteady motions has been developed. The model is based on a viscous-inviscid interaction technique using strong coupling between the viscous and inviscid parts. The inviscid part...... transition model. Validation of the steady two dimensional version of the code has been carried out against experiments for different airfoil geometries and Reynolds numbers. The unsteady version of the code has been benchmarked against experiments for different airfoil geometries at various reduced...... frequencies and oscillation amplitudes, and generally a good agreement is obtained. The capability of the code to simulate a trailing edge flap under steady or unsteady flow conditions has been proven. A parametric study on rotational effects induced by Coriolis and centrifugal forces in the boundary layer...

  4. The Use of Tensor Fascia Lata Pedicled Flap in Reconstructing Full Thickness Abdominal Wall Defects and Groin Defects Following Tumor Ablation

    International Nuclear Information System (INIS)

    Rifaat, M.A.; Abdel Gawad, W.S.

    2005-01-01

    The tensor fascia lata is a versatile flap with many uses in reconstructive plastic surgery. As a pedicled flap its reach to the lower abdomen and groin made it an attractive option for reconstructing soft tissue defects after tumor ablation. However, debate exists on the safe dimension of the flap, as distal tip necrosis is common. Also, the adequacy of the fascia lata as a sole substitute for abdominal wall muscles has been disputable. The aim of the current study is to report our experience and clinical observations with this flap in reconstructing those challenging defects and to discuss the possible options to minimize the latter disputable issues. Patients and Methods: From April 2001 to April 2004, 12 pedicled TFL flaps were used to reconstruct 5 central abdominal wall full thickness defects and 6 groin soft tissue defects following tumor resection. ]n one case, bilateral flaps were used to reconstruct a large central abdominal wall defect. There were 4 males and 7 females. Their age ranged from 19 to 60. From the abdominal wall defects group, all repairs were enforced primarily with a prolene mesh except for one patient who was the first in this study. Patients presenting with groin defects required coverage of exposed vessels following tumor resection. All patients in the current study underwent immediate reconstruction. The resulting soft tissue defects in this study were due to resection of 4 abdominal wall desmoid tumors, a colonic carcinoma infiltrating the abdominal wall, 4 primary groin soft developed in a flap used to cover a groin defect. In the former 3 cases, The flap was simply transposed without complete islanding of the flap. In the latter case, a very large flap was harvested beyond the safe limits with its distal edge just above the knee. In addition, wound dehiscence of the flap occurred in 2 other cases from the groin group. Nevertheless, all the wounds healed spontaneously with repeated dressings. Out of the 5 cases that underwent

  5. Face resurfacing using a cervicothoracic skin flap prefabricated by lateral thigh fascial flap and tissue expander.

    Science.gov (United States)

    Li, Qingfeng; Zan, Tao; Gu, Bin; Liu, Kai; Shen, Guoxiong; Xie, Yun; Weng, Rui

    2009-01-01

    Resurfacing of facial massive soft tissue defect is a formidable challenge because of the unique character of the region and the limitation of well-matched donor site. In this report, we introduce a technique for using the prefabricated cervicothoracic skin flap for facial resurfacing, in an attempt to meet the principle of flap selection in face reconstructive surgery for matching the color and texture, large dimension, and thinner thickness (MLT) of the recipient. Eleven patients with massive facial scars underwent resurfacing procedures with prefabricated cervicothoracic flaps. The vasculature of the lateral thigh fascial flap, including the descending branch of the lateral femoral circumflex vessels and the surrounding muscle fascia, was used as the vascular carrier, and the pedicles of the fascial flap were anastomosed to either the superior thyroid or facial vessels in flap prefabrication. A tissue expander was placed beneath the fascial flap to enlarge the size and reduce the thickness of the flap. The average size of the harvested fascia flap was 6.5 x 11.7 cm. After a mean interval of 21.5 weeks, the expanders were filled to a mean volume of 1,685 ml. The sizes of the prefabricated skin flaps ranged from 12 x 15 cm to 15 x 32 cm. The prefabricated skin flaps were then transferred to the recipient site as pedicled flaps for facial resurfacing. All facial soft tissue defects were successfully covered by the flaps. The donor sites were primarily closed and healed without complications. Although varied degrees of venous congestion were developed after flap transfers, the marginal necrosis only occurred in two cases. The results in follow-up showed most resurfaced faces restored natural contour and regained emotional expression. MLT is the principle for flap selection in resurfacing of the massive facial soft tissue defect. Our experience in this series of patients demonstrated that the prefabricated cervicothoracic skin flap could be a reliable alternative

  6. Treatment of ischial pressure sores with both profunda femoris artery perforator flaps and muscle flaps.

    Science.gov (United States)

    Kim, Chae Min; Yun, In Sik; Lee, Dong Won; Lew, Dae Hyun; Rah, Dong Kyun; Lee, Won Jai

    2014-07-01

    Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. We retrospectively analyzed data from 14 patients (16 ischial sores) whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. All flaps survived the entire follow-up period. Seven patients (50%) had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years). The mean follow-up period was 27.9 months (range, 3-57 months). In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%), wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%), but resolved with conservative treatment. Among 16 cases, there was only one (6%) recurrence at 34 months. The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores.

  7. Route Flap Damping Made Usable

    Science.gov (United States)

    Pelsser, Cristel; Maennel, Olaf; Mohapatra, Pradosh; Bush, Randy; Patel, Keyur

    The Border Gateway Protocol (BGP), the de facto inter-domain routing protocol of the Internet, is known to be noisy. The protocol has two main mechanisms to ameliorate this, MinRouteAdvertisementInterval (MRAI), and Route Flap Damping (RFD). MRAI deals with very short bursts on the order of a few to 30 seconds. RFD deals with longer bursts, minutes to hours. Unfortunately, RFD was found to severely penalize sites for being well-connected because topological richness amplifies the number of update messages exchanged. So most operators have disabled it. Through measurement, this paper explores the avenue of absolutely minimal change to code, and shows that a few RFD algorithmic constants and limits can be trivially modified, with the result being damping a non-trivial amount of long term churn without penalizing well-behaved prefixes' normal convergence process.

  8. Postirradiation flap infection about the oral cavity

    International Nuclear Information System (INIS)

    Cabbabe, E.B.; Herbold, D.R.; Sunwoo, Y.C.; Baroudi, I.F.

    1983-01-01

    Postirradiation alteration of oral flora is well documented in the literature. Infection as a complication leading to partial or complete loss of a flap used to reconstruct a defect in the oral cavity is a worrisome outcome. We describe how a flap that was judged clinically to be viable became overwhelmingly infected with the Klebsiella oxytoca, an oral cavity pathogen encountered in this patient following irradiation. Local and systemic changes led to detachment of the flap. This complication may be explained, in view of the absence of venous congestion or arterial ischemia both clinically and pathologically, by the proven contamination of the flap by the Klebsiella pathogen. Local factors resulted in lower resistance and subsequent overwhelming infection. Discussion of the case, review of pertinent literature, and proposed solutions are presented

  9. Intraoperative indocyanine green fluorescent angiography-assisted modified superior gluteal artery perforator flap for reconstruction of sacral pressure sores.

    Science.gov (United States)

    Chang, Chun-Kai; Wu, Chien-Ju; Chen, Chun-Yu; Wang, Chi-Yu; Chu, Tzi-Shiang; Hsu, Kuo-Feng; Chiu, Han-Ting; Liu, Hung-Hui; Chou, Chang-Yi; Wang, Chih-Hsin; Lin, Chin-Ta; Dai, Niann-Tzyy; Tzeng, Yuan-Sheng

    2017-12-01

    Pressure sores are often observed in patients who are bedridden. They can be a severe problem not only for patients and their caregivers but also for plastic surgeons. Here, we describe a new method of superior gluteal artery perforator flap harvesting and anchoring with the assistance of intraoperative indocyanine green fluorescent angiography. In this report, we describe the procedure and outcomes for 19 patients with grades III and IV sacral pressure sores who underwent the operation between September 2015 and November 2016. All flaps survived, and two experienced wound-edge partial dehiscence. With the assistance of this imaging device, we were able to acquire a reliable superior gluteal artery perforator flap and perform modified operations with it that are safe, easy to learn and associated with fewer complications than are traditional. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  10. The role of postoperative hematoma on free flap compromise.

    Science.gov (United States)

    Ahmad, Faisal I; Gerecci, Deniz; Gonzalez, Javier D; Peck, Jessica J; Wax, Mark K

    2015-08-01

    Hematomas may develop in the postoperative setting after free tissue transfer. When hematomas occur, they can exert pressure on surrounding tissues. Their effect on the vascular pedicle of a free flap is unknown. We describe our incidence of hematoma in free flaps and outcomes when the flap is compromised. Retrospective chart review of 1,883 free flaps performed between July 1998 and June 2014 at a tertiary referral center. Patients with free flap compromise due to hematoma were identified. Etiology, demographic data, and outcomes were evaluated. Eighty-eight (4.7%) patients developed hematomas. Twenty (22.7%) of those had flap compromise. Twelve compromises (60%) showed evidence of pedicle thrombosis. The salvage rate was 75% versus 54% in 79 flaps with compromise from other causes (P = .12). Mean time to detection of the hematoma was 35.3 hours in salvaged flaps compared to 91.6 hours in unsalvageable flaps (P = .057). Time to operating room (OR) from detection was 2.8 hours in salvageable flaps compared to 12.4 hours in nonsalvageable flaps (P = .053). The salvage rate for flaps that returned to the OR in hematomas developed rarely. When they did, 23% went on to develop flap compromise. Prompt recognition and re-exploration allowed for a high salvage rate. Vessel thrombosis predicted inability to salvage the flap. 4 © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  11. Use of Adipose-Derived Mesenchymal Stem Cells to Accelerate Neovascularization in Interpolation Flaps.

    Science.gov (United States)

    Izmirli, Hakki Hayrettin; Alagoz, Murat Sahin; Gercek, Huseyin; Eren, Guler Gamze; Yucel, Ergin; Subasi, Cansu; Isgoren, Serkan; Muezzinoglu, Bahar; Karaoz, Erdal

    2016-01-01

    Interpolation flaps are commonly used in plastic surgery to cover wide and deep defects. The need to, wait for 2 to 3 weeks until the division of the pedicle still, however, poses a serious challenge, not only extending treatment and hospital stay, but also increasing hospital expenses. To solve this problem, we have aimed to use the angiogenic potential of stem cells to selectively accelerate neovascularization with a view to increasing the viability of interpolation flaps and achieving early pedicle removal. A total of 32 rats were allocated to 2 groups as control (N = 16) and experiment (N = 16). The cranial flaps 6 × 5 cm in size located on the back of the rats were raised. Then, a total suspension containing 3 × 10(6) adipose-derived mesenchymal stem cells (ADSC) tagged with a green fluorescent protein (GFP) was injected diffusely into the distal part of the flap, receiving bed, and wound edges. In the control group, only a medium solution was injected into the same sites. After covering the 3 × 5 cm region in the proximal part of the area where the flap was removed, the distal part of the flap was adapted to the uncovered distal area. The pedicles of 4 rats in each group were divided on postoperative days 5, 8, 11, and 14. The areas were photographed 7 days after the pedicles were released. The photographs were processed using Adobe Acrobat 9 Pro software (San Jose, CA) to measure the flap survival area in millimeters and to compare groups. Seven days after the flap pedicle was divided, the rats were injected with 250 mCi Tc-99 mm (methoxy-isobutyl-isonitrie) from the penile vein, and scintigraphic images were obtained. The images obtained from each group were subjected to a numerical evaluation, which was then used in the comparison between groups. The flaps were then examined by histology to numerically compare the number of newly formed vessels. Neovascularization was also assessed by microangiography. In addition, radiographic images were obtained by

  12. An analytical model and scaling of chordwise flexible flapping wings in forward flight.

    Science.gov (United States)

    Kodali, Deepa; Kang, Chang-Kwon

    2016-12-13

    Aerodynamic performance of biological flight characterized by the fluid structure interaction of a flapping wing and the surrounding fluid is affected by the wing flexibility. One of the main challenges to predict aerodynamic forces is that the wing shape and motion are a priori unknown. In this study, we derive an analytical fluid-structure interaction model for a chordwise flexible flapping two-dimensional airfoil in forward flight. A plunge motion is imposed on the rigid leading-edge (LE) of teardrop shape and the flexible tail dynamically deforms. The resulting unsteady aeroelasticity is modeled with the Euler-Bernoulli-Theodorsen equation under a small deformation assumption. The two-way coupling is realized by considering the trailing-edge deformation relative to the LE as passive pitch, affecting the unsteady aerodynamics. The resulting wing deformation and the aerodynamic performance including lift and thrust agree well with high-fidelity numerical results. Under the dynamic balance, the aeroelastic stiffness decreases, whereas the aeroelastic stiffness increases with the reduced frequency. A novel aeroelastic frequency ratio is derived, which scales with the wing deformation, lift, and thrust. Finally, the dynamic similarity between flapping in water and air is established.

  13. Triple flap technique for vulvar reconstruction.

    Science.gov (United States)

    Mercut, R; Sinna, R; Vaucher, R; Giroux, P A; Assaf, N; Lari, A; Dast, S

    2018-04-09

    Perineal defects are encountered ever more frequently, in the treatment of vulvar cancers or abdominoperineal resection. The surgical treatment of vulvar cancer leads to significant skin defect. The aim of the reconstruction is not to provide volume but rather to resurface perineum. We propose a new solution to cover the extensive skin defect remaining after excision. We report 3 patients who underwent large excision for vulvar cancer, with lymph node dissection. For reconstruction, we performed 3 advancement flaps. Two V-Y flaps cantered on the infra-gluteal folds and based on pudendal perforator arteries were used to cover the postero-lateral parts of the defect. The third advancement flap from the superior aspect of the defect was a Y-V Mons pubis flap. The defects were successfully covered by the 3 flap technique. The first patient suffered a non-union that slowly healed by secondary intention. For the other cases, we used the same technique, but applied negative pressure wound therapy on the sutures, with excellent results. The 3 flap technique is a simple and reliable method and the donor site morbidity is minimal. It can be realised without changing the position of the patient after tumour excision, and does not require delicate perforator dissection. This surgical option can be easily applied, allowing better management of these cases. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  14. [A variant of island flaps for the covering of pressure sores: the hatchet flap. Apropos of 31 cases].

    Science.gov (United States)

    Quillot, M; Lodde, J P; Pegorier, O; Reynaud, J P; Cormerais, A

    1994-08-01

    The authors propose a modification of the classical design of island flaps for cover of pressure sores, applied to gluteus maximus and tensor fascia lata muscles: the hatchet flap. 31 flaps have been used including 13 gluteus maximus superior flaps for sacral pressure sores, 9 gluteal inferior flaps for ischial pressure sores and 9 tensor fascia lata flaps for trochanteric pressure sores. A small partial necrosis and two cases of sepsis were observed in this series, but did not require surgical revision. The authors emphasize the value of this modification of the classical flap design, which preserves an even better musculocutaneous capital in these patients, who are often already multi-operated. The very rapid recovery of patients supports the authors' application of hatchet flaps to the surgery of pressure sores, and suggests the extension to other musculocutaneous flaps in the future.

  15. Treatment of soft-tissue loss with nerve defect in the finger using the boomerang nerve flap.

    Science.gov (United States)

    Chen, Chao; Tang, Peifu; Zhang, Xu

    2013-01-01

    This study reports simultaneous repair of soft-tissue loss and proper digital nerve defect in the finger using a boomerang nerve flap including nerve graft from the dorsal branch of the proper digital nerve. From July of 2007 to May of 2010, the flap was used in 17 fingers in 17 patients. The injured fingers included five index, seven long, and five ring fingers. The mean soft-tissue loss was 2.5 × 1.9 cm. The mean flap size was 2.8 × 2.1 cm. Proper digital nerve defects were reconstructed using nerve graft harvested from the dorsal branch of the adjacent finger's proper digital nerve. The average nerve graft length was 2.5 cm. The comparison group included 32 patients treated using a cross-finger flap and a secondary free nerve graft. In the study group, 15 flaps survived completely. Partial necrosis at the distal edge of the flap occurred in two cases. At a mean follow-up of 22 months, the average static two-point discrimination and Semmes-Weinstein monofilament test results on the pulp of the reconstructed finger were 7.5 mm and 3.86, respectively. In the comparison group, the results were 9.3 mm and 3.91, respectively. The study group presented better discriminatory sensation on the pulp and milder pain and cold intolerance in the reconstructed finger. The boomerang nerve flap is useful and reliable for reconstructing complicated finger damage involving soft-tissue loss and nerve defect, especially in difficult anatomical regions. Therapeutic, II.

  16. Aerodynamics power consumption for mechanical flapping wings undergoing flapping and pitching motion

    Science.gov (United States)

    Razak, N. A.; Dimitriadis, G.; Razaami, A. F.

    2017-07-01

    Lately, due to the growing interest in Micro Aerial Vehicles (MAV), interest in flapping flight has been rekindled. The reason lies in the improved performance of flapping wing flight at low Reynolds number regime. Many studies involving flapping wing flight focused on the generation of unsteady aerodynamic forces such as lift and thrust. There is one aspect of flapping wing flight that received less attention. The aspect is aerodynamic power consumption. Since most mechanical flapping wing aircraft ever designed are battery powered, power consumption is fundamental in improving flight endurance. This paper reports the results of experiments carried out on mechanical wings under going active root flapping and pitching in the wind tunnel. The objective of the work is to investigate the effect of the pitch angle oscillations and wing profile on the power consumption of flapping wings via generation of unsteady aerodynamic forces. The experiments were repeated for different airspeeds, flapping and pitching kinematics, geometric angle of attack and wing sections with symmetric and cambered airfoils. A specially designed mechanical flapper modelled on large migrating birds was used. It will be shown that, under pitch leading conditions, less power is required to overcome the unsteady aerodnamics forces. The study finds less power requirement for downstroke compared to upstroke motion. Overall results demonstrate power consumption depends directly on the unsteady lift force.

  17. Rescue of Primary Incomplete Microkeratome Flap with Secondary Femtosecond Laser Flap in LASIK

    Directory of Open Access Journals (Sweden)

    E. A. Razgulyaeva

    2014-01-01

    Full Text Available For laser-assisted in situ keratomileusis (LASIK retreatments with a previous unsuccessful mechanical microkeratome-assisted surgery, some surgical protocols have been described as feasible, such as relifting of the flap or the creation of a new flap and even the change to a surface ablation procedure (photorefractive keratectomy (PRK. This case shows the use of femtosecond technology for the creation of a secondary flap to perform LASIK in a cornea with a primary incomplete flap obtained with a mechanical microkeratome. As we were unable to characterize the interface of the first partial lamellar cut, a thick flap was planned and created using a femtosecond laser platform. As the primary cut was very thick in the nasal quadrant, a piece of loose corneal tissue appeared during flap lifting which was fitted in its position and not removed. Despite this condition and considering the regularity of the new femtosecond laser cut, the treatment was uneventful. This case report shows the relevance of a detailed corneal analysis with an advanced imaging technique before performing a secondary flap in a cornea with a primary incomplete flap. The femtosecond laser technology seems to be an excellent tool to manage such cases successfully.

  18. The Internal Pudendal Artery Perforator Thigh Flap: A New Freestyle Pedicle Flap for the Ischial Region

    Directory of Open Access Journals (Sweden)

    Ichiro Hashimoto, MD

    2014-05-01

    Conclusions: The perforator vessels of the internal pudendal artery are very close to the ischial tuberosity. Blood flow to the flap is reliable when careful debridement of the pressure sore is performed. The iPap thigh flap is a new option for soft-tissue defects in the ischial region, including ischial pressure sores.

  19. The prepuce free flap in 10 patients : modifications in flap design and surgical technique

    NARCIS (Netherlands)

    Werker, Paul M N

    The prepuce free flap was used in 10 oral and oropharyngeal reconstructions. During the course of this study, various modifications took place. Residual penile skin necrosis and skin island necrosis early in the series led to modification of flap design. This solved the donor-site problem by placing

  20. Aspects of the influence of an oscillating mini-flap upon the near wake of an airfoil NACA 4412

    Energy Technology Data Exchange (ETDEWEB)

    Delnero, J S; Di Leo, J Maranon; Colman, J; Garcia Sainz, M; Munoz, F; Herouard, N; Camocardi, M E, E-mail: delnero@ing.unlp.edu.ar [LaCLyFA, Departamento Aeronautica, Facultad de Ingenieria, Universidad Nacional de La Plata, calle 116 entre 47 y 48, CP 1900, La Plata (Argentina)

    2011-05-01

    A NACA 4412 airfoil was tested, in a boundary layer wind tunnel, with the aim to study the effect of a Gurney mini-flap, as an active and passive flow control device submitted to a turbulent flow field. The main objective was the experimental determination of flow pattern characteristics downstream the airfoil in the near wake. The untwisted wing model used for the experiments had 80 cm wingspan and 50 cm chord, with airfoil NACA 4412. The mini-flap was located on the lower surface at a distance, from the trailing edge, of 8%c (c airfoil chord). The Reynolds number, based upon the wing chord and the mean free stream velocity was 326,000 and 489,000. The turbulence intensity was 1.8%. The model was located into the wind tunnel between two panels, in order to assure a close approximation to two-dimensional flow over the model. As an active control device a rotating mini-flaps, geared by an electromechanical system (which rotate to a 30{sup 0}) was constructed. The wake pattern and pressure values near the trailing edge were measured. The results obtained, for this mechanism, show us that the oscillating mini-flap change the wake flow pattern, alleviating the near wake turbulence and enhancing the vortex pair near the trailing edge at the mini-flap level and below that level, magnifying the effect described first by Liebeck. That effect grows with the oscillating frequency. Additionally, the wake alleviation probably affects also the far wake. All of these facts suggest us to continue with the experiments, trying to measure the pressure distribution around the airfoil in all the cases, obtaining the lift and drag characteristics.

  1. Stability of edge states and edge magnetism in graphene nanoribbons

    OpenAIRE

    Kunstmann, Jens; Özdoğan, Cem; Quandt, Alexander; Fehske, Holger

    2010-01-01

    We critically discuss the stability of edge states and edge magnetism in zigzag edge graphene nanoribbons (ZGNRs). We point out that magnetic edge states might not exist in real systems, and show that there are at least three very natural mechanisms - edge reconstruction, edge passivation, and edge closure - which dramatically reduce the effect of edge states in ZGNRs or even totally eliminate them. Even if systems with magnetic edge states could be made, the intrinsic magnetism would not be ...

  2. A study on forces acting on a flapping wing

    Directory of Open Access Journals (Sweden)

    Cetiner O.

    2013-04-01

    Full Text Available In order to study the forces acting on a flapping wing, an experimental investigation is performed in steady water flow. In this study, a SD7003 airfoil undergoes combined pitching and plunging motion which simulates the forward flight of small birds. The frequency of pitching motion is equal to the frequency of plunging motion and pitch leads the plunge by a phase angle of 90 degrees. The experiments are conducted at Reynolds numbers of 2500 ≤ Re ≤ 13700 and the vortex formation is recorded using the digital particle image velocimetry (DPIV technique. A prediction of thrust force and efficiency is calculated from the average wake deficit of DPIV data, the near-wake vorticity patterns and time dependent velocity vectors are determined to comment on the thrust and drag indication. Direct force measurements are attempted using a Force/Torque sensor which is capable of measuring forces and moments in three axial directions.

  3. Mechanisms of Wing Beat Sound in Flapping Wings of Beetles

    Science.gov (United States)

    Allen, John

    2017-11-01

    While the aerodynamic aspects of insect flight have received recent attention, the mechanisms of sound production by flapping wings is not well understood. Though the harmonic structure of wing beat frequency modulation has been reported with respect to biological implications, few studies have rigorously quantified it with respect directionality, phase coupling and vortex tip scattering. Moreover, the acoustic detection and classification of invasive species is both of practical as well scientific interest. In this study, the acoustics of the tethered flight of the Coconut Rhinoceros Beetle (Oryctes rhinoceros) is investigated with four element microphone array in conjunction with complementary optical sensors and high speed video. The different experimental methods for wing beat determination are compared in both the time and frequency domain. Flow visualization is used to examine the vortex and sound generation due to the torsional mode of the wing rotation. Results are compared with related experimental studies of the Oriental Flower Beetle. USDA, State of Hawaii.

  4. Free flap reconstruction for diabetic foot limb salvage.

    Science.gov (United States)

    Sato, Tomoya; Yana, Yuichiro; Ichioka, Shigeru

    2017-12-01

    Although free flap is gaining popularity for the reconstruction of diabetic foot ulcers, it is unclear whether free flap reconstruction increases the chances of postoperative independent ambulation. The aim of this study is to evaluate the relationship between free flap success and postoperative ambulation. This study reviewed 23 cases of free flap reconstruction for diabetic foot ulcers between January 2007 and March 2014. Free rectus abdominis, latissimus dorsi, and anterolateral thigh flaps were used in ten, eight, and five patients, respectively. A comparison was made between free flap success and postoperative independent ambulation using Fisher's exact test. Two patients developed congestive heart failure with fatal consequences within 14 days postoperatively, resulting in an in-hospital mortality rate of 8.7%. Five patients lost their flaps (21.7%). Of the 16 patients who had flap success, 12 achieved independent ambulation. Five patients with flap loss did not achieve independent ambulation, except one patient who underwent secondary flap reconstruction using a distally based sural flap. Fisher's exact test revealed that independent ambulation was associated with free flap success (p = 0.047). The present study indicates that free flap reconstruction may increase the possibility of independent ambulation for patients with extensive tissue defects due to diabetic ulcers. Intermediate limb salvage rates and independent ambulation rates were favourable in patients with successful reconstruction. The use of foot orthoses and a team approach with pedorthists were effective to prevent recurrence.

  5. Chimeric superficial temporal artery based skin and temporal fascia flap plus temporalis muscle flap - An alternative to free flap for suprastructure maxillectomy with external skin defect

    Directory of Open Access Journals (Sweden)

    Dushyant Jaiswal

    2011-01-01

    Full Text Available Flaps from temporal region have been used for mid face, orbital and peri-orbital reconstruction. The knowledge of the vascular anatomy of the region helps to dissect and harvest the muscle/fascia/skin/combined tissue flaps from that region depending upon the requirement. Suprastructure maxillectomy defects are usually covered with free flaps to fill the cavity. Here we report an innovative idea in which a patient with a supra structure maxillectomy with external skin defect was covered with chimeric flap based on the parietal and frontal branches of superficial temporal artery and the temporalis muscle flap based on deep temporal artery.

  6. Nanoindentation near the edge

    Science.gov (United States)

    J.E. Jakes; C.R. Frihart; J.F. Beecher; R.J. Moon; P.J. Resto; Z.H. Melgarejo; O.M. Saurez; H. Baumgart; A.A. Elmustafa; D.S. Stone

    2009-01-01

    Whenever a nanoindent is placed near an edge, such as the free edge of the specimen or heterophase interface intersecting the surface, the elastic discontinuity associated with the edge produces artifacts in the load-depth data. Unless properly handled in the data analysis, the artifacts can produce spurious results that obscure any real trends in properties as...

  7. Comparison of Dorsal Intercostal Artery Perforator Propeller Flaps and Bilateral Rotation Flaps in Reconstruction of Myelomeningocele Defects.

    Science.gov (United States)

    Tenekeci, Goktekin; Basterzi, Yavuz; Unal, Sakir; Sari, Alper; Demir, Yavuz; Bagdatoglu, Celal; Tasdelen, Bahar

    2018-04-09

    Bilateral rotation flaps are considered the workhorse flaps in reconstruction of myelomeningocele defects. Since the introduction of perforator flaps in the field of reconstructive surgery, perforator flaps have been used increasingly in the reconstruction of various soft tissue defects all over the body because of their appreciated advantages. The aim of this study was to compare the complications and surgical outcomes between bilateral rotation flaps and dorsal intercostal artery perforator (DICAP) flaps in the soft tissue reconstruction of myelomeningocele defects. Between January 2005-February 2017, we studied 47 patients who underwent reconstruction of myelomeningocele defects. Patient demographics, operative data, and postoperative data were reviewed retrospectively and are included in the study. We found no statistically significant differences in patient demographics and surgical complications between these two groups; this may be due to small sample size. With regard to complications-partial flap necrosis, cerebrospinal fluid (CSF) leakage, necessity for reoperation, and wound infection-DICAP propeller flaps were clinically superior to rotation flaps. Partial flap necrosis was associated with CSF leakage and wound infection, and CSF leakage was associated with wound dehiscence. Although surgical outcomes obtained with DICAP propeller flaps were clinically superior to those obtained with rotation flaps, there was no statistically significant difference between the two patient groups. A well-designed comparative study with adequate sample size is needed. Nonetheless, we suggest using DICAP propeller flaps for reconstruction of large myelomeningocele defects.

  8. Propeller Flap for Complex Distal Leg Reconstruction: A Versatile ...

    African Journals Online (AJOL)

    equipment, cost, steep learning curve, and prolonged operating ... A Versatile Alternative when Reverse Sural Artery Flap is .... He had wound debridement, fracture reduction, and .... flaps that were raised in the patient and the logistics of limb.

  9. 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

  10. Scrotal reconstruction with superomedial fasciocutaneous thigh flap

    Directory of Open Access Journals (Sweden)

    DANIEL FRANCISCO MELLO

    2018-02-01

    Full Text Available ABSTRACT Objective: to describe the use of a superomedial fasciocutaneous thigh flap for scrotal reconstruction in open areas secondary to the surgical treatment of perineal necrotizing fasciitis (Fournier’s gangrene. Methods: retrospective analysis of cases treated at the Plastic Surgery Service of Santa Casa de Misericórdia, São Paulo, from 2009 to 2015. Results: fifteen patients underwent scrotal reconstruction using the proposed flap. The mean age was 48.9 years (28 to 66. Skin loss estimates in the scrotal region ranged from 60 to 100%. Definitive reconstruction was performed on average 30.6 days (22 to 44 after the initial surgical treatment. The mean surgical time was 76 minutes (65 to 90 to obtain the flaps, bilateral in all cases. Flap size ranged from 10cm to 13cm in the longitudinal direction and 8cm to 10cm in the cross-sectional direction. The complication rate was 26.6% (four cases, related to the occurrence of segmental and partial dehiscence. Conclusion: the superomedial fasciocutaneous flap of thigh is a reliable and versatile option for the reconstruction of open areas in the scrotal region, showing adequate esthetic and functional results.

  11. The forked flap repair for hypospadias

    Directory of Open Access Journals (Sweden)

    Anil Chadha

    2012-01-01

    Full Text Available Context: Despite the abundance of techniques for the repair of Hypospadias, its problems still persist and a satisfactory design to correct the penile curvature with the formation of neourethra from the native urethral tissue or genital or extragenital tissues, with minimal postoperative complications has yet to evolve. Aim: Persisting with such an endeavor, a new technique for the repair of distal and midpenile hypospadias is described. Materials and Methods: The study has been done in 70 cases over the past 11 years. The "Forked-Flap" repair is a single stage method for the repair of such Hypospadias with chordee. It takes advantage of the rich vascular communication at the corona and capitalizes on the established reliability of the meatal based flip-flap. The repair achieves straightening of the curvature of the penis by complete excision of chordee tissue from the ventral surface of the penis beneath the urethral plate. The urethra is reconstructed using the native plate with forked flap extensions and genital tissue relying on the concept of meatal based flaps. Water proofing by dartos tissue and reinforcement by Nesbit′s prepucial tissue transfer completes the one stage procedure. Statistical Analysis: An analysis of 70 cases of this single stage technique of repair of penile hypospadias with chordee, operated at 3 to 5 years of age over the past 11 years is presented. Results and Conclusion: The Forked Flap gives comparable and replicable results; except for a urethrocutaneous fistula rate of 4% no other complications were observed.

  12. Perforator plus flaps: Optimizing results while preserving function and esthesis

    Directory of Open Access Journals (Sweden)

    Mehrotra Sandeep

    2010-01-01

    Full Text Available Background: The tenuous blood supply of traditional flaps for wound cover combined with collateral damage by sacrifice of functional muscle, truncal vessels, or nerves has been the bane of reconstructive procedures. The concept of perforator plus flaps employs dual vascular supply to flaps. By safeguarding perforators along with supply from its base, robust flaps can be raised in diverse situations. This is achieved while limiting collateral damage and preserving nerves, vessels, and functioning muscle with better function and aesthesis. Materials and Methods: The perforator plus concept was applied in seven different clinical situations. Functional muscle and fasciocutaneous flaps were employed in five and adipofascial flaps in two cases, primarily involving lower extremity defects and back. Adipofascial perforator plus flaps were employed to provide cover for tibial fracture in one patients and chronic venous ulcer in another. Results: All flaps survived without any loss and provided long-term stable cover, both over soft tissue and bone. Functional preservation was achieved in all cases where muscle flaps were employed with no clinical evidence of loss of power. There was no sensory loss or significant oedema in or distal to the flap in both cases where neurovascular continuity was preserved during flap elevation. Fracture union and consolidation were satisfactory. One patient had minimal graft loss over fascia which required application of stored grafts with subsequent take. No patient required re-operation. Conclusions: Perforator plus concept is holistic and applicable to most flap types in varied situations. It permits the exercise of many locoregional flap options while limiting collateral functional damage. Aesthetic considerations are also addressed while raising adipofascial flaps because of no appreciable donor defects. With quick operating times and low failure risk, these flaps can be a better substitute to traditional flaps and at

  13. Curative effect observation of n-flap and off-flap EPi-LASIK in ametropia

    Directory of Open Access Journals (Sweden)

    Chao Liu

    2015-11-01

    Full Text Available AIM:To observe the clinical effect of on-flap and off-flap epipolis laser in situ keratomileusis(EPi-LASIKin ametropia.METHODS: Sixty-eight myopia patients(136 eyesreceiving surgical treatment were selected and divided into research group and control group according to different therapies. The patients in research group adopted off-flap EPi-LASIK and those in control group adopted on-flap EPi-LASIK. The index like uncorrected visual acuity, diopter and Haze of two groups before surgery, 1wk, 1 and 4mo after surgery was observed. RESULTS: One month after surgery, the uncorrected visual acuity of research group was 1.33±0.22 while that of control group was 1.22±0.19(PPPCONCLUSION:On-flap and off-flap EPi-LASIK are safe and effective surgery approaches in the clinical treatment of ametropia. The presence of corneal epithelial flap has a certain effect in the postoperative clinical outcome at early stage. The impact will be gradually reduced over time.

  14. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    Directory of Open Access Journals (Sweden)

    Chae Min Kim

    2014-07-01

    Full Text Available Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. Methods We retrospectively analyzed data from 14 patients (16 ischial sores whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. Results All flaps survived the entire follow-up period. Seven patients (50% had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years. The mean follow-up period was 27.9 months (range, 3-57 months. In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%, wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%, but resolved with conservative treatment. Among 16 cases, there was only one (6% recurrence at 34 months. Conclusions The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores.

  15. Reconstruction of eyelids with Washio flap in anophthalmia.

    Science.gov (United States)

    Tvrdek, M; Kozák, J

    2014-01-01

    The authors present a case report of a patient with anophthalmia in whom retroauriculo-temporal flap (Washio flap) was used for reconstruction of eyelids. This flap, which is mostly used for reconstructions of nasal defects, was not used in this way according to available literature.

  16. Prospective evaluation of outcome measures in free-flap surgery.

    LENUS (Irish Health Repository)

    Kelly, John L

    2004-08-01

    Free-flap failure is usually caused by venous or arterial thrombosis. In many cases, lack of experience and surgical delay also contribute to flap loss. The authors prospectively analyzed the outcome of 57 free flaps over a 28-month period (January, 1999 to April, 2001). The setting was a university hospital tertiary referral center. Anastomotic technique, ischemia time, choice of anticoagulant, and the grade of surgeon were recorded. The type of flap, medications, and co-morbidities, including preoperative radiotherapy, were also documented. Ten flaps were re-explored (17 percent). There were four cases of complete flap failure (6.7 percent) and five cases of partial failure (8.5 percent). In patients who received perioperative systemic heparin or dextran, there was no evidence of flap failure (p = .08). The mean ischemia time was similar in flaps that failed (95 +\\/- 29 min) and in those that survived (92 +\\/- 34 min). Also, the number of anastomoses performed by trainees in flaps that failed (22 percent), was similar to the number in flaps that survived (28 percent). Nine patients received preoperative radiotherapy, and there was complete flap survival in each case. This study reveals that closely supervised anastomoses performed by trainees may have a similar outcome to those performed by more senior surgeons. There was no adverse effect from radiotherapy or increased ischemia time on flap survival.

  17. Dual omental flap in obliterating post-pneumonectomy ...

    African Journals Online (AJOL)

    Background: Post-pneumonectomy bronchopleural fistulae is associated with high mortality and morbidity. The omental flap has been widely used to manage this condition either through laparoscopic or open surgery with varied degrees of success. We present a modification of the omental flap by using two flaps of the ...

  18. Blood flow autoregulation in pedicled flaps

    DEFF Research Database (Denmark)

    Bonde, Christian T; Holstein-Rathlou, Niels-Henrik; Elberg, Jens J

    2009-01-01

    was to evaluate if, and to what extent, a tissue flap could compensate a reduction in blood flow due to an acute constriction of the feed artery. Further, we wanted to examine the possible role of smooth muscle L-type calcium channels in the autoregulatory mechanism by pharmacological intervention with the L......, the flow in the pedicle was reduced and the flow was recorded. RESULTS: The flaps showed a strong autoregulatory response with complete compensation for flow reductions of up to 70-80%. Infusion of nimodipine caused a 28+/-10% increase in blood flow and removed the autoregulation. Papaverine caused...... a further increase in blood flow by 61+/-19%. The time control experiments proved that the experimental procedure was reproducible and stable over time. CONCLUSIONS: A tissue flap can nearly completely compensate for repeated flow reductions of up to 70-80%. This is due to a decrease in the peripheral...

  19. Double papilla flap technique for dual purpose

    Directory of Open Access Journals (Sweden)

    P Mohan Kumar

    2012-01-01

    Full Text Available Marginal tissue recession exposes the anatomic root on the teeth, which gives rise to -common patient complaints. It is associated with sensitivity, tissue irritation, cervical abrasions, and esthetic concerns. Various types of soft tissue grafts may be performed when recession is deep and marginal tissue health cannot be maintained. Double papilla flap is an alternative technique to cover isolated recessions and correct gingival defects in areas of insufficient attached gingiva, not suitable for a lateral sliding flap. This technique offers the advantages of dual blood supply and denudation of interdental bone only, which is less susceptible to permanent damage after surgical exposure. It also offers the advantage of quicker healing in the donor site and reduces the risk of facial bone height loss. This case report presents the advantages of double papilla flap in enhancing esthetic and functional outcome of the patient.

  20. Computational Investigations on the Effects of Gurney Flap on Airfoil Aerodynamics.

    Science.gov (United States)

    Jain, Shubham; Sitaram, Nekkanti; Krishnaswamy, Sriram

    2015-01-01

    The present study comprises steady state, two-dimensional computational investigations performed on NACA 0012 airfoil to analyze the effect of Gurney flap (GF) on airfoil aerodynamics using k-ε RNG turbulence model of FLUENT. Airfoil with GF is analyzed for six different heights from 0.5% to 4% of the chord length, seven positions from 0% to 20% of the chord length from the trailing edge, and seven mounting angles from 30° to 120° with the chord. Computed values of lift and drag coefficients with angle of attack are compared with experimental values and good agreement is found at low angles of attack. In addition static pressure distribution on the airfoil surface and pathlines and turbulence intensities near the trailing edge are present. From the computational investigation, it is recommended that Gurney flaps with a height of 1.5% chord be installed perpendicular to chord and as close to the trailing edge as possible to obtain maximum lift enhancement with minimum drag penalty.

  1. An edge pedestal model

    International Nuclear Information System (INIS)

    Stacev, W.M.

    2001-01-01

    A new model for calculation of the gradient scale lengths in the edge pedestal region and of the edge transport barrier width in H-mode tokamak plasmas will be described. Model problem calculations which demonstrate the promise of this model for predicting experimental pedestal properties will be discussed. The density and Prague gradient scale lengths (L) in the edge are calculated from the particle and ion and electron energy radial transport equations, making use of (presumed) known particle and energy fluxes flowing across the edge transport barrier from the core into the SOL and of edge transport coefficients. The average values of the particle and heat fluxes in the edge transport barrier are calculated in terms of the fluxes crossing into the SOL and the atomic physics reaction rates (ionisation, charge-exchange, elastic scattering, impurity radiation) in the edge by integrating the respective transport equations from the pedestal to the separatrix. An important implication of this model is that the pedestal gradient scale lengths depend not just on local pedestal platers properties but also on particle and energy fluxes from the core plasma and on recycling neutral fluxes that penetrate into the plasma edge, both of which in turn depend on the pedestal properties. The MHD edge pressure gradient constraint α≤ α C is used to determine the pressure width of the edge transport barrier, Δ TB = Δ TB (α c ). Three different models for the MHD edge pressure gradient constraint have been investigated: (1) nominal ideal ballooning mode theory, (2) ballooning mode theory taking into account the edge geometry and shear to access He second stability region; and pedestal β-limit theory when the ballooning modes are stabilised by diamagnetic effects. A series of calculations have been made for a DIII-D model problem. The calculated gradient scale lengths and edge transport barrier widths are of the magnitude of values observed experimentally, and certain trends

  2. Unit Advancement Flap for Lower Lip Reconstruction.

    Science.gov (United States)

    Ogino, Akihiro; Onishi, Kiyoshi; Okada, Emi; Nakamichi, Miho

    2018-05-01

    Lower lip reconstruction requires consideration of esthetic and functional outcome in selecting a surgical procedure, and reconstruction with local tissue is useful. The authors reconstructed full-thickness defects with a unit advancement flap. Reconstruction was performed using this method in 4 patients with lower lip squamous cell carcinoma in whom tumor resection with preservation of the mouth angle was possible. The lower lip resection width was 30 to 45 mm, accounting for 50% to 68% of the entire width of the lower lip. The flap was prepared by lateral extension from above the mental unit and matched with the potential wrinkle line of the lower lip in order to design a unit morphology surrounded by the anterior margin of the depressor labii inferioris muscle. It was elevated as a full-thickness flap composed of the orbicularis oris muscle, skin, and mucosa of the residual lower lip from the bilateral sides, and advanced to the defect. Flap transfer was adjusted by small triangular resection of the skin on the lateral side of the mental unit. The postoperative scar was inconspicuous in all patients and there was no impairment of the mouth opening-closing or articulation functions. This was a relatively simple surgical procedure. A blood supply of the flap was stable, and continuity of the orbicularis oris muscle was reconstructed by transferred the residual lower lip advancement flap from the bilateral sides. The postoperative mouth opening-closing function was sufficient, and dentures could be placed from an early phase in elderly patients. The postoperative scar was consistent with the lip unit morphology, being esthetically superior. This procedure may be applicable for reconstruction of defects approximately 1/3 to 2/3 the width of the lower lip where the mouth angle is preserved.

  3. Flapping model of scalar mixing in turbulence

    International Nuclear Information System (INIS)

    Kerstein, A.R.

    1991-01-01

    Motivated by the fluctuating plume model of turbulent mixing downstream of a point source, a flapping model is formulated for application to other configurations. For the scalar mixing layer, simple expressions for single-point scalar fluctuation statistics are obtained that agree with measurements. For a spatially homogeneous scalar mixing field, the family of probability density functions previously derived using mapping closure is reproduced. It is inferred that single-point scalar statistics may depend primarily on large-scale flapping motions in many cases of interest, and thus that multipoint statistics may be the principal indicators of finer-scale mixing effects

  4. Hyperbaric oxygen therapy and surgical delay improve flap survival of reverse pedicle flaps for lower third leg and foot reconstruction

    Directory of Open Access Journals (Sweden)

    Pradeoth Mukundan Korambayil

    2015-06-01

    Full Text Available Aim: The purpose of the study is to present a management protocol for various types of soft tissue defects of the distal third region of leg and foot treated with pedicle flaps, by including hyperbaric oxygen (HBO therapy in the treatment regimen with flap delay. Methods: We present a prospective study of 23 patients with various types of soft tissue defects of the foot, and lower third of leg managed in our institution from December 2012 to December 2013. All soft tissue defects were treated by a reverse pedicle flap. Twelve patients were managed with flap delay with HBO therapy and 11 patients with immediate flaps without HBO therapy. The postoperative period, hospital course, and follow-up were documented. Results: Of 12 patients with flap delay and HBO, 10 patients did not suffer any complications secondary to flap transfer. One patient had discoloration of the tip of the flap, which settled without the intervention, and 1 patient had recurrent abscess formation, which required debridement and closure. Of 11 patients with direct transfer, 6 patients presented with complications including flap congestion, partial flap loss, and tip necrosis, which required secondary intervention. Conclusion: HBO therapy is a useful adjunct in flap delay of the reverse pedicle flap for soft tissue reconstruction of the lower third of the leg and foot regions.

  5. "The Practical Perforator Flap": the sural artery flap for lower extremity soft tissue reconstruction in wounds of war

    NARCIS (Netherlands)

    O.J.F. van Waes (Oscar); J.A. Halm (Jens); J. Vermeulen (Jefrey); S. Ashford (Sofie)

    2012-01-01

    textabstractBackground: Sural artery perforator flaps have been described for use as both local flaps and in free tissue transfer. We present the use of this flap for compound soft tissue defects of the lower limb in civilian casualties of armed conflict in Afghanistan. Methods/results: Detailed

  6. Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction

    NARCIS (Netherlands)

    Hekner, D.D.; Roeling, TAP; van Cann, EM

    The aim of this study was to investigate the vascular anatomy of the distal forearm in order to optimize the choice between the radial forearm free flap and the ulnar forearm free flap and to select the best site to harvest the flap. The radial and ulnar arteries of seven fresh cadavers were

  7. Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

    Science.gov (United States)

    Lin, Chin-Ta; Chen, Shih-Yi; Chen, Shyi-Gen; Tzeng, Yuan-Sheng; Chang, Shun-Cheng

    2015-07-01

    Despite advances in reconstruction techniques, pressure sores continue to present a challenge to the plastic surgeon. The parasacral perforator flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We present our experience of using parasacral perforator flaps in reconstructing sacral defects. Between August 2004 and January 2013, 19 patients with sacral defects were included in this study. All the patients had undergone surgical reconstruction of sacral defects with a parasacral perforator flap. The patients' sex, age, cause of sacral defect, flap size, flap type, numbers of perforators used, rotation angle, postoperative complications, and hospital stay were recorded. There were 19 parasacral perforator flaps in this series. All flaps survived uneventfully except for 1 parasacral perforator flap, which failed because of methicillin-resistant Staphylococcus aureus infection. The overall flap survival rate was 95% (18/19). The mean follow-up period was 17.3 months (range, 2-24 months). The average length of hospital stay was 20.7 days (range, 9-48 days). No flap surgery-related mortality was found. Also, there was no recurrence of sacral pressure sores or infected pilonidal cysts during the follow-up period. Perforator-based flaps have become popular in modern reconstructive surgery because of low donor-site morbidity and good preservation of muscle. Parasacral perforator flaps are durable and reliable in reconstructing sacral defects. We recommend the parasacral perforator flap as a good choice for reconstructing sacral defects.

  8. Aerodynamic Flight-Test Results for the Adaptive Compliant Trailing Edge

    Science.gov (United States)

    Cumming, Stephen B.; Smith, Mark S.; Ali, Aliyah N.; Bui, Trong T.; Ellsworth, Joel C.; Garcia, Christian A.

    2016-01-01

    The aerodynamic effects of compliant flaps installed onto a modified Gulfstream III airplane were investigated. Analyses were performed prior to flight to predict the aerodynamic effects of the flap installation. Flight tests were conducted to gather both structural and aerodynamic data. The airplane was instrumented to collect vehicle aerodynamic data and wing pressure data. A leading-edge stagnation detection system was also installed. The data from these flights were analyzed and compared with predictions. The predictive tools compared well with flight data for small flap deflections, but differences between predictions and flight estimates were greater at larger deflections. This paper describes the methods used to examine the aerodynamics data from the flight tests and provides a discussion of the flight-test results in the areas of vehicle aerodynamics, wing sectional pressure coefficient profiles, and air data.

  9. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

    Active vibration control of long span suspension bridge flutter using separated control flaps (SFSC) has shown to increase effectively the critical wind speed of bridges. In this paper, an SFSC calculation based on modal equations of the vertical and torsional motions of the bridge girder including...... the flaps is presented. The length of the flaps attached to the girder, the flap configuration and the flap rotational angles are parameters used to increase the critical wind speed of the bridge. To illustrate the theory a numerical example is shown for a suspension bridge of 1000m+2500m+1000m span based...... on the Great Belt Bridge streamlined girder....

  10. Development and Realization of a Shock Wave Test on Expert Flap Qualification Model

    Science.gov (United States)

    De Fruytier, C.; Dell'Orco, F.; Ullio, R.; Gomiero, F.

    2012-07-01

    This paper presents the methodology and the results of the shock test campaign conducted by TAS-I and TAS ETCA to qualify the EXPERT Flap in regards of shock wave and acoustic load generated by pyrocord detonation at stages 2/3 separation phase of the EXPERT vehicle. The design concept of the open flap (manufactured by MT AEROSPACE) is a fully integral manufactured, four sided control surface, with an additional stiffening rib and flanges to meet the first eigenfrequency and the allowable deformation requirement with a minimum necessary mass. The objectives were to reproduce equivalent loading at test article level in terms of pulse duration, front pressure, front velocity and acoustic emission. The Thales Alenia Space ETCA pyrotechnic shock test device is usually used to produce high level shocks by performing a shock on a test fixture supporting the unit under test. In this case, the facility has been used to produce a shock wave, with different requested physical characteristics, directed to the unit under test. Different configurations have been tried on a dummy of the unit to test, following an empirical process. This unusual work has lead to the definition of a nominal set- up meeting the requested physical parameters. Two blast sensors have been placed to acquire the pressure around the flap. The distance between the two sensors has allowed estimating the front pressure velocity. Then, several locations have been selected to acquire the acceleration responses on the unit when it was submitted to this environment. Additionally, a “standard” shock test has been performed on this model. The qualification of the flap, in regards of shock environment, has been successfully conducted.

  11. Edge printability: techniques used to evaluate and improve extreme wafer edge printability

    Science.gov (United States)

    Roberts, Bill; Demmert, Cort; Jekauc, Igor; Tiffany, Jason P.

    2004-05-01

    The economics of semiconductor manufacturing have forced process engineers to develop techniques to increase wafer yield. Improvements in process controls and uniformities in all areas of the fab have reduced film thickness variations at the very edge of the wafer surface. This improved uniformity has provided the opportunity to consider decreasing edge exclusions, and now the outermost extents of the wafer must be considered in the yield model and expectations. These changes have increased the requirements on lithography to improve wafer edge printability in areas that previously were not even coated. This has taxed all software and hardware components used in defining the optical focal plane at the wafer edge. We have explored techniques to determine the capabilities of extreme wafer edge printability and the components of the systems that influence this printability. We will present current capabilities and new detection techniques and the influence that the individual hardware and software components have on edge printability. We will show effects of focus sensor designs, wafer layout, utilization of dummy edge fields, the use of non-zero overlay targets and chemical/optical edge bead optimization.

  12. Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

    Science.gov (United States)

    Li, Zonghuan; Yu, Aixi; Qi, Baiwen; Pan, Zhenyu; Ding, Junhui

    2017-08-01

    The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects. Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients. Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally. Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

  13. Donor-site morbidity of the radial forearm free flap versus the ulnar forearm free flap.

    Science.gov (United States)

    Hekner, Dominique D; Abbink, Jan H; van Es, Robert J; Rosenberg, Antoine; Koole, Ronald; Van Cann, Ellen M

    2013-08-01

    Donor-site morbidity following harvest of the radial forearm free flap was compared with that following harvest of the ulnar forearm free flap. Twenty-eight radial forearm and 27 ulnar forearm flaps were harvested in 55 patients with head and neck defects. Pressure perception was measured with Semmes-Weinstein monofilaments. Cold perception was tested with chloroethyl. Donor-site healing was evaluated. Patients were interviewed about grip and pinch strength and donor-site appearance. In the radial forearm free flap group, pressure perception and cold perception were reduced in the donor hand, whereas in the ulnar group, no differences were observed between the donor and unoperated hands. In the radial forearm group, 15 percent of patients experienced reduced strength in the donor hand, whereas in the ulnar forearm group, none of the patients reported reduced strength in the donor hand. In the radial forearm group, 14 percent had partial or complete loss of the skin graft, whereas in the ulnar forearm group, 4 percent had partial loss of the skin graft. In the radial forearm group, 18 percent of patients were dissatisfied with the appearance of the donor site, and no complaints were reported in the ulnar forearm group. The authors' study shows less donor site-morbidity following harvest of the ulnar forearm free flap than following harvest of the radial forearm free flap. These results emphasize that the ulnar forearm free flap should be considered as an alternative for the radial forearm free flap for reconstruction of soft-tissue defects. Therapeutic, III.

  14. "Apron" flap and re-creation of the inframammary fold following TRAM flap breast reconstruction.

    Science.gov (United States)

    Amir, A; Silfen, R; Hauben, D J

    2000-03-01

    To the best of our knowledge, the recreation of an inframammary fold after TRAM flap breast reconstruction has not yet been described. This article offers a technique for the creation of an inframammary fold as a secondary procedure. The technique has been performed thus far in two patients with good aesthetic outcomes and no postoperative complications. It may also be suitable for adding bulk to the TRAM flap, especially in bilateral breast reconstruction, and for other minor chest deformities.

  15. Design & fabrication of two seated aircraft with an advanced rotating leading edge wing

    Science.gov (United States)

    Al Ahmari, Saeed Abdullah Saeed

    The title of this thesis is "Design & Fabrication of two Seated Aircraft with an Advanced Rotating Leading Edge Wing", this gives almost a good description of the work has been done. In this research, the moving surface boundary-layer control (MSBC) concept was investigated and implemented. An experimental model was constructed and tested in wind tunnel to determine the aerodynamic characteristics using the leading edge moving surface of modified semi-symmetric airfoil NACA1214. The moving surface is provided by a high speed rotating cylinder, which replaces the leading edge of the airfoil. The angle of attack, the cylinder surfaces velocity ratio Uc/U, and the flap deflection angle effects on the lift and drag coefficients and the stall angle of attack were investigated. This new technology was applied to a 2-seat light-sport aircraft that is designed and built in the Aerospace Engineering Department at KFUPM. The project team is led by the aerospace department chairman Dr. Ahmed Z. AL-Garni and Dr. Wael G. Abdelrahman and includes graduate and under graduate student. The wing was modified to include a rotating cylinder along the leading edge of the flap portion. This produced very promising results such as the increase of the maximum lift coefficient at Uc/U=3 by 82% when flaps up and 111% when flaps down at 40° and stall was delayed by 8degrees in both cases. The laboratory results also showed that the effective range of the leading-edge rotating cylinder is at low angles of attack which reduce the need for higher angles of attack for STOL aircraft.

  16. Flap Lymphedema after Successful Reconstruction of the Chronic Inguinal Wound with a Vertical Rectus Abdominis Flap (VRAM

    Directory of Open Access Journals (Sweden)

    Yalcin Kulahci

    2012-07-01

    Full Text Available The reconstruction of extensive and complex wounds represents a challenging problem for reconstructive surgeon. The reconstructive options to provide cover-age following debridment of these complicated wounds are local, distant flaps, or freetissue transfer. Vertical rectus abdominis flaps have been used succes-sully to repair defects in the groin, hip, perineal, trunk, and breast regions. We encountered flap lymphedema after successful reconstruction of the chronic in-guinal wound with a vertical rectus abdominis (VRAM flap. As far as were able to ascertain, there is no report in the literature related to flap lymphedema.

  17. Tubularized Penile-Flap Urethroplasty Using a Fasciocutaneous Random Pedicled Flap for Recurrent Anterior Urethral Stricture

    Directory of Open Access Journals (Sweden)

    Yong Jig Lee

    2012-05-01

    Full Text Available This report describes the use of a tubularized random flap for the curative treatment of recurrent anterior urethral stricture. Under the condition of pendulous lithotomy and suprapubic cystostomy, the urethral stricture was removed via a midline ventral penile incision followed by elevation of the flap and insertion of an 18-Fr catheter. Subcutaneous buried interrupted sutures were used to reapproximate the waterproof tubularized neourethra and to coapt with the neourethra and each stump of the urethra, first proximally and then distally. The defect of the penile shaft was covered by advancement of the surrounding scrotal flap. The indwelling catheter was maintained for 21 days. A 9 month postoperative cystoscopy showed no flap necrosis, no mechanical stricture, and no hair growth on the lumen of the neourethra. The patient showed no voiding discomfort 6 months after the operation. The advantages of this procedure are the lack of need for microsurgery, shortening of admission, the use of only spinal anesthesia (no general anesthesia, and a relatively short operative time. The tubularized unilateral penile fasciocutaneous flap should be considered an option for initial flap urethroplasty as a curative technique.

  18. Development of Advanced High Lift Leading Edge Technology for Laminar Flow Wings

    Science.gov (United States)

    Bright, Michelle M.; Korntheuer, Andrea; Komadina, Steve; Lin, John C.

    2013-01-01

    This paper describes the Advanced High Lift Leading Edge (AHLLE) task performed by Northrop Grumman Systems Corporation, Aerospace Systems (NGAS) for the NASA Subsonic Fixed Wing project in an effort to develop enabling high-lift technology for laminar flow wings. Based on a known laminar cruise airfoil that incorporated an NGAS-developed integrated slot design, this effort involved using Computational Fluid Dynamics (CFD) analysis and quality function deployment (QFD) analysis on several leading edge concepts, and subsequently down-selected to two blown leading-edge concepts for testing. A 7-foot-span AHLLE airfoil model was designed and fabricated at NGAS and then tested at the NGAS 7 x 10 Low Speed Wind Tunnel in Hawthorne, CA. The model configurations tested included: baseline, deflected trailing edge, blown deflected trailing edge, blown leading edge, morphed leading edge, and blown/morphed leading edge. A successful demonstration of high lift leading edge technology was achieved, and the target goals for improved lift were exceeded by 30% with a maximum section lift coefficient (Cl) of 5.2. Maximum incremental section lift coefficients ( Cl) of 3.5 and 3.1 were achieved for a blown drooped (morphed) leading edge concept and a non-drooped leading edge blowing concept, respectively. The most effective AHLLE design yielded an estimated 94% lift improvement over the conventional high lift Krueger flap configurations while providing laminar flow capability on the cruise configuration.

  19. Machine Learning for Flapping Wing Flight Control

    NARCIS (Netherlands)

    Goedhart, Menno; van Kampen, E.; Armanini, S.F.; de Visser, C.C.; Chu, Q.

    2018-01-01

    Flight control of Flapping Wing Micro Air Vehicles is challenging, because of their complex dynamics and variability due to manufacturing inconsistencies. Machine Learning algorithms can be used to tackle these challenges. A Policy Gradient algorithm is used to tune the gains of a

  20. Oral cavity reconstruction with the masseter flap

    NARCIS (Netherlands)

    Mahieu, R.; Russo, S.; Gualtieri, T.; Colletti, G.; Deganello, A.

    The purpose of this report is to highlight how an unusual, outdated, unpopular and overlooked reconstructive method such as the masseter flap can be a reliable, straightforward and effective solution for oral reconstruction in selected cases. We report the transposition of the masseter crossover

  1. Omental Pedicled Flap for Pulmonary Tuberculosis Sequelae ...

    African Journals Online (AJOL)

    The omental flap should be prophylactically used in post-pneumonectomy bronchial stump reinforcement where the underlying chronic inflammatory condition poses high risk for bronchial dehiscence. We present a unique case of pulmonary tuberculosis (TB) complicated by empyema, chronic pulmonary aspergillosis and ...

  2. Accelerating recovery after trauma with free flaps.

    Science.gov (United States)

    Harris, G D; Nagle, D J; Lewis, V L; Bauer, B S

    1987-08-01

    Free flap versatility and dependability make the final result of microvascular reconstruction highly predictable. Free tissue transplantation should be considered as a primary treatment after trauma. The early use of free tissue transfer will result in fewer operations and a shortened duration of hospitalization in the initial post-trauma period.

  3. Morphological effect of a scallop shell on a flapping-type tidal stream generator

    International Nuclear Information System (INIS)

    Le, Tuyen Quang; Ko, Jin Hwan; Byun, Doyoung

    2013-01-01

    Inspired by nature, flapping-type tidal stream generators have been introduced in recent years. The improvement in their power generation ability is known to be a critical factor in the success of these generators. So far, corrugation and camber observed in flying insects and swimming animals are known to enhance the performance of a flapping-type propulsive system. In this study, we explore the effect of corrugation and camber in a system that mimics a scallop shell in terms of its ability to extract flow energy through a two-dimensional Navier–Stokes simulation. The simulations show that the size and the activity of the leading edge vortex are strongly affected by the morphological factors of the mimicked foils, the effects of which are then advantageous in terms of the power efficiency of the flapping-type tidal stream generator. Eventually, an optimal mimicked foil, as suggested based on the morphological effects, would be a good alternative type of foil with a typical section with regard to the hydrodynamic performance and structural properties of tidal stream generators. (paper)

  4. Reconstruction of the Upper Eyelid with Flaps and Free Grafts after Excision of Basal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Alessandro Guido Actis

    2011-11-01

    Full Text Available Purpose: To describe a reconstructive technique of the superior eyelid with flaps and free grafts after excision of a basal cell carcinoma. Methods: Single case report of a 79-year-old woman who presented to our hospital with a basal cell carcinoma of the upper eyelid margin with initial erosion. Results: A large and full-thickness excision of the carcinoma was performed. The reconstruction technique should be customized to the individual patient. In this case, the use of a full-thickness tarsal graft from the contralateral upper eyelid, followed by an ipsilateral bipedicled flap and finally by a skin graft, was an effective surgical procedure, performed in one stage, without complications, and with good functional and esthetic results. Conclusions: Malignant neoplasms represent the leading cause of plastic reconstruction in the orbital region. Surgical techniques must be individualized for each patient and for each type of carcinoma. Reconstructive techniques with free grafts and flaps yield excellent results in the orbital region, particularly when some advice and a few fundamental rules are followed, namely accurate hemostasis of the receiving graft bed by moderate use of diathermy, careful suturing of the edges, and application of a compressive dressing for at least 4 days. Postoperative complications are very rare.

  5. Results of auricular helical rim reconstruction with post-auricular tube flap.

    Science.gov (United States)

    Iljin, Aleksandra; Lewandowicz, Edward; Antoszewski, Bogusław; Zieliński, Tomasz

    2016-01-01

    The aim of the study was to present our experience with post-auricular tube flap (ptf) and clinical evaluation of the results following auricular helical rim reconstruction with this technique in patients after trauma. We analyzed the results in 12 patients who underwent three-staged auricular helical rim reconstruction with ptf following trauma in the Department of Plastic, Reconstructive and Aesthetic Surgery between 2005-2014. The patients were followed-up for at least 1 year. We evaluated early and long-term results after surgery including plastic surgeon's and patient's opinion. Postoperative results were satisfactory (very good) in 10 cases, both in the opinion of the plastic surgeon and patients. Transient venous congestion of the helix occurred in two cases (16.6%). This complication did not have any influence on estimation of the results after surgery. Delayed wound healing in the poles of the reconstructed helical edge, as well as non-aesthetic helical scars with imperfections of helical rim, were seen in another two patients (16.6%). 1. Post-auricular tube flap reconstructions after helical rim trauma allowed for complete restoration of contour, size and orientation of the helix and the whole operated ear, which confirms the efficiency of the applied technique. 2. Reconstructive surgery with post-auricular tube flap in patients with auricular helical rim defects contributed to postoperative satisfaction in both patients and doctors' estimations.

  6. Assessment of a Conceptual Flap System Intended for Enhanced General Aviation Safety

    Science.gov (United States)

    Campbell, Bryan A.; Carter, Melissa B.

    2017-01-01

    A novel multielement trailing-edge flap system for light general aviation airplanes was conceived for enhanced safety during normal and emergency landings. The system is designed to significantly reduce stall speed, and thus approach speed, with the goal of reducing maneuveringflight accidents and enhancing pilot survivability in the event of an accident. The research objectives were to assess the aerodynamic performance characteristics of the system and to evaluate the extent to which it provided both increased lift and increased drag required for the low-speed landing goal. The flap system was applied to a model of a light general aviation, high-wing trainer and tested in the Langley 12- Foot Low-Speed Wind Tunnel. Data were obtained for several device deflection angles, and component combinations at a dynamic pressure of 4 pounds per square foot. The force and moment data supports the achievement of the desired increase in lift with substantially increased drag, all at relatively shallow angles of attack. The levels of lift and drag can be varied through device deflection angles and inboard/outboard differential deflections. As such, it appears that this flap system may provide an enabling technology to allow steep, controllable glide slopes for safe rapid descent to landing with reduced stall speed. However, a simple flat-plate lower surface spoiler (LSS) provided either similar or superior lift with little impact on pitch or drag as compared to the proposed system. Higher-fidelity studies are suggested prior to use of the proposed system.

  7. Aerodynamic characteristics of a large-scale semispan model with a swept wing and an augmented jet flap with hypermixing nozzles. [Ames 40- by 80-Foot Wind Tunnel and Static Test Facility

    Science.gov (United States)

    Aiken, T. N.; Falarski, M. D.; Koenin, D. G.

    1979-01-01

    The aerodynamic characteristics of the augmentor wing concept with hypermixing primary nozzles were investigated. A large-scale semispan model in the Ames 40- by 80-Foot Wind Tunnel and Static Test Facility was used. The trailing edge, augmentor flap system occupied 65% of the span and consisted of two fixed pivot flaps. The nozzle system consisted of hypermixing, lobe primary nozzles, and BLC slot nozzles at the forward inlet, both sides and ends of the throat, and at the aft flap. The entire wing leading edge was fitted with a 10% chord slat and a blowing slot. Outboard of the flap was a blown aileron. The model was tested statically and at forward speed. Primary parameters and their ranges included angle of attack from -12 to 32 degrees, flap angles of 20, 30, 45, 60 and 70 degrees, and deflection and diffuser area ratios from 1.16 to 2.22. Thrust coefficients ranged from 0 to 2.73, while nozzle pressure ratios varied from 1.0 to 2.34. Reynolds number per foot varied from 0 to 1.4 million. Analysis of the data indicated a maximum static, gross augmentation of 1.53 at a flap angle of 45 degrees. Analysis also indicated that the configuration was an efficient powered lift device and that the net thrust was comparable with augmentor wings of similar static performance. Performance at forward speed was best at a diffuser area ratio of 1.37.

  8. LES tests on airfoil trailing edge serration

    International Nuclear Information System (INIS)

    Zhu, Wei Jun; Shen, Wen Zhong

    2016-01-01

    In the present study, a large number of acoustic simulations are carried out for a low noise airfoil with different Trailing Edge Serrations (TES). The Ffowcs Williams-Hawkings (FWH) acoustic analogy is used for noise prediction at trailing edge. The acoustic solver is running on the platform of our in-house incompressible flow solver EllipSys3D. The flow solution is first obtained from the Large Eddy Simulation (LES), the acoustic part is then carried out based on the instantaneous hydrodynamic pressure and velocity field. To obtain the time history data of sound pressure, the flow quantities are integrated around the airfoil surface through the FWH approach. For all the simulations, the chord based Reynolds number is around 1.5x10 6 . In the test matrix, the effects from angle of attack, the TE flap angle, the length/width of the TES are investigated. Even though the airfoil under investigation is already optimized for low noise emission, most numerical simulations and wind tunnel experiments show that the noise level is further decreased by adding the TES device. (paper)

  9. [Pedicle flap transfer combined with external fixator to treat leg open fracture with soft tissue defect].

    Science.gov (United States)

    Luo, Zhongchun; Lou, Hua; Jiang, Junwei; Song, Chunlin; Gong, Min; Wang, Yongcai

    2008-08-01

    To investigate the clinical results of treating leg open fracture with soft tissue defect by pedicle flap transfer in combination with external fixator. From May 2004 to June 2007, 12 cases of leg open fracture with soft tissue defect, 9 males and 3 females aged 18-75 years, were treated. Among them, 8 cases were caused by traffic accidents, 2 crush, 1 falling and 1 mechanical accident. According to the Gustilo Classification, there were 2 cases of type II, 5 of type IIIA and 5 of type IIIB. There were 2 cases of upper-tibia fracture, 3 of middle-tibia and 7 of middle-lower. The sizes of soft tissue defect ranged from 5 cm x 3 cm to 22 cm x 10 cm.The sizes of exposed bone ranged from 3 cm x 2 cm to 6 cm x 3 cm. The course of the disease was 1-12 hours. Fracture fixation was reached by external fixators or external fixators and limited internal fixation with Kirschner wire. The wounds with exposed tendons and bones were repaired by ipsilateral local rotation flap, sural neurocutaneous flap and saphenous nerve flap. The size of selected flap ranged from 5 cm x 4 cm to 18 cm x 12 cm. Granulation wounds were repaired by skin grafting or direct suture. All patients were followed up for 6 months to 2 years. All patients survived, among whom 2 with the wound edge infection and 1 with the distal necrosis were cured by changing the dressing, 8 with pin hole infection were treated by taking out the external fixator, 1 with nonunion received fracture healing after bone graft in comminuted fracture of lower tibia, 2 suffered delayed union in middle-lower tibia fracture. The ROM of ankle in 3 cases was mildly poor with surpass-joint fixation, with plantar extension of 0-10 degrees and plantar flexion of 10-30 degrees, while the others had plantar extension of 10-20 degrees and plantar flexion of 30-50 degrees. The method of pedicle flap transfer combined with external fixator is safe and effective for the leg open fracture with soft tissue defect.

  10. Flow-Field Investigation of Gear-Flap Interaction on a Gulfstream Aircraft Model

    Science.gov (United States)

    Yao, Chung-Sheng; Jenkins, Luther N.; Bartram, Scott M.; Harris, Jerome; Khorrami, Mehdi R.; Mace, W. Derry

    2014-01-01

    Off-surface flow measurements of a high-fidelity 18% scale Gulfstream aircraft model in landing configuration with the main landing gear deployed are presented. Particle Image Velocimetry (PIV) and Laser Velocimetry (LV) were used to measure instantaneous velocities in the immediate vicinity of the main landing gear and its wake and near the inboard tip of the flap. These measurements were made during the third entry of a series of tests conducted in the NASA Langley Research Center (LaRC) 14- by 22-Foot Subsonic Tunnel (14 x 22) to obtain a comprehensive set of aeroacoustic measurements consisting of both aerodynamic and acoustic data. The majority of the off-body measurements were obtained at a freestream Mach number of 0.2, angle of attack of 3 degrees, and flap deflection angle of 39 degrees with the landing gear on. A limited amount of data was acquired with the landing gear off. LV was used to measure the velocity field in two planes upstream of the landing gear and to measure two velocity profiles in the landing gear wake. Stereo and 2-D PIV were used to measure the velocity field over a region extending from upstream of the landing gear to downstream of the flap trailing edge. Using a special traverse system installed under the tunnel floor, the velocity field was measured at 92 locations to obtain a comprehensive picture of the pertinent flow features and characteristics. The results clearly show distinct structures in the wake that can be associated with specific components on the landing gear and give insight into how the wake is entrained by the vortex at the inboard tip of the flap.

  11. Robot-Assisted Free Flap in Head and Neck Reconstruction

    Directory of Open Access Journals (Sweden)

    Han Gyeol Song

    2013-07-01

    Full Text Available Background  Robots have allowed head and neck surgeons to extirpate oropharyngealtumors safely without the need for lip-split incision or mandibulotomy. Using robots inoropharyngealreconstruction is newbut essentialfor oropharyngeal defectsthatresultfromrobotic tumor excision. We report our experience with robotic free-flap reconstruction ofhead and neck defectsto exemplify the necessity forrobotic reconstruction.Methods  We investigated head and neck cancer patients who underwent ablation surgeryand free-flap reconstruction by robot. Between July 1, 2011 andMarch 31, 2012, 5 caseswereperformed and patient demographics, location of tumor, pathologic stage, reconstructionmethods, flap size, recipient vessel, necessary pedicle length, and operation time wereinvestigated.Results  Among five free-flap reconstructions, four were radial forearm free flaps and onewas an anterolateral thigh free-flap. Four flaps used the superior thyroid artery and oneflap used a facial artery as the recipient vessel. The average pedicle length was 8.8 cm. Flapinsetting and microanastomosis were achieved using a specially manufactured roboticinstrument. The total operation timewas 1,041.0 minutes(range, 814 to 1,132 minutes, andcomplicationsincluding flap necrosis, hematoma, andwound dehiscence did not occur.Conclusions  Thisstudy demonstratesthe clinically applicable use ofrobotsin oropharyngealreconstruction, especially using a free flap. A robot can assist the operator in insettingthe flap at a deep portion of the oropharynx without the need to perform a traditionalmandibulotomy. Robot-assisted reconstruction may substitute for existing surgical methodsand is accepted asthemost up-to-datemethod.

  12. Defining the Role of Free Flaps in Partial Breast Reconstruction.

    Science.gov (United States)

    Smith, Mark L; Molina, Bianca J; Dayan, Erez; Jablonka, Eric M; Okwali, Michelle; Kim, Julie N; Dayan, Joseph H

    2018-03-01

     Free flaps have a well-established role in breast reconstruction after mastectomy; however, their role in partial breast reconstruction remains poorly defined. We reviewed our experience with partial breast reconstruction to better understand indications for free tissue transfer.  A retrospective review was performed of all patients undergoing partial breast reconstruction at our center between February 2009 and October 2015. We evaluated the characteristics of patients who underwent volume displacement procedures versus volume replacement procedures and free versus pedicled flap reconstruction.  There were 78 partial breast reconstructions, with 52 reductions/tissue rearrangements (displacement group) and 26 flaps (replacement group). Bra cup size and body mass index (BMI) were significantly smaller in the replacement group. Fifteen pedicled and 11 free flaps were performed. Most pedicled flaps (80.0%) were used for lateral or upper pole defects. Most free flaps (72.7%) were used for medial and inferior defects or when there was inadequate donor tissue for a pedicled flap. Complications included hematoma, cellulitis, and one aborted pedicled flap.  Free and pedicled flaps are useful for partial breast reconstruction, particularly in breast cancer patients with small breasts undergoing breast-conserving treatment (BCT). Flap selection depends on defect size, location, and donor tissue availability. Medial defects are difficult to reconstruct using pedicled flaps due to arc of rotation and intervening breast tissue. Free tissue transfer can overcome these obstacles. Confirming negative margins before flap reconstruction ensures harvest of adequate volume and avoids later re-operation. Judicious use of free flaps for oncoplastic reconstruction expands the possibility for breast conservation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  13. Reconstruction of the Lower Extremity Using Free Flaps

    Directory of Open Access Journals (Sweden)

    Min Jo Kang

    2013-09-01

    Full Text Available Background The aim of lower-extremity reconstruction has focused on wound coverage andfunctional recovery. However, there are limitations in the use of a local flap in cases of extensivedefects of the lower-extremities. Therefore, free flap is a useful option in lower-extremityreconstruction.Methods We performed a retrospective review of 49 patients (52 cases who underwentlower-extremity reconstruction at our institution during a 10-year period. In these patients,we evaluated causes and sites of defects, types of flaps, recipient vessels, types of anastomosis,survival rate, and complications.Results There were 42 men and 10 women with a mean age of 32.7 years (range, 3-72years. The sites of defects included the dorsum of the foot (19, pretibial area (17, ankle(7, heel (5 and other sites (4. The types of free flap included latissimus dorsi muscle flap(10, scapular fascial flap (6, anterolateral thigh flap (6, and other flaps (30. There werefour cases of vascular complications, out of which two flaps survived after intervention. Theoverall survival of the flaps was 96.2% (50/52. There were 19 cases of other complications atrecipient sites such as partial graft loss (8, partial flap necrosis (6 and infection (5. However,these complications were not notable and were resolved with skin grafts.Conclusions The free flap is an effective method of lower-extremity reconstruction. Goodoutcomes can be achieved with complete debridement and the selection of appropriaterecipient vessels and flaps according to the recipient site.

  14. Reconstruction of the Lower Extremity Using Free Flaps

    Directory of Open Access Journals (Sweden)

    Min Jo Kang

    2013-09-01

    Full Text Available BackgroundThe aim of lower-extremity reconstruction has focused on wound coverage and functional recovery. However, there are limitations in the use of a local flap in cases of extensive defects of the lower-extremities. Therefore, free flap is a useful option in lower-extremity reconstruction.MethodsWe performed a retrospective review of 49 patients (52 cases who underwent lower-extremity reconstruction at our institution during a 10-year period. In these patients, we evaluated causes and sites of defects, types of flaps, recipient vessels, types of anastomosis, survival rate, and complications.ResultsThere were 42 men and 10 women with a mean age of 32.7 years (range, 3-72 years. The sites of defects included the dorsum of the foot (19, pretibial area (17, ankle (7, heel (5 and other sites (4. The types of free flap included latissimus dorsi muscle flap (10, scapular fascial flap (6, anterolateral thigh flap (6, and other flaps (30. There were four cases of vascular complications, out of which two flaps survived after intervention. The overall survival of the flaps was 96.2% (50/52. There were 19 cases of other complications at recipient sites such as partial graft loss (8, partial flap necrosis (6 and infection (5. However, these complications were not notable and were resolved with skin grafts.ConclusionsThe free flap is an effective method of lower-extremity reconstruction. Good outcomes can be achieved with complete debridement and the selection of appropriate recipient vessels and flaps according to the recipient site.

  15. Influence of Thickness Variation on the Flapping Performance of Symmetric NACA Airfoils in Plunging Motion

    Directory of Open Access Journals (Sweden)

    Liangyu Zhao

    2010-01-01

    Full Text Available In order to investigate the impact of airfoil thickness on flapping performance, the unsteady flow fields of a family of airfoils from an NACA0002 airfoil to an NACA0020 airfoil in a pure plunging motion and a series of altered NACA0012 airfoils in a pure plunging motion were simulated using computational fluid dynamics techniques. The “class function/shape function transformation“ parametric method was employed to decide the coordinates of these altered NACA0012 airfoils. Under specified plunging kinematics, it is observed that the increase of an airfoil thickness can reduce the leading edge vortex (LEV in strength and delay the LEV shedding. The increase of the maximum thickness can enhance the time-averaged thrust coefficient and the propulsive efficiency without lift reduction. As the maximum thickness location moves towards the leading edge, the airfoil obtains a larger time-averaged thrust coefficient and a higher propulsive efficiency without changing the lift coefficient.

  16. Edge effects in composites

    International Nuclear Information System (INIS)

    Guz, A.N.; Kokhanenko, Yu.V.

    1995-01-01

    In the present article we survey papers on edge effects investigated by the rigorous approach. We interpret edge effects as stressed states created in a composite as a result of zones in which the stresses exhibit a rapidly changing behavior in comparison with the slow variation of the stresses outside such zones. Here the range of the edge effect is defined as the distance from the point of its inception to the boundary of the edge zone in a given direction. The transition of the stresses to the slowly varying state is determined within prescribed error limits. The size and configuration of the edge zone depends on the tolerated error. Clearly, the main difficulty associated with the rigorous approach is finding solutions of the elasticity problems. The finite-difference approach is suggested for the approximate solution of these problems. In light of the comparative time consumption of the finite-difference approach, it is best directed at certain classes of problems rather than at particular individual problems. Not too many papers on the investigation of edge effects by the rigorous approach have been published to date. Below, following in their footsteps, we formulate edge effect problems in composites, determine classes of problems, and investigate edge effects in composite materials and structural elements using them in Cartesian (planar and three-dimensional problems) and cylindrical (axisymmetric problems) coordinate frames. We note that the division of approaches to the study of edge effects into qualitative (nonrigorous) and quantitative (rigorous) reflects the authors own point of view. Of course, other schemes of classification of the approaches to the investigation of the regions of rapidly varying states in composites are possible

  17. Falling, flapping, flying, swimming,...: High-Re fluid-solid interactions with vortex shedding

    Science.gov (United States)

    Michelin, Sebastien Honore Roland

    The coupling between the motion of a solid body and the dynamics of the surrounding flow is essential to the understanding of a large number of engineering and physical problems, from the stability of a slender structure exposed to the wind to the locomotion of insects, birds and fishes. Because of the strong coupling on a moving boundary of the equations for the solid and fluid, the simulation of such problems is computationally challenging and expensive. This justifies the development of simplified models for the fluid-solid interactions to study their physical properties and behavior. This dissertation proposes a reduced-order model for the interaction of a sharp-edged solid body with a strongly unsteady high Reynolds number flow. In such a case, viscous forces in the fluid are often negligible compared to the fluid inertia or the pressure forces, and the thin boundary layers separate from the solid at the edges, leading to the shedding of large and persistent vortices in the solid's wake. A general two-dimensional framework is presented based on complex potential flow theory. The formation of the solid's vortical wake is accounted for by the shedding of point vortices with unsteady intensity from the solid's sharp edges, and the fluid-solid problem is reformulated exclusively as a solid-vortex interaction problem. In the case of a rigid solid body, the coupled problem is shown to reduce to a set of non-linear ordinary differential equations. This model is used to study the effect of vortex shedding on the stability of falling objects. The solid-vortex model is then generalized to study the fluttering instability and non-linear flapping dynamics of flexible plates or flags. The uttering instability and resulting flapping motion result from the competing effects of the fluid forcing and of the solid's flexural rigidity and inertia. Finally, the solid-vortex model is applied to the study of the fundamental effect of bending rigidity on the flapping performance of

  18. Edge colouring by total labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Stiebitz, M.

    2010-01-01

    We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...

  19. Adobe Edge Quickstart Guide

    CERN Document Server

    Labrecque, Joseph

    2012-01-01

    Adobe Edge Quickstart Guide is a practical guide on creating engaging content for the Web with Adobe's newest HTML5 tool. By taking a chapter-by-chapter look at each major aspect of Adobe Edge, the book lets you digest the available features in small, easily understandable chunks, allowing you to start using Adobe Edge for your web design needs immediately. If you are interested in creating engaging motion and interactive compositions using web standards with professional tooling, then this book is for you. Those with a background in Flash Professional wanting to get started quickly with Adobe

  20. Design considerations for TES and QET sensors

    International Nuclear Information System (INIS)

    Cabrera, B.

    2000-01-01

    We summarize some of the effects that must be taken into account in the design of superconducting Transition Edge Sensors (TES) and Quasiparticle-trap-assisted Electrothermal-feedback Transition-edge-sensors (QET). For the TES these include determining time constants, maintaining voltage bias, avoid electrothermal oscillations, critical current limitations, and saturation. For QET phonon sensors, voltage bias was conceived to allow the simultaneous biasing of parallel TESs with different transition temperatures, and preventing normal-superconducting phase separation

  1. Flapping foil power generator performance enhanced with a spring-connected tail

    Science.gov (United States)

    Liu, Zhengliang; Tian, Fang-Bao; Young, John; Lai, Joseph C. S.

    2017-12-01

    The flexibility effects on the performance of a flapping foil power generator are numerically studied by using the immersed boundary-lattice Boltzmann method at a Reynolds number of 1100. The flapping foil system consists of a rigid NACA0015 foil undergoing harmonic pitch and plunge motions and a passively actuated flat plate pinned to the trailing edge of the rigid foil. The flexibility is modeled by a torsional spring model at the conjuncture of the rigid foil and the tail. Here, a parametric study on mass density and natural frequency is conducted under the optimum kinematic condition of the rigid system identified from the literature and numerical simulations made for reduced frequency f* = 0.04-0.24 and pitch amplitude θ0 = 40°-90°. Four typical cases are discussed in detail by considering time histories of hydrodynamic loads and tail deformations under the optimal and non-optimal kinematic conditions. Results show that under the rigid-system optimal kinematic condition, a tail with appropriate mass density (μ = 0.60) and resonant frequency ( fr*=1.18 ) can improve the maximum efficiency by 7.24% accompanied by an increase of 6.63% in power compared to those of a rigid foil with a rigid tail. This is because the deflection of the tail reduces the low pressure region on the pressure surface (i.e., the lower surface during the upstroke or the upper surface during the downstroke) caused by the leading edge vortex after the stroke reversal, resulting in a higher efficiency. At high flapping frequencies, a spring-connected tail ( fr*=0.13 ) eliminates the large spike in the moment observed in high stiffness cases, reducing the power required for the pitch motion, resulting in 117% improvement in efficiency over that with a rigid tail at a reduced frequency of 0.24.

  2. A Dynamic Stall Model for Airfoils with Deformable Trailing Edges

    International Nuclear Information System (INIS)

    Andersen, Peter Bjoern; Gaunaa, Mac; Bak, Christian; Hansen, Morten Hartvig

    2007-01-01

    The present work contains an extension of the Beddoes-Leishman (B-L) type dynamic stall model, as described by Hansen et al. In this work a Deformable Trailing Edge Geometry (DTEG) has been added to the dynamic stall model. The model predicts the unsteady aerodynamic forces and moments on an airfoil section undergoing arbitrary motion in heave, lead-lag, pitch, Trailing Edge (TE) flapping. In the linear region, the model reduces to the inviscid model of Gaunaa, which includes the aerodynamic effect of a thin airfoil with a deformable camberline in inviscid flow. Therefore, the proposed model can be considered a crossover between the work of Gaunaa for the attached flow region and Hansen et al. The model will be compared to wind tunnel measurements from Velux described by Bak et al

  3. Use of the Anterolateral Thigh and Vertical Rectus Abdominis Musculocutaneous Flaps as Utility Flaps in Reconstructing Large Groin Defects

    Directory of Open Access Journals (Sweden)

    Edwin Jonathan Aslim

    2014-09-01

    Full Text Available BackgroundGroin dissections result in large wounds with exposed femoral vessels requiring soft tissue coverage, and the reconstructive options are diverse. In this study we reviewed our experience with the use of the pedicled anterolateral thigh and vertical rectus abdominis musculocutaneous flaps in the reconstruction of large groin wounds.MethodsGroin reconstructions performed over a period of 10 years were evaluated, with a mean follow up of two years. We included all cases with large or complex (involving perineum defects, which were reconstructed with the pedicled anterolateral thigh musculocutaneous or the vertical rectus abdominis musculocutaneous (VRAM flaps. Smaller wounds which were covered with skin grafts, locally based flaps and pedicled muscle flaps were excluded.ResultsTwenty-three reconstructions were performed for large or complex groin defects, utilising the anterolateral thigh (n=10 and the vertical rectus abdominis (n=13 pedicled musculocutaneous flaps. Femoral vein reconstruction with a prosthetic graft was required in one patient, and a combination flap (VRAM and gracilis muscle flap was performed in another. Satisfactory coverage was achieved in all cases without major complications. No free flaps were used in our series.ConclusionsThe anterolateral thigh and vertical rectus abdominis pedicled musculocutaneous flaps yielded consistent results with little morbidity in the reconstruction of large and complex groin defects. A combination of flaps can be used in cases requiring extensive cover.

  4. 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.

  5. Three-dimensional vortex wake structure of flapping wings in hovering flight.

    Science.gov (United States)

    Cheng, Bo; Roll, Jesse; Liu, Yun; Troolin, Daniel R; Deng, Xinyan

    2014-02-06

    Flapping wings continuously create and send vortices into their wake, while imparting downward momentum into the surrounding fluid. However, experimental studies concerning the details of the three-dimensional vorticity distribution and evolution in the far wake are limited. In this study, the three-dimensional vortex wake structure in both the near and far field of a dynamically scaled flapping wing was investigated experimentally, using volumetric three-component velocimetry. A single wing, with shape and kinematics similar to those of a fruitfly, was examined. The overall result of the wing action is to create an integrated vortex structure consisting of a tip vortex (TV), trailing-edge shear layer (TESL) and leading-edge vortex. The TESL rolls up into a root vortex (RV) as it is shed from the wing, and together with the TV, contracts radially and stretches tangentially in the downstream wake. The downwash is distributed in an arc-shaped region enclosed by the stretched tangential vorticity of the TVs and the RVs. A closed vortex ring structure is not observed in the current study owing to the lack of well-established starting and stopping vortex structures that smoothly connect the TV and RV. An evaluation of the vorticity transport equation shows that both the TV and the RV undergo vortex stretching while convecting downwards: a three-dimensional phenomenon in rotating flows. It also confirms that convection and secondary tilting and stretching effects dominate the evolution of vorticity.

  6. Decomposing the aerodynamic forces of low-Reynolds flapping airfoils

    Science.gov (United States)

    Moriche, Manuel; Garcia-Villalba, Manuel; Flores, Oscar

    2016-11-01

    We present direct numerical simulations of flow around flapping NACA0012 airfoils at relatively small Reynolds numbers, Re = 1000 . The simulations are carried out with TUCAN, an in-house code that solves the Navier-Stokes equations for an incompressible flow with an immersed boundary method to model the presence of the airfoil. The motion of the airfoil is composed of a vertical translation, heaving, and a rotation about the quarter of the chord, pitching. Both motions are prescribed by sinusoidal laws, with a reduced frequency of k = 1 . 41 , a pitching amplitude of 30deg and a heaving amplitude of one chord. Both, the mean pitch angle and the phase shift between pitching and heaving motions are varied, to build a database with 18 configurations. Four of these cases are analysed in detail using the force decomposition algorithm of Chang (1992) and Martín Alcántara et al. (2015). This method decomposes the total aerodynamic force into added-mass (translation and rotation of the airfoil), a volumetric contribution from the vorticity (circulatory effects) and a surface contribution proportional to viscosity. In particular we will focus on the second, analysing the contribution of the leading and trailing edge vortices that typically appear in these flows. This work has been supported by the Spanish MINECO under Grant TRA2013-41103-P. The authors thankfully acknowledge the computer resources provided by the Red Española de Supercomputacion.

  7. Gust alleviation for a STOL transport by using elevator, spoilers, and flaps

    Science.gov (United States)

    Lallman, F. J.

    1974-01-01

    Control laws were developed to investigate methods of alleviating the response of a STOL transport to gusty air. The transport considered in the study had triple-slotted, externally blown jet flaps and a large T-tail. The control devices used were the elevator, spoilers, and flaps. A hybrid computing system was used to simulate linearized longitudinal dynamics of the aircraft and to implement a conjugate gradient optimal search algorithm. The aircraft was simulated in the low-speed approach condition only. Feedback control matrices were found which minimized the average of a quadratic functional involving passenger compartment accelerations, pitch angle and rate, flight path angle and speed variations. The optimization was performed for artificially designed gust inputs in the form of predetermined rectangular waveforms. Results were obtained for elevator, spoilers, and flaps acting singly and in combination. Additional results were obtained for unit sinusoidal gust inputs by using the gain matrices computed for the artificial test gusts. Various sensor configurations were also investigated.

  8. Adobe Edge Preview 3

    CERN Document Server

    Grover, Chris

    2011-01-01

    Want to use an Adobe tool to design animated web graphics that work on iPhone and iPad? You've come to the right book. Adobe Edge Preview 3: The Missing Manual shows you how to build HTML5 graphics using simple visual tools. No programming experience? No problem. Adobe Edge writes the underlying code for you. With this eBook, you'll be designing great-looking web elements in no time. Get to know the workspace. Learn how Adobe Edge Preview 3 performs its magic.Create and import graphics. Make drawings with Edge's tools, or use art you designed in other programs.Work with text. Build menus, lab

  9. Pavement edge treatment.

    Science.gov (United States)

    2013-01-01

    Four projects were built over two construction seasons using special devices attached to the paving machine that produces a 30 slope on the outside pavement edge instead of the near vertical drop-off common with conventional paving equipment. This ...

  10. Edge Simulation Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Krasheninnikov, Sergei I. [Univ. of California, San Diego, CA (United States); Angus, Justin [Univ. of California, San Diego, CA (United States); Lee, Wonjae [Univ. of California, San Diego, CA (United States)

    2018-01-05

    The goal of the Edge Simulation Laboratory (ESL) multi-institutional project is to advance scientific understanding of the edge plasma region of magnetic fusion devices via a coordinated effort utilizing modern computing resources, advanced algorithms, and ongoing theoretical development. The UCSD team was involved in the development of the COGENT code for kinetic studies across a magnetic separatrix. This work included a kinetic treatment of electrons and multiple ion species (impurities) and accurate collision operators.

  11. Flapping dynamics of a thin liquid sheet

    Science.gov (United States)

    Vadivukkarasan, M.; Kumaran, Dhivyaraja; Panchagnula, Mahesh; Multi-phase flow physics Group Team

    2017-11-01

    We attempt to delineate and describe the complete evolution of a thin soap film when air is blown through a nozzle in the normal direction. The sequence of events and its intrinsic dynamics are captured using high speed imaging. By careful observation, it was observed that multiple mechanisms occur in the same system and each event is triggered by an independent mechanism. The events include (a) flapping of a liquid sheet and pinching of the bubble, (b) onset of rupture on the liquid sheet, (c) formation of ligaments and (d) ejection of drops. From this study, it is shown that these events are predominantly governed by Kelvin-Helmholtz instability, Taylor - Culick law, Rayleigh-Taylor instability and capillary instability, respectively. The present experiments can be considered as an extension to the previous studies on soap films as well as thin flapping sheets which has direct relevance to coaxial atomizers used in aircraft applications.

  12. Subcutaneous tissue flaps for hallux covering.

    Science.gov (United States)

    Vaienti, Luca; Urzola, Victor; Scotti, Andrea; Masetto, L

    2010-03-01

    With the understanding of the extensive vascular supply of the subcutaneous tissue, of its efficacy in the protection of the anatomical structures and of its capability of promoting the adequate functioning of very stressed regions of the human body, the use of subcutaneous adipose flaps has become a valid and sometimes the only reasonable therapeutic weapon in the treatment of small and medium-sized tissue loss. Such a defect represents a common complication of great toe injuries and surgery. Here subcutaneous flap reconstruction is proposed for the treatment of dorsal and medial soft tissue losses of the hallux complicated with infection. Two case are reported. To the best of the authors' knowledge, this application has not been reported in this anatomical site so far. The technique might be worth knowing both for orthopedic and plastic surgeons, as it may represent a safe, less invasive solution for most tegumentary problems of the dorso-medial side of the first ray.

  13. Elbow Reconstruction Using Island Flap for Burn Patients

    Directory of Open Access Journals (Sweden)

    Gi Yeun Hur

    2012-11-01

    Full Text Available BackgroundDeep burns of the elbow lead to soft tissue necrosis and infection, with exposure of deep structures. Adequate wound coverage of this area requires thin, pliable, and durable tissue, while optimal functional recovery requires early coverage and functional rehabilitation. We have found 3 types of island flaps that provide reliable coverage for the elbow.MethodsA retrospective study was performed on all patients who underwent flap coverage of an elbow defect at our hospital. The patients' data including age, sex, cause of injury, wound dimensions, timing of flap coverage, postoperative elbow motion, and complications were investigated.ResultsBetween 2001 and 2012, 16 patients were treated at our hospital. The mean age was 53.3 years. Three kinds of flaps were performed: 9 latissimus dorsi flaps, 4 lateral arm flaps, and 4 radial forearm flaps. The average defect size was 183.5 cm2 (range, 28 to 670 cm2. Wound coverage was performed at mean duration of 45.9 days (range, 14 to 91 days. The mean postoperative active elbow flexion was 98° (range, 85° to 115°. Partial flap failure occurred in 1 latissimus dorsi flap. Minor complications included partial flap loss (11.8%, hematoma (23.5%, seroma (35.3%, and wound infection (5.9%.ConclusionsFlap selection for elbow reconstruction is determined by the defect size and the extent of the adjacent tissue injury. Elbow reconstruction using an island flap is a single-staged, reliable, and relatively simple procedure that permits initiation of early rehabilitation, thereby improving a patient's functional outcome.

  14. Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK).

    Science.gov (United States)

    Tsai, Tsung-Han; Peng, Kai-Ling; Lin, Chien-Jen

    2017-01-01

    Laser in situ keratomileusis (LASIK) is the most common and popular procedure performed for the correction of refractive errors in the last two decades. We report a case of traumatic flap displacement with flap folding which occurred 3 years after LASIK was performed. Previous literature suggests that vision prognosis would be closely related to proper and prompt management of traumatic flap displacement with flap folding 3 years after LASIK. A 23-year-old female presented to our hospital who had undergone uneventful LASIK in both eyes 3 years prior. Unfortunately, she had suffered a blunt trauma in her right eye in a car accident. A late onset of corneal flap displacement was found with upper and lower portion of the flap being folded inside the corneal bed. Surgical intervention for debridement with subsequent reposition of corneal flap was performed as soon as possible in the operating room. A bandage contact lens was placed, and topical antibiotic and corticosteroids were given postoperatively. Two days after the operation, the displaced corneal flap was found to be well attached smoothly on the corneal bed without folds. The best-corrected visual acuity was 6/6 with refraction of -0.75 D to 1.0 D ×175° in her right eye 1 month later. We reviewed a total of 19 published cases of late-onset traumatic flap dislocations or displacements after LASIK with complete data from 2000 to 2014. Traumatic displacement of corneal flaps after LASIK may occur after blunt injury with specific direction of force to the flap margin, especially tangential one. According to the previous literature, late-onset traumatic flap displacement may happen at any time after LASIK and be caused by various types of injuries. Fortunately, good visual function could mostly be restored with immediate and proper management.

  15. Robot-Assisted Free Flap in Head and Neck Reconstruction

    Directory of Open Access Journals (Sweden)

    Han Gyeol Song

    2013-07-01

    Full Text Available BackgroundRobots have allowed head and neck surgeons to extirpate oropharyngeal tumors safely without the need for lip-split incision or mandibulotomy. Using robots in oropharyngeal reconstruction is new but essential for oropharyngeal defects that result from robotic tumor excision. We report our experience with robotic free-flap reconstruction of head and neck defects to exemplify the necessity for robotic reconstruction.MethodsWe investigated head and neck cancer patients who underwent ablation surgery and free-flap reconstruction by robot. Between July 1, 2011 and March 31, 2012, 5 cases were performed and patient demographics, location of tumor, pathologic stage, reconstruction methods, flap size, recipient vessel, necessary pedicle length, and operation time were investigated.ResultsAmong five free-flap reconstructions, four were radial forearm free flaps and one was an anterolateral thigh free-flap. Four flaps used the superior thyroid artery and one flap used a facial artery as the recipient vessel. The average pedicle length was 8.8 cm. Flap insetting and microanastomosis were achieved using a specially manufactured robotic instrument. The total operation time was 1,041.0 minutes (range, 814 to 1,132 minutes, and complications including flap necrosis, hematoma, and wound dehiscence did not occur.ConclusionsThis study demonstrates the clinically applicable use of robots in oropharyngeal reconstruction, especially using a free flap. A robot can assist the operator in insetting the flap at a deep portion of the oropharynx without the need to perform a traditional mandibulotomy. Robot-assisted reconstruction may substitute for existing surgical methods and is accepted as the most up-to-date method.

  16. [Pedicled versus free TRAM flap for breast reconstruction].

    Science.gov (United States)

    Galla, T J; Lukas, B; Feller, A M

    1999-03-01

    In breast reconstruction, the free TRAM-flap offers many advantages over the pedicled TRAM-flap. Due to its superior perfusion, the free flap rarely develops necrosis. Shaping of the flap is easier due to the lack of the thick muscle pedicle. Because the rectus muscle is spared, there is minimal donor site morbidity. However, the necessary microvascular anastomoses reduced the acceptance of the free TRAM-flap. During a 13-months period, 51 breast reconstructions were performed in 41 patients, 31 unilateral and ten bilateral. 45 flaps served for delayed reconstruction and six flaps for immediate reconstruction. The operations were performed by two teams working simultaneously. The average operating time was 3.9 hours for unilateral and 6.9 hours for bilateral delayed reconstruction. For immediate reconstruction, 6.2 and 6.3 hours were required for uni- and bilateral procedures, respectively. In 38 flaps, the thoracodorsal vessels served as recipient vessels; 13 flaps were anastomosed to the internal mammary artery and vein. Postoperative complications were observed in 13 patients. Three vessel anastomoses had to be revised. In one flap, a partial necrosis occurred; in two flaps hematoma evacuation was necessary. Two patients suffered from fat necroses at the abdomen and one umbilicus was lost. Skin irritations and seromas at the abdomen occurred in five patients. Pulmonary embolism was diagnosed in one patient three weeks postoperatively. Abdominal hernias or bulging in the epigastric area were not observed up to 15 months after reconstruction. These results reveal a low complication rate for breast reconstruction with the free TRAM-flap. The advantages of this technique as compared to the pedicled technique are discussed.

  17. Anatomy of vastus lateralis muscle flap.

    Science.gov (United States)

    Tayfur, Volkan; Magden, Orhan; Edizer, Mete; Atabey, Atay

    2010-11-01

    A vastus lateralis muscle flap is used as a pedicled and free flap. In this study, the vastus lateralis muscles of 15 adult formalin-fixed cadavers (30 cases) were dissected. The dominant pedicle was found to be descending branch of the lateral circumflex femoral artery. The mean diameter of the artery was found to be 2.1 mm. This pedicle was located 119.4 mm distal to the pubic symphysis. The mean length of the major pedicle was found to be 56.8 mm when the dominant pedicle was chosen to nourish the flap. The dominant pedicle entered the muscle 155.8 and 213.7 mm from the greater trochanter and the anterior superior iliac spine, respectively. The muscle had proximal minor pedicles from the ascending and transverse branches of lateral circumflex femoral artery. These arteries had mean diameters of 1.8 and 2.0 mm, respectively. The distal minor branches were present in all of the dissections. The distal branch had a mean diameter of 1.8 mm. The origin of this distal branch was located 83.7 mm proximal to the intercondylar line. The motor nerve of the vastus lateralis was found to be originating from femoral nerve. The nerve entered the muscle 194.6 mm from the anterior superior iliac spine.

  18. Flapping inertia for selected rotor blades

    Science.gov (United States)

    Berry, John D.; May, Matthew J.

    1991-01-01

    Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected.

  19. A Mission-Adaptive Variable Camber Flap Control System to Optimize High Lift and Cruise Lift-to-Drag Ratios of Future N+3 Transport Aircraft

    Science.gov (United States)

    Urnes, James, Sr.; Nguyen, Nhan; Ippolito, Corey; Totah, Joseph; Trinh, Khanh; Ting, Eric

    2013-01-01

    Boeing and NASA are conducting a joint study program to design a wing flap system that will provide mission-adaptive lift and drag performance for future transport aircraft having light-weight, flexible wings. This Variable Camber Continuous Trailing Edge Flap (VCCTEF) system offers a lighter-weight lift control system having two performance objectives: (1) an efficient high lift capability for take-off and landing, and (2) reduction in cruise drag through control of the twist shape of the flexible wing. This control system during cruise will command varying flap settings along the span of the wing in order to establish an optimum wing twist for the current gross weight and cruise flight condition, and continue to change the wing twist as the aircraft changes gross weight and cruise conditions for each mission segment. Design weight of the flap control system is being minimized through use of light-weight shape memory alloy (SMA) actuation augmented with electric actuators. The VCCTEF program is developing better lift and drag performance of flexible wing transports with the further benefits of lighter-weight actuation and less drag using the variable camber shape of the flap.

  20. Medial circumflex femoral artery flap for ischial pressure sore

    Directory of Open Access Journals (Sweden)

    Palanivelu S

    2009-01-01

    Full Text Available A new axial pattern flap based on the terminal branches of the medial circumflex femoral artery is described for coverage of ischial pressure sore. Based on the terminal branches of the transverse branch of medial circumflex femoral artery, which exit through the gap between the quadratus femoris muscle above and the upper border of adductor magnus muscle below, this fascio cutaneous flap is much smaller than the posterior thigh flap but extremely useful to cover ischeal pressure sores. The skin redundancy below the gluteal fold allows a primary closure of the donor defect. It can also be used in combination with biceps femoris muscle flap.

  1. Reconstruction of radionecrotic ulcer using a myocutaneous flap

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Okano, Shinji; Iwasaki, Yasumasa; Mori, Tamotsu; Miyamoto, Yoshihiro; Shigeki, Sadayuki

    1990-01-01

    Problems in the surgical treatment of radionecrotic ulcers, using a myocutaneous flap, have been reviewed in 21 patients. These problems included poor wound healing, radiation damage to important nerves and vessels there by making dissection difficult, malignant changes, infections, continuing necrosis of the tissue, and bleeding during surgery and secondary hemorrhaging. The use of a myocutaneous flap has many advantages when compared with conventional flaps and free skin grafts in the reconstruction of radionecrotic ulcers. Flap survival was good, but an incomplete excision of the ulcer delayed primary wound healing. Therefore, complete excision of the radionecrotic ulcer is imperative. (author)

  2. Reverse Saphenous Conduit Flap in 19 Dogs and 1 Cat.

    Science.gov (United States)

    Cavalcanti, Jacqueline V J; Barry, Sabrina L; Lanz, Otto I; Barnes, Katherine; Coutin, Julia V

    2018-05-14

    The purpose of this retrospective study was to report the outcomes of 19 dogs and 1 cat undergoing reverse saphenous conduit flap between 1999 and 2016. Reverse saphenous conduit flap was used to treat traumatic wounds and wounds resulting from tumor excision in the hind limb; the majority of cases had medial shearing injuries. All animals had complete flap survival. In five animals (20%), minor donor site dehiscence occurred, which did not require surgery. Other postoperative complications included signs of severe venous congestion in one dog. Reverse saphenous conduit flap is a useful technique to repair skin defects of the distal hind limb.

  3. Development of a morphing flap using shape memory alloy actuators: the aerodynamic characteristics of a morphing flap

    International Nuclear Information System (INIS)

    Ko, Seung-Hee; Bae, Jae-Sung; Rho, Jin-Ho

    2014-01-01

    The discontinuous contour of a wing with conventional flaps diminishes the aerodynamic performance of an aircraft. A wing with a continuous contour does not experience extreme flow stream fluctuations during flight, and consequently has good aerodynamic characteristics. In this study, a morphing flap using shape memory alloy actuators is proposed, designed and fabricated, and its aerodynamic characteristics are investigated using aerodynamic analyses and wind tunnel tests. The ribs of the morphing flap are designed and fabricated with multiple elements joined together in a way that allows relative rotations of adjacent elements and forms a smooth contour of the morphing flap. The aerodynamic analyses of this multiple-element morphing-flap wing are performed using XFLR pro; its aerodynamic performance is compared with that of a mechanical-flap wing, and is measured through wind-tunnel tests. (papers)

  4. The Edge supersonic transport

    Science.gov (United States)

    Agosta, Roxana; Bilbija, Dushan; Deutsch, Marc; Gallant, David; Rose, Don; Shreve, Gene; Smario, David; Suffredini, Brian

    1992-01-01

    As intercontinental business and tourism volumes continue their rapid expansion, the need to reduce travel times becomes increasingly acute. The Edge Supersonic Transport Aircraft is designed to meet this demand by the year 2015. With a maximum range of 5750 nm, a payload of 294 passengers and a cruising speed of M = 2.4, The Edge will cut current international flight durations in half, while maintaining competitive first class, business class, and economy class comfort levels. Moreover, this transport will render a minimal impact upon the environment, and will meet all Federal Aviation Administration Part 36, Stage III noise requirements. The cornerstone of The Edge's superior flight performance is its aerodynamically efficient, dual-configuration design incorporating variable-geometry wingtips. This arrangement combines the benefits of a high aspect ratio wing at takeoff and low cruising speeds with the high performance of an arrow-wing in supersonic cruise. And while the structural weight concerns relating to swinging wingtips are substantial, The Edge looks to ever-advancing material technologies to further increase its viability. Heeding well the lessons of the past, The Edge design holds economic feasibility as its primary focus. Therefore, in addition to its inherently superior aerodynamic performance, The Edge uses a lightweight, largely windowless configuration, relying on a synthetic vision system for outside viewing by both pilot and passengers. Additionally, a fly-by-light flight control system is incorporated to address aircraft supersonic cruise instability. The Edge will be produced at an estimated volume of 400 aircraft and will be offered to airlines in 2015 at $167 million per transport (1992 dollars).

  5. Properties on the edge: graphene edge energies, edge stresses, edge warping, and the Wulff shape of graphene flakes

    International Nuclear Information System (INIS)

    Branicio, Paulo S; Jhon, Mark H; Gan, Chee Kwan; Srolovitz, David J

    2011-01-01

    It has been shown that the broken bonds of an unreconstructed graphene edge generate compressive edge stresses leading to edge warping. Here, we investigate edge energies and edge stresses of graphene nanoribbons with arbitrary orientations from armchair to zigzag, considering both flat and warped edge shapes in the presence and absence of hydrogen. We use the second generation reactive empirical bond order potential to calculate the edge energies and stresses for clean and hydrogenated edges. Using these energies, we perform a Wulff construction to determine the equilibrium shapes of flat graphene flakes as a function of hydrogen chemical potential. While edge stresses for clean, flat edges are compressive, they become tensile if allowed to warp. Conversely, we find that edge energies change little (∼1%) with edge warping. Hydrogenation of the edges virtually eliminates both the edge energy and edge stresses. For warped edges an approximately linear relationship is found between amplitudes and wavelengths. The equilibrium shape of a graphene flake is determined by the value of the hydrogen chemical potential. For very small (and large) values of it the flakes have a nearly hexagonal (dodecagon) shape with zigzag oriented edges, while for intermediate values graphene flakes are found with complex shapes

  6. Theory of edge radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Kocharyan, V.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2008-08-15

    We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition UndulatorRadiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and other issues becoming important at high electron energy and long radiation wavelength. Based on this work we also study the impact of Edge Radiation on XFEL setups and we discuss recent results. (orig.)

  7. Exploratory study of the effects of wing-leading-edge modifications on the stall/spin behavior of a light general aviation airplane

    Science.gov (United States)

    1979-01-01

    Configurations with full-span and segmented leading-edge flaps and full-span and segmented leading-edge droop were tested. Studies were conducted with wind-tunnel models, with an outdoor radio-controlled model, and with a full-scale airplane. Results show that wing-leading-edge modifications can produce large effects on stall/spin characteristics, particularly on spin resistance. One outboard wing-leading-edge modification tested significantly improved lateral stability at stall, spin resistance, and developed spin characteristics.

  8. Elbow Reconstruction Using Island Flap for Burn Patients

    Directory of Open Access Journals (Sweden)

    Gi Yeun Hur

    2012-11-01

    Full Text Available Background Deep burns of the elbow lead to soft tissue necrosis and infection, with exposureof deep structures. Adequate wound coverage of this area requires thin, pliable, and durabletissue, while optimal functional recovery requires early coverage and functional rehabilitation.We have found 3 types of island flaps that provide reliable coverage for the elbow.Methods A retrospective study was performed on all patients who underwent flap coverageof an elbow defect at our hospital. The patients’ data including age, sex, cause of injury, wounddimensions, timing of flap coverage, postoperative elbow motion, and complications wereinvestigated.Results Between 2001 and 2012, 16 patients were treated at our hospital. The mean agewas 53.3 years. Three kinds of flaps were performed: 9 latissimus dorsi flaps, 4 lateral armflaps, and 4 radial forearm flaps. The average defect size was 183.5 cm2 (range, 28 to 670cm2. Wound coverage was performed at mean duration of 45.9 days (range, 14 to 91 days.The mean postoperative active elbow flexion was 98° (range, 85° to 115°. Partial flap failureoccurred in 1 latissimus dorsi flap. Minor complications included partial flap loss (11.8%,hematoma (23.5%, seroma (35.3%, and wound infection (5.9%.Conclusions Flap selection for elbow reconstruction is determined by the defect size andthe extent of the adjacent tissue injury. Elbow reconstruction using an island flap is a singlestaged,reliable, and relatively simple procedure that permits initiation of early rehabilitation,thereby improving a patient’s functional outcome.

  9. 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

  10. Numerical simulation of X-wing type biplane flapping wings in 3D using the immersed boundary method

    International Nuclear Information System (INIS)

    Tay, W B; Van Oudheusden, B W; Bijl, H

    2014-01-01

    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

  11. High Speed Edge Detection

    Science.gov (United States)

    Prokop, Norman F (Inventor)

    2016-01-01

    Analog circuits for detecting edges in pixel arrays are disclosed. A comparator may be configured to receive an all pass signal and a low pass signal for a pixel intensity in an array of pixels. A latch may be configured to receive a counter signal and a latching signal from the comparator. The comparator may be configured to send the latching signal to the latch when the all pass signal is below the low pass signal minus an offset. The latch may be configured to hold a last negative edge location when the latching signal is received from the comparator.

  12. Structural Health Monitoring Analysis for the Orbiter Wing Leading Edge

    Science.gov (United States)

    Yap, Keng C.

    2010-01-01

    This viewgraph presentation reviews Structural Health Monitoring Analysis for the Orbiter Wing Leading Edge. The Wing Leading Edge Impact Detection System (WLE IDS) and the Impact Analysis Process are also described to monitor WLE debris threats. The contents include: 1) Risk Management via SHM; 2) Hardware Overview; 3) Instrumentation; 4) Sensor Configuration; 5) Debris Hazard Monitoring; 6) Ascent Response Summary; 7) Response Signal; 8) Distribution of Flight Indications; 9) Probabilistic Risk Analysis (PRA); 10) Model Correlation; 11) Impact Tests; 12) Wing Leading Edge Modeling; 13) Ascent Debris PRA Results; and 14) MM/OD PRA Results.

  13. Applying the computer code ''beam scanning' for obtaining the electron beam energy spectrum and monitoring the beam scanning system with a faraday cup and edge current sensors

    International Nuclear Information System (INIS)

    Bystrov, P.A.

    2014-01-01

    The results of experiments simulation, obtained in the development of technique for controlling the parameters of the electron beam in a compact radiation sterilization installation are presented. Calculations were performed with a help of a computer code ''BEAM SCANNING'', developed in MRTI. Proposed a method to obtain the spectrum of the electron beam by simulation the experiments in which a Faraday cup waveforms were measured. Preliminary results are presented. Also the results of the experiments and calculations obtained in the development of the amplitude angle sensors are presented. The experiments for the beam irradiation of lead plates proposed as current sensors were modeled. Results are presented in comparison with experimental data. Also are presented the simulation results for the device designed to control scanning system.

  14. Free Boomerang-shaped Extended Rectus Abdominis Myocutaneous flap: The longest possible skin/myocutaneous free flap for soft tissue reconstruction of extremities

    Directory of Open Access Journals (Sweden)

    Ashok R Koul

    2011-01-01

    Full Text Available Background: A soft tissue defect requiring flap cover which is longer than that provided by the conventional "long" free flaps like latissimus dorsi (LD and anterolateral thigh (ALT flap is a challenging problem. Often, in such a situation, a combination of flaps is required. Over the last 3 years, we have managed nine such defects successfully with a free "Boomerang-shaped" Extended Rectus Abdominis Myocutaneous (BERAM flap. This flap is the slightly modified and "free" version of a similar flap described by Ian Taylor in 1983. Materials and Methods: This is a retrospective study of patients who underwent free BERAM flap reconstruction of soft tissue defects of extremity over the last 3 years. We also did a clinical study on 30 volunteers to compare the length of flap available using our design of BERAM flap with the maximum available flap length of LD and ALT flaps, using standard markings. Results: Our clinical experience of nine cases combined with the results of our clinical study has confirmed that our design of BERAM flap consistently provides a flap length which is 32.6% longer than the standard LD flap and 42.2% longer than the standard ALT flap in adults. The difference is even more marked in children. The BERAM flap is consistently reliable as long as the distal end is not extended beyond the mid-axillary line. Conclusion: BERAM flap is simple in design, easy to harvest, reliable and provides the longest possible free skin/myocutaneous flap in the body. It is a useful new alternative for covering long soft tissue defects in the limbs.

  15. Free Boomerang-shaped Extended Rectus Abdominis Myocutaneous flap: The longest possible skin/myocutaneous free flap for soft tissue reconstruction of extremities.

    Science.gov (United States)

    Koul, Ashok R; Nahar, Sushil; Prabhu, Jagdish; Kale, Subhash M; Kumar, Praveen H P

    2011-09-01

    A soft tissue defect requiring flap cover which is longer than that provided by the conventional "long" free flaps like latissimus dorsi (LD) and anterolateral thigh (ALT) flap is a challenging problem. Often, in such a situation, a combination of flaps is required. Over the last 3 years, we have managed nine such defects successfully with a free "Boomerang-shaped" Extended Rectus Abdominis Myocutaneous (BERAM) flap. This flap is the slightly modified and "free" version of a similar flap described by Ian Taylor in 1983. This is a retrospective study of patients who underwent free BERAM flap reconstruction of soft tissue defects of extremity over the last 3 years. We also did a clinical study on 30 volunteers to compare the length of flap available using our design of BERAM flap with the maximum available flap length of LD and ALT flaps, using standard markings. Our clinical experience of nine cases combined with the results of our clinical study has confirmed that our design of BERAM flap consistently provides a flap length which is 32.6% longer than the standard LD flap and 42.2% longer than the standard ALT flap in adults. The difference is even more marked in children. The BERAM flap is consistently reliable as long as the distal end is not extended beyond the mid-axillary line. BERAM flap is simple in design, easy to harvest, reliable and provides the longest possible free skin/myocutaneous flap in the body. It is a useful new alternative for covering long soft tissue defects in the limbs.

  16. Repair of nostril stenosis using a triple flap combination: boomerang, nasolabial, and vestibular rotation flaps.

    Science.gov (United States)

    Bozkurt, Mehmet; Kapi, Emin; Kuvat, Samet Vasfi; Selçuk, Caferi Tayyar

    2012-11-01

    Tissue losses within the nose due to various reasons result in the loss of normal anatomy and function. The external nasal valve area is one of the most important functional components of the nose. The columella, lobule, nostril, and alar region are among the components forming the external nasal valve area. Deformities of the nostrils are among the most frequently observed features that interfere with the functional anatomy of the nose. Malformations of the nostrils often emerge subsequent to cleft lip repairs. Stenoses are a common type of pathology among nostril deformities. In cases where a stenosis has formed, breathing problems and developmental anomalies may occur. In the patient with nostril stenosis presented in this report, there was a serious alar collapse and contracture subsequent to a cleft lip repair. In order to repair the nostril stenosis, a "boomerang flap" was chosen. This boomerang flap was used in combination with a nasolabial flap, a vestibular rotation flap, and a conchal cartilage graft to achieve a satisfactory repair.

  17. Rotational accelerations stabilize leading edge vortices on revolving fly wings.

    Science.gov (United States)

    Lentink, David; Dickinson, Michael H

    2009-08-01

    The aerodynamic performance of hovering insects is largely explained by the presence of a stably attached leading edge vortex (LEV) on top of their wings. Although LEVs have been visualized on real, physically modeled, and simulated insects, the physical mechanisms responsible for their stability are poorly understood. To gain fundamental insight into LEV stability on flapping fly wings we expressed the Navier-Stokes equations in a rotating frame of reference attached to the wing's surface. Using these equations we show that LEV dynamics on flapping wings are governed by three terms: angular, centripetal and Coriolis acceleration. Our analysis for hovering conditions shows that angular acceleration is proportional to the inverse of dimensionless stroke amplitude, whereas Coriolis and centripetal acceleration are proportional to the inverse of the Rossby number. Using a dynamically scaled robot model of a flapping fruit fly wing to systematically vary these dimensionless numbers, we determined which of the three accelerations mediate LEV stability. Our force measurements and flow visualizations indicate that the LEV is stabilized by the ;quasi-steady' centripetal and Coriolis accelerations that are present at low Rossby number and result from the propeller-like sweep of the wing. In contrast, the unsteady angular acceleration that results from the back and forth motion of a flapping wing does not appear to play a role in the stable attachment of the LEV. Angular acceleration is, however, critical for LEV integrity as we found it can mediate LEV spiral bursting, a high Reynolds number effect. Our analysis and experiments further suggest that the mechanism responsible for LEV stability is not dependent on Reynolds number, at least over the range most relevant for insect flight (100wind turbines at much higher Reynolds numbers suggest that even large flying animals could potentially exploit LEV-based force augmentation during slow hovering flight, take-offs or landing

  18. Repair of large palatal fistula using tongue flap

    Directory of Open Access Journals (Sweden)

    Fejjal Nawfal

    2014-01-01

    Full Text Available Large palatal fistulas are a challenging problem in cleft surgery. Many techniques are used to close the defect. The tongue flap is an easy and reproductible procedure for managing this complication. The authors report a case of a large palatal fistula closure with anteriorly based tongue flap.

  19. Treatment of ischial pressure sores with double adipofascial turnover flaps.

    Science.gov (United States)

    Lin, Haodong; Hou, Chunlin; Xu, Zhen; Chen, Aiming

    2010-01-01

    Despite a variety of flap reconstruction options, the ischium remains the most difficult pressure sore site to treat. This article describes the authors' successful surgical procedure for coverage of ischial ulcers using double adipofascial turnover flaps.After debridement, the adipofascial flaps are harvested both cephalad and caudal to the defect. The flaps are then turned over to cover the exposed bone in a manner so as to overlap the 2 flaps. The skin is then closed with sutures in 2 layers. A total of 15 patients with ischial sores were treated using this surgical procedure.The follow-up period ranged from 11 to 159 months, with a mean of 93.6 months. Overall, 86.7% of the flaps (13 of 15) healed primarily. One patient had a recurrent grade II ischial pressure sore again 11 months after the operation. The other 14 patients did not have a recurrence.Treatment of ischial pressure sores with adipofascial turnover flaps provides an easy, minimally invasive procedure, with preservation of future flap options, and a soft-tissue supply sufficient for covering the bony prominence and filling dead space. This technique is a reliable and safe reconstructive modality for the management of minor ischial pressure sores.

  20. Upper lip reconstruction using a pedicel superficial temporal artery flap

    Directory of Open Access Journals (Sweden)

    Mohammad M. Al-Qattan

    2018-01-01

    Conclusion: We demonstrate that the pedicle flap is much simpler than the free flap and is adequate for reconstruction of partial upper lip defects. We also demonstrate a good cosmetic and functional outcome; and highlight several technical points to ensure a satisfactory outcome.

  1. Accuracy of Visual Estimation of LASIK Flap Thickness.

    Science.gov (United States)

    Brenner, Jason E; Fadlallah, Ali; Hatch, Kathryn M; Choi, Catherine; Sayegh, Rony R; Kouyoumjian, Paul; Wu, Simon; Frangieh, George T; Melki, Samir A

    2017-11-01

    To assess the accuracy of surgeons' visual estimation of LASIK flap thickness when created by a femtosecond laser by comparing it to ultrasound measurements. Surgeons were asked to visually estimate the thickness of a femtosecond flap during the procedure. Total corneal thickness was measured by ultrasound pachymetry prior to the procedure and the stromal bed was similarly measured after flap lifting. The estimates from three experienced surgeons (cornea fellowship trained and more than 5 years in practice) were compared to those of three cornea fellows, with each surgeon evaluating 20 eyes (120 total). Surgeons were not told the thickness of the flaps unless required for safety reasons. The average difference between visual and ultrasonic estimation of LASIK flap thickness was 15.20 μm. The flap was 10 μm thicker than estimated in 37% of eyes, 20 μm thicker in 17% of eyes, and 30 μm thicker in 10% of eyes. The largest deviation was 53 μm. There was no statistically significant difference between the accuracy of experienced surgeons and fellows (P = .51). There are significant differences between surgeons' visual estimates and ultrasonic measurements of LASIK flap thickness. Relying on these visual estimates may lead to deeper excimer laser ablation than intended. This could lead to thinner residual stromal beds and higher percent tissue altered than planned. The authors recommend that surgeons measure flaps intraoperatively to maximize accuracy and safety. [J Refract Surg. 2017;33(11):765-767.]. Copyright 2017, SLACK Incorporated.

  2. Preoperative CT angiography reduces surgery time in perforator flap reconstruction

    NARCIS (Netherlands)

    Smit, Jeroen M.; Dimopoulou, Angeliki; Liss, Anders G.; Zeebregts, Clark J.; Kildal, Morten; Whitaker, Iain S.; Magnusson, Anders; Acosta, Rafael

    The use of perforator flaps in breast reconstructions has increased considerably in the past decade. A disadvantage of the perforator flap is difficult dissection, which results in a longer procedure. During spring 2006, we introduced CT angiography (CTA) as part of the diagnostic work-up in

  3. The management of pelvic pressure ulcers by myocutaneous flaps ...

    African Journals Online (AJOL)

    Pressure ulcers or ischaemic necrosis of tissues over bony eminences due to pressure, heal very slowly. Vascularised tissues such as myocutaneous flaps are necessary to cover the ulcer and accelerate healing. This study was done to share our experience with methods of myocutaneous flaps in the treatment of pressure ...

  4. Regional Myocutaneous Flaps for Head and Neck Reconstruction ...

    African Journals Online (AJOL)

    Regional myocutaneous pedicle flaps (RMF) are known to be relevant in the reconstruction of major head and neck oncologic defects with pectoralis major myocutaneous pedicle flap (PMMC) being the best-known RMF. For over three decades, since first described by Ariyan in 1979, PMMC has continually been used in the ...

  5. Scrotal Reconstruction with a Pedicled Gracilis Muscle Flap after ...

    African Journals Online (AJOL)

    Several scrotal reconstructive options are available including split thickness skin grafts, scrotal advancement flaps, local fasciocutaneous, muscle or myocutaneous flaps, and free tissue transfer. We report a case of a 34 year old African male who presented as a referral from a district hospital with a scrotal defect and ...

  6. Propeller flaps for lower-limb trauma | Rogers | South African ...

    African Journals Online (AJOL)

    The propeller flap has become a versatile and important component in our reconstructive algorithm following complex lower limb trauma. First described by Hyakusoku in 1991, it has since been adapted and modified by Hallock and Teo. This article outlines our experience specifically with perforator pedicled propeller flaps ...

  7. Peri-Vesical Fat Interposition Flap Reinforcement in High Vesico ...

    African Journals Online (AJOL)

    Background and Aim: The urinary bladder becomes small, contracted and is associated with excess pelvic fat in long standing cases of vesico-vaginal fistulas (VVFs). The aim of this new technique was to use this excess pelvic fat for harvesting an interposition flap. Materials and Methods: An interposition flap of peri-vesical ...

  8. Low-speed tests of a high-aspect-ratio, supercritical-wing transport model equipped with a high-lift flap system in the Langley 4- by 7-meter and Ames 12-foot pressure tunnels

    Science.gov (United States)

    Morgan, H. L., Jr.; Kjelgaard, S. O.

    1983-01-01

    The Ames 12-Foot Pressure Tunnel was used to determine the effects of Reynolds number on the static longitudinal 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. The model had a wing span of 7.5 ft and was tested through a free stream Reynolds number range from 1.3 to 6.0 x 10 to 6th power per foot at a Mach number of 0.20. Prior to the Ames tests, an investigation was also conducted in the Langley 4 by 7 Meter Tunnel at a Reynolds number of 1.3 x 10 to 6th power per foot with the model mounted on an Ames strut support system and on the Langley sting support system to determine strut interference corrections. The data obtained from the Langley tests were also used to compare the aerodynamic charactertistics of the rather stiff, 7.5-ft-span steel wing model tested during this investigation and the larger, and rather flexible, 12-ft-span aluminum-wing model tested during a previous investigation. During the tests in both the Langley and Ames tunnels, the model was tested with six basic wing configurations: (1) cruise; (2) climb (slats only extended); (3) 15 deg take-off flaps; (4) 30 deg take-off flaps; (5) 45 deg landing flaps; and (6) 60 deg landing flaps.

  9. Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK

    Directory of Open Access Journals (Sweden)

    Tsai TH

    2017-04-01

    Full Text Available Tsung-Han Tsai,1 Kai-Ling Peng,1 Chien-Jen Lin2 1Department of Ophthalmology, 2Department of Radiology, Chi Mei Medical Center, Tainan, Taiwan Background: Laser in situ keratomileusis (LASIK is the most common and popular procedure performed for the correction of refractive errors in the last two decades. We report a case of traumatic flap displacement with flap folding which occurred 3 years after LASIK was performed. Previous literature suggests that vision prognosis would be closely related to proper and prompt management of traumatic flap displacement with flap folding 3 years after LASIK.Case presentation: A 23-year-old female presented to our hospital who had undergone uneventful LASIK in both eyes 3 years prior. Unfortunately, she had suffered a blunt trauma in her right eye in a car accident. A late onset of corneal flap displacement was found with upper and lower portion of the flap being folded inside the corneal bed. Surgical intervention for debridement with subsequent reposition of corneal flap was performed as soon as possible in the operating room. A bandage contact lens was placed, and topical antibiotic and corticosteroids were given postoperatively. Two days after the operation, the displaced corneal flap was found to be well attached smoothly on the corneal bed without folds. The best-corrected visual acuity was 6/6 with refraction of −0.75 D to 1.0 D ×175° in her right eye 1 month later.Literature review: We reviewed a total of 19 published cases of late-onset traumatic flap dislocations or displacements after LASIK with complete data from 2000 to 2014.Conclusion: Traumatic displacement of corneal flaps after LASIK may occur after blunt injury with specific direction of force to the flap margin, especially tangential one. According to the previous literature, late-onset traumatic flap displacement may happen at any time after LASIK and be caused by various types of injuries. Fortunately, good visual function could

  10. Triangulation-based edge measurement using polyview optics

    Science.gov (United States)

    Li, Yinan; Kästner, Markus; Reithmeier, Eduard

    2018-04-01

    Laser triangulation sensors as non-contact measurement devices are widely used in industry and research for profile measurements and quantitative inspections. Some technical applications e.g. edge measurements usually require a configuration of a single sensor and a translation stage or a configuration of multiple sensors, so that they can measure a large measurement range that is out of the scope of a single sensor. However, the cost of both configurations is high, due to the additional rotational axis or additional sensor. This paper provides a special measurement system for measurement of great curved surfaces based on a single sensor configuration. Utilizing a self-designed polyview optics and calibration process, the proposed measurement system allows an over 180° FOV (field of view) with a precise measurement accuracy as well as an advantage of low cost. The detailed capability of this measurement system based on experimental data is discussed in this paper.

  11. Elastomeric Structural Attachment Concepts for Aircraft Flap Noise Reduction - Challenges and Approaches to Hyperelastic Structural Modeling and Analysis

    Science.gov (United States)

    Sreekantamurthy, Thammaiah; Turner, Travis L.; Moore, James B.; Su, Ji

    2014-01-01

    Airframe noise is a significant part of the overall noise of transport aircraft during the approach and landing phases of flight. Airframe noise reduction is currently emphasized under the Environmentally Responsible Aviation (ERA) and Fixed Wing (FW) Project goals of NASA. A promising concept for trailing-edge-flap noise reduction is a flexible structural element or link that connects the side edges of the deployable flap to the adjacent main-wing structure. The proposed solution is distinguished by minimization of the span-wise extent of the structural link, thereby minimizing the aerodynamic load on the link structure at the expense of increased deformation requirement. Development of such a flexible structural link necessitated application of hyperelastic materials, atypical structural configurations and novel interface hardware. The resulting highly-deformable structural concept was termed the FLEXible Side Edge Link (FLEXSEL) concept. Prediction of atypical elastomeric deformation responses from detailed structural analysis was essential for evaluating feasible concepts that met the design constraints. The focus of this paper is to describe the many challenges encountered with hyperelastic finite element modeling and the nonlinear structural analysis of evolving FLEXSEL concepts. Detailed herein is the nonlinear analysis of FLEXSEL concepts that emerged during the project which include solid-section, foamcore, hollow, extended-span and pre-stressed concepts. Coupon-level analysis performed on elastomeric interface joints, which form a part of the FLEXSEL topology development, are also presented.

  12. The Inner Urban Edge

    Science.gov (United States)

    Ferebee, Ann; Carpenter, Edward K.

    1974-01-01

    In this article, renewal of the inner urban edge is discussed. Norfolk (Virginia) is attempting to blur the difference between old and new neighbor hoods through zoning and architectural controls. Cincinnati (Ohio) is developing an environmentally sound hillside design. Reading (Pennsylvania) is utilizing old railyards for greenbelts of hiking and…

  13. Swords with Blunt Edges

    Science.gov (United States)

    Popham, W. James

    2004-01-01

    Many U.S. educators now wonder whether they're teachers or targets. This mentality stems from the specter of their school being sanctioned for failing the state accountability tests mandated under No Child Left Behind (NCLB). According to this author, most of those tests are like blunt-edged swords: They function badly in two directions. While…

  14. LASIK flap buttonhole treated immediately by PRK with mitomycin C.

    Science.gov (United States)

    Kymionis, George D; Portaliou, Dimitra M; Karavitaki, Alexandra E; Krasia, Maria S; Kontadakis, Georgios A; Stratos, Aimilianos; Yoo, Sonia H

    2010-03-01

    To describe the visual outcomes of three patients who had LASIK flap buttonhole and were treated immediately with photorefractive keratectomy (PRK) and topical mitomycin C (MMC) 0.02%. Three patients underwent bilateral LASIK with the SCHWIND Carriazo-Pendula 90 microm head microkeratome. In all three cases, a buttonhole flap occurred in the left eye. The flap was repositioned and phototherapeutic keratectomy for 50 microm was used for epithelial removal while immediate PRK with MMC was performed to treat the buttonhole flap. Three months after the procedure, uncorrected distance visual acuity and corrected distance visual acuity were 20/20 with regular topographic findings. Using PRK with MCC immediately after the occurrence of the LASIK flap buttonhole may be an effective treatment.

  15. Clinical application of scrotal flap on penis lengthening.

    Science.gov (United States)

    Zhuo, Qinqiang; Li, Shirong; Wu, Julong; Wang, Zhenxiang; Yang, Dongyun; Tao, Ling

    2009-03-01

    To investigate the clinical application of the scrotal flap on penis lengthening. One hundred and fifty-two patients were operated using the scrotal flap from July 1998 to January 2008 at the Department of Plastic and Aesthetic, Surgery Southwest Hospital, Chongqing, China. The procedure consisted of designing a positive sign shaped incision 1.5cm above the root of the penis, dissect and release the superficial suspensory ligament and part of the deep suspensory ligament, then cover the elongated cavernosum with proper scrotal flap. Six-month to 5-year follow-up showed that all patients were satisfied with the good contour and function of the penis. The operation was successful. The method of using scrotal flap on penis lengthening has the following advantages: simple operation, reliable blood supply of the flap, one-stage operation, and satisfactory postoperative results. It is a preferable operation technique for penis lengthening.

  16. Study of Flapping Flight Using Discrete Vortex Method Based Simulations

    Science.gov (United States)

    Devranjan, S.; Jalikop, Shreyas V.; Sreenivas, K. R.

    2013-12-01

    In recent times, research in the area of flapping flight has attracted renewed interest with an endeavor to use this mechanism in Micro Air vehicles (MAVs). For a sustained and high-endurance flight, having larger payload carrying capacity we need to identify a simple and efficient flapping-kinematics. In this paper, we have used flow visualizations and Discrete Vortex Method (DVM) based simulations for the study of flapping flight. Our results highlight that simple flapping kinematics with down-stroke period (tD) shorter than the upstroke period (tU) would produce a sustained lift. We have identified optimal asymmetry ratio (Ar = tD/tU), for which flapping-wings will produce maximum lift and find that introducing optimal wing flexibility will further enhances the lift.

  17. The expanded "BAT" flap for treatment of male pattern baldness.

    Science.gov (United States)

    Anderson, R D

    1993-11-01

    A new combination of expanded simultaneous transposition and advancement flaps is reported for the treatment of extensive male pattern baldness. Although vertical transposition and parieto-occipital advancement flaps in themselves are not new, their combination and simultaneous bilateral use combined with the use of expansion is new. The advantages of the expanded bilateral advancement transposition flap procedure are presented, along with the technique and results. The results are predictable, providing a more pleasing result, with a natural immediate temporal recession, avoidance of temporal dog-ears, and desirable anterior-superior direction of hair growth. Although flaps do require surgical skill and training, and there are risks and possible complications involved, the results are achieved in a relatively short time compared with grafting techniques. Flaps also provide the advantages of a full and natural hairline contrasted with the sparse look afforded by multiple grafts. The described procedures are very effective and reliable when properly planned and properly executed.

  18. Tensor fascia lata flap versus tensor fascia lata perforator-based island flap for the coverage of extensive trochanteric pressure sores.

    Science.gov (United States)

    Kim, Youn Hwan; Kim, Sang Wha; Kim, Jeong Tae; Kim, Chang Yeon

    2013-06-01

    Tensor fascia lata (TFL) musculocutaneous flaps often require a donor site graft when harvesting a large flap. However, a major drawback is that it also sacrifices the muscle. To overcome this disadvantage, we designed a TFL perforator-based island flap that was harvested from a site near the defect and involved transposition within 90 degrees without full isolation of the pedicles. We performed procedures on 17 musculocutaneous flaps and 23 perforator-based island flaps, and compared the outcomes of these surgeries. The overall complication rate was 27.5% (11 regions). There were 7 complications related to the musculocutaneous flaps and 4 complications related to the perforator flaps. Although there were no statistical differences between those groups, lower complication rates were associated with procedures involving perforator flaps. The TFL perforator procedure is a simple and fast operation that avoids sacrificing muscle. This decreases complication rates compared to true perforator flap techniques that require dissection around the perforator or pedicle.

  19. The SKED: speckle knife edge detector

    International Nuclear Information System (INIS)

    Sharpies, S D; Light, R A; Achamfuo-Yeboah, S O; Clark, M; Somekh, M G

    2014-01-01

    The knife edge detector—also known as optical beam deflection—is a simple and robust method of detecting ultrasonic waves using a laser. It is particularly suitable for detection of high frequency surface acoustic waves as the response is proportional to variation of the local tilt of the surface. In the case of a specular reflection of the incident laser beam from a smooth surface, any lateral movement of the reflected beam caused by the ultrasonic waves is easily detected by a pair of photodiodes. The major disadvantage of the knife edge detector is that it does not cope well with optically rough surfaces, those that give a speckled reflection. The optical speckles from a rough surface adversely affect the efficiency of the knife edge detector, because 'dark' speckles move synchronously with 'bright' speckles, and their contributions to the ultrasonic signal cancel each other out. We have developed a new self-adapting sensor which can cope with the optical speckles reflected from a rough surface. It is inelegantly called the SKED—speckle knife edge detector—and like its smooth surface namesake it is simple, cheap, compact, and robust. We describe the theory of its operation, and present preliminary experimental results validating the overall concept and the operation of the prototype device

  20. The SKED: speckle knife edge detector

    Science.gov (United States)

    Sharpies, S. D.; Light, R. A.; Achamfuo-Yeboah, S. O.; Clark, M.; Somekh, M. G.

    2014-06-01

    The knife edge detector—also known as optical beam deflection—is a simple and robust method of detecting ultrasonic waves using a laser. It is particularly suitable for detection of high frequency surface acoustic waves as the response is proportional to variation of the local tilt of the surface. In the case of a specular reflection of the incident laser beam from a smooth surface, any lateral movement of the reflected beam caused by the ultrasonic waves is easily detected by a pair of photodiodes. The major disadvantage of the knife edge detector is that it does not cope well with optically rough surfaces, those that give a speckled reflection. The optical speckles from a rough surface adversely affect the efficiency of the knife edge detector, because 'dark' speckles move synchronously with 'bright' speckles, and their contributions to the ultrasonic signal cancel each other out. We have developed a new self-adapting sensor which can cope with the optical speckles reflected from a rough surface. It is inelegantly called the SKED—speckle knife edge detector—and like its smooth surface namesake it is simple, cheap, compact, and robust. We describe the theory of its operation, and present preliminary experimental results validating the overall concept and the operation of the prototype device.

  1. Aerodynamic Optimization of Vertical Axis Wind Turbine with Trailing Edge Flap

    DEFF Research Database (Denmark)

    Ertem, Sercan; Ferreira, Carlos Simao; Gaunaa, Mac

    2016-01-01

    Vertical Axis Wind Turbines (VAWT) are competitive concepts for very large scale (10-20 MW)floating ofshore applications. Rotor circulation control (loading control) opens a wide design space to enhance the aerodynamic and operational features of VAWT. The modied linear derivation of the Actuator...

  2. Towards an Industrial Manufactured Morphing Trailing Edge Flap System for Wind Turbines

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Løgstrup Andersen, Tom; Bergami, Leonardo

    2014-01-01

    Several numerical studies in the past 10 years have shown big potentials for load reduction on MW turbines using distributed control for alleviation of the fluctuating loads along the blade span. However, the requirements by the wind turbine industry of robust actuator solutions where the stronge...

  3. A comparison of smart rotor control approaches using trailing edge flaps and individual pitch control

    NARCIS (Netherlands)

    Lackner, M.A.; van Kuik, G.A.M.

    2009-01-01

    Modern wind turbines have been steadily increasing in size, and have now become very large, with recent models boasting rotor diameters greater than 120 m. Reducing the loads experienced by the wind turbine rotor blades is one means of lowering the cost of energy of wind turbines. Wind turbines are

  4. Material matters: Controllable rubber trailing edge flap regulates load on wind turbine blades

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge

    2010-01-01

    In wind farms, nearby wind turbines exert considerable influence and generate turbulence on turbine blades. Because the blades are so long, there can be considerable differences in localized loading from the gusts along the blade. The Risø DTU researchers has developed a controllable rubber trail...... in an open jet wind tunnel shows promising results. In the wind tunnel, it is possible to regulate the wind speed as well as turn the blade profile to simulate a change in wind direction in relation to the profile....

  5. Novel design and sensitivity analysis of displacement measurement system utilizing knife edge diffraction for nanopositioning stages.

    Science.gov (United States)

    Lee, ChaBum; Lee, Sun-Kyu; Tarbutton, Joshua A

    2014-09-01

    This paper presents a novel design and sensitivity analysis of a knife edge-based optical displacement sensor that can be embedded with nanopositioning stages. The measurement system consists of a laser, two knife edge locations, two photodetectors, and axillary optics components in a simple configuration. The knife edge is installed on the stage parallel to its moving direction and two separated laser beams are incident on knife edges. While the stage is in motion, the direct transverse and diffracted light at each knife edge is superposed producing interference at the detector. The interference is measured with two photodetectors in a differential amplification configuration. The performance of the proposed sensor was mathematically modeled, and the effect of the optical and mechanical parameters, wavelength, beam diameter, distances from laser to knife edge to photodetector, and knife edge topography, on sensor outputs was investigated to obtain a novel analytical method to predict linearity and sensitivity. From the model, all parameters except for the beam diameter have a significant influence on measurement range and sensitivity of the proposed sensing system. To validate the model, two types of knife edges with different edge topography were used for the experiment. By utilizing a shorter wavelength, smaller sensor distance and higher edge quality increased measurement sensitivity can be obtained. The model was experimentally validated and the results showed a good agreement with the theoretically estimated results. This sensor is expected to be easily implemented into nanopositioning stage applications at a low cost and mathematical model introduced here can be used for design and performance estimation of the knife edge-based sensor as a tool.

  6. Desferrioxamine: a practical method for improving neovascularization of prefabricated flaps.

    Science.gov (United States)

    Li, Bin; Li, Hua; Jin, Rui; Cheng, Chen; Wang, Jing; Zhu, Hainan; Zan, Tao; Li, Qingfeng; Hao, Lijun

    2015-02-01

    Prefabricated flaps are an ideal alternative to repair massive and complex tissue defects. Nevertheless, the risk of necrosis due to unpredictable blood supplies is a major obstacle to the application of prefabricated flaps. The survival of a prefabricated flap depends on the neovascularization between the vascular carrier and the donor tissue. Here, we proposed that the iron chelator, desferrioxamine (DFX), owned therapeutic effects that promoted the neovascularization of prefabricated flaps. An abdominal prefabricated flap model was created in rats via a 2-stage operation. The rats were allocated into 4 groups as follows: 2 groups of rats received DFX treatments during the first or the second stage of the operation, respectively; 1 group of rats received a delay procedure 1 week before the second operation; and the final group was used as a blank control. Flap survival rates and capillary densities were evaluated between groups. The influence of DFX on the dermal fibroblasts was also studied in vitro. Desferrioxamine treatment during the first stage of the operation greatly increased flap survival rate compared to the blank control. The results were similar to those produced by the delay treatment. The vessel count results were consistent with the flap survival rate findings. In vitro, DFX treatment up-regulated the expression levels of several angiogenic factors in the dermal fibroblasts. Nevertheless, DFX treatment during the second stage of the operation was therapeutically detrimental. The application of DFX around the time of vascular carrier implantation greatly promoted neovascularization of prefabricated flaps, but was therapeutically detrimental after the flaps had been elevated.

  7. Release of hand burn contracture: comparing the ALT perforator flap with the gracilis free flap with split skin graft.

    Science.gov (United States)

    Misani, M; Zirak, C; Hau, Lê Thua Trung; De Mey, A; Boeckx, W

    2013-08-01

    The use of microsurgery in the management of burn sequelae is not a new idea. According to the properties of various types of free flaps different goals can be achieved or various additional procedures have to be combined. We report the comparison of two different free flaps on a single patient for reconstruction of both upper extremities for burn sequelae. A 1-year-old child sustained severe burns on both hands, arms and thorax and was initially only treated conservatively. This resulted in severe contractures. At the age of 4-years a free gracilis flap was selected for reconstruction of his left hand and a free anterolateral thigh flap for the right hand. We noticed a better functional and esthetic result for the gracilis flap associated with a shorter operative time and a minor donor site morbidity. The intraoperative technique and time, postoperative complications, functional and esthetic results and donor site morbidities were studied in the two types of flaps chosen. A review of literature was also performed. Our experience reported a better success of the gracilis muscle flap covered with a split skin graft compared to the anterolateral thigh flap in the reconstruction of hand function after severe burn sequelae. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  8. Reconstructive Surgery for Severe Penile Inadequacy: Phalloplasty with a Free Radial Forearm Flap or a Pedicled Anterolateral Thigh Flap

    Directory of Open Access Journals (Sweden)

    N. Lumen

    2008-01-01

    Full Text Available Objectives. Severe penile inadequacy in adolescents is rare. Phallic reconstruction to treat this devastating condition is a major challenge to the reconstructive surgeon. Phallic reconstruction using the free radial forearm flap (RFF or the pedicled anterolateral thigh flap (ALTF has been routinely used in female-to-male transsexuals. Recently we started to use these techniques in the treatment of severe penile inadequacy. Methods. Eleven males (age 15 to 42 years were treated with a phallic reconstruction. The RFF is our method of choice; the ALTF is an alternative when a free flap is contraindicated or less desired by the patient. The RFF was used in 7 patients, the ALTF in 4 patients. Mean followup was 25 months (range: 4–49 months. Aesthetic and functional results were evaluated. Results. There were no complications related to the flap. Aesthetic results were judged as “good” in 9 patients and “moderate” in 2 patients. Sensitivity in the RFF was superior compared to the ALTF. Four patients developed urinary complications (stricture and/or fistula. Six patients underwent erectile implant surgery. In 2 patients the erectile implant had to be removed due to infection or erosion. Conclusion. In case of severe penile inadequacy due to whatever condition, a phalloplasty is the preferred treatment nowadays. The free radial forearm flap is still the method of choice. The anterolateral thigh flap can be a good alternative, especially when free flaps are contraindicated, but sensitivity is markedly inferior in these flaps.

  9. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 1...

  10. High-resolution three-dimensional imaging of a depleted CMOS sensor using an edge Transient Current Technique based on the Two Photon Absorption process (TPA-eTCT)

    CERN Document Server

    García, Marcos Fernández; Echeverría, Richard Jaramillo; Moll, Michael; Santos, Raúl Montero; Moya, David; Pinto, Rogelio Palomo; Vila, Iván

    2016-01-01

    For the first time, the deep n-well (DNW) depletion space of a High Voltage CMOS sensor has been characterized using a Transient Current Technique based on the simultaneous absorption of two photons. This novel approach has allowed to resolve the DNW implant boundaries and therefore to accurately determine the real depleted volume and the effective doping concentration of the substrate. The unprecedented spatial resolution of this new method comes from the fact that measurable free carrier generation in two photon mode only occurs in a micrometric scale voxel around the focus of the beam. Real three-dimensional spatial resolution is achieved by scanning the beam focus within the sample.

  11. High-resolution three-dimensional imaging of a depleted CMOS sensor using an edge Transient Current Technique based on the Two Photon Absorption process (TPA-eTCT)

    Energy Technology Data Exchange (ETDEWEB)

    García, Marcos Fernández; Sánchez, Javier González; Echeverría, Richard Jaramillo [Instituto de Física de Cantabria (CSIC-UC), Avda. los Castros s/n, E-39005 Santander (Spain); Moll, Michael [CERN, Organisation europénne pour la recherche nucléaire, CH-1211 Genéve 23 (Switzerland); Santos, Raúl Montero [SGIker Laser Facility, UPV/EHU, Sarriena, s/n - 48940 Leioa-Bizkaia (Spain); Moya, David [Instituto de Física de Cantabria (CSIC-UC), Avda. los Castros s/n, E-39005 Santander (Spain); Pinto, Rogelio Palomo [Departamento de Ingeniería Electrónica, Escuela Superior de Ingenieros Universidad de Sevilla (Spain); Vila, Iván [Instituto de Física de Cantabria (CSIC-UC), Avda. los Castros s/n, E-39005 Santander (Spain)

    2017-02-11

    For the first time, the deep n-well (DNW) depletion space of a High Voltage CMOS sensor has been characterized using a Transient Current Technique based on the simultaneous absorption of two photons. This novel approach has allowed to resolve the DNW implant boundaries and therefore to accurately determine the real depleted volume and the effective doping concentration of the substrate. The unprecedented spatial resolution of this new method comes from the fact that measurable free carrier generation in two photon mode only occurs in a micrometric scale voxel around the focus of the beam. Real three-dimensional spatial resolution is achieved by scanning the beam focus within the sample.

  12. Experience with Perforator Based Flaps for Wound Cover of the Leg ...

    African Journals Online (AJOL)

    Background: Open fractures of the distal third of the tibia and fibular offer a challenge to the orthopedic surgeon because of skin coverage. The reconstructive surgeon's help is often required in trying to achieve this. There are several options: - local flap, free flap or a cross leg flap. Local flaps have always had limitations ...

  13. Reconstruction of the anterior floor of the mouth with the inferiorly based nasolabial flap

    NARCIS (Netherlands)

    van Wijk, MP; Damen, A; Nauta, JM; Lichtendahl, DHE; Dhar, BK

    The results of reconstruction of the anterior floor of the mouth, using 105 nasolabial flaps in 79 patients were reviewed in a retrospective study. Of those flaps, 82% healed uneventfully; flap survival was 95%. Considerable flap loss occurred in 5%. Primary dehiscence was observed in 5% of all

  14. Increased Flap Weight and Decreased Perforator Number Predict Fat Necrosis in DIEP Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Carolyn L. Mulvey, BS

    2013-05-01

    Conclusions: Flaps with increasing weight have increased risk of fat necrosis. These data suggest that inclusion of more than 1 perforator may decrease odds of fat necrosis in large flaps. Perforator flap breast reconstruction can be performed safely; however, considerations concerning race, body mass index, staging with tissue expanders, perforator number, and flap weight may optimize outcomes.

  15. The effect of atorvastatin on survival of rat ischemic flap

    Directory of Open Access Journals (Sweden)

    Jian-Xun Chen

    2013-04-01

    Full Text Available Management of skin avulsion with tissue exposure is a challenge for plastic surgeons. Clinical observations have suggested that longer survival of skin flap prevents further contamination and infection. Less well known is the role of atorvastatin in avulsion skin flap. Therefore, we attempted to determine whether atorvastatin could alleviate avulsion skin flap in a rat model. Twenty male Sprague–Dawley rats were randomized into two groups: the atorvastatin group and the control. Before operation, each rat received an initial blood perfusion scan as baseline data. Then, each rat received an operation of skin flap incision, elevation, and resuturing to the original position under general anesthesia. Another blood perfusion scan was performed on each rat 30 minutes, 4 days, and 7 days postoperatively. On the 7th postoperative day, the necrotic area of skin flap was measured as the skin flap viability. The skin flap tissues at 2.5 and 5 cm distal to the skin flap base were collected for histopathological analysis, as well as measurement of vascular endothelial growth factor (VEGF mRNA expression, and vascular density. Compared with 30 minutes postoperation, there was a significant increase in the ratio of skin flap blood perfusion on the 4th and 7th days postoperation in both control and atorvastatin groups (p<0.05. Compared with the control group, there was a significant decrease in necrotic area, significant increase in ratio of skin flap blood perfusion on postoperation days 4 and 7, and significant increase in vascular density under high field at 2.5 cm distal to the base of skin flap in the atorvastatin group (p<0.05. The VEGF121 and VEGF165 mRNA expression at 2.5 cm distal to the base of skin flap differed significantly between the two groups (p<0.05. Compared with the control group, atorvastatin treatment improved skin flap blood perfusion, vascular density, and necrotic area dependent on VEGF mRNA expression.

  16. Use if a soecuak sokubt ub reverse syrak artery flap to reduce venous congestion and flap necrosis

    International Nuclear Information System (INIS)

    Masood, T.; Ahmed, R.; Obaidullah, M.

    2016-01-01

    Background: Distally based sural fascio-cutaneous flap is a commonly performed plastic surgery procedure for the coverage of distal third of leg, ankle and foot defects. However congestion is the main complication of this flap which results into partial or complete loss of the flap. We devised a special splint to reduce this complication and retrospectively reviewed its effect on this complication between two groups. Methods: This retrospective study was carried out at Northwest General hospital between 1995 and 2012. Group-A included 30 patients who were managed without the splint between 1995 and 2005 and group B comprised of 35 patients were treated with the splint between 2006 and 2012. Complications like venous congestion, epidermolysis, and partial and complete flap failure were documented. Data were analyzed by SPSS.16.5 software. Chi- square test was used for data analysis. P value less than 0.05 was considered as the level of significance. Results: Total 65 patients were operated. Age of the patients ranged from 7 to 60 years. Road traffic accident and spoke wheel injury was the main cause of soft tissue loss in our patients. In group A 12 patients suffered from venous congestion. Out of 12, three patients had epidermolysis while partial flap necrosis occurred in 9 patients. Only 3 patients had venous congestion in group B. Two patients suffered from epidermolysis and one had partial flap necrosis. None of patient suffered from complete flap loss in both groups. Conclusion: Reverse sural artery flap continues to be a versatile flap for distal lower extremity reconstruction. By using a special splint to reduce pressure on the pedicle site as a modification, flap complication rate can be decreased significantly. (author)

  17. Complications Following Autologous Latissimus Flap Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Mufid Burgić

    2010-02-01

    Full Text Available Use of an autologous latissimus flap in breast reconstruction accounts for a supple and natural look of reconstructed breast. Most common postoperative complication, seroma, became more of a rule then an exception when it comes to postoperative evaluation of the patients who underwent this reconstructive procedure. A retrospective study analysing and evaluating different complication rates in 20 patients who underwent breast reconstruction by autologous latissimus flap, was conducted. All patients included in the study were operated at the Department of plastic surgery of Hôpital Civil in Strasbourg, France, between 1996 and 2008. The complication rates were noted as follows: seroma in 19 of our 20 patients (95%, late hypertrophic scarring in 3 patients (15%, postoperative surgical site hematoma in 3 patients (15%, and 2 patients (10% presented postoperative chronic back pain. Different options used in seroma treatment and prevention (subcutaneous-fascia anchor sutures of donor site, application of corticosteroids by injection into donor site postoperatively, passive drainage can reduce seroma formation and thus overall complication rates, leading to much faster patient’s recovery time and return to normal daily activities.

  18. Nanophotonic Image Sensors.

    Science.gov (United States)

    Chen, Qin; Hu, Xin; Wen, Long; Yu, Yan; Cumming, David R S

    2016-09-01

    The increasing miniaturization and resolution of image sensors bring challenges to conventional optical elements such as spectral filters and polarizers, the properties of which are determined mainly by the materials used, including dye polymers. Recent developments in spectral filtering and optical manipulating techniques based on nanophotonics have opened up the possibility of an alternative method to control light spectrally and spatially. By integrating these technologies into image sensors, it will become possible to achieve high compactness, improved process compatibility, robust stability and tunable functionality. In this Review, recent representative achievements on nanophotonic image sensors are presented and analyzed including image sensors with nanophotonic color filters and polarizers, metamaterial-based THz image sensors, filter-free nanowire image sensors and nanostructured-based multispectral image sensors. This novel combination of cutting edge photonics research and well-developed commercial products may not only lead to an important application of nanophotonics but also offer great potential for next generation image sensors beyond Moore's Law expectations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. ICRF edge modeling

    International Nuclear Information System (INIS)

    1991-01-01

    This report describes the technical progress for the DOE sponsored grant, ''ICRF Edge Modeling.'' An emphasis is placed on the progress since the Technical Progress Report (January 10, 1990) was submitted to the Department of Energy. The design of ICRF antennas for C-Mod and TFTR was investigated during this period. In addition, quasilinear models for electron heating were refined and applied to the design of ICRF antennas. The relevant professional activities sponsored by this grant are given. 4 refs., 11 figs

  20. ICRF edge modeling studies

    Energy Technology Data Exchange (ETDEWEB)

    Lehrman, I.S. (Grumman Corp. Research Center, Princeton, NJ (USA)); Colestock, P.L. (Princeton Univ., NJ (USA). Plasma Physics Lab.)

    1990-04-01

    Theoretical models have been developed, and are currently being refined, to explain the edge plasma-antenna interaction that occurs during ICRF heating. The periodic structure of a Faraday shielded antenna is found to result in strong ponderomotive force in the vicinity of the antenna. A fluid model, which incorporates the ponderomotive force, shows an increase in transport to the Faraday shield. A kinetic model shows that the strong antenna near fields act to increase the energy of deuterons which strike the shield, thereby increasing the sputtering of shield material. Estimates of edge impurity harmonic heating show no significant heating for either in or out-of-phase antenna operation. Additionally, a particle model for electrons near the shield shows that heating results from the parallel electric field associated with the fast wave. A quasilinear model for edge electron heating is presented and compared to the particle calculations. The models' predictions are shown to be consistent with measurements of enhanced transport. (orig.).