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Sample records for edge flap located

  1. Flap Edge Noise Reduction Fins

    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.

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

    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.

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

    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...

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

    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.

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

    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

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

    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.

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

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

    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

  10. Flap Side Edge Liners for Airframe Noise Reduction

    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.

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

    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.

  12. Detached Eddy Simulation of Flap Side-Edge Flow

    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.

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

    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...

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

    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.

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

    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

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

    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...

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

    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.

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

    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...

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

    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...

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

    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...

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

    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

  2. Optimal pitching axis location of flapping wings for efficient hovering flight.

    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

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

    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...

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

    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.

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

    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...

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

    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...

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

    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...

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

    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.

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

    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....

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

    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...

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

    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.)

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

    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

    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

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

    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...

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

    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...

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

    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)

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

    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.

  19. 2D numerical comparison of trailing edge flaps - UpWind WP1B3

    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)

  20. Blowing Flap Experiment: PIV Measurements

    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.

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

    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.

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

    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

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

    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.

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

    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.

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

    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...

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

    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...

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

    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.

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

    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...

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

    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....

  10. 2D numerical comparison of trailing edge flaps - UpWind WP1B3

    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...

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

    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...

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

    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.

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

    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)

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

    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.

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

    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

  16. Usefulness of a Lateral Thoracodorsal Flap after Breast Conserving Surgery in Laterally Located Breast Cancer

    Jung Dug Yang

    2013-07-01

    Full Text Available BackgroundBreast-conserving surgery is widely accepted as an appropriate method in breast cancer, and the lateral thoracodorsal flap provides a simple, reliable technique, especially when a mass is located in the lateral breast. This study describes the usefulness of a lateral thoracodorsal flap after breast conserving surgery in laterally located breast cancer.MethodsFrom September 2008 to February 2013, a lateral thoracodorsal flap was used in 20 patients with laterally located breast cancer treated at our institution. The technique involves a local medially based, wedge shaped, fasciocutaneous transposition flap from the lateral region of the thoracic area. Overall satisfaction and aesthetic satisfaction surveys were conducted with the patients during a 6-month postoperative follow-up period. Aesthetic results in terms of breast shape and symmetry were evaluated by plastic surgeons.ResultsThe average specimen weight was 76.8 g. The locations of the masses were the upper lateral quadrant (n=15, the lower lateral quadrant (n=2, and the central lateral area (n=3. Complications developed in four of the cases, partial flap necrosis in one, wound dehiscence in one, and fat necrosis in two. The majority of the patients were satisfied with their cosmetic outcomes.ConclusionsPartial breast reconstruction using a lateral thoracodorsal flap is well matched with breast color and texture, and the surgery is less aggressive than other techniques with few complications. Therefore, the lateral thoracodorsal flap can be a useful, reliable technique in correcting breast deformity after breast conserving surgery, especially in laterally located breast cancer.

  17. Usefulness of a Lateral Thoracodorsal Flap after Breast Conserving Surgery in Laterally Located Breast Cancer

    Ho Yong Park

    2013-07-01

    Full Text Available Background Breast-conserving surgery is widely accepted as an appropriate method in breast cancer, and the lateral thoracodorsal flap provides a simple, reliable technique, especially when a mass is located in the lateral breast. This study describes the usefulness of a lateral thoracodorsal flap after breast conserving surgery in laterally located breast cancer.Methods From September 2008 to February 2013, a lateral thoracodorsal flap was used in 20 patients with laterally located breast cancer treated at our institution. The technique involves a local medially based, wedge shaped, fasciocutaneous transposition flap from the lateral region of the thoracic area. Overall satisfaction and aesthetic satisfaction surveys were conducted with the patients during a 6-month postoperative follow-up period. Aesthetic results in terms of breast shape and symmetry were evaluated by plastic surgeons.Results The average specimen weight was 76.8 g. The locations of the masses were the upper lateral quadrant (n=15, the lower lateral quadrant (n=2, and the central lateral area (n=3. Complications developed in four of the cases, partial flap necrosis in one, wound dehiscence in one, and fat necrosis in two. The majority of the patients were satisfied with their cosmetic outcomes.Conclusions Partial breast reconstruction using a lateral thoracodorsal flap is well matched with breast color and texture, and the surgery is less aggressive than other techniques with few complications. Therefore, the lateral thoracodorsal flap can be a useful, reliable technique in correcting breast deformity after breast conserving surgery, especially in laterally located breast cancer.

  18. PIV Measurements on a Blowing Flap

    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.

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

    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.

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

    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)

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

    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...

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

    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.

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

    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.

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

    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

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

    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...

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

    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...

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

    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...

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

    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.

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

    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.

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

    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)

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

    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...

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

    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...

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

    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...

  14. The Pacman Perforator-Based V-Y Advancement Flap for Reconstruction of Pressure Sores at Different Locations.

    Bonomi, Stefano; Salval, André; Brenta, Federica; Rapisarda, Vincenzo; Settembrini, Fernanda

    2016-09-01

    Many procedures have been proposed for the treatment of pressure sores, and V-Y advancement flaps are widely used to repair a defect. Unfortunately, the degree of mobility of a V-Y advancement flap is dependent on the laxity of the underlying subcutaneous tissue. This is an important disadvantage of traditional V-Y advancement flap and limits its use.We used V-Y advancement flaps as perforator-based to overcome mobility restriction problem, with a further modification (Pacman-like shape) to improve the covering surface area of the flap. Between January 2012 and December 2014, the authors used 37 V-Y Pacman perforator-based flaps in 33 consecutive patients for coverage of defects located at sacral (n = 21), ischial (n = 13), trochanter (n = 1) regions. There were 27 male and 6 female patients with a mean age of 49.9 years (range, 15-74 years). All flaps survived completely (92.3%) except 3 in which one of them had undergone total necrosis due to hematoma and the other 2 had partial necrosis. No venous congestion was observed. The mean follow-up period was 14.9 months (range, 2-38 months). No flap surgery-related mortality or recurrence of pressure sores was noted. The V-Y Pacman perforator-based advancement flaps are safe and very effective for reconstruction of pressure sores at various regions. The advantage of our modification procedure include shorter operative time, lesser pedicle dissection, low donor site morbidity, good preservation of muscle, and offers remarkable excursion to the V-Y flap, which make the V-Y Pacman perforator-based flaps an excellent choice for large pressure sore coverage.

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

    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.

  16. 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

    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.

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

    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.

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

    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.

  19. 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

    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.

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

    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....

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

    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

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

    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....

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

    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

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

    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...

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

    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

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

    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...

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

    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...

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

    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...

  9. Location of the levator veli palatini insertion following levator retropositioning, palatal pushback, and pharyngeal flap procedures.

    Mulliken, J B; Giargiana, F A; Claybaugh, G J; Hoopes, J E

    1975-07-01

    A long-term cineradiographic follow-up study of twenty patients with velo-pharyngeal incompetence fails to demonstrate predictable retrodisplacement of the levator insertion following combined levator retropositioning, pushback, and pharyngeal flap procedures. Simple levator retropositioning gave posterior displacement in the two patients evaluated. Patients with normal or posterior levator insertions pre-operatively all demonstrated post-operative anterior displacement following pharyngeal flap procedures, either alone or in combination with pushback. Anterior levator displacement may be the result of scar contraction or division of the levator sling (during insetting of a pharyngeal flap). Pre-operative and post-operative speech evaluation demonstrated substantial improvement in all except 3 patients; 2 of the poor speech results were patients with demonstrated levator retrodisplacement on post-operative cineradiography.

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

    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.

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

    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.

  12. Sea Ice Edge Location and Extent in the Russian Arctic, 1933-2006

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Ice Edge Location and Extent in the Russian Arctic, 1933-2006 data are derived from sea ice charts from the Arctic and Antarctic Research Institute (AARI),...

  13. Applying the Keystone Design Perforator Island Flap Concept in a Variety of Anatomic Locations: A Review of 60 Consecutive Cases by a Single Surgeon.

    Lanni, Michael Alan; Van Kouwenberg, Emily; Yan, Alan; Rezak, Kristen M; Patel, Ashit

    2017-07-01

    The keystone design perforator island flap has been gaining popularity for reconstruction of cutaneous defects. Published experience of this technique in North America is limited predominantly to the trunk and extremities; our study aims to demonstrate expanding applications. Retrospective chart review was conducted on all patients who underwent keystone flap reconstruction by a single surgeon. Outcomes of interest were wound healing complications (WHC) and surgical site infections (SSI). Mean follow up time was 24.4 months. Sixty consecutive flaps were performed with an overall WHC rate of 26.7% and SSI rate of 11.7%. Reconstructed sites included 25 lower extremity, 20 trunk, 5 upper extremity, and 10 head and neck. Flap size averaged 405.6 cm (range 16-2303). Wound healing complications were associated with coronary artery disease (P = 0.04) and traumatic defects (P = 0.043). Surgical site infections were associated with coronary artery disease (P = 0.02) and flap size of 251 to 500 cm (P = 0.039), although this association was not seen among flaps greater than 500 cm. Although more common in lower extremity reconstructions, no statistically significant associations between flap location and WHC (P = 0.055) or SSI (P = 0.29) were identified. There were no reconstructive failures and no patients required reoperation. This series demonstrates the versatility of the keystone flap in a wide variety of anatomic locations, with similar complication rates to those previously reported and no reoperations. Flap design was frequently modified based on the anatomical topography and adjacent subunits. To our knowledge, this is the largest and most diverse North American series of keystone flap reconstructions to date.

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

    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

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

    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

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

    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

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

    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...

  18. Improvement of vision measurement accuracy using Zernike moment based edge location error compensation model

    Cui, J W; Tan, J B; Zhou, Y; Zhang, H

    2007-01-01

    This paper presents the Zernike moment based model developed to compensate edge location errors for further improvement of the vision measurement accuracy by compensating the slight changes resulting from sampling and establishing mathematic expressions for subpixel location of theoretical and actual edges which are either vertical to or at an angle with X-axis. Experimental results show that the proposed model can be used to achieve a vision measurement accuracy of up to 0.08 pixel while the measurement uncertainty is less than 0.36μm. It is therefore concluded that as a model which can be used to achieve a significant improvement of vision measurement accuracy, the proposed model is especially suitable for edge location of images with low contrast

  19. Pedicled perforator flaps

    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...

  20. A Comparison of the Local Flap and Skin Graft by Location of Face in Reconstruction after Resection of Facial Skin Cancer.

    Lee, Kyung Suk; Kim, Jun Oh; Kim, Nam Gyun; Lee, Yoon Jung; Park, Young Ji; Kim, Jun Sik

    2017-12-01

    Surgery for reconstruction of defects after surgery should be performed selectively and the many points must be considered. The authors conducted this study to compare the local flap and skin graft by facial location in the reconstruction after resection of facial skin cancer. The authors performed the study in patients that had received treatment in Department of Plastic Surgery, Gyeongsang National University. The cases were analyzed according to the reconstruction methods for the defects after surgery, sex, age, tumor site, and tumor size. Additionally, the authors compared differences of aesthetic satisfaction (out of 5 points) of patients in the local flap and skin graft by facial location after resection of facial skin cancer by dividing the face into eight areas. A total of 153 cases were confirmed. The most common facial skin cancer was basal cell carcinoma (56.8%, 87 cases), followed by squamous cell carcinoma (37.2%, 57 cases) and bowen's disease (5.8%, 9 cases). The most common reconstruction method was local flap 119 cases (77.7%), followed by skin graft 34 cases (22.3%). 86 patients answered the questionnaire and mean satisfaction of the local flap and skin graft were 4.3 and 3.5 ( p =0.04), respectively, indicating that satisfaction of local flap was significantly high. When comparing satisfaction of patients according to results, local flap shows excellent effects in functional and cosmetic aspects would be able to provide excellent results rather than using a skin graft with poor touch and tone compared to the surrounding normal skin.

  1. 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

    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.

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

    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.

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

    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.

  4. The Versatile Modiolus Perforator Flap

    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. Active Control of Long Bridges Using Flaps

    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....

  6. On the location of spectral edges in \\mathbb {Z}-periodic media

    Exner, Pavel; Kuchment, Peter; Winn, Brian

    2010-01-01

    Periodic second-order ordinary differential operators on ℝ are known to have the edges of their spectra to occur only at the spectra of periodic and antiperiodic boundary value problems. The multi-dimensional analog of this property is false, as was shown in a 2007 paper by some of the authors of this paper. However, one sometimes encounters the claims that in the case of a single periodicity (i.e., with respect to the lattice ℤ), the 1D property still holds, and spectral edges occur at the periodic and anti-periodic spectra only. In this work, we show that even in the simplest case of quantum graphs this is not true. It is shown that this is true if the graph consists of a 1D chain of finite graphs connected by single edges, while if the connections are formed by at least two edges, the spectral edges can already occur away from the periodic and anti-periodic spectra. © 2010 IOP Publishing Ltd.

  7. On the location of spectral edges in \\mathbb {Z}-periodic media

    Exner, Pavel

    2010-11-09

    Periodic second-order ordinary differential operators on ℝ are known to have the edges of their spectra to occur only at the spectra of periodic and antiperiodic boundary value problems. The multi-dimensional analog of this property is false, as was shown in a 2007 paper by some of the authors of this paper. However, one sometimes encounters the claims that in the case of a single periodicity (i.e., with respect to the lattice ℤ), the 1D property still holds, and spectral edges occur at the periodic and anti-periodic spectra only. In this work, we show that even in the simplest case of quantum graphs this is not true. It is shown that this is true if the graph consists of a 1D chain of finite graphs connected by single edges, while if the connections are formed by at least two edges, the spectral edges can already occur away from the periodic and anti-periodic spectra. © 2010 IOP Publishing Ltd.

  8. 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

    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.

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

    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.

  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.

    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

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

    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....

  13. LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM

    Capelo, Holly L.; Herbst, William; Leggett, S. K.; Hamilton, Catrina M.; Johnson, John A.

    2012-01-01

    Following two years of complete occultation of both stars in the binary T Tauri star KH 15D by its opaque circumbinary ring, KH 15D has abruptly brightened again during apastron phases, reaching I = 15 mag. Here, we show that the brightening is accompanied by a change in spectral class from K6/K7 (the spectral class of star A) to ∼K1, and a bluing of the system in V – I by about 0.3 mag. A radial velocity measurement confirms that, at apastron, we are now seeing direct light from star B, which is more luminous and of earlier spectral class than star A. Evidently, the trailing edge of the occulting screen has just become tangent to one anse of star B's projected orbit. This confirms a prediction of the precession models, supports the view that the tilted ring is self-gravitating, and ushers in a new era of the system's evolution that should be accompanied by the same kind of dramatic phenomena observed from 1995 to 2009. It also promotes KH 15D from a single-lined to a double-lined eclipsing binary, greatly enhancing its value for testing pre-main-sequence models. The results of our study strengthen the case for truncation of the outer ring at around 4 AU by a sub-stellar object such as an extremely young giant planet. The system is currently at an optimal configuration for detecting the putative planet and we urge expedient follow-up observations.

  14. Fast retinal vessel detection and measurement using wavelets and edge location refinement.

    Peter Bankhead

    Full Text Available The relationship between changes in retinal vessel morphology and the onset and progression of diseases such as diabetes, hypertension and retinopathy of prematurity (ROP has been the subject of several large scale clinical studies. However, the difficulty of quantifying changes in retinal vessels in a sufficiently fast, accurate and repeatable manner has restricted the application of the insights gleaned from these studies to clinical practice. This paper presents a novel algorithm for the efficient detection and measurement of retinal vessels, which is general enough that it can be applied to both low and high resolution fundus photographs and fluorescein angiograms upon the adjustment of only a few intuitive parameters. Firstly, we describe the simple vessel segmentation strategy, formulated in the language of wavelets, that is used for fast vessel detection. When validated using a publicly available database of retinal images, this segmentation achieves a true positive rate of 70.27%, false positive rate of 2.83%, and accuracy score of 0.9371. Vessel edges are then more precisely localised using image profiles computed perpendicularly across a spline fit of each detected vessel centreline, so that both local and global changes in vessel diameter can be readily quantified. Using a second image database, we show that the diameters output by our algorithm display good agreement with the manual measurements made by three independent observers. We conclude that the improved speed and generality offered by our algorithm are achieved without sacrificing accuracy. The algorithm is implemented in MATLAB along with a graphical user interface, and we have made the source code freely available.

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

    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.

  16. Experimental and numerical study of an autonomous flap

    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

  17. Propeller Flaps: A Literature Review.

    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.

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

    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.

  19. Exotic wakes of flapping fins

    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...

  20. Modified cup flap for volar oblique fingertip amputations

    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.

  1. Management of Vortices Trailing Flapped Wings via Separation Control

    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.

  2. Aromatic residues located close to the active center are essential for the catalytic reaction of flap endonuclease-1 from hyperthermophilic archaeon Pyrococcus horikoshii.

    Matsui, Eriko; Abe, Junko; Yokoyama, Hideshi; Matsui, Ikuo

    2004-04-16

    Flap endonuclease-1 (FEN-1) possessing 5'-flap endonuclease and 5'-->3' exonuclease activity plays important roles in DNA replication and repair. In this study, the kinetic parameters of mutants at highly conserved aromatic residues, Tyr33, Phe35, Phe79, and Phe278-Phe279, in the vicinity of the catalytic centers of FEN-1 were examined. The substitution of these aromatic residues with alanine led to a large reduction in kcat values, although these mutants retained Km values similar to that of the wild-type enzyme. Notably, the kcat of Y33A and F79A decreased 333-fold and 71-fold, respectively, compared with that of the wild-type enzyme. The aromatic residues Tyr33 and Phe79, and the aromatic cluster Phe278-Phe279 mainly contributed to the recognition of the substrates without the 3' projection of the upstream strand (the nick, 5'-recess-end, single-flap, and pseudo-Y substrates) for the both exo- and endo-activities, but played minor roles in recognizing the substrates with the 3' projection (the double flap substrate and the nick substrate with the 3' projection). The replacement of Tyr33, Phe79, and Phe278-Phe279, with non-charged aromatic residues, but not with aliphatic hydrophobic residues, recovered the kcat values almost fully for the substrates without the 3' projection of the upstream strand, suggesting that the aromatic groups of Tyr33, Phe79, and Phe278-Phe279 might be involved in the catalytic reaction, probably via multiple stacking interactions with nucleotide bases. The stacking interactions of Tyr33 and Phe79 might play important roles in fixing the template strand and the downstream strand, respectively, in close proximity to the active center to achieve the productive transient state leading to the hydrolysis.

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

    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. Flexible wings in flapping flight

    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.

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

    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.

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

    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.

  7. Energy management - The delayed flap approach

    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.

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

    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...

  9. Aspects of the influence of an oscillating mini-flap upon the near wake of an airfoil NACA 4412

    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.

  10. Magnetic Data Interpretation for the Source-Edge Locations in Parts of the Tectonically Active Transition Zone of the Narmada-Son Lineament in Central India

    Ghosh, G. K.

    2016-02-01

    The study has been carried out in the transition zone of the Narmada-Son lineament (NSL) which is seismically active with various geological complexities, upwarp movement of the mantle material into the crust through fault, fractures lamination and upwelling. NSL is one of the most prominent lineaments in central India after the Himalaya in the Indian geology. The area of investigation extends from longitude 80.25°E to 81.50°E and latitude 23.50°N to 24.37°N in the central part of the Indian continent. Different types of subsurface geological formations viz. alluvial, Gondwana, Deccan traps, Vindhyan, Mahakoshal, Granite and Gneisses groups exist in this area with varying geological ages. In this study area tectonic movement and crustal variation have been taken place during the past time and which might be reason for the variation of magnetic field. Magnetic anomaly suggests that the area has been highly disturbed which causes the Narmada-Son lineament trending in the ENE-WSW direction. Magnetic anomaly variation has been taken place due to the lithological variations subject to the changes in the geological contacts like thrusts and faults in this area. Shallow and deeper sources have been distinguished using frequency domain analysis by applying different filters. To enhance the magnetic data, various types of derivatives to identify the source-edge locations of the causative source bodies. The present study carried out the interpretation using total horizontal derivative, tilt angle derivative, horizontal tilt angle derivative and Cos (θ) derivative map to get source-edge locations. The results derived from various derivatives of magnetic data have been compared with the basement depth solutions calculated from 3D Euler deconvolution. It is suggested that total horizontal derivative, tilt angle derivative and Cos (θ) derivative are the most useful tools for identifying the multiple source edge locations of the causative bodies in this tectonically active

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

    Runckel, Jack F.; Hieser, Gerald

    1961-01-01

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

  12. Edge Matters

    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...

  13. Robot-Assisted Free Flap in Head and Neck Reconstruction

    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.

  14. Water Tunnel Studies of Dynamic Wing Flap Effects

    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

  15. Defining the Role of Free Flaps in Partial Breast Reconstruction.

    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.

  16. Use of Adipose-Derived Mesenchymal Stem Cells to Accelerate Neovascularization in Interpolation Flaps.

    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

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

    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...

  18. Propeller TAP flap

    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...

  19. Robot-Assisted Free Flap in Head and Neck Reconstruction

    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.

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

    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,

  1. Location, location, location

    Anderson, S.P.; Goeree, J.K.; Ramer, R.

    1997-01-01

    We analyze the canonical location-then-price duopoly game with general log- concave consumer densities. A unique pure-strategy equilibrium to the two-stage game exists if the density is not "too asymmetric" and not "too concave." These criteria are satisfied by many commonly used densities.

  2. Influence of Thickness Variation on the Flapping Performance of Symmetric NACA Airfoils in Plunging Motion

    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.

  3. [Saphenous perforator flap].

    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

  4. Reconstruction of various perinasal defects using facial artery perforator-based nasolabial island flaps.

    Yoon, Tae Ho; Yun, In Sik; Rha, Dong Kyun; Lee, Won Jai

    2013-11-01

    Classical flaps for perinasal defect reconstruction, such as forehead or nasolabial flaps, have some disadvantages involving limitations of the arc of rotation and two stages of surgery. However, a perforator-based flap is more versatile and allows freedom in flap design. We introduced our experience with reconstruction using a facial artery perforator-based propeller flap on the perinasal area. We describe the surgical differences between different defect subtypes. Between December 2005 and August 2013, 10 patients underwent perinasal reconstruction in which a facial artery perforator-based flap was used. We divided the perinasal defects into types A and B, according to location. The operative results, including flap size, arc of rotation, complications, and characteristics of the perforator were evaluated by retrospective chart review and photographic evaluation. Eight patients were male and 2 patients were female. Their mean age was 61 years (range, 35-75 years). The size of the flap ranged from 1 cm×1.5 cm to 3 cm×6 cm. Eight patients healed uneventfully, but 2 patients presented with mild flap congestion. However, these 2 patients healed by conservative management without any additional surgery. All of the flaps survived completely with aesthetically pleasing results. The facial artery perforator-based flap allowed for versatile customized flaps, and the donor site scar was concealed using the natural nasolabial fold.

  5. Flow field of flexible flapping wings

    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

  6. Flow-Field Investigation of Gear-Flap Interaction on a Gulfstream Aircraft Model

    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.

  7. A histopathological study of bulbar conjunctival flaps occurring in 2 contact lens wearers.

    Markoulli, Maria; Francis, Ian C; Yong, Jim; Jalbert, Isabelle; Carnt, Nicole; Cole, Nerida; Papas, Eric

    2011-09-01

    To study the histopathology of paralimbal bulbar conjunctival flaps occurring secondary to soft contact lens wear. Slit-lamp biomicroscopy using sodium fluorescein, cobalt blue light, and a Wratten filter was used to observe the presence, location, and dimensions of bulbar conjunctival flaps presenting in a cohort of contact lens wearers. Two subjects who exhibited such flaps agreed to undergo conjunctival biopsy. Tissue samples, obtained from the region of the flap, and an adjacent unaffected area were processed by standard histopathological methods. In the first subject, analysis of the flap tissue showed even collagen distribution and overall normal histology. The flap of the second subject displayed a mild focal increase in collagen and mild degeneration of collagen, but no increase in elastic tissue. Conjunctival epithelium was normal in both cases. In these 2 subjects, conjunctival flap tissue either was normal or showed only minimal abnormality. There is insufficient evidence for significant pathological change on the time scale of this study.

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

    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.

  9. Extended Islanded Reverse Sural Artery flap for Staged Reconstruction of Foot Defects Proximal to Toes.

    Yousaf, Muhammad Amin; Abidin, Zain Ul; Khalid, Kamran; Haq, Ata Ul; Khalid, Farrukh Aslam; Tarar, Faraz Ahmad; Asif, Muhammad Umar; Tarar, Moazzam Nazeer

    2018-02-01

    Obective:To assess the outcome of extended delayed reverse sural artery flap for reconstruction of foot defects proximal to toes in terms of flap survival, complication and extended area. Case series. Jinnah Burn and Reconstructive Surgery Centre, Lahore, from February 2015 to April 2017. Cases who underwent delayed sural artery flap were inducted. Preoperative hand-held doppler was done to confirm the location of perforator. Two suitable perforators were chosen to raise the extended flap by crossing the proximal limit in all cases. The pedicle was kept minimum 3 cm wide and perfusion was assessed. Flap was delayed for one week and vaccum-assisted closure (VAC) dressing was applied over wound. The second surgery was performed after one week. Proximal perforator was clamped and ligated after checking adequate perfusion of flap. Flap was insetted into defect. Thirty-two patients were reconstructed with delayed reverse sural artery flap. The mean age of the patients was 26.5 12.2 years. Twenty-four (75%) patients were males and 8 (25%) were females. Twenty-two (68.7%) cases were degloving wounds after road traffic accidents (RTA), 6 (18.7%) were diabetic foot wounds, 4 (12.5%) sustained injury after falling from height and 7 (21.8%) patients had fracture of metatarsals. Twenty-eight flaps were transferred after one week delay, and only in 4 cases, flap were transferred after two weeks. All flaps survived completely. Complications of infection noted in 3 (9.3%) flaps, 3 (9.3%) flaps showed tip necrosis, 2 (6.2%) flaps undergone epidermolysis and only 2 (6.2%) showed venous congestion. Delayed islanded reverse sural artery perforator flap is a reliable and versatile option for resurfacing soft tissue defects of lower limb proximal to the toes with lesser complications and extended coverage area.

  10. Extended Islanded Reverse Sural Artery Flap for Staged Reconstruction of Foot Defects Proximal to Toes

    Yousaf, M.A.; Abidin, Z.U.; Khalid, K.; Haq, A.U.; Tarar, F.A.; Asif, M.U.; Tarar, M.N.

    2018-01-01

    To assess the outcome of extended delayed reverse sural artery flap for reconstruction of foot defects proximal to toes in terms of flap survival, complication and extended area. Study Design:Case series. Place and Duration of Study:Jinnah Burn and Reconstructive Surgery Centre, Lahore, from February 2015 to April 2017. Methodology:Cases who underwent delayed sural artery flap were inducted. Preoperative hand-held doppler was done to confirm the location of perforator. Two suitable perforators were chosen to raise the extended flap by crossing the proximal limit in all cases. The pedicle was kept minimum 3 cm wide and perfusion was assessed. Flap was delayed for one week and vaccum-assisted closure (VAC) dressing was applied over wound. The second surgery was performed after one week. Proximal perforator was clamped and ligated after checking adequate perfusion of flap. Flap was insetted into defect. Results:Thirty-two patients were reconstructed with delayed reverse sural artery flap. The mean age of the patients was 26.5 +12.2 years. Twenty-four (75%) patients were males and 8 (25%) were females. Twenty-two (68.7%) cases were degloving wounds after road traffic accidents (RTA), 6 (18.7%) were diabetic foot wounds, 4 (12.5%) sustained injury after falling from height and 7 (21.8%) patients had fracture of metatarsals. Twenty-eight flaps were transferred after one week delay, and only in 4 cases, flap were transferred after two weeks. All flaps survived completely. Complications of infection noted in 3 (9.3%) flaps, 3 (9.3%) flaps showed tip necrosis, 2 (6.2%) flaps undergone epidermolysis and only 2 (6.2%) showed venous congestion. Conclusion:Delayed islanded reverse sural artery perforator flap is a reliable and versatile option for resurfacing soft tissue defects of lower limb proximal to the toes with lesser complications and extended coverage area. (author)

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

    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.

  12. [COMPARISON OF REPAIR EFFECT BETWEEN CHIMERIC ANTEROLATERAL THIGH FLAP AND SERIES-WOUND FLAPS FOR DEFECT AFTER RESECTION OF ORAL AND MAXILLOFACIAL CANCER].

    Yang, Heping; Zhang, Hongwu; Chen, Haidi; Yang, Shuxiong; Wang, Jun; Hu, Dawang

    2016-04-01

    To compare the effectiveness of complex defects repair between using chimeric anterolateral thigh flap and series-wound flaps after resection of oral and maxillofacial cancer. After resection of oral and maxillofacial cancer, defect was repaired with chimeric anterolateral thigh flap in 39 patients between January 2011 and July 2014 (chimeric anterolateral thigh flap group); and defect was repaired with series-wound flaps in 35 patients between January 2009 and December 2010 (series-wound flaps group). There was no significant difference in gender, age, duration of disease, tumor type, tumor staging, defect location, and defect area between 2 groups (P > 0.05). The operation time, flap harvesting and microvascular anastomosis time, stomach tube extraction time, and oral feeding time were recorded and compared between 2 groups, and postoperative complications were observed; the effectiveness was evaluated according to clinical efficacy evaluation table of bone and soft tissue defects reconstruction surgery in oral and maxillofacial region. Vascular crisis occurred in 2 cases of chimeric anterolateral thigh flap group, and 4 cases of series-wound flaps group. Partial necrosis appeared at distal end of a series-wound flaps, and oral fistula and infection developed in 3 series-wound flaps. The other flaps and the grafted skin at donor site survived; wounds at recipient site healed by first intention. The operation time, stomach tube extraction time, and oral feeding time of chimeric anterolateral thigh flap group were significantly shorter than those of series-wound flaps group (P oral closure function, chew, language performance, and swallowing scores of the chimeric anterolateral thigh-flap group were significantly better than those of the series-wound flaps group (P oral cavity holding water test, and occlusion scores between the 2 groups (P > 0.05). Using chimeric anterolateral thigh flap for defect repair after resection of oral and maxillofacial cancer can

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

    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...

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

    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.

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

    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.

  16. Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction.

    Hekner, D D; Roeling, T A P; Van Cann, E M

    2016-08-01

    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 injected with epoxy resin (Araldite) and the perforating arteries were dissected. The number of clinically relevant perforators from the radial and ulnar arteries was not significantly different in the distal forearm. Most perforators were located in the proximal half of the distal one third, making this part probably the safest location for flap harvest. Close to the wrist, i.e. most distally, there were more perforators on the ulnar side than on the radial side. The ulnar artery stained 77% of the skin surface area of the forearm, showing the ulnar forearm free flap to be more suitable than the radial forearm free flap for the restoration of large defects. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  17. Reconstruction of distal hand and foot defects with the free proximal peroneal artery perforator flap.

    Scaglioni, Mario F; Kuo, Yur-Ren; Chen, Yen-Chou

    2016-03-01

    The proximal peroneal artery perforator (PPAP) flap is a reliable, thin fasciocutaneous flap. The purpose of this article was to report our experience with the use of free PPAP flaps for reconstruction of defects of the distal hand and foot. From November 2012 to September 2013, 9 patients received reconstruction with 10 free PPAP flaps. The defect locations included the big toe (2 cases), metatarsophalangeal joint (5 cases), dorsal finger (2 cases) and volar finger (1 case). Flaps were raised based on proximal peroneal perforator vessels without sacrificing the peroneal artery. The first dorsal metatarsal artery (5 cases) and digital artery (5 cases) were dissected as recipient vessels. The flap sizes varied from 2.5 x 2 cm to 9 x 5 cm. All of flaps were survival after surgery. One flap suffered from venous thrombosis and was successfully salvaged by performing a venous thrombectomy and vein graft. The donor sites were all primarily closed with minimal morbidities. Follow-up observations were conducted for 7 to 20 months, and all patients had good functional recovery with satisfying cosmetic results. Perforators arising from the peroneal artery in the proximal lateral leg can be used to design small, pliable fasciocutaneous flaps. Although the pedicle is short, the vessel diameter is adequate for microvascular anastomosis to the distal foot and hand recipient vessels. The free PPAP flap may be a good option for reconstructing distal hand and foot defects. © 2014 Wiley Periodicals, Inc.

  18. The Anconeus Muscle Free Flap: Clinical Application to Lesions on the Hand

    Byung-Joon Jeon

    2017-09-01

    Full Text Available Background It can be difficult to select an appropriate flap for various defects on the hand. Although defects of the hand usually must be covered with a skin flap, some defects require a flap with rich blood supply and adequate additive soft tissue volume. The authors present their experience with the anconeus muscle free flap in the reconstruction of various defects and the release of scar contractures of the hand. Methods Ten patients underwent reconstruction of the finger or release of the first web space using the anconeus muscle free flap from May 1998 to October 2013. Adequate bed preparations with thorough debridement or contracture release were performed. The entire anconeus muscle, located at the elbow superficially, was harvested, with the posterior recurrent interosseous artery as a pedicle. The defects were covered with a uniformly trimmed anconeus muscle free flap. Additional debulking of the flap and skin coverage using a split-thickness skin graft were performed 3 weeks after the first operation. Results The average flap size was 18.7 cm2 (range, 13.5–30 cm2. All flaps survived without significant complications. Vein grafts for overcoming a short pedicle were necessary in 4 cases. Conclusions The anconeus muscle free flap can be considered a reliable reconstructive option for small defects on the hand or contracture release of the web space, because it has relatively consistent anatomy, provides robust blood supply within the same operative field, and leads to no functional loss at the donor site.

  19. The freestyle pedicle perforator flap

    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...

  20. The value of dynamic infrared thermography (DIRT) in perforatorselection and planning of free DIEP flaps.

    de Weerd, Louis; Weum, Sven; Mercer, James B

    2009-09-01

    The aim of this paper is to evaluate dynamic infrared thermography (DIRT) as a technique to assist in preoperative perforator selection and planning of free deep inferior epigastric perforator (DIEP) flaps. Twenty-seven patients, scheduled for secondary autologous breast reconstruction with either a free DIEP flap or superficial inferior epigastric artery flap, were included in this prospective clinical study. Preoperative mapping of perforators was performed with a hand-held Doppler and DIRT. A multidetector computer tomography scan was additionally carried out in the last 8 patients. In 23 patients a DIEP flap was used. The perforator as selected from DIRT was a suitable perforator in all DIEP flaps. The location and quality of the selected perforator from DIRT corresponded well with the multidetector computer tomography scan results. Preoperative perforator selection and planning of DIEP flaps is facilitated with the use of DIRT. The technique is noninvasive and easy to use.

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

    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.

  2. Anatomy of vastus lateralis muscle flap.

    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.

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

    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...

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

    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.

  5. Influence of hinge point on flexible flap aerodynamic performance

    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

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

    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....

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

    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...

  8. The Temporalis Muscle Flap in Maxillofacial Reconstruction

    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)

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

    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.

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

    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.

  11. [Reconstruction of ankle and foot with combination of free perforator flaps and skin graft].

    Yin, Lu; Gong, Ketong; Yin, Zhonggang; Zhang, Bo; Xu, Jianhua

    2017-03-01

    To evaluate the clinical outcomes of free perforator flaps combined with skin graft for reconstruction of ankle and foot soft tissue defects. Between June 2014 and October 2015, 20 cases of ankle and foot soft tissue defects were treated. There were 16 males and 4 females, aged from 19 to 61 years (mean, 43.3 years). Injury was caused by traffic accident in 7 cases, by crashing in 9 cases, and machine twist in 4 cases. The locations were the ankle in 6 cases, the heel in 3 cases, the dorsum pedis in 4 cases, and the plantar forefoot in 7 cases of avulsion injury after toes amputation. The size of wound ranged from 15 cm×10 cm to 27 cm×18 cm. The time from injury to treatment was from 11 to 52 days (mean, 27 days). The anterolateral thigh perforator flap was used in 11 cases, thoracodorsal antery perforator flap in 3 cases, medial sural artery perforator flap in 4 cases, deep inferior epigastric perforator flap in 1 case, and anteromedial thigh perforator flap in 1 case, including 5 chimeric perforator flaps, 5 polyfoliate perforator flaps, 3 flow-through perforator flaps, and 3 conjoined perforator flaps. The size of the perforator flap ranged from 10.0 cm×6.5 cm to 36.0 cm×8.0 cm, the size of skin graft from 5 cm×3 cm to 18 cm×12 cm. Venous crisis occurred in 2 flaps which survived after symptomatic treatment; 18 flaps survived successfully and skin grafting healed well. The follow-up time ranged 4-18 months (mean, 8.3 months). The flaps had good appearance, texture and color, without infection. The patients could walk normally and do daily activities. Only linear scars were observed at the donor sites. Free perforator flap can be used to reconstruct defects in the ankle and foot, especially in the weight-bearing area of the plantar forefoot. A combination of free perforator flap and skin graft is ideal in reconstruction of great soft tissue defects in the ankle and foot.

  12. Soap films burst like flapping flags.

    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.

  13. RECONSTRUCTION OF FACIAL SKIN DEFECT BY VARIOUS FLAPS : OUR EXPERIENCE

    Atishkumar B.

    2015-08-01

    Full Text Available INTRODUCTION : Face represents complete personality of human being. Cosmetically it is very important part of a person especially for woman. There are many situations when due to disease or trauma, facial defect arises, which requires reconstruction by either local or distant surgical flaps . METHODS AND MATERIALS : In rural places, we come across many patients suffering from trauma and skin malignancy of face. These patients require reconstruction done esthetically with local flaps. Objective of this study is to share our exper ience of providing esthetically good results at our secondary referral care center. Hereby, we present case series of 14 patients operated at our institute. These patients were analyzed according to the age, sex, nature of injury and anatomical location of lesion on the face. All these patients were operated and reconstruction of defect was done with various local flaps best suited for respective lesion, under local anesthesia or sedation. Post - operative nature of wound was analyzed for flap viability or fl ap necrosis . RESULTS : Amongst them were 7 male and 7 female, ages ranging from 4 to 80 years. 7out of 14 patients were of basal cell carcinoma, 4 were due to trauma, 2 were due to dog bite and 1 case of recurrent pleomorphic adenoma at root of nose. All patients had excellent flap viability at end of 6 months and flap achieving almost similar color and contour as that of surrounding skin. CONCLUSION : Reconstruction of facial defects by local flaps is very easy and cost effective technique. This can be don e even at secondary referral care centre with minimal availability of facilities

  14. Application of Indocyanine Green in Flap Surgery: A Systematic Review.

    Li, Ke; Zhang, Zheng; Nicoli, Fabio; D'Ambrosia, Christopher; Xi, Wenjing; Lazzeri, Davide; Feng, Shaoqing; Su, Weijie; Li, Hua; Ciudad, Pedro; Tremp, Mathias; Zhang, Yi Xin

    2018-02-01

     The vascularization of the distal portions of transferred tissue represents the most critical factor in the success of reconstructive surgery. In recent years, indocyanine green (ICG) fluorescence imaging techniques have been applied during surgery to evaluate flap perfusion. However, this investigation has found that there is little consensus regarding the standard dose of ICG as well as the pre-operative requirements of ICG allergy testing. The aim of this study is to summarize the applications of ICG to tissue transfers and safe dosing practices and to provide insight to the possible adverse effects of ICG on flap surgery with the goal of helping clinicians apply ICG safely and efficiently to tissue transfer procedures.  A literature search was performed using, Wiley InterScience, and Springer with the key words, 'Flap,' 'indocyanine green,' 'surgery,' and related mesh words for all publications between 2005 and 2015. Title and abstract screening was performed using predefined in- and exclusion criteria.  Seventy-three articles were included. These were classified as "application of ICG in flap surgery" and "the security of applying ICG in flap surgery".  ICG fluorescence imaging preoperatively facilitates the detection of perforators in tissue flaps with thickness <20 mm, aids in the evaluation of flap microcirculation and perfusion, and allows surgeons to select dominant cutaneous nerves while evaluating the quality of vascular anastomoses and locating thromboses. The literature also concluded that potential allergic reactions to ICG should be taken into consideration. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

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

    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.

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

    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

    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. Reconstruction of Nasal Skin Cancer Defects with Local Flaps

    A. C. Salgarelli

    2011-01-01

    Full Text Available Reconstruction of nasal defects must preserve the integrity of complex facial functions and expressions, as well as facial symmetry and a pleasing aesthetic outcome. The reconstructive modality of choice will depend largely on the location, size, and depth of the surgical defect. Individualized therapy is the best course, and numerous flaps have been designed to provide coverage of a variety of nasal-specific defects. We describe our experience in the aesthetic reconstruction of nasal skin defects following oncological surgery. The use of different local flaps for nasal skin cancer defects is reported in 286 patients. Complications in this series were one partial flap dehiscence that healed by secondary intention, two forehead flaps, and one bilobed flap with minimal rim necrosis that resulted in an irregular scar requiring revision. Aesthetic results were deemed satisfactory by all patients and the operating surgeons. The color and texture matches were aesthetically good, and the nasal contour was distinct in all patients. All scars were inconspicuous and symmetrical. No patient had tenting or a flat nose.

  19. Reconstruction of Nasal Skin Cancer Defects with Local Flaps

    Salgarelli, A. C.; Bellini, P.; Multinu, A.; Consolo, U.; Magnoni, C.; Francomano, M.; Fantini, F.; Seidenari, S.

    2011-01-01

    Reconstruction of nasal defects must preserve the integrity of complex facial functions and expressions, as well as facial symmetry and a pleasing aesthetic outcome. The reconstructive modality of choice will depend largely on the location, size, and depth of the surgical defect. Individualized therapy is the best course, and numerous flaps have been designed to provide coverage of a variety of nasal-specific defects. We describe our experience in the aesthetic reconstruction of nasal skin defects following oncological surgery. The use of different local flaps for nasal skin cancer defects is reported in 286 patients. Complications in this series were one partial flap dehiscence that healed by secondary intention, two forehead flaps, and one bilobed flap with minimal rim necrosis that resulted in an irregular scar requiring revision. Aesthetic results were deemed satisfactory by all patients and the operating surgeons. The color and texture matches were aesthetically good, and the nasal contour was distinct in all patients. All scars were inconspicuous and symmetrical. No patient had tenting or a flat nose.

  20. Foot reconstruction using a free proximal peroneal artery perforator flap: Anatomical study and clinical application.

    Han, Hyun Ho; Lee, Yeon Ji; Moon, Suk-Ho

    2018-02-22

    When a small, thin, and durable flap is required for coverage of the foot, the proximal peroneal artery perforator (PPAP) free flap may be a novel option. However, few clinical results and anatomical studies on the PPAP flap have been published. A total of 24 PPAP flaps used in 22 patients from January 2013 to December 2016 were analyzed. All flaps were elevated in the subfascial plane based on a single perforator from the peroneal artery between the soleus and peroneus muscles. The average harvested flap size was 18.9 cm 2 (range, 9-40 cm 2 ), pedicle length was 4.3 cm (range, 3.1-5.5 cm), and pedicle artery diameter was 1.1 mm (range, 0.8-1.5 mm). Twenty-three of the 24 PPAP flaps survived. Average time to harvest the flap was 35 minutes (range, 20-55 minutes). Perforator location (ratio by fibula length) was confirmed at the 0.32 site (standard deviation, ±0.04) from the fibular head. Percentages of septocutaneous and musculocutaneous types were 42% (10/24) and 58% (14/24), respectively, for perforator vessel course; average intramuscular course was 1.3 cm (range, 0.7-2.4 cm). Vessel graft was conducted in four cases, with an average length of 2.2 cm (range, 1.5-3.0 cm). The PPAP flap is one of the thinnest flaps available and is relatively easy to elevate. Moreover, it can be elevated in the same operative field as the foot, and primary closure is available for the donor site. Thus, the PPAP flap may be a good surgical option for soft tissue coverage of the foot. Copyright © 2018 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

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

    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.

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

    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)

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

    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 ...

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

    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. High Speed Edge Detection

    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.

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

    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.

  7. Effects of irradiation of skin flaps

    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

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

    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 ...

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

    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

  10. Efficient flapping flight of pterosaurs

    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

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

    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

  12. [The sural medial perforator flap: Anatomical bases, surgical technique and indications in head and neck reconstruction].

    Struk, S; Schaff, J-B; Qassemyar, Q

    2018-04-01

    The medial sural artery perforator (MSAP) flap is defined as a thin cutaneo-adipose perforator flap harvested on the medial aspect of the leg. The aims of this study were to describe the anatomical basis as well as the surgical technique and discuss the indications in head and neck reconstructive surgery. We harvested 10 MSAP flap on 5 fresh cadavers. For each case, the number and the location of the perforators were recorded. For each flap, the length of pedicle, the diameter of source vessels and the thickness of the flap were studied. Finally, we performed a clinical application of a MSAP flap. A total of 23 perforators with a diameter superior than 1mm were dissected on 10 legs. The medial sural artery provided between 1 and 4 musculocutaneous perforators. Perforators were located in average at 10.3cm±2cm from the popliteal fossa and at 3.6cm±1cm from the median line of the calf. The mean pedicle length was 12.1cm±2.5cm. At its origin, the source artery diameter was 1.8mm±0.25mm and source veins diameters were 2.45mm±0.9mm in average. There was no complication in our clinical application. This study confirms the reliability of previous anatomical descriptions of the medial sural artery perforator flap. This flap was reported as thin and particularly adapted for oral cavity reconstruction and for facial or limb resurfacing. Sequelae might be reduced as compared to those of the radial forearm flap with comparable results. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Bilateral simultaneous breast reconstruction with SGAP flaps.

    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.

  14. The boomerang flap in managing injuries of the dorsum of the distal phalanx.

    Chen, S L; Chou, T D; Chen, S G; Cheng, T Y; Chen, T M; Wang, H J

    2000-09-01

    Finding an appropriate soft-tissue grafting material to close a wound located over the dorsum of a finger, especially the distal phalanx, can be a difficult task. The boomerang flap mobilized from the dorsum of the proximal phalanx of an adjacent digit can be useful when applied as an island pedicle skin flap. The vascular supply to the skin flap is derived from the retrograde perfusion of the dorsal digital artery. Mobilization and lengthening of the vascular pedicle are achieved by dividing the distal end of the dorsal metacarpal artery at the bifurcation and incorporating two adjacent dorsal digital arteries into one. The boomerang flap was used in seven individuals with injuries involving the dorsal aspect of the distal phalanx over the past year. Skin defects in all patients were combined with bone,joint, or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-step procedure preserves the proper palmar digital artery to the fingertip and has proven valuable for the coverage of wide and distal defects because it has the advantages of an extended skin paddle and a lengthened vascular pedicle. When conventional local flaps are inadequate, the boomerang flap should be considered for its reliability and low associated morbidity.

  15. Reconstruction of Facial Defect Using Deltopectoral Flap.

    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.

  16. Innervated boomerang flap for finger pulp reconstruction.

    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.

  17. Cost-effectiveness of monitoring free flaps.

    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.

  18. Microvascular free flaps in the management of war wounds with tissue defects

    Kozarski Jefta

    2003-01-01

    Full Text Available Background. War wounds caused by modern infantry weapons or explosive devices are very often associated with the defects of soft and bone tissue. According to their structure, tissue defects can be simple or complex. In accordance with war surgical doctrine, at the Clinic for Plastic Surgery and Burns of the Military Medical Academy, free flaps were used in the treatment of 108 patients with large tissue defects. With the aim of closing war wounds, covering deep structures, or making the preconditions for reconstruction of deep structures, free flaps were applied in primary, delayed, or secondary term. The main criteria for using free flaps were general condition of the wounded, extent, location, and structure of tissue defects. The aim was also to point out the advantages and disadvantages of the application of free flaps in the treatment of war wounds. Methods. One hundred and eleven microvascular free flaps were applied, both simple and complex, for closing the war wounds with extensive tissue defects. The main criteria for the application of free flaps were: general condition of the wounded, size, localization, and structure of tissue defects. For the extensive defects of the tissue, as well as for severely contaminated wounds latissimus dorsi free flaps were used. For tissue defects of distal parts of the lower extremities, scapular free flaps were preferred. While using free tissue transfer for recompensation of bone defects, free vascularized fibular grafts were applied, and in skin and bone defects complex free osteoseptocutaneous fibular, free osteoseptocutaneous radial forearm, and free skin-bone scapular flaps were used. Results. After free flap transfer 16 (14,4% revisions were performed, and after 8 unsuccessful revisions another free flaps were utilized in 3 (37,5% patients, and cross leg flaps in 5 (62,5% patients. Conclusion. The treatment of war wounds with large tissue defects by the application of free microvascular flaps

  19. Lift production through asymmetric flapping

    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.

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

    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

  1. Perforator anatomy of the ulnar forearm fasciocutaneous flap.

    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.

  2. Edge Detection,

    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

  3. Magnetic resonance imaging and clinical features of glenoid labral flap tears

    Stewart, Jessica K.; Vinson, Emily N. [Duke University Hospital, Department of Radiology, Durham, NC (United States); Taylor, Dean C. [Duke University Hospital, Department of Orthopaedic Surgery, Durham, NC (United States)

    2017-08-15

    Displaced flaps of glenoid labral tissue are an uncommonly encountered finding on MRI of the shoulder, and are of unclear clinical significance. The purpose of this study is to describe the imaging characteristics of displaced glenoid labral flaps, evaluate for any common concomitant injuries, and identify the typical clinical presentation and management of patients with this lesion. This retrospective, observational study was approved by the institutional review board. Nineteen patients with flap-type tears of the labrum on preoperative MRI were identified. Each examination was retrospectively reviewed by two radiologists for size, location, and signal intensity of the displaced flap of tissue, in addition to any co-existing labrum or cartilage pathological conditions and clinical information. All displaced flaps extended from the inferior margin of the glenoid into the axillary recess. The average size of the visualized flap was 10.9 by 6.0 by 2.6 mm. Seventy percent of the flaps had signal intensity isointense to labrum and hypointense to hyaline cartilage on T2-weighted images. All 19 patients had concomitant labral pathological conditions and 63% had cartilage defects, visualized on MRI. Clinical evidence of shoulder instability was seen in 83% of patients, and 67% were managed surgically. Glenoid labral flap tears have distinct imaging characteristics that may aid in their identification. Their presence should prompt careful evaluation of the glenoid articular cartilage. Recognition of a labral flap tear may have clinical importance, as 83% of patients with this finding demonstrated clinical evidence of shoulder instability, often requiring surgical intervention. (orig.)

  4. Magnetic resonance imaging and clinical features of glenoid labral flap tears

    Stewart, Jessica K.; Vinson, Emily N.; Taylor, Dean C.

    2017-01-01

    Displaced flaps of glenoid labral tissue are an uncommonly encountered finding on MRI of the shoulder, and are of unclear clinical significance. The purpose of this study is to describe the imaging characteristics of displaced glenoid labral flaps, evaluate for any common concomitant injuries, and identify the typical clinical presentation and management of patients with this lesion. This retrospective, observational study was approved by the institutional review board. Nineteen patients with flap-type tears of the labrum on preoperative MRI were identified. Each examination was retrospectively reviewed by two radiologists for size, location, and signal intensity of the displaced flap of tissue, in addition to any co-existing labrum or cartilage pathological conditions and clinical information. All displaced flaps extended from the inferior margin of the glenoid into the axillary recess. The average size of the visualized flap was 10.9 by 6.0 by 2.6 mm. Seventy percent of the flaps had signal intensity isointense to labrum and hypointense to hyaline cartilage on T2-weighted images. All 19 patients had concomitant labral pathological conditions and 63% had cartilage defects, visualized on MRI. Clinical evidence of shoulder instability was seen in 83% of patients, and 67% were managed surgically. Glenoid labral flap tears have distinct imaging characteristics that may aid in their identification. Their presence should prompt careful evaluation of the glenoid articular cartilage. Recognition of a labral flap tear may have clinical importance, as 83% of patients with this finding demonstrated clinical evidence of shoulder instability, often requiring surgical intervention. (orig.)

  5. Long-term Outcomes After Flap Reconstruction in Pediatric Pressure Ulcers.

    Firriolo, Joseph M; Ganske, Ingrid M; Pike, Carolyn M; Caillouette, Catherine; Faulkner, Heather R; Upton, Joseph; Labow, Brian I

    2018-02-01

    Pressure ulcers refractory to nonoperative management may undergo flap reconstruction. This study aims to evaluate the long-term outcomes and recurrence rates of flap reconstruction for pediatric pressure ulcers. We reviewed the records of patients who underwent flap reconstruction for pressure ulcer(s) from 1995 to 2013. Twenty-four patients with 30 pressure ulcers, requiring 52 flaps were included. Ulcers were stages III and IV and mostly involved either the ischia (15/30) or sacrum (8/30). Flaps were followed for a median of 4.9 years. Twenty-three patients were wheelchair dependent, and 20 had sensory impairment at their ulcer site(s). Ten patients had a history of noncompliance with preoperative management, 8 of whom experienced ulcer recurrence. Twenty-one ulcers had underlying osteomyelitis, associated with increased admissions (P = 0.019) and cumulative length of stay (P = 0.031). Overall, there was a 42% recurrence rate in ulceration after flap reconstruction. Recurrence was associated with a preoperative history of noncompliance with nonoperative therapy (P = 0.030), but not with flap type or location, age, sex, body mass index, osteomyelitis, or urinary/fecal incontinence (P > 0.05, all). Flap reconstruction can be beneficial in the management of pediatric pressure ulcers. Although high rates of long-term success with this intervention have been reported in children, we found rates of ulcer recurrence similar to that seen in adults. Poor compliance with nonoperative care and failure to modify the biopsychosocial perpetuators of pressure ulcers will likely eventuate in postoperative recurrence. Despite the many comorbidities observed in our patient sample, compliance was the best indicator of long-term skin integrity and flap success.

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

    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 ...

  7. Flow structures around a flapping wing considering ground effect

    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.

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

    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.

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

    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.

  10. Living edge

    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...

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

    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

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

    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

  13. Influence of inflow angle on flexible flap aerodynamic performance

    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

  14. Dermatosurgery Rounds - The Island SKIN Infraorbital Flap

    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.

  15. Root coverage with bridge flap

    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.

  16. Medial canthal reconstruction with multiple local flaps

    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.

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

    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.

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

    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.

  19. Refining the intrinsic chimera flap: a review.

    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.

  20. Optimal propulsive flapping in Stokes flows.

    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.

  1. Optimal propulsive flapping in Stokes flows

    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)

  2. The location of cemento enamel junction for CAL measurement: A clinical crisis

    Vandana K

    2009-01-01

    Full Text Available Background: We face various problems while measuring the Clinical attachment level (CAL from Cemento-enamel junction (CEJ. This study aims to record and compare the CEJ location measurements using a xed reference point (FRP [Custom made stent] before and after ap elevation. Materials and Methods: A custom made stent and UNC-15 probe were used. Recording of CEJ location was made using a UNC-15 (Hu-Friedy probe, before (close CEJ and after (Open CEJ the reflection of the flap from the lower edge of the stent in those subjects who were indicated for flap surgery, at baseline. Results: We used statistical analysis involving intra-group comparison done by Paired-′t′ test. The close and the open CEJ measurements demonstrated a, statistically, non-significant difference. The equi-measurements of close and open CEJ numerical data were remarkably lower than the under and overestimation of measurements. Thus, despite certain disadvantages of stent, the FRP provides a simple solution for CAL measurement. Conclusion: The results of this study confirms the objective of the study and strongly suggests that CAL measurements done without FRP is subjected to great variation and the diagnostic and prognostic interpretation of CAL should be viewed seriously in periodontics.

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

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

    2017-08-01

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

  4. Patient-based outcomes following surgical debridement and flap coverage of digital mucous cysts.

    Hojo, Junya; Omokawa, Shohei; Shigematsu, Koji; Onishi, Tadanobu; Murata, Keiichi; Tanaka, Yasuhito

    2016-01-01

    The purpose of this prospective cohort study was to evaluate patient-based outcomes and complications following excision of mucous cysts, joint debridement, and closure with one of three types of local flaps. From 2000-2011, 35 consecutive patients with 37 digital mucous cysts were treated surgically. The surgical procedure included excision of the cyst together with the attenuated skin, joint debridement on the affected side including capsulectomy, and removal of osteophytes. Depending on the size and location of the cyst, the skin defect was covered by a transposition flap (31 cysts), an advancement flap (two cysts), or a rotation flap (four cysts). At an average follow-up time of 4 years, 4 months, there was no wound infection, flap necrosis, or joint stiffness. Preoperative nail ridging resolved in seven of nine fingers, and no nail deformities developed after surgery. One cyst, treated with a transposition flap, recurred 10 months after surgery. The average satisfaction score for the affected finger significantly improved from 4.3 to 6.8, and the average pain score decreased from 4.7 to 2.3. This treatment protocol provides reliable results. Patients were satisfied with the reduction of associated pain and the postoperative appearance of the treated finger, and postoperative complications were minimal.

  5. Design and stable flight of a 21 g insect-like tailless flapping wing micro air vehicle with angular rates feedback control.

    Phan, Hoang Vu; Kang, Taesam; Park, Hoon Cheol

    2017-04-04

    An insect-like tailless flapping wing micro air vehicle (FW-MAV) without feedback control eventually becomes unstable after takeoff. Flying an insect-like tailless FW-MAV is more challenging than flying a bird-like tailed FW-MAV, due to the difference in control principles. This work introduces the design and controlled flight of an insect-like tailless FW-MAV, named KUBeetle. A combination of four-bar linkage and pulley-string mechanisms was used to develop a lightweight flapping mechanism that could achieve a high flapping amplitude of approximately 190°. Clap-and-flings at dorsal and ventral stroke reversals were implemented to enhance vertical force. In the absence of a control surface at the tail, adjustment of the location of the trailing edges at the wing roots to modulate the rotational angle of the wings was used to generate control moments for the attitude control. Measurements by a 6-axis load cell showed that the control mechanism produced reasonable pitch, roll and yaw moments according to the corresponding control inputs. The control mechanism was integrated with three sub-micro servos to realize the pitch, roll and yaw controls. A simple PD feedback controller was implemented for flight stability with an onboard microcontroller and a gyroscope that sensed the pitch, roll and yaw rates. Several flight tests demonstrated that the tailless KUBeetle could successfully perform a vertical climb, then hover and loiter within a 0.3 m ground radius with small variations in pitch and roll body angles.

  6. [Fasciocutaneous flap reliable by deep femoral artery perforator for the treatment of ischial pressure ulcers].

    Gebert, L; Boucher, F; Lari, A; Braye, F; Mojallal, A; Ismaïl, M

    2018-04-01

    The surgical management of pressure ulcers in the paraplegic or quadriplegic population is marked by the high risk of recurrence in the long-term. In the current era of perforator flaps, newer reconstructive options are available for the management of pressure ulcers, decreasing the need to use the classically described muscular or musculocutaneous locoregional flaps. The coverage of ischial sores described in this article by a pedicled flap based on a deep femoral artery perforator, appears to be an effective first-line reconstructive option for the management of limited size pressure ulcers. A number of fifteen paraplegic or quadriplegic patients having at least one ischial bed sore with underlying osteomyelitis were included in this series. The approximate location of the deep femoral artery perforator was initially identified using the "The Atlas of the perforator arteries of the skin, the trunk and limbs", which was confirmed, with the use of a Doppler device. A fasciocutaneous transposition flap was elevated, with the pivot point based on the cutaneous bridge centered on the perforator, and then transposed to cover the area of tissue loss. The donor site was closed primarily. A total of fifteen patients were operated from November 2015 to November 2016. The series comprised of 16 first presentations of a stage 4 pressure ulcers associated with underlying osteomyelitis that were subsequently reconstructed by the pedicled deep femoral artery perforator flap. The healing rate and functional results were both satisfactory. Fasciocutaneous flap reliable by deep femoral artery perforator appears to have a promising role in the treatment of ischial pressure sores. It is an attractive option to spare the use of musculocutaneous flaps in the area. Thus this flap could be used as a first-line option to cover ischial pressure ulcers of limited size. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

    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.

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

    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.

  9. Median forehead flap - beyond classic indication

    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.

  10. Versatality of Nasolabial Flap in Orofacial Reconstruction

    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.

  11. Usefulness of V-Y Advancement Flap for Defects after Skin Tumor Excision

    Ki Hyun Kwon

    2012-11-01

    Full Text Available BackgroundAfter skin tumor excision on the face, extremities, or trunk, the choice of treatment for a skin defect is highly variable. Many surgeons prefer to use a local flap rather than a skin graft or free flap for small- or moderately-sized circular defects. We have used unilateral or bilateral V-Y advancement flaps, especially on the face. Here we evaluated the functional and aesthetic results of this technique.MethodsAll of the patients were pathologically diagnosed with squamous cell carcinoma (SCC, basal cell carcinoma (BCC, or malignant melanoma or premalignant lesion (Bowen's disease. Thirty-two patients underwent V-Y advancement flap repair (11 unilateral and 21 bilateral from January 2007 to June 2011. We analyzed the patients' age and satisfaction, and location and size of defect. The patients were followed up for 6 months or more.ResultsThere were 22 women and 10 men. The ages ranged from 47 to 93 years with a mean age of 66 years. The causes were SCC in 15 cases, BCC in 13 cases, malignant melanoma in 1 case, Bowen's disease in 2 cases, and another cause in 1 case. The tumor locations were the face in 28 patients, and the scalp, upper limb, and flank each in one patient. All of the flaps survived and the aesthetic results were good. Postoperative recovery was usually rapid, and no complication or tumor recurrence was observed.ConclusionsThe V-Y advancement flap is often used not only for facial circular defects but also for defects of the trunk and extremities. Its advantages are less scarring and superior aesthetic results as compared with other local flap methods, because of less scarification of adjacent tissue and because it is an easy surgical technique.

  12. Laser resurfacing of skin flaps: an experimental comparison

    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.

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

    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

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

    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...

  15. Dorsal hand coverage with free serratus fascia flap

    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....

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

    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 ...

  17. Total endoscopic free flap harvest of a serratus anterior fascia flap for microsurgical lower leg reconstruction

    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.

  18. Comparison of gluteal perforator flaps and gluteal fasciocutaneous rotation flaps for reconstruction of sacral pressure sores.

    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.

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

    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...

  20. Hydrodynamic schooling of flapping swimmers

    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

  1. Hydrodynamic schooling of flapping swimmers

    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.

  2. Unsteady aerodynamics of a pitching-flapping-perturbed revolving wing at low Reynolds number

    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.

  3. Oscillation of Vortex Breakdown Location and Blowing Control of Time-Averaged Location

    Mitchell, Anthony

    2000-01-01

    The goal of this research is the control of leading-edge vortex breakdown location utilizing along-the-core blowing near the apex on the leeward surface of sharp-edged, slender, delta wings at high angles of attack...

  4. Particle image velocimetry investigation of flow over unsteady airfoil with trailing-edge strip

    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.)

  5. Boomerang flap reconstruction for the breast.

    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.

  6. The transverse musculocutaneous gracilis flap for breast reconstruction: guidelines for flap and patient selection.

    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.

  7. Quasi-3d aerodynamic code for analyzing dynamic flap response

    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...

  8. Titanium Aluminide Scramjet Inlet Flap Subelement Benchmark Tested

    Krause, David L.; Draper, Susan L.

    2005-01-01

    A subelement-level ultimate strength test was completed successfully at the NASA Glenn Research Center (http://www.nasa.gov/glenn/) on a large gamma titanium aluminide (TiAl) inlet flap demonstration piece. The test subjected the part to prototypical stress conditions by using unique fixtures that allowed both loading and support points to be located remote to the part itself (see the photograph). The resulting configuration produced shear, moment, and the consequent stress topology proportional to the design point. The test was conducted at room temperature, a harsh condition for the material because of reduced available ductility. Still, the peak experimental load-carrying capability exceeded original predictions.

  9. The Use of Tensor Fascia Lata Pedicled Flap in Reconstructing Full Thickness Abdominal Wall Defects and Groin Defects Following Tumor Ablation

    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

  10. Closure of Myelomeningocele Defects Using a Limberg Flap or Direct Repair

    Jung-Hwan Shim

    2016-01-01

    Full Text Available BackgroundThe global prevalence of myelomeningocele has been reported to be 0.8–1 per 1,000 live births. Early closure of the defect is considered to be the standard of care. Various surgical methods have been reported, such as primary skin closure, local skin flaps, musculocutaneous flaps, and skin grafts. The aim of this study was to describe the clinical characteristics of myelomeningocele defects and present the surgical outcomes of recent cases of myelomeningocele at our institution.MethodsPatients who underwent surgical closure of myelomeningocele at our institution from January 2004 to December 2013 were included in this study. A retrospective chart review of their medical records was performed, and comorbidities, defect size, location, surgical procedures, complications, and the final results were analyzed.ResultsA total of 14 patients underwent surgical closure for myelomeningocele defects. Twelve cases were closed with direct skin repair, while two cases required local skin flaps to cover the skin defects. Three cases of infection occurred, requiring incision and either drainage or removal of allogenic materials. One case of partial flap necrosis occurred, requiring secondary revision using a rotational flap and a full-thickness skin graft. Despite these complications, all wounds eventually healed completely.ConclusionsMost myelomeningocele defects can be managed by direct skin repair alone. In cases of large defects, in which direct repair is not possible, local flaps may be used to cover the defect. Complications such as wound dehiscence and partial flap necrosis occurred in this study; however, all such complications were successfully managed with simple ancillary procedures.

  11. [Effectiveness of dorsal metacarpal island flap for treating scar contracture of finger web].

    Qian, Jun; Rui, Yongjun; Zhang, Quanrong; Xue, Mingyu; Zhang, Zhihai

    2011-11-01

    To investigate the effectiveness of dorsal metacarpal island flap for treating scar contracture of the finger web. Between June 2009 and December 2010, 10 patients with scar contracture of the finger web were treated. There were 6 males and 4 females with an average age of 30 years (range, 14-57 years). Scar contracture was caused by injury in 8 cases, by burn in 1 case, and by operation in 1 case. The locations were the 1st web space in 1 case, the 2nd web space in 3 cases, the 3rd web space in 5 cases, and the 4th web space in 1 case. The disease duration was 3 to 9 months with an average of 5 months. The maximum abduction was 10-20 degrees. After web space scar release, the dorsal metacarpal island flap (3.5 cm x 1.2 cm-4.0 cm x 2.0 cm in size) was used to reconstruct web space (2.0 cm x 1.0 cm-3.0 cm x 1.8 cm in size). The donor site was directly sutured or repaired with local flaps. At 2 days after operation, necrosis occurred in 1 flap, which healed by extractive treatment. The other flaps survived and wound healed by first intention; all the flaps at donor sites survived and incision healed by first intention. Ten patients were followed up 6 to 15 months (mean, 9 months). The reconstructed web space had good appearance, the maximum abduction was 80 degrees in 1 case of the 1st web space scars contracture, and the maximum abduction was 35-45 degrees (mean, 40 degrees) in the other 9 cases. In 8 scar patients causing by injury, no scar contracture recurred during follow-up. It can achieve good results in appearance and function to use dorsal metacarpal island flap for treating scar contracture of the finger web.

  12. Face resurfacing using a cervicothoracic skin flap prefabricated by lateral thigh fascial flap and tissue expander.

    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

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

    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...

  14. Treatment of ischial pressure sores with both profunda femoris artery perforator flaps and muscle flaps.

    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.

  15. An experimental study of the unsteady vortex structures in the wake of a root-fixed flapping wing

    Hu, Hui; Clemons, Lucas; Igarashi, Hirofumi

    2011-08-01

    An experimental study was conducted to characterize the evolution of the unsteady vortex structures in the wake of a root-fixed flapping wing with the wing size, stroke amplitude, and flapping frequency within the range of insect characteristics for the development of novel insect-sized nano-air-vehicles (NAVs). The experiments were conducted in a low-speed wing tunnel with a miniaturized piezoelectric wing (i.e., chord length, C = 12.7 mm) flapping at a frequency of 60 Hz (i.e., f = 60 Hz). The non-dimensional parameters of the flapping wing are chord Reynolds number of Re = 1,200, reduced frequency of k = 3.5, and non-dimensional flapping amplitude at wingtip h = A/C = 1.35. The corresponding Strouhal number (Str) is 0.33 , which is well within the optimal range of 0.2 flying insects and birds and swimming fishes for locomotion. A digital particle image velocimetry (PIV) system was used to achieve phased-locked and time-averaged flow field measurements to quantify the transient behavior of the wake vortices in relation to the positions of the flapping wing during the upstroke and down stroke flapping cycles. The characteristics of the wake vortex structures in the chordwise cross planes at different wingspan locations were compared quantitatively to elucidate underlying physics for a better understanding of the unsteady aerodynamics of flapping flight and to explore/optimize design paradigms for the development of novel insect-sized, flapping-wing-based NAVs.

  16. Pre-operative CT angiography and three-dimensional image post processing for deep inferior epigastric perforator flap breast reconstructive surgery.

    Lam, D L; Mitsumori, L M; Neligan, P C; Warren, B H; Shuman, W P; Dubinsky, T J

    2012-12-01

    Autologous breast reconstructive surgery with deep inferior epigastric artery (DIEA) perforator flaps has become the mainstay for breast reconstructive surgery. CT angiography and three-dimensional image post processing can depict the number, size, course and location of the DIEA perforating arteries for the pre-operative selection of the best artery to use for the tissue flap. Knowledge of the location and selection of the optimal perforating artery shortens operative times and decreases patient morbidity.

  17. Route Flap Damping Made Usable

    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.

  18. Shape optimisation and performance analysis of flapping wings

    Ghommem, Mehdi

    2012-09-04

    In this paper, shape optimisation of flapping wings in forward flight is considered. This analysis is performed by combining a local gradient-based optimizer with the unsteady vortex lattice method (UVLM). Although the UVLM applies only to incompressible, inviscid flows where the separation lines are known a priori, Persson et al. [1] showed through a detailed comparison between UVLM and higher-fidelity computational fluid dynamics methods for flapping flight that the UVLM schemes produce accurate results for attached flow cases and even remain trend-relevant in the presence of flow separation. As such, they recommended the use of an aerodynamic model based on UVLM to perform preliminary design studies of flapping wing vehicles Unlike standard computational fluid dynamics schemes, this method requires meshing of the wing surface only and not of the whole flow domain [2]. From the design or optimisation perspective taken in our work, it is fairly common (and sometimes entirely necessary, as a result of the excessive computational cost of the highest fidelity tools such as Navier-Stokes solvers) to rely upon such a moderate level of modelling fidelity to traverse the design space in an economical manner. The objective of the work, described in this paper, is to identify a set of optimised shapes that maximise the propulsive efficiency, defined as the ratio of the propulsive power over the aerodynamic power, under lift, thrust, and area constraints. The shape of the wings is modelled using B-splines, a technology used in the computer-aided design (CAD) field for decades. This basis can be used to smoothly discretize wing shapes with few degrees of freedom, referred to as control points. The locations of the control points constitute the design variables. The results suggest that changing the shape yields significant improvement in the performance of the flapping wings. The optimisation pushes the design to "bird-like" shapes with substantial increase in the time

  19. Postirradiation flap infection about the oral cavity

    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

  20. Intraoperative indocyanine green fluorescent angiography-assisted modified superior gluteal artery perforator flap for reconstruction of sacral pressure sores.

    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.

  1. Prefabricated neck expanded skin flap with the superficial temporal vessels for facial resurfacing.

    Lazzeri, Davide; Su, Weijie; Qian, Yunliang; Messmer, Caroline; Agostini, Tommaso; Spinelli, Giuseppe; Marcus, Jeffrey R; Levin, L Scott; Zenn, Micheal R; Zhang, Yi Xin

    2013-05-01

    The achievement of a normal-appearing face after surgical resurfacing remains an elusive goal. This is due in part to insufficient color matching, restoration of contours, and the persistence of visible scars. Flap prefabrication is a staged procedure that provides an independent axial blood supply to local expanded tissues. We describe a new reconstructive alternative with superior reconstructive surgical options for facial resurfacing that better matches damaged or discarded facial tissues. A superficial temporal fascial flap was harvested as the vascular supply of the prefabricated neck flap and located in a subcutaneous neck pocket over a tissue expander. After a 5-month period for expansion and maturation, the prefabricated skin flap was raised, islanded, and rotated to resurface the facial defect. Four patients with hemifacial postburn contracture and two patients affected by hemifacial vascular malformations aged 17 to 42 years (mean 29 years) were successfully treated with no major complication after a mean period of 15 months. Prefabricated neck-expanded skin flap demonstrated an excellent color and texture match with facial skin that surrounded the repair sites, and optimal aesthetic results were obtained. Importantly, facial expression was completely maintained due to thinness and pliability of the rotated skin. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  2. The role of postoperative hematoma on free flap compromise.

    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.

  3. An analytical model and scaling of chordwise flexible flapping wings in forward flight.

    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.

  4. Triple flap technique for vulvar reconstruction.

    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.

  5. [A variant of island flaps for the covering of pressure sores: the hatchet flap. Apropos of 31 cases].

    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.

  6. Treatment of soft-tissue loss with nerve defect in the finger using the boomerang nerve flap.

    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.

  7. Aerodynamics power consumption for mechanical flapping wings undergoing flapping and pitching motion

    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.

  8. Rescue of Primary Incomplete Microkeratome Flap with Secondary Femtosecond Laser Flap in LASIK

    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.

  9. The Internal Pudendal Artery Perforator Thigh Flap: A New Freestyle Pedicle Flap for the Ischial Region

    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.

  10. The prepuce free flap in 10 patients : modifications in flap design and surgical technique

    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

  11. Stability of edge states and edge magnetism in graphene nanoribbons

    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 ...

  12. Free flap reconstruction for diabetic foot limb salvage.

    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.

  13. 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

    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.

  14. Nanoindentation near the edge

    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...

  15. Free-flap cover of complex defects around the knee using the descending genicular artery as the recipient pedicle.

    Venkatramani, H; Sabapathy, S R; Nayak, S

    2014-01-01

    Selection of ideal recipient vessels is one of the most important factors determining success in free-flap reconstruction of the lower limb. At the knee, the choice of vessels has traditionally been either the common femoral or the popliteal vessels and their branches but these are often difficult to use or cannot be used. A series of 32 free flaps for cover of complex injuries of the knee involving the distal femur, the knee joint and the upper tibia were reconstructed using the descending genicular branch of the femoral artery in the adductor canal and its muscular branches to the vastus medialis as the recipient vessels. All but one flap survived with no major complications. The use of the descending genicular artery as the recipient vessel for reconstruction with free flaps around the knee has various advantages including: (i) it is mostly remote from the zone of trauma, (ii) it is constant in location, (iii) the recipient vessels are an excellent size match for end-to-end anastomosis, (iv) there is no need for changes of position of the patient when using most free flaps commonly used for knee reconstruction, (v) it is easy to harvest these simultaneously, (vi) secondary exposure of the underlying skeleton from all quadrants is unlikely to divide the flap pedicle as it is superior and (vii), perhaps most important of all, it obviates the need for exploration of the popliteal fossa. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. Comparison of Dorsal Intercostal Artery Perforator Propeller Flaps and Bilateral Rotation Flaps in Reconstruction of Myelomeningocele Defects.

    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.

  17. IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

    纳瑟; 刘重庆

    2002-01-01

    A method that incorporates edge detection technique, Markov Random field (MRF), watershed segmentation and merging techniques was presented for performing image segmentation and edge detection tasks. It first applies edge detection technique to obtain a Difference In Strength (DIS) map. An initial segmented result is obtained based on K-means clustering technique and the minimum distance. Then the region process is modeled by MRF to obtain an image that contains different intensity regions. The gradient values are calculated and then the watershed technique is used. DIS calculation is used for each pixel to define all the edges (weak or strong) in the image. The DIS map is obtained. This help as priority knowledge to know the possibility of the region segmentation by the next step (MRF), which gives an image that has all the edges and regions information. In MRF model,gray level l, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The segmentation results are improved by using watershed algorithm. After all pixels of the segmented regions are processed, a map of primitive region with edges is generated. The edge map is obtained using a merge process based on averaged intensity mean values. A common edge detectors that work on (MRF) segmented image are used and the results are compared. The segmentation and edge detection result is one closed boundary per actual region in the image.

  18. Salient points in reconstruction of nasal skin after tumor ablation with local flaps

    Ali Ebrahimi

    2016-01-01

    Full Text Available Objective: A variety of nasal skin reconstruction methods are available to meet the esthetic patient's needs. In this article, we review some of modifications of these procedures and share our experience in reconstruction of different parts of the nasal skin following skin tumor ablation. Patients and Methods : From January 2010 to January 2014, 171 patients underwent nasal skin reconstruction after excising cancerous lesions of the involved nasal skin. The patient's history, pre- and post-operation photographs, and the surgery data were collected and assessed. Demographic data related to the type of cancer, defect size and location, type of reconstruction were collected. Results: A variety of local flaps were used based on location and defect features. Nearly all flaps healed primarily without postsurgical significant complications. Conclusion: According to the results and the outcomes of the operations, we concluded that a certain flaps are more effective than others in nasal skin reconstruction. Local flap reconstruction of the nose has good esthetic result with low complication rate.

  19. [APPLICATION OF V-Y ADVANCED SENSE-REMAINED POSTERIOR TIBIAL ARTERY PERFORATOR FLAP IN REPAIRING WOUND AROUND ANKLE].

    Tang, Xiujun; Wang, Bo; Wei, Zairong; Wang, Dali; Han, Wenjie; Zhang, Wenduo; Li, Shujun

    2015-12-01

    OBJECTIVE To explore the feasibility and effectiveness of V-Y advanced sense-remained posterior tibial artery perforator flap in repairing wound around the ankle. METHODS Between March 2012 and January 2015, 11 patients with wounds around the ankle were treated by V-Y advanced sense-remained posterior tibial artery perforator flap. There were 6 males and 5 females with a median age of 37 years (range, 21-56 years). The causes were traffic accident injury in 3 cases, thermal injury in 2 cases, burn in 2 cases, iatrogenic wounds in 2 cases, and local contusion in 2 cases. The disease duration ranged from 1 to 3 weeks (mean, 2 weeks). Injury was located at the medial malleolus in 4 cases, at the lateral malleolus in 3 cases, and at the heel in 4 cases. All had exposure of bone, tendon, or plate. The defect area ranged from 4 cmx2 cm to 5 cmx3 cm; the area of the flap ranged from 11 cmx4 cm to 15 cmx6 cm. Necrosis of distal flap occurred in 1 case after operation; re-operation to amputate the posterior tibial artery was given and the wound was repaired by proximal skin graft. Light necrosis of distal end was observed in 2 cases, and wound healed at 3 weeks after dressing. And other flaps successfully survived, and primary healing of wounds were obtained. The patients were followed up 6-24 months (mean, 11 months). The flaps were good in color, texture, and appearance. The ankle joint had normal activity. At last follow-up, 10 cases restored fine sense, and 1 case restored protective feeling with posterior tibial artery advanced flap after amputation. V-Y advanced sense-remained posterior tibial artery perforator flap has the advantages of reliable blood supply, simple operation, good appearance, and sensory recovery. Therefore, it is an ideal method to repair wound around the ankle.

  20. Clinical applications of the superior epigastric artery perforator (SEAP) flap: anatomical studies and preoperative perforator mapping with multidetector CT.

    Hamdi, Moustapha; Van Landuyt, Koenraad; Ulens, Sara; Van Hedent, Eddy; Roche, Nathalie; Monstrey, Stan

    2009-09-01

    Pedicled superior epigastric artery perforator (SEAP) flaps can be raised to cover challenging thoracic defects. We present an anatomical study based on multidetector computerized tomography (MDCT) scan findings of the SEA perforators in addition to the first reported clinical series of SEAP flaps in anterior chest wall reconstruction. (a) In the CT scan study, images of a group of 20 patients who underwent MDCT scan analysis were used to visualise bilaterally the location of musculocutaneous SEAP. X- and Y-axes were used as landmarks to localise the perforators. The X-axis is a horizontal line at the junction of sternum and xyphoid (JCX) and the Y-axis is at the midline. (b) In the clinical study, seven pedicled SEAP flaps were performed in another group of patients. MDCT images revealed totally 157 perforators with a mean of 7.85 perforators per patient. The dominant perforators (137 perforators) were mainly localised in an area between 1.5 and 6.5 cm from the X-axis on both sides and between 3 and 16 cm below the Y-axis. The calibre of these dominant perforators was judged as 'good' to 'very good' in 82.5% of the cases. The average dimension of the flap was 21.7x6.7 cm. All flaps were based on one perforator. Mean harvesting time was 110 min. There were no flap losses. Minor tip necrosis occurred in two flaps. One of them was treated with excision and primary closure. Our clinical experience indicates that the SEAP flap provides a novel and useful approach for reconstruction of anterior chest wall defects. CT-based imaging allows for anatomical assessment of the perforators of the superior epigastric artery (SEA).

  1. Propeller Flap for Complex Distal Leg Reconstruction: A Versatile ...

    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.

  2. Scrotal reconstruction with superomedial fasciocutaneous thigh flap

    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.

  3. The forked flap repair for hypospadias

    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.

  4. MR imaging characteristics and clinical symptoms related to displaced meniscal flap tears

    Lance, Valentin; Heilmeier, Ursula R.; Joseph, Gabby B.; Steinbach, Lynne; Link, Thomas M. [University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ma, Benjamin [University of California, Department of Orthopedic Surgery and Sports Medicine, San Francisco (United States)

    2014-11-16

    The purpose of our study was (1) to analyze the flap tear location, direction of displacement and size on magnetic resonance (MR) imaging, (2) to describe associated knee abnormalities including presence of effusion, synovitis, bone marrow edema pattern or ligamentous tear, and (3) to assess clinical findings found with flap tears, including the pain score, and determine differences between operative and nonoperative groups. A retrospective radiology database search over the last 3 years identified 238 patients with flap tears, of which ultimately 58 with isolated flap tears were included after exclusion of patients with other significant knee internal derangement, severe degenerative change or prior surgery. MR studies of the knee were analyzed by two radiologists. Imaging characteristics were correlated with associated knee abnormalities and clinical findings. Statistical analysis employed linear and logistic regression models. Inter- and intrareader reliability was calculated. The medial meniscus was the most common site of flap tears (52/60, 87 %), with inferior displacement (47/60, 78 %). The degree of tibial cartilage loss had a positive correlation with the visual analog pain scale (p = 0.03). Patients who underwent arthroscopy were younger than those who did not (p = 0.01) and more likely to have a positive clinical McMurray test (p = 0.01). Medially and inferiorly displaced flap tears are the most common tear pattern. Those undergoing arthroscopy are more likely to have positive meniscal signs on clinical examination. A greater degree of cartilage loss involving the tibia on MR imaging was associated with increasing visual analog pain scores. (orig.)

  5. MR imaging characteristics and clinical symptoms related to displaced meniscal flap tears

    Lance, Valentin; Heilmeier, Ursula R.; Joseph, Gabby B.; Steinbach, Lynne; Link, Thomas M.; Ma, Benjamin

    2015-01-01

    The purpose of our study was (1) to analyze the flap tear location, direction of displacement and size on magnetic resonance (MR) imaging, (2) to describe associated knee abnormalities including presence of effusion, synovitis, bone marrow edema pattern or ligamentous tear, and (3) to assess clinical findings found with flap tears, including the pain score, and determine differences between operative and nonoperative groups. A retrospective radiology database search over the last 3 years identified 238 patients with flap tears, of which ultimately 58 with isolated flap tears were included after exclusion of patients with other significant knee internal derangement, severe degenerative change or prior surgery. MR studies of the knee were analyzed by two radiologists. Imaging characteristics were correlated with associated knee abnormalities and clinical findings. Statistical analysis employed linear and logistic regression models. Inter- and intrareader reliability was calculated. The medial meniscus was the most common site of flap tears (52/60, 87 %), with inferior displacement (47/60, 78 %). The degree of tibial cartilage loss had a positive correlation with the visual analog pain scale (p = 0.03). Patients who underwent arthroscopy were younger than those who did not (p = 0.01) and more likely to have a positive clinical McMurray test (p = 0.01). Medially and inferiorly displaced flap tears are the most common tear pattern. Those undergoing arthroscopy are more likely to have positive meniscal signs on clinical examination. A greater degree of cartilage loss involving the tibia on MR imaging was associated with increasing visual analog pain scores. (orig.)

  6. The posterolateral mid-forearm perforator flap: anatomical study and clinical application.

    Zhuang, Yue-Hong; Lin, Jian; Fu, Fei-Huan; Cai, Zhen-De; Huang, Hui-Mei; Zheng, He-Ping

    2013-11-01

    Defects sustained at the distal forearm are common and pedicled perforator flaps have unique advantages in resurfacing it. The purpose of this study is to reappraise the anatomy of the perforator in the posterolateral aspect of the mid-forearm and present our clinical experience on using perforator flaps based on it for reconstruction of defects in the distal forearm. This study was divided into anatomical study and clinical application. In the anatomical study, 30 preserved upper limbs were used. Clinically, 11 patients with defects at the forearm underwent reconstruction with the posterolateral mid-forearm perforator flaps. The defects, ranging from 4.5 × 2.5 cm to 10.5 × 4.5 cm, were located at the dorsal aspect of the distal forearm in 6 cases and at the volar aspect of the distal forearm in 5 cases. Three patterns of the perforator were observed in the posterolateral aspect of the mid-forearm, which originated from the posterior interosseous artery, the proximal segment of the radial artery or the radial recurrent artery, and the middle segment of the radial artery, respectively. The perforator was located 11.8 ± 0.2 cm to 15.8 ± 0.4 cm inferior to the lateral humeral epicondyle. Clinically, flaps in 8 cases survived uneventfully, while the other 3 cases suffered mild marginal epidermal necrosis, which was cured with continuous dress changing. The location of the perforator at the posterolateral aspect of the mid-forearm is consistent; the posterolateral mid-forearm perforator flap is particularly suitable to cover defects in the distal one-third of the forearm. Copyright © 2013 Wiley Periodicals, Inc.

  7. Perforator plus flaps: Optimizing results while preserving function and esthesis

    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

  8. Curative effect observation of n-flap and off-flap EPi-LASIK in ametropia

    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.

  9. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    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.

  10. Reconstruction of eyelids with Washio flap in anophthalmia.

    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.

  11. Prospective evaluation of outcome measures in free-flap surgery.

    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.

  12. Dual omental flap in obliterating post-pneumonectomy ...

    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 ...

  13. Blood flow autoregulation in pedicled flaps

    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...

  14. Double papilla flap technique for dual purpose

    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.

  15. Computational Investigations on the Effects of Gurney Flap on Airfoil Aerodynamics.

    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.

  16. Waters Edge Land Company, LLC - Clean Water Act Public Notice

    The EPA is providing notice of an Administrative Penalty Assessment in the form of an Expedited Storm Water Settlement Agreement against Waters Edge Land Company, LLC, a business located at 10800 Farley St. Overland Park, KS, for alleged violations located

  17. Locative media

    Wilken, Rowan

    2014-01-01

    Not only is locative media one of the fastest growing areas in digital technology, but questions of location and location-awareness are increasingly central to our contemporary engagements with online and mobile media, and indeed media and culture generally. This volume is a comprehensive account of the various location-based technologies, services, applications, and cultures, as media, with an aim to identify, inventory, explore, and critique their cultural, economic, political, social, and policy dimensions internationally. In particular, the collection is organized around the perception that the growth of locative media gives rise to a number of crucial questions concerning the areas of culture, economy, and policy.

  18. An edge pedestal model

    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

  19. Unit Advancement Flap for Lower Lip Reconstruction.

    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.

  20. Flapping model of scalar mixing in turbulence

    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

  1. Hyperbaric oxygen therapy and surgical delay improve flap survival of reverse pedicle flaps for lower third leg and foot reconstruction

    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.

  2. "The Practical Perforator Flap": the sural artery flap for lower extremity soft tissue reconstruction in wounds of war

    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

  3. Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction

    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

  4. Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

    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.

  5. Aerodynamic Flight-Test Results for the Adaptive Compliant Trailing Edge

    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.

  6. Suspension Bridge Flutter for Girder with Separate Control Flaps

    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....

  7. Anatomical study of the popliteal artery perforator-based propeller flap and its clinical application.

    Onishi, Tadanobu; Shimizu, Takamasa; Omokawa, Shohei; Sananpanich, Kanit; Kido, Akira; Mahakkanukrauh, Pasuk; Tanaka, Yasuhito

    2018-05-30

    There is lack of anatomical information regarding cutaneous perforator of the popliteal artery and its connections with the descending branch of the inferior gluteal and profunda femoris arteries. We aimed to evaluate the anatomical basis of popliteal artery perforator-based propeller flap from the posterior thigh region and to demonstrate our experience utilizing this flap. Ten fresh cadaveric lower extremities were dissected following injection of a silicone compound into the femoral artery. We investigated the number, location, length, and diameter of cutaneous perforators of the popliteal artery. Based on the results, we treated three cases with a large soft tissue defect around the knee using popliteal artery perforator-based propeller flap. We found a mean of 1.9 cutaneous perforators arising from the popliteal artery with a mean pedicle length of 6 cm and a mean arterial internal diameter of 0.9 mm, which were located at an average of 4 cm proximal to the bicondylar line. The most distal perforator consistently arose along the small saphenous vein and connected proximally with concomitant artery of the posterior femoral cutaneous nerve, forming a connection with perforating arteries of the profunda femoris artery. A mean of 4.5 cutaneous perforators branched from the arterial connection sites. All clinical cases healed without any complications. The popliteal artery perforator-based propeller flap is reliable for reconstruction of soft tissue defects around the knee. The flap should include the deep fascia and concomitant artery along with the posterior femoral cutaneous nerve for maintaining the blood supply.

  8. Location, location, location: Extracting location value from house prices

    Kolbe, Jens; Schulz, Rainer; Wersing, Martin; Werwatz, Axel

    2012-01-01

    The price for a single-family house depends both on the characteristics of the building and on its location. We propose a novel semiparametric method to extract location values from house prices. After splitting house prices into building and land components, location values are estimated with adaptive weight smoothing. The adaptive estimator requires neither strong smoothness assumptions nor local symmetry. We apply the method to house transactions from Berlin, Germany. The estimated surface...

  9. Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

    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.

  10. Donor-site morbidity of the radial forearm free flap versus the ulnar forearm free flap.

    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.

  11. "Apron" flap and re-creation of the inframammary fold following TRAM flap breast reconstruction.

    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.

  12. Versatility of the Distally-Based Sural Artery Fasciocutaneous Flap on the Lower Leg and Foot in Patients with Chronic Disease

    Jin-Su Park

    2013-05-01

    Full Text Available Background  A recent advancement in microsurgery, the free flap is widely used in the re­construction ofthe lowerleg and foot. The simple and effective methods oflocal flaps, inclu­ding transposition and advancement flaps, have been considered for patients with chronicdebilitationwho are unable to endure long surgical procedures or general anesthesia.However,the location and size of the wound may restrict the clinical application of a local flap. Underthese circumstances, a sural flap can be an excellent alternative, rendering satisfying clinicaloutcomesin chronically debilitated patients.Methods  Between 2008 and 2012, 39 patients underwent soft tissue defect treatment bysural artery flap as a final method. All ofthe patients had atleast one chronic disease or more(diabetes, hypertension, vascular disease, etc.. Also, all ofthe patients had a history of chroniclower extremity ulceration, which revealed no response to several months of conservativetreatment.Results  The results of the 39 cases had a successrate of 100% with 39 complete recoveries.Nine casessuffered complications: partial necrosis(n= 4,wound dehiscencewithout necrosis(n= 3, hematoma (n= 1, and infection (n= 1.Conclusions  The sural artery flap is not only usefulforthe lowerleg but also forthe heel, andother various parts. Furthermore, itis a relatively simple surgicaltechnique forreconstructingthe defect area for patients with various chronic conditions with a high surgical risk or con­traindicationsto surgery

  13. Delayed closure of the palatal defect using buccal inversion and palatal rotation flaps after maxillectomy.

    Jung, Seunggon; Kook, Min-Suk; Park, Hong-Ju; Oh, Hee-Kyun

    2013-03-01

    Maxillectomy leaves oronasal and oroantral defects that result in functional impairment of mastication, deglutition, and speech. Many treatment options are suggested and tried including the palatal flap as local flap. Although palatal flaps have been used to repair various oral cavity defects, they have certain limitations due to the dimensions. The amount and location of the palatal tissues available are important for palatal repair. Secondary intentional healing after maxillectomy will allow the epithelialization of the defect margin adjacent to remained palate, and there will be more mucosa that is available for closure of the defect. We delayed the closure of the palatal defect, while the patient underwent prosthetic treatment for functional recovery in 5 maxillectomy patients. Delayed closure of palatal defect with local flap was done at 10.8 ± 7.9 months after the maxillectomy. While delayed closure in hemimaxillectomy patients left postoperative fistula, it provided separation of the oral cavity and nasal/sinus cavity and adequate surface for prosthesis in partial maxillectomy patients.

  14. Design & fabrication of two seated aircraft with an advanced rotating leading edge wing

    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.

  15. Flap Lymphedema after Successful Reconstruction of the Chronic Inguinal Wound with a Vertical Rectus Abdominis Flap (VRAM

    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.

  16. Tubularized Penile-Flap Urethroplasty Using a Fasciocutaneous Random Pedicled Flap for Recurrent Anterior Urethral Stricture

    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.

  17. Development of Advanced High Lift Leading Edge Technology for Laminar Flow Wings

    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.

  18. Machine Learning for Flapping Wing Flight Control

    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

  19. Oral cavity reconstruction with the masseter flap

    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

  20. Omental Pedicled Flap for Pulmonary Tuberculosis Sequelae ...

    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 ...

  1. Accelerating recovery after trauma with free flaps.

    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.

  2. Morphological effect of a scallop shell on a flapping-type tidal stream generator

    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)

  3. Reconstruction of the Upper Eyelid with Flaps and Free Grafts after Excision of Basal Cell Carcinoma

    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.

  4. Results of auricular helical rim reconstruction with post-auricular tube flap.

    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.

  5. Assessment of a Conceptual Flap System Intended for Enhanced General Aviation Safety

    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.

  6. [CLINICAL APPLICATION AND EXPERIENCE IN RECONSTRUCTION OF SOFT TISSUE DEFECTS FOLLOWING MALIGNANT TUMOR REMOVAL OF LIMBS USING PERFORATOR PROPELLER FLAPS].

    Zhu, Shan; Liu, Yuanbo; Yu, Shengji; Zang, Mengqing; Zhao, Zhenguo; Xu, Libin; Zhang, Xinxin; Chen, Bo; Ding, Qiang

    2016-01-01

    To explore the feasibility and technical essentials of soft tissue defect reconstruction following malignant tumor removal of limbs using perforator propeller flaps. Between July 2008 and July 2015, 19 patients with malignant limb tumor underwent defect reconstruction following tumor removal using the perforator propeller flaps. There were 13 males and 6 females with an average age of 53.4 years (range, 20-82 years). The disease duration ranged from 1 to 420 months (mean, 82 months). The tumors located at the thigh in 10 cases, at the leg in 2 cases, at the arm in 1 case, at the forearm in 1 case, around the knee in 2 cases, and around the elbow joint in 3 cases. Totally 23 flaps (from 8 cm x 3 cm to 30 cm x 13 cm in size) were used to reconstruct defects (from 4 cm x 4 cm to 24 cm x 16 cm in size). The potential source arteries included the femoral artery (n = 2), profunda femoral artery (n = 3), superficial circumflex iliac artery (n = 1), lateral circumflex femoral artery (n = 6), superior lateral genicular artery (n = 2), peroneal artery (n = 2), anterior tibial artery (n = 1), brachial artery (n = 4), and radial artery (n = 1). The remaining one was a free style perforator flap. Partial distal flap necrosis occurred in 3 cases after surgery with rotation angles of 180, 150, and 100 degrees respectively, which were reconstructed after debridement using a free-style perforator flap in 1 case and using free skin grafting in the other 2 cases. The other 20 flaps survived completely after surgery. Primary healing of incisions was obtained at the donor and recipient sites. There was no severe complication such as infection, hematoma, and total flap failure. All patients were followed up 3 months to 5 years (mean, 19 months). One patient with malignant melanoma around the elbow joint had tumor recurrence, and underwent secondary tumor resection. The appearance, texture, and color of the flaps were similar to those at the recipient site. For patients with malignant

  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

    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. Edge-effect interactions in fragmented and patchy landscapes.

    Porensky, Lauren M; Young, Truman P

    2013-06-01

    Ecological edges are increasingly recognized as drivers of landscape patterns and ecosystem processes. In fragmented and patchy landscapes (e.g., a fragmented forest or a savanna with scattered termite mounds), edges can become so numerous that their effects pervade the entire landscape. Results of recent studies in such landscapes show that edge effects can be altered by the presence or proximity of other nearby edges. We considered the theoretical significance of edge-effect interactions, illustrated various landscape configurations that support them and reviewed existing research on this topic. Results of studies from a variety of locations and ecosystem types show that edge-effect interactions can have significant consequences for ecosystems and conservation, including higher tree mortality rates in tropical rainforest fragments, reduced bird densities in grassland fragments, and bush encroachment and reduced wildlife densities in a tropical savanna. To clarify this underappreciated concept and synthesize existing work, we devised a conceptual framework for edge-effect interactions. We first worked to reduce terminological confusion by clarifying differences among terms such as edge intersection and edge interaction. For cases in which nearby edge effects interact, we proposed three possible forms of interaction: strengthening (presence of a second edge causes stronger edge effects), weakening (presence of a second edge causes weaker edge effects), and emergent (edge effects change completely in the presence of a second edge). By clarifying terms and concepts, this framework enables more precise descriptions of edge-effect interactions and facilitates comparisons of results among disparate study systems and response variables. A better understanding of edge-effect interactions will pave the way for more appropriate modeling, conservation, and management in complex landscapes. © 2013 Society for Conservation Biology.

  9. LES tests on airfoil trailing edge serration

    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)

  10. Anatomical basis of the lateral superior gluteal artery perforator (LSGAP) flap and role in bilateral breast reconstruction.

    Fade, Geraldine; Gobel, Fabienne; Pele, Eric; Chaput, Benoit; Garrido, Ignacio; Pinsolle, Vincent; Pelissier, Philippe; Sinna, Raphael

    2013-06-01

    Deep inferior epigastric perforator (DIEP) flap is one of the gold standards in autologous breast reconstruction. When the abdominal tissue is not available, the superior gluteal artery perforator (SGAP) is often a second option with its drawback, especially the donor-site deformity. Reports have highlighted that a higher and more lateral SGAP flap can be harvested to overcome several drawbacks of the classical SGAP, allowing in the same procedure a body-contouring procedure. In order to set the anatomical basis of this flap, we proposed to study the characteristics of a reliable and easily identifiable superior and lateral perforator of the superior gluteal artery (lateral SGAP (LSGAP)) situated in the region of the lower body-lift resection allowing to perform bilateral breast reconstruction at the same time. The anatomical study of 50 scans (or 100 buttocks) allows us to set forth a diagnostic assumption on the localisation of the perforator with respect to osseous landmarks (coccyx, iliac crest and great trochanter) which will be verified during the dissection of 10 cadavers (or 20 buttocks) and during the 20 colour Doppler examination (or 40 buttocks). In our computed tomography (CT) scan study, in 96% of cases, the perforator was situated in a circle with a radius≤3 cm with a 95% confidence interval and located at the junction of the proximal third-middle third of the distance summit of the posterior iliac crest (point B), most lateral point of the greater trochanter (point C). This assumption was verified by the cadaveric dissection and in vivo studies. Our study sets the anatomical landmarks of the LSGAP flap. This option allows the raising of an SGAP flap avoiding the main drawbacks of this flap and allows harvesting a flap with the tissue that is often discarded during the body-lift procedure. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  11. SU-F-P-58: Squamous Cell and Basal Cell Carcinoma of the Skin Treated with a Freiburg Flap Applicator

    Dou, K; Li, B; Jacobs, M; Laser, B

    2016-01-01

    Purpose: To treat squamous cell and basal cell carcinoma of the skin with the Freiburg flap applicator using a high dose rate modality of an Elekta Flexitron or MicroSelectron for radiation delivery by compensating the dose deviation resulting from the incomplete scatter environment. Methods: Patients were selected to have lesions greater than or equal to 2cm. A mask might be needed depending on special locations. The lesions on the eyelid and face presented in this research were, however, treated without a mask. Cutting the flap into a shape conformal to the target and attaching it to the mask were used in order to make the treatment reproducible. Patients were scanned with a Philips Big Bore Brilliant CT. A 1cm margin was added to the lesion. An Elekta Oncentra Brachy treatment planning system ver. 4.3 was used for treatment planning. 40 Gy in 10 or 8 fractions was prescribed to the 1cm depth. The Freiburg flap was aligned and verified by CT scanning prior to treatment. Results: Three patients with squamous cell and basal cell carcinoma of the skin were treated with the Freiburg flap applicator. Lesion sizes ranged from 2cm to 6 cm in a maximum dimension. With treatment planning, we made a dose correction for compensating the dose deviation resulting from the incomplete scatter environment of the flap applicators exposed to air. The flap was also covered by a 4cm bolus in order to obtain more back scattered radiation during treatment. Six month follow up showed a very good cosmetic result. Conclusion: The Freiburg flap brachytherapy offers a non-invasive skin cancer treatment with a high skin dose delivered to the tumor while a low dose sparing the surrounding health tissue. It is a promising alternative to skin cancer surgery or external beam radiation therapy.

  12. SU-F-P-58: Squamous Cell and Basal Cell Carcinoma of the Skin Treated with a Freiburg Flap Applicator

    Dou, K; Li, B [MedStar Health RadAmerica, Mercy Radiation Oncology, Baltimore, MD (United States); Jacobs, M; Laser, B [Mercy Medical Center Radiation Oncology, Baltimore, MD (United States)

    2016-06-15

    Purpose: To treat squamous cell and basal cell carcinoma of the skin with the Freiburg flap applicator using a high dose rate modality of an Elekta Flexitron or MicroSelectron for radiation delivery by compensating the dose deviation resulting from the incomplete scatter environment. Methods: Patients were selected to have lesions greater than or equal to 2cm. A mask might be needed depending on special locations. The lesions on the eyelid and face presented in this research were, however, treated without a mask. Cutting the flap into a shape conformal to the target and attaching it to the mask were used in order to make the treatment reproducible. Patients were scanned with a Philips Big Bore Brilliant CT. A 1cm margin was added to the lesion. An Elekta Oncentra Brachy treatment planning system ver. 4.3 was used for treatment planning. 40 Gy in 10 or 8 fractions was prescribed to the 1cm depth. The Freiburg flap was aligned and verified by CT scanning prior to treatment. Results: Three patients with squamous cell and basal cell carcinoma of the skin were treated with the Freiburg flap applicator. Lesion sizes ranged from 2cm to 6 cm in a maximum dimension. With treatment planning, we made a dose correction for compensating the dose deviation resulting from the incomplete scatter environment of the flap applicators exposed to air. The flap was also covered by a 4cm bolus in order to obtain more back scattered radiation during treatment. Six month follow up showed a very good cosmetic result. Conclusion: The Freiburg flap brachytherapy offers a non-invasive skin cancer treatment with a high skin dose delivered to the tumor while a low dose sparing the surrounding health tissue. It is a promising alternative to skin cancer surgery or external beam radiation therapy.

  13. Vascular anatomy of the medial sural artery perforator flap: a new classification system of intra-muscular branching patterns.

    Dusseldorp, Joseph R; Pham, Quy J; Ngo, Quan; Gianoutsos, Mark; Moradi, Pouria

    2014-09-01

    The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap. The main difficulty encountered when raising the MSAP flap is in obtaining adequate pedicle length during intra-muscular dissection. The objective of this study was to determine the pattern of intra-muscular course of the MSAP flap pedicle. 14 cadaveric specimens were dissected and CT angiograms of 84 legs were examined. The intra-muscular branching pattern and depths of the medial sural artery branches were analyzed. The number of perforators, position of the dominant perforator and both intra-muscular and total pedicle length were also recorded and compared to existing anatomical data. Three types of arterial branching pattern were identified within the medial gastrocnemius, demonstrating one (31%), two (59%) or three or more (10%) main branches. A dominant perforator from the medial sural artery was present in 92% of anatomical specimens (13/14). Vertically, the location of the perforator from the popliteal crease was on average 13 cm (±2 cm). Transversely, the perforator originated 2.5 cm (±1 cm) from the posterior midline. Using CT angiography it was possible in 10 consecutive patients to identify a more superficial intra-muscular branch and determine the leg with the optimal branching pattern type for flap harvest. This study is the first to describe the variability of the intra-muscular arterial anatomy of the medial head of gastrocnemius muscle. Surgeons utilizing the MSAP flap option should be aware of the possible branching pattern types and consequently the differing perforator distribution and depths of intra-muscular branches. Routine use of pre-operative CT angiogram may help determine which leg has the most favorable branching pattern type and intra-muscular course for flap harvest. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  14. [Pedicle flap transfer combined with external fixator to treat leg open fracture with soft tissue defect].

    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.

  15. Library Locations

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Carnegie Library of Pittsburgh locations including address, coordinates, phone number, square footage, and standard operating hours. The map below does not display...

  16. Reconstruction of the Lower Extremity Using Free Flaps

    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.

  17. Reconstruction of the Lower Extremity Using Free Flaps

    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.

  18. Edge effects in composites

    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

  19. Falling, flapping, flying, swimming,...: High-Re fluid-solid interactions with vortex shedding

    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

  20. Edge colouring by total labellings

    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...

  1. Adobe Edge Quickstart Guide

    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

  2. Emergent properties of patch shapes affect edge permeability to animals.

    Vilis O Nams

    Full Text Available Animal travel between habitat patches affects populations, communities and ecosystems. There are three levels of organization of edge properties, and each of these can affect animals. At the lowest level are the different habitats on each side of an edge, then there is the edge itself, and finally, at the highest level of organization, is the geometry or structure of the edge. This study used computer simulations to (1 find out whether effects of edge shapes on animal behavior can arise as emergent properties solely due to reactions to edges in general, without the animals reacting to the shapes of the edges, and to (2 generate predictions to allow field and experimental studies to test mechanisms of edge shape response. Individual animals were modeled traveling inside a habitat patch that had different kinds of edge shapes (convex, concave and straight. When animals responded edges of patches, this created an emergent property of responding to the shape of the edge. The response was mostly to absolute width of the shapes, and not the narrowness of them. When animals were attracted to edges, then they tended to collect in convexities and disperse from concavities, and the opposite happened when animals avoided edges. Most of the responses occurred within a distance of 40% of the perceptual range from the tip of the shapes. Predictions were produced for directionality at various locations and combinations of treatments, to be used for testing edge behavior mechanisms. These results suggest that edge shapes tend to either concentrate or disperse animals, simply because the animals are either attracted to or avoid edges, with an effect as great as 3 times the normal density. Thus edge shape could affect processes like pollination, seed predation and dispersal and predator abundance.

  3. Flapping foil power generator performance enhanced with a spring-connected tail

    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.

  4. A Dynamic Stall Model for Airfoils with Deformable Trailing Edges

    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

  5. Use of the Anterolateral Thigh and Vertical Rectus Abdominis Musculocutaneous Flaps as Utility Flaps in Reconstructing Large Groin Defects

    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.

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

    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.

  7. Three-dimensional vortex wake structure of flapping wings in hovering flight.

    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.

  8. Decomposing the aerodynamic forces of low-Reynolds flapping airfoils

    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.

  9. Gene Locater

    Anwar, Muhammad Zohaib; Sehar, Anoosha; Rehman, Inayat-Ur

    2012-01-01

    software's for calculating recombination frequency is mostly limited to the range and flexibility of this type of analysis. GENE LOCATER is a fully customizable program for calculating recombination frequency, written in JAVA. Through an easy-to-use interface, GENE LOCATOR allows users a high degree...... of flexibility in calculating genetic linkage and displaying linkage group. Among other features, this software enables user to identify linkage groups with output visualized graphically. The program calculates interference and coefficient of coincidence with elevated accuracy in sample datasets. AVAILABILITY...

  10. Adobe Edge Preview 3

    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

  11. Pavement edge treatment.

    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 ...

  12. Edge Simulation Laboratory

    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.

  13. Flapping dynamics of a thin liquid sheet

    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.

  14. Subcutaneous tissue flaps for hallux covering.

    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.

  15. Elbow Reconstruction Using Island Flap for Burn Patients

    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.

  16. Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK).

    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.

  17. [Pedicled versus free TRAM flap for breast reconstruction].

    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.

  18. Flapping inertia for selected rotor blades

    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

    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. Aerodynamic Analysis of Trailing Edge Enlarged Wind Turbine Airfoils

    Xu, Haoran; Shen, Wen Zhong; Zhu, Wei Jun

    2014-01-01

    characteristics of blunt trailing edge airfoils are caused by blunt body vortices at low angles of attack, and by the combined effect of separation and blunt body vortices at large angles of attack. With the increase of thickness of blunt trailing edge, the vibration amplitudes of lift and drag curves increase......The aerodynamic performance of blunt trailing edge airfoils generated from the DU- 91-W2-250, DU-97-W-300 and DU-96-W-350 airfoils by enlarging the thickness of trailing edge symmetrically from the location of maximum thickness to chord to the trailing edge were analyzed by using CFD and RFOIL...... methods at a chord Reynolds number of 3 × 106. The goal of this study is to analyze the aerodynamic performance of blunt trailing edge airfoils with different thicknesses of trailing edge and maximum thicknesses to chord. The steady results calculated by the fully turbulent k-ω SST, transitional k-ω SST...

  1. The Use of Magnetic Resonance Imaging in Planning a Pedicled Perforator Flap for Pressure Sores in the Gluteal Region.

    Park, Sun-June; Lee, Kyeong-Tae; Jeon, Byung-Joon; Woo, Kyong-Je

    2018-04-01

    Pedicled perforator flaps (PPFs) have been widely used to treat pressure sores in the gluteal region. Selection of a reliable perforator is crucial for successful surgical treatment of pressure sores using PPFs. In this study, we evaluate the role of magnetic resonance imaging (MRI) in planning PPF reconstruction of pressure sores in the gluteal region. A retrospective chart review was performed in patients who had undergone these PPF reconstructions and who had received preoperative MRI. Preoperatively, the extent of infection and necrotic tissue was evaluated using MRI, and a reliable perforator was identified, considering the perforator location in relation to the defect, perforator size, and perforator courses. Intraoperatively, the targeted perforator was marked on the skin at the locations measured on the MRI images, and the marked location was confirmed using intraoperative handheld Doppler. Superior gluteal artery, inferior gluteal artery, or parasacral perforators were used for the PPFs. Surgical outcomes were evaluated. A total of 12 PPFs were performed in 12 patients. Superior gluteal artery perforator flaps were performed in 7 patients, inferior gluteal artery perforator flaps were performed in 3 patients, and parasacral perforator flaps were performed in 2 patients. We could identify a reliable perforator on MRI, and it was found at the predicted locations in all cases. There was only one case of partial flap necrosis. There was no recurrence of the pressure sores during the mean follow-up period of 6.7 months (range = 3-15 months). In selected patients with gluteal pressure sores, MRI is a suitable means for not only providing information about disease extent and comorbidities but also for evaluating perforators for PPF reconstructions.

  2. Medial circumflex femoral artery flap for ischial pressure sore

    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.

  3. Reconstruction of radionecrotic ulcer using a myocutaneous flap

    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)

  4. Reverse Saphenous Conduit Flap in 19 Dogs and 1 Cat.

    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.

  5. Development of a morphing flap using shape memory alloy actuators: the aerodynamic characteristics of a morphing flap

    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)

  6. The Edge supersonic transport

    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).

  7. Properties on the edge: graphene edge energies, edge stresses, edge warping, and the Wulff shape of graphene flakes

    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

  8. Unsteady phenomena in the edge tone

    Paal, G.; Vaik, I.

    2007-01-01

    Despite its geometrical simplicity, the edge tone displays a remarkably complex behaviour. A plane jet oscillates around the wedge-shaped object with a relatively stable frequency and under certain circumstances emits an audible tone. This configuration plays a central role in the sound production of several wind instruments but occurs in industrial situations too. The flow exhibits various interesting nonlinear phenomena reported in the literature which are not entirely explained. In this paper, detailed high precision numerical simulations of the flow are reported under various conditions. Several phenomena are reproduced in agreement with the literature such as the existence of 'stages', the dependence of oscillation frequency on the outflow velocity and the orifice-edge distance within one stage, the pressure distribution on the edge surface, etc. A criterion for the appropriate time step for constant accuracy has been derived. The location of force action is surprisingly stable; it remains in a very narrow region of the wedge surface independently of the Reynolds number and the orifice-edge distance but it is much further behind the edge tip than reported in the literature. The various stages can coexist in different ways: jumping back and forth between stages or being superposed on each other. Regardless of the form, the first stage continues to be dominant even when the second and third stage appears. The question of disturbance propagation velocity and disturbance wavelength is also investigated. The development of higher harmonics of a single stage along the orifice-edge tip distance is presented

  9. Theory of edge radiation

    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.)

  10. Exploratory study of the effects of wing-leading-edge modifications on the stall/spin behavior of a light general aviation airplane

    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.

  11. Unusual explosive growth of a squamous cell carcinoma of the scalp after electrical burn injury and subsequent coverage by sequential free flap vascular connection – a case report

    Horch, Raymund E; Stark, G Bjoern; Beier, Justus P

    2005-01-01

    Squamous cell carcinomos may arise from chronic ulcerating wounds in scars, most commonly postburn scars. Tumour growth usually takes place over months to years. Localization on the scalp is a relatively rare condition. This report presents the case of a 63-year-old man with chronic ulceration of a postburn scar of the scalp due to an electrical burn 58 years ago. Sudden tumour growth started within weeks and on presentation already had extended through the skull into frontal cortex. After radical tumour resection, defect was covered with a free radial forearm flap. Local recurrence occurred 6 weeks later. Subsequent wide excision including discard of the flap and preservation of the radial vessels was followed by transfer of a free latissimus dorsi muscle flap, using the radial vessels of the first flap as recipient vessels. The patient received radiotherapy post-operatively. There were no problems with flap survivals or wound healing. Due to rapidly growing recurrence the patient died 2 months later. Explosive SCC tumour growth might occur in post-burn scars after more than 50 years. As a treatment option the use of sequential free flap connections might serve in repeated extensive tumour resections, especially in the scalp region, where suitable donor vessels are often located in distance to the defect

  12. Elbow Reconstruction Using Island Flap for Burn Patients

    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.

  13. Folding in and out: passive morphing in flapping wings.

    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

  14. Investigating chaotic wake dynamics past a flapping airfoil and the role of vortex interactions behind the chaotic transition

    Bose, Chandan; Sarkar, Sunetra

    2018-04-01

    The present study investigates the complex vortex interactions in two-dimensional flow-field behind a symmetric NACA0012 airfoil undergoing a prescribed periodic pitching-plunging motion in low Reynolds number regime. The flow-field transitions from periodic to chaotic through a quasi-periodic route as the plunge amplitude is gradually increased. This study unravels the role of the complex interactions that take place among the main vortex structures in making the unsteady flow-field transition from periodicity to chaos. The leading-edge separation plays a key role in providing the very first trigger for aperiodicity. Subsequent mechanisms like shredding, merging, splitting, and collision of vortices in the near-field that propagate and sustain the disturbance have also been followed and presented. These fundamental mechanisms are seen to give rise to spontaneous and irregular formation of new vortex couples at arbitrary locations, which are the primary agencies for sustaining chaos in the flow-field. The interactions have been studied for each dynamical state to understand the course of transition in the flow-field. The qualitative changes observed in the flow-field are manifestation of changes in the underlying dynamical system. The overall dynamics are established in the present study by means of robust quantitative measures derived from classical and non-classical tools from the dynamical system theory. As the present analysis involves a high fidelity multi-unknown system, non-classical dynamical tools such as recurrence-based time series methods are seen to be very efficient. Moreover, their application is novel in the context of pitch-plunge flapping flight.

  15. Integrated core-edge-divertor modeling studies

    Stacey, W.M.

    2001-01-01

    An integrated calculation model for simulating the interaction of physics phenomena taking place in the plasma core, in the plasma edge and in the SOL and divertor of tokamaks has been developed and applied to study such interactions. The model synthesises a combination of numerical calculations (1) the power and particle balances for the core plasma, using empirical confinement scaling laws and taking into account radiation losses (2), the particle, momentum and power balances in the SOL and divertor, taking into account the effects of radiation and recycling neutrals, (3) the transport of feeling and recycling neutrals, explicitly representing divertor and pumping geometry, and (4) edge pedestal gradient scale lengths and widths, evaluation of theoretical predictions (5) confinement degradation due to thermal instabilities in the edge pedestals, (6) detachment and divertor MARFE onset, (7) core MARFE onsets leading to a H-L transition, and (8) radiative collapse leading to a disruption and evaluation of empirical fits (9) power thresholds for the L-H and H-L transitions and (10) the width of the edge pedestals. The various components of the calculation model are coupled and must be iterated to a self-consistent convergence. The model was developed over several years for the purpose of interpreting various edge phenomena observed in DIII-D experiments and thereby, to some extent, has been benchmarked against experiment. Because the model treats the interactions of various phenomena in the core, edge and divertor, yet is computationally efficient, it lends itself to the investigation of the effects of different choices of various edge plasma operating conditions on overall divertor and core plasma performance. Studies of the effect of feeling location and rate, divertor geometry, plasma shape, pumping and over 'edge parameters' on core plasma properties (line average density, confinement, density limit, etc.) have been performed for DIII-D model problems. A

  16. Edge and coupled core/edge transport modelling in tokamaks

    Lodestro, L.L.; Casper, T.A.; Cohen, R.H.

    1999-01-01

    Recent advances in the theory and modelling of tokamak edge, scrape-off-layer (SOL) and divertor plasmas are described. The effects of the poloidal E x B drift on inner/outer divertor-plate asymmetries within a 1D analysis are shown to be in good agreement with experimental trends; above a critical v ExB , the model predicts transitions to supersonic flow at the inboard midplane. 2D simulations show the importance of E x B flow in the private-flux region and of ∇ B-drifts. A theory of rough plasma-facing surfaces is given, predicting modifications to the SOL plasma. The parametric dependence of detached-plasma states in slab geometry has been explored; with sufficient pumping, the location of the ionization front can be controlled; otherwise only fronts near the plate or the X-point are stable. Studies with a more accurate Monte-Carlo neutrals model and a detailed non-LTE radiation-transport code indicate various effects are important for quantitative modelling. Detailed simulations of the DIII-D core and edge are presented; impurity and plasma flow are discussed and shown to be well modelled with UEDGE. (author)

  17. Edge and coupled core-edge transport modelling in tokamaks

    Lodestro, L.L.; Casper, T.A.; Cohen, R.H.

    2001-01-01

    Recent advances in the theory and modelling of tokamak edge, scrape-off-layer (SOL) and divertor plasmas are described. The effects of the poloidal ExB drift on inner/outer divertor-plate asymmetries within a 1D analysis are shown to be in good agreement with experimental trends; above a critical v ExB, the model predicts transitions to supersonic SOL flow at the inboard midplane. 2D simulations show the importance of ExB flow in the private-flux region and of ∇ B-drifts. A theory of rough plasma-facing surfaces is given, predicting modifications to the SOL plasma. The parametric dependence of detached-plasma states in slab geometry has been explored; with sufficient pumping, the location of the ionization front can be controlled; otherwise only fronts near the plate or the X-point are stable. Studies with a more accurate Monte-Carlo neutrals model and a detailed non-LTE radiation-transport code indicate various effects are important for quantitative modelling. Detailed simulations of the DIII-D core and edge are presented; impurity and plasma flow are discussed and shown to be well modelled with UEDGE. (author)

  18. Versatility of Pedicled Tensor Fascia Lata Flap: A Useful and Reliable Technique for Reconstruction of Different Anatomical Districts

    Md. Sohaib Akhtar

    2014-01-01

    Full Text Available Aims and Objectives. The aim of this study was to evaluate the versatility of pedicled tensor fascia lata flap for reconstruction of various anatomical regions. Materials and Methods. In this retrospective study a total of 34 patients with defects over various anatomical regions were included. The defects were located over the trochanter (n=12, groin (n=8, perineum (n=6, lower anterior abdomen (n=6, gluteal region (n=1, and ischial region (n=1. The etiology of defects included trauma (n=12, infection (n=8, pressure sores (n=8, and malignancy (n=6. Reconstruction was performed using pedicled tensor fascia lata flaps. Patients were evaluated in terms of viability of the flap and donor site morbidity. The technical details of the operative procedure have also been outlined. Results. All the flaps survived well except 5 patients in which minor complications were noted and 1 who experienced complete flap loss. Of those with minor complications, 1 patient developed distal marginal necrosis and 1 developed infection which subsided within three days by dressings and antibiotics and in 2 patients partial loss of the skin graft occurred at the donor site out of which 1 required regrafting and another one healed completely with dressing and antibiotics. All the patients were followed up for an average period of 6 months, ranging from 1 to 12 months. Donor site morbidity was minimal. Conclusion. It was concluded that the pedicled tensor fascia lata flap is a versatile, reliable, easy, and less time consuming procedure for the coverage of defects around trochanter, groin, lower anterior abdomen, perineum, and ischial region.

  19. Numerical simulation of X-wing type biplane flapping wings in 3D using the immersed boundary method

    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

  20. X-point effect on edge stability

    Saarelma, S; Kirk, A; Kwon, O J

    2011-01-01

    We study the effects of the X-point configuration on edge localized mode (ELM) triggering peeling and ballooning modes using fixed boundary equilibria and modifying the plasma shape to approach the limit of a true X-point. The current driven pure peeling modes are asymptotically stabilized by the X-point while the stabilizing effect on ballooning modes depends on the poloidal location of the X-point. The coupled peeling-ballooning modes experience the elimination of the peeling component as the X-point is introduced. This can significantly affect the edge stability diagrams used to analyse the ELM triggering mechanisms.

  1. Free Boomerang-shaped Extended Rectus Abdominis Myocutaneous flap: The longest possible skin/myocutaneous free flap for soft tissue reconstruction of extremities

    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.

  2. Free Boomerang-shaped Extended Rectus Abdominis Myocutaneous flap: The longest possible skin/myocutaneous free flap for soft tissue reconstruction of extremities.

    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.

  3. Repair of nostril stenosis using a triple flap combination: boomerang, nasolabial, and vestibular rotation flaps.

    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.

  4. [Applied anatomy study and clinical application of great saphenous veno-saphenous neurocutaneous vascular flap].

    Li, Zelong; Ding, Zihai; Wang, Peixin; Xie, Yibo; Zeng, Bo

    2006-03-01

    To provide the anatomic basis for defect repair of the knee, leg, foot and ankle with great saphenous veno-saphenous neurocutaneous vascular island flaps. The origin, diameter, branches, distribution and anastomoses of the saphenous artery and saphenous neurocutaneous vascular were observed on 20 sides of adult leg specimens and 4 fresh cadaver voluntary legs. Another 4 fresh cadaver voluntary legs were radiographed with a soft X-ray system after the intravenous injection of Vermilion and cross-sections under profound fascial, other hand, micro-anatomic examination was also performed in these 4 fresh cadaver legs. The soft tissue defects in lower extremity, upper extremity, heel or Hucou in hand were repaired with the proximal or distal pedicle flaps or free flaps in 18 patients (12 males and 6 females,aging from 7 to 53 years). The defect was caused by trauma, tumour, ulcer and scar. The locations were Hucou (1 case), upper leg (3 cases), lower extremity and heal (14 cases). Of then, 7 cases were complicated by bone exposure, 3 cases by tendon exposure and 1 case by steel espouse, the defect size were 4 cm x 4 cm to 7 cm x 13 cm. The flap sizes were 4 cm x 6 cm to 8 cm x 15 cm, which pedicle length was 8-11 cm with 2.5-4.0 cm fascia and 1-2 cm skin at width. Genus descending genicular artery began from 9.33 +/- 0.81 cm away from upper the condyles medialis, it branched saphenous artery accompanying saphenous nerve descendent. And saphenous artery reached the surface of the skin 7.21 +/- 0.82 cm away from lower the condyles medialis, and anastomosed with the branches of tibialis posterior artery, like "Y" or "T" pattern. The chain linking system of arteries were found accompanying along the great saphenous vein as saphenous nerve, and then a axis blood vessel was formed. The small artery of only 0.05-0.10 mm in diameter, distributed around the great saphenous vein within 5-8 mm and arranged parallelly along the vein like water wave in soft X-ray film. All proximal

  5. Rotational accelerations stabilize leading edge vortices on revolving fly wings.

    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

  6. Repair of large palatal fistula using tongue flap

    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.

  7. Treatment of ischial pressure sores with double adipofascial turnover flaps.

    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.

  8. Upper lip reconstruction using a pedicel superficial temporal artery flap

    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.

  9. Accuracy of Visual Estimation of LASIK Flap Thickness.

    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.

  10. Preoperative CT angiography reduces surgery time in perforator flap reconstruction

    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

  11. The management of pelvic pressure ulcers by myocutaneous flaps ...

    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 ...

  12. Regional Myocutaneous Flaps for Head and Neck Reconstruction ...

    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 ...

  13. Scrotal Reconstruction with a Pedicled Gracilis Muscle Flap after ...

    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 ...

  14. Propeller flaps for lower-limb trauma | Rogers | South African ...

    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 ...

  15. Peri-Vesical Fat Interposition Flap Reinforcement in High Vesico ...

    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 ...

  16. Vascular Displacement in Idiopathic Macular Hole after Single-layered Inverted Internal Limiting Membrane Flap Surgery.

    Lee, Jae Jung; Lee, In Ho; Park, Keun Heung; Pak, Kang Yeun; Park, Sung Who; Byon, Ik Soo; Lee, Ji Eun

    2017-08-01

    To compare vascular displacement in the macula after surgical closure of idiopathic macular hole (MH) after single-layered inverted internal limiting membrane (ILM) flap technique and conventional ILM removal. This retrospective study included patients who underwent either vitrectomy and ILM removal only or vitrectomy with single-layered inverted ILM flap for idiopathic MH larger than 400 μm from 2012 to 2015. A customized program compared the positions of the retinal vessels in the macula between preoperative and postoperative photographs. En face images of 6 × 6 mm optical coherence tomography volume scans were registered to calculate the scale. Retinal vessel displacement was measured as a vector value by comparing its location in 16 sectors of a grid partitioned into eight sectors in two rings (inner, 2 to 4 mm; outer, 4 to 6 mm). The distance and angle of displacement were calculated as an average vector and were compared between the two groups for whole sectors, inner ring, outer ring, and for each sector. Twenty patients were included in the ILM flap group and 22 in the ILM removal group. There were no statistical differences between the groups for baseline characteristics. The average displacement in the ILM flap group and the ILM removal group was 56.6 μm at -3.4° and 64.9 μm at -2.7°, respectively, for the whole sectors (p = 0.900), 76.1 μm at -1.1° and 87.3 μm at -0.9° for the inner ring (p = 0.980), and 37.4 μm at -8.2° and 42.7 μm at -6.3° for the outer ring (p = 0.314). There was no statistical difference in the displacement of each of the sectors. Postoperative topographic changes showed no significant differences between the ILM flap and the ILM removal group for idiopathic MH. The single-layered ILM flap technique did not appear to cause additional displacement of the retinal vessels in the macula. © 2017 The Korean Ophthalmological Society

  17. 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

    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.

  18. Theory, Computation and Experiment on Criticality and Stability of Vortices Separating from Edges

    2016-08-15

    location. The motion rig consists of a triplet of H2W linear motors, driven by AMC DigiFlex servo -drives 18 DISTRIBUTION A: Distribution approved for...Speed Aerodynamics, Cambridge university press , 2nd ed., 2001. 77 Garrick, I. E., “Propulsion of a Flapping and Oscillating Airfoil,” Tech. Rep. NACA TR

  19. Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK

    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

  20. Tangential 2-D Edge Imaging for GPI and Edge/Impurity Modeling

    Maqueda, Ricardo; Levinton, Fred M.

    2011-01-01

    Nova Photonics, Inc. has a collaborative effort at the National Spherical Torus Experiment (NSTX). This collaboration, based on fast imaging of visible phenomena, has provided key insights on edge turbulence, intermittency, and edge phenomena such as edge localized modes (ELMs) and multi-faceted axisymmetric radiation from the edge (MARFE). Studies have been performed in all these areas. The edge turbulence/intermittency studies make use of the Gas Puff Imaging diagnostic developed by the Principal Investigator (Ricardo Maqueda) together with colleagues from PPPL. This effort is part of the International Tokamak Physics Activity (ITPA) edge, scrape-off layer and divertor group joint activity (DSOL-15: Inter-machine comparison of blob characteristics). The edge turbulence/blob study has been extended from the current location near the midplane of the device to the lower divertor region of NSTX. The goal of this effort was to study turbulence born blobs in the vicinity of the X-point region and their circuit closure on divertor sheaths or high density regions in the divertor. In the area of ELMs and MARFEs we have studied and characterized the mode structure and evolution of the ELM types observed in NSTX, as well as the study of the observed interaction between MARFEs and ELMs. This interaction could have substantial implications for future devices where radiative divertor regions are required to maintain detachment from the divertor plasma facing components.

  1. Elastomeric Structural Attachment Concepts for Aircraft Flap Noise Reduction - Challenges and Approaches to Hyperelastic Structural Modeling and Analysis

    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.

  2. The Inner Urban Edge

    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…

  3. Swords with Blunt Edges

    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…

  4. LASIK flap buttonhole treated immediately by PRK with mitomycin C.

    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.

  5. Clinical application of scrotal flap on penis lengthening.

    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.

  6. Study of Flapping Flight Using Discrete Vortex Method Based Simulations

    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.

  7. The expanded "BAT" flap for treatment of male pattern baldness.

    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.

  8. Tensor fascia lata flap versus tensor fascia lata perforator-based island flap for the coverage of extensive trochanteric pressure sores.

    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.

  9. Aerodynamic Optimization of Vertical Axis Wind Turbine with Trailing Edge Flap

    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...

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

    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...

  11. Towards an Industrial Manufactured Morphing Trailing Edge Flap System for Wind Turbines

    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...

  12. A comparison of smart rotor control approaches using trailing edge flaps and individual pitch control

    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

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

    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)

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

    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....

  15. Material matters: Controllable rubber trailing edge flap regulates load on wind turbine blades

    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....

  16. Desferrioxamine: a practical method for improving neovascularization of prefabricated flaps.

    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.

  17. Release of hand burn contracture: comparing the ALT perforator flap with the gracilis free flap with split skin graft.

    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.

  18. Reconstructive Surgery for Severe Penile Inadequacy: Phalloplasty with a Free Radial Forearm Flap or a Pedicled Anterolateral Thigh Flap

    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.

  19. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    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...

  20. Endoscopic partial medial maxillectomy with mucosal flap for maxillary sinus mucoceles.

    Durr, Megan L; Goldberg, Andrew N

    2014-01-01

    To describe a technique of endoscopic medial maxillectomy with mucosal flap for postoperative maxillary sinus mucoceles and to present a case series of subjects who underwent this procedure. This case series includes four subjects with postoperative maxillary sinus mucoceles who underwent resection via endoscopic partial medial maxillectomy with a mucosal flap. We will discuss the clinical presentation, imaging characteristics, operative details, and outcomes. Four subjects are included in this study. The average age at the time of medial maxillectomy was 52 years (range 35-65 years). Three subjects (75%) were female. One subject (25%) had bilateral postoperative maxillary sinus mucoceles. Two subjects (50%) had unilateral right sided mucoceles, and the remaining subject had a unilateral left sided mucocele. All subjects had a history of multiple sinus procedures for chronic sinusitis including Caldwell-Luc procedures ipsilateral to the postoperative mucocele. All subjects underwent endoscopic medial maxillectomy without complication and were symptom free at the last follow up appointment, average 24 months (range 3-71 months) after medial maxillectomy. For postoperative maxillary sinus mucoceles in locations that are difficult to access via the middle meatus antrostomy, we recommend endoscopic medial maxillectomy with mucosal flap. Our preliminary experience with four subjects demonstrates complete resolution of symptoms after this procedure. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Use of early hard palate closure using a vomer flap in cleft lip and palate patients.

    Smarius, Bram J A; Breugem, Corstiaan C

    2016-08-01

    The aim of the present study was to determine the influence of the vomer flap during cleft palate closure. A retrospective review was performed of all consecutive unilateral/bilateral complete cleft lip and palate (Veau III en IV) children who were treated by a simultaneous lip and hard palate closure using a vomer flap. Data were collected for sex, date of birth, syndrome, adoption, cleft palate type, type of repair, date of cleft repair, cleft width, lateral incisions, fistula and location of fistula. Ninety-one children (M = 62, F 29) were operated. Mean age at time of lip closure and vomer flap was 5.8 months (range 2.9 months to 49.2 months, SD 7.1) and the mean age at palate closure was 13.6 months (range 6.3 months to 79.9 months, SD 10.8). The mean cleft width at first assessment was 13.0 mm (range 7-22 mm) compared to 8.8 mm (range 4-15 mm) at second assessment (mean difference 4.6 mm, 95% CI 3.93-5.35, p cleft width, subsequently leading to a low fistula incidence (1.1%). Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  2. Evaluation of tissue oxygen measurements for flap monitoring in an animal model

    Bonde, Christian; Elberg, Jens; Holstein-Rathlou, N.-H.

    2008-01-01

    Tissue oxygen tension (p(ti)O(2)) measurements are common in neurosurgery but uncommon in plastic surgery. We examined this technique as a monitoring method with probe placement in the subcutaneous tissue and addressed the importance of probe placement. Myocutaneous flaps were raised in an animal...... model and p(ti)O(2) measurements performed at different levels in the subcutaneous fat. Flap artery and vein were occluded until a 50% p(ti)O(2) reduction had occurred (T(1/2)). We found no significant effect of depth (P>0.10) on the level of p(ti)O(2). T(1/2)(arterial) was 7.2 minutes and T(1/2)(venous......) was 18 minutes. We found no significant relation between initial levels of p(ti)O(2) and T(1/2). Location of the probe and absolute p(ti)O(2) value is of little relevance for flap monitoring. It is the relative change in p(ti)O(2) that is important. The p(ti)O(2) technique is well suited for monitoring...

  3. Aerodynamic performance and particle image velocimetery of piezo actuated biomimetic manduca sexta engineered wings towards the design and application of a flapping wing flight vehicle

    DeLuca, Anthony M.

    the wing. Th 60° angle stop wing achieved the largest total stroke angle and generated the most lift for the lowest power consumption of the wings tested. 2. Phase averaged stereo Particle Image Velocimetry (PIV) data was collected at eight phases through the flap cycle on the 30°, 45°, and 60° angle stop wings. Wings were mounted transverse and parallel to the interrogating laser sheet, and planar velocity intersections at the wing mid-span, one chord below the wing, were compared to one another to verify data fidelity. A Rankine-Froude actuator disk model was adapted to calculate the approximate vertical thrust generated from the total momentum flux through the flapping semi-disk using the velocity field measurements. Three component stereo u, v, and w-velocity contour measurements confirmed the presence of extensive vortical structures in the vicinity of the wing. The leading edge vortex was successfully tracked through the stroke cycle appearing at approximately 25% span, increasing in circulatory strength and translational velocity down the span toward the tip, and dissipating just after 75% span. Thrust calculations showed the vertically mounted wing more accurately represented the vertical forces when compared to its corresponding force balance measurement than the horizontally mounted wing. The mid-span showed the highest vertical velocity profile below the wing; and hence, was the location responsible for the majority of lift production along the span.

  4. Edge effect modeling of small tool polishing in planetary movement

    Li, Qi-xin; Ma, Zhen; Jiang, Bo; Yao, Yong-sheng

    2018-03-01

    As one of the most challenging problems in Computer Controlled Optical Surfacing (CCOS), the edge effect greatly affects the polishing accuracy and efficiency. CCOS rely on stable tool influence function (TIF), however, at the edge of the mirror surface,with the grinding head out of the mirror ,the contact area and pressure distribution changes, which resulting in a non-linear change of TIF, and leads to tilting or sagging at the edge of the mirror. In order reduce the adverse effects and improve the polishing accuracy and efficiency. In this paper, we used the finite element simulation to analyze the pressure distribution at the mirror edge and combined with the improved traditional method to establish a new model. The new method fully considered the non-uniformity of pressure distribution. After modeling the TIFs in different locations, the description and prediction of the edge effects are realized, which has a positive significance on the control and suppression of edge effects

  5. Structural and aerodynamic considerations of an active piezoelectric trailing-edge tab on a helicopter rotor

    Murray, Gabriel Jon

    This dissertation is concerned with an active tab for use on a rotorcraft for noise and vibration reduction. The tab is located at the trailing edge of the airfoil. The tab consists of a shim sandwiched by layers of the piezoelectric actuators, macro fiber composites, of varying length. This configuration is similar to a bimorph. The modus operandi is similar to that of a trailing edge flap. The actuators deform the tab, bending it to achieve a tip displacement. This provides a change in the lift, moment, and drag coefficients of the airfoil. By actuating the system at 3/rev to 5/rev, reductions in noise and vibration can be realized. The system was examined and designed around using the UH-60 Blackhawk as the model rotorcraft. The tab is envisioned to operate between 65% to 85% of the main rotor span. The tab's chordwise dimensions considered were 20% and 15% of the blade chord. In order to assess the potential of the tab to change the lift and moment coefficients of the airfoil-tab system, a steady computational fluid dynamics study was conducted. The results were generated via the University of Maryland's Transonic Unsteady Navier-Stokes code. Various tab deflection angles, Mach numbers, and angle-of-attack values were computed. These results were compared to a trailing edge flap of similar size. The comparison shows that the tab produces lift and moment increments similar to that of the trailing edge flap. The design of the tab---composed of both active piezoelectric actuators and passive materials---was conducted using finite element analysis. The objectives were to maximize the tip deflection due to the actuators, while minimizing the deformation due to inertial and aerodynamic forces and loads. The inertial loads (acceleration terms) come from both blade motion, such as flapping and pitch, as well as the rotation of the rotor (centrifugal force). All of these previously mentioned terms cause the tab to undergo undesirable deflections. The original concept

  6. Development and Realization of a Shock Wave Test on Expert Flap Qualification Model

    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.

  7. Experience with Perforator Based Flaps for Wound Cover of the Leg ...

    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 ...

  8. Reconstruction of the anterior floor of the mouth with the inferiorly based nasolabial flap

    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

  9. Increased Flap Weight and Decreased Perforator Number Predict Fat Necrosis in DIEP Breast Reconstruction

    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.

  10. The effect of atorvastatin on survival of rat ischemic flap

    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.

  11. Edge effects on the electronic properties of phosphorene nanoribbons

    Peng, Xihong; Copple, Andrew; Wei, Qun

    2014-01-01

    Two dimensional few-layer black phosphorus crystal structures have recently been fabricated and have demonstrated great potential in electronic applications. In this work, we employed first principles density functional theory calculations to study the edge and quantum confinement effects on the electronic properties of the phosphorene nanoribbons (PNR). Different edge functionalization groups, such as H, F, Cl, OH, O, S, and Se, in addition to a pristine case were studied for a series of ribbon widths up to 3.5 nm. It was found that the armchair-PNRs (APNRs) are semiconductors for all edge groups considered in this work. However, the zigzag-PNRs (ZPNRs) show either semiconductor or metallic behavior in dependence on their edge chemical species. Family 1 edges (i.e., H, F, Cl, OH) form saturated bonds with P atoms in the APNRs and ZPNRs, and the edge states keep far away from the band gap. However, Family 2 edges (pristine, O, S, Se) form weak unsaturated bonds with the p z orbital of the phosphorus atoms and bring edge states within the band gap of the ribbons. For the ZPNRs, the edge states of Family 2 are present around the Fermi level within the band gap, which close up the band gap of the ZPNRs. For the APNRs, these edge states are located at the bottom of the conduction band and result in a reduced band gap.

  12. Edge effects on the electronic properties of phosphorene nanoribbons

    Peng, Xihong, E-mail: xihong.peng@asu.edu [School of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States); Copple, Andrew [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Wei, Qun [School of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States); School of Physics and Optoelectronic Engineering, Xidian University, Xi' an 710071 (China)

    2014-10-14

    Two dimensional few-layer black phosphorus crystal structures have recently been fabricated and have demonstrated great potential in electronic applications. In this work, we employed first principles density functional theory calculations to study the edge and quantum confinement effects on the electronic properties of the phosphorene nanoribbons (PNR). Different edge functionalization groups, such as H, F, Cl, OH, O, S, and Se, in addition to a pristine case were studied for a series of ribbon widths up to 3.5 nm. It was found that the armchair-PNRs (APNRs) are semiconductors for all edge groups considered in this work. However, the zigzag-PNRs (ZPNRs) show either semiconductor or metallic behavior in dependence on their edge chemical species. Family 1 edges (i.e., H, F, Cl, OH) form saturated bonds with P atoms in the APNRs and ZPNRs, and the edge states keep far away from the band gap. However, Family 2 edges (pristine, O, S, Se) form weak unsaturated bonds with the p{sub z} orbital of the phosphorus atoms and bring edge states within the band gap of the ribbons. For the ZPNRs, the edge states of Family 2 are present around the Fermi level within the band gap, which close up the band gap of the ZPNRs. For the APNRs, these edge states are located at the bottom of the conduction band and result in a reduced band gap.

  13. Use if a soecuak sokubt ub reverse syrak artery flap to reduce venous congestion and flap necrosis

    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)

  14. Complications Following Autologous Latissimus Flap Breast Reconstruction

    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.

  15. ICRF edge modeling

    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

  16. Effectiveness Using Circular Fibre Steel Flap Gate As a Control Structure Towards the Hydraulic Characteristics in Open Channel

    Adib, M. R. M.; Amirza, A. R. M.; Wardah, T.; Junaidah, A.

    2016-07-01

    Hydraulic control gate structure plays an important role in regulating the flow of water in river, canal or water reservoir. One of the most appropriate structures in term of resolving the problem of flood occured is the construction of circular fibre steel flap gate. Therefore, an experiment has been conducted by using an open channel model at laboratory. In this case, hydraulic jump and backwater were the method to determined the hydraulic characteristics of circular fibre steel flap gate in an open channel model. From the experiment, the opening angle of flap gate can receive discharges with the highest flow rate of 0.035 m3/s with opening angle was 47°. The type of jump that occurs at the slope of 1/200 for a distance of 5.0 m is a standing jump or undulating wave. The height of the backwater can be identified based on the differences of specific force which is specific force before jump, F1 and specific force after jump, F2 from the formation of backwater. Based on the research conducted, the tendency of incident backwater wave occurred was high in every distance of water control location from water inlet is flap slope and the slope of 1/300 which is 0.84 m/s and 0.75 m/s of celerity in open channel model.

  17. Panorama of Reconstruction of Skull Base Defects: From Traditional Open to Endonasal Endoscopic Approaches, from Free Grafts to Microvascular Flaps

    Reyes, Camilo; Mason, Eric; Solares, C. Arturo

    2014-01-01

    Introduction A substantial body of literature has been devoted to the distinct characteristics and surgical options to repair the skull base. However, the skull base is an anatomically challenging location that requires a three-dimensional reconstruction approach. Furthermore, advances in endoscopic skull base surgery encompass a wide range of surgical pathology, from benign tumors to sinonasal cancer. This has resulted in the creation of wide defects that yield a new challenge in skull base reconstruction. Progress in technology and imaging has made this approach an internationally accepted method to repair these defects. Objectives Discuss historical developments and flaps available for skull base reconstruction. Data Synthesis Free grafts in skull base reconstruction are a viable option in small defects and low-flow leaks. Vascularized flaps pose a distinct advantage in large defects and high-flow leaks. When open techniques are used, free flap reconstruction techniques are often necessary to repair large entry wound defects. Conclusions Reconstruction of skull base defects requires a thorough knowledge of surgical anatomy, disease, and patient risk factors associated with high-flow cerebrospinal fluid leaks. Various reconstruction techniques are available, from free tissue grafting to vascularized flaps. Possible complications that can befall after these procedures need to be considered. Although endonasal techniques are being used with increasing frequency, open techniques are still necessary in selected cases. PMID:25992142

  18. ICRF edge modeling studies

    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.).

  19. Colgajo perforante tóracodorsal Toracodorsal perforator flap

    C. Angrigiani

    2006-12-01

    Full Text Available La espalda es una excelente zona dadora de colgajos. El colgajo perforante tóracodorsal basado en ramas cutáneas de la arteria y vena tóracodorsales que perforan el músculo dorsal ancho, es una modifica ción del tradicional colgajo musculocutáneo de dorsal ancho que permite lograr una mayor flexibilidad en su traslado y una disminución de su volumen. Puede emplearse como colgajo libre o en isla. Presentamos su anatomía, disección e indicaciones.Back is an excellent donor site for flaps. The tora codorsal perforator flap, based on cutaneous vessels from toracodorsal artery and vein that pass through Latissimus Dorsi muscle, is a modified conventional musculocutaneous Latissimus Dorsi flap that allows easier movility and a volume reduction. This flap can be used both, free flap or island flap. We present the anatomy, dissection and applica tions of this flap.

  20. Droplet ejection and sliding on a flapping film

    Xi Chen

    2017-03-01

    Full Text Available Water recovery and subsequent reuse are required for human consumption as well as industrial, and agriculture applications. Moist air streams, such as cooling tower plumes and fog, represent opportunities for water harvesting. In this work, we investigate a flapping mechanism to increase droplet shedding on thin, hydrophobic films for two vibrational cases (e.g., ± 9 mm and 11 Hz; ± 2 mm and 100 Hz. Two main mechanisms removed water droplets from the flapping film: vibrational-induced coalescence/sliding and droplet ejection from the surface. Vibrations mobilized droplets on the flapping film, increasing the probability of coalescence with neighboring droplets leading to faster droplet growth. Droplet departure sizes of 1–2 mm were observed for flapping films, compared to 3–4 mm on stationary films, which solely relied on gravity for droplet removal. Additionally, flapping films exhibited lower percentage area coverage by water after a few seconds. The second removal mechanism, droplet ejection was analyzed with respect to surface wave formation and inertia. Smaller droplets (e.g., 1-mm diameter were ejected at a higher frequency which is associated with a higher acceleration. Kinetic energy of the water was the largest contributor to energy required to flap the film, and low energy inputs (i.e., 3.3 W/m2 were possible. Additionally, self-flapping films could enable novel water collection and condensation with minimal energy input.

  1. The anatomy of forearm free flap phalloplasty for transgender surgery.

    Kim, S; Dennis, M; Holland, J; Terrell, M; Loukas, M; Schober, J

    2018-03-01

    Transgender surgeries are becoming more frequent and visual interpretation of anatomy is essential for both surgeons and patients. Since the forearm free flap phalloplasty was introduced in 1984, it has been known to provide reliable cosmetic and functional results for transitioning men compared with phalloplasty by different flaps. Surgical text descriptions were enhanced by the creation of new anatomic illustrations. The forearm free flap consists of the anterior forearm skin, subcutaneous tissue, fascia containing the radial artery as the perforator and its venae comitantes, cephalic and basilic veins, and lateral and medial antebrachial cutaneous nerves are demonstrated in relation to the surgically derived flap. Song's forearm free flap phalloplasty requires two surgical stages with a three-month interval between the stages: prelamination of a neourethra and construction of a neophallus. The neophallus created by forearm flap phalloplasty is reported to achieve acceptable aesthetical and psychological satisfaction, appropriate size and shape, and satisfying sexual intercourse. Despite increasing experiences in gender confirming surgery with modifications made by many authors, urethral complications including fistula and/or stricture formation are the leading causes of reoperation. The poor esthetic outcome of the forearm donor site and a decrease in rigidity of the neophallus are the main limitations. Illustrations of anatomy help inform surgical choice and understanding of risks and benefits by patients. The anatomy of the free forearm flap phalloplasty supports creation of a neophallus for transsexual anatomy revision. Clin. Anat. 31:145-151, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. EXTENDED REVERSE SURAL FLAP FOR LOWER LIMB COVERAGE

    Biswajit Mishra

    2018-12-01

    Full Text Available BACKGROUND The reverse sural artery flap has been a workhorse for the reconstruction of distal third of leg, ankle, sole and foot. Major limitation of reverse sural flap has been venous congestion particularly when harvested from proximal third of the leg. Objective- To evaluate the efficacy, safety of the extended reverse sural flap from proximal third of the leg. MATERIALS AND METHODS A prospective study was conducted at the department of plastic surgery on twenty patients who needed soft tissue reconstruction in the distal third of the leg, ankle, heel, forefoot and midfoot due to various cause. In all cases flap was extended proximally to the upper third of the calf and neurovenoadipo fascial pedicled sural fasciocutaneous flap was harvested. RESULTS There were only two cases of marginal necrosis. None of the patients had complete necrosis. Two patients developed hypertrophy of the flap margin. CONCLUSION Distally based neuroveno adipofascial pedicled sural fasciocutaneous flap can be safely extended to proximal third of the leg and is a reliable option for reconstruction of the defects in the foot, ankle and sole.

  3. Numerical study on the power extraction performance of a flapping foil with a flexible tail

    Wu, J.; Shu, C.; Zhao, N.; Tian, F.-B.

    2015-01-01

    The numerical study on the power extraction performance of a flapping foil with a flexible tail is performed in this work. A NACA0015 airfoil is arranged in a two-dimensional laminar flow and imposed with a synchronous harmonic plunge and pitch rotary motion. A flat plate that is attached to the trailing edge of the foil is utilized to model a tail, and so they are viewed as a whole for the purpose of power extraction. In addition, the tail either is rigid or can deform due to the exerted hydrodynamic forces. To implement numerical simulations, an immersed boundary-lattice Boltzmann method is employed. At a Reynolds number of 1100 and the position of the pitching axis at third chord, the influences of the mass and flexibility of the tail as well as the frequency of motion on the power extraction are systematically examined. It is found that compared to the foil with a rigid tail, the efficiency of power extraction for the foil with a deformable tail can be improved. Based on the numerical analysis, it is indicated that the enhanced plunging component of the power extraction, which is caused by the increased lift force, directly contributes to the efficiency improvement. Since a flexible tail with medium and high masses is not beneficial to the efficiency improvement, a flexible tail with low mass together with high flexibility is recommended in the flapping foil based power extraction system.

  4. Wind tunnel tests with combined pitch and free-floating flap control: data-driven iterative feedforward controller tuning

    S. T. Navalkar

    2016-10-01

    Full Text Available Wind turbine load alleviation has traditionally been addressed in the literature using either full-span pitch control, which has limited bandwidth, or trailing-edge flap control, which typically shows low control authority due to actuation constraints. This paper combines both methods and demonstrates the feasibility and advantages of such a combined control strategy on a scaled prototype in a series of wind tunnel tests. The pitchable blades of the test turbine are instrumented with free-floating flaps close to the tip, designed such that they aerodynamically magnify the low stroke of high-bandwidth actuators. The additional degree of freedom leads to aeroelastic coupling with the blade flexible modes. The inertia of the flaps was tuned such that instability occurs just beyond the operational envelope of the wind turbine; the system can however be stabilised using collocated closed-loop control. A feedforward controller is shown to be capable of significant reduction of the deterministic loads of the turbine. Iterative feedforward tuning, in combination with a stabilising feedback controller, is used to optimise the controller online in an automated manner, to maximise load reduction. Since the system is non-linear, the controller gains vary with wind speed; this paper also shows that iterative feedforward tuning is capable of generating the optimal gain schedule online.

  5. Smoothness in Binomial Edge Ideals

    Hamid Damadi

    2016-06-01

    Full Text Available In this paper we study some geometric properties of the algebraic set associated to the binomial edge ideal of a graph. We study the singularity and smoothness of the algebraic set associated to the binomial edge ideal of a graph. Some of these algebraic sets are irreducible and some of them are reducible. If every irreducible component of the algebraic set is smooth we call the graph an edge smooth graph, otherwise it is called an edge singular graph. We show that complete graphs are edge smooth and introduce two conditions such that the graph G is edge singular if and only if it satisfies these conditions. Then, it is shown that cycles and most of trees are edge singular. In addition, it is proved that complete bipartite graphs are edge smooth.

  6. Adipofascial Anterolateral Thigh Flap Safety: Applications and Complications

    Tommaso Agostini

    2013-03-01

    Full Text Available BackgroundA thinned anterolateral thigh (ALT flap is often harvested to achieve optimal skin resurfacing. Several techniques have been described to thin an ALT flap including an adipocutaneous flap, an adipofascial flap and delayed debulking.MethodsBy systematically reviewing all of the available literature in English and French, the present manuscript attempts to identify the common surgical indications, complications and donor site morbidity of the adipofascial variant of the ALT flap. The studies were identified by performing a systematic search on Medline, Ovid, EMBASE, the Cochrane Database of Systematic Reviews, Current Contents, PubMed, Google, and Google Scholar.ResultsThe study selection process was adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, and 15 articles were identified using the study inclusion criteria. These articles were then reviewed for author name(s, year of publication, flap dimensions and thickness following defatting, perforator type, type of transfer, complications, thinning technique, number of cases with a particular area of application and donor site morbidity.ConclusionsThe adipofascial variant of the ALT flap provides tissue to fill large defects and improve pliability. Its strong and safe blood supply permits adequate immediate or delayed debulking without vascular complications. The presence of the deep fascia makes it possible to prevent sagging by suspending and fixing the flap for functional reconstructive purposes (e.g., the intraoral cavity. Donor site morbidity is minimal, and thigh deformities can be reduced through immediate direct closure or liposuction and direct closure. A safe blood supply was confirmed by the rate of secondary flap debulking.

  7. "Internet of Things" Real-Time Free Flap Monitoring.

    Kim, Sang Hun; Shin, Ho Seong; Lee, Sang Hwan

    2018-01-01

    Free flaps are a common treatment option for head and neck reconstruction in plastic reconstructive surgery, and monitoring of the free flap is the most important factor for flap survival. In this study, the authors performed real-time free flap monitoring based on an implanted Doppler system and "internet of things" (IoT)/wireless Wi-Fi, which is a convenient, accurate, and efficient approach for surgeons to monitor a free flap. Implanted Doppler signals were checked continuously until the patient was discharged by the surgeon and residents using their own cellular phone or personal computer. If the surgeon decided that a revision procedure or exploration was required, the authors checked the consumed time (positive signal-to-operating room time) from the first notification when the flap's status was questioned to the determination for revision surgery according to a chart review. To compare the efficacy of real-time monitoring, the authors paired the same number of free flaps performed by the same surgeon and monitored the flaps using conventional methods such as a physical examination. The total survival rate was greater in the real-time monitoring group (94.7% versus 89.5%). The average time for the real-time monitoring group was shorter than that for the conventional group (65 minutes versus 86 minutes). Based on this study, real-time free flap monitoring using IoT technology is a method that surgeon and reconstruction team can monitor simultaneously at any time in any situation.

  8. Osteoradionecrosis of the olecranon: treatment by radial forearm flap

    Thornton, J.W.; Stevenson, T.R.; VanderKolk, C.A.

    1987-01-01

    Osteoradionecrosis of the olecranon is an unusual pathologic entity, treated best by debridement and wound closure using vascularized tissue. Local skin is often unavailable for flap design and transposition. The radial forearm flap can be isolated on a proximal vascular pedicle and transposed to cover the wound. In the case presented, healing was brisk and complete, allowing early elbow mobilization. Although the donor site is not easily concealed, no functional impairment results from flap elevation and all full-thickness wounds are confined to the involved extremity

  9. Management of a Traumatic Flap Dislocation Seven Years after LASIK

    Majid Moshirfar

    2011-01-01

    Full Text Available Seven years after uneventful laser in situ keratomileusis (LASIK, a 48-year-old woman presented one week after being hit with an iron cord with blurry vision, pain, and irritation. The injury resulted in traumatic flap dislocation, epithelial ingrowth, and macrostriae. Following epithelial removal, the flap was refloated and repositioned. Nine interrupted sutures were used to secure the flap. Three-weeks after surgery with no sutures remaining, the epithelial ingrowth and macrostriae had resolved with a visual acuity of 20/20.

  10. Edge Effects and Ecological Traps: Effects on Shrubland Birds in Missouri

    April A. Woodward; Alix D. Fink; Frank R. Thompson III

    2001-01-01

    The effect of habitat edge on avian nesting success has been the focus of considerable debate. We studied relationships between habitat edges, locations of nests, and predation. We tested the ecological trap hypothesis for 5 shrubland bird species in the Missouri Ozarks. We compared habitat selection and daily nest predation rates among 3 distance-to-edge categories....

  11. Aerodynamic Characteristic of the Active Compliant Trailing Edge Concept

    Nie, Rui; Qiu, Jinhao; Ji, Hongli; Li, Dawei

    2016-06-01

    This paper introduces a novel Morphing Wing structure known as the Active Compliant Trailing Edge (ACTE). ACTE structures are designed using the concept of “distributed compliance” and wing skins of ACTE are fabricated from high-strength fiberglass composites laminates. Through the relative sliding between upper and lower wing skins which are connected by a linear guide pairs, the wing is able to achieve a large continuous deformation. In order to present an investigation about aerodynamics and noise characteristics of ACTE, a series of 2D airfoil analyses are established. The aerodynamic characteristics between ACTE and conventional deflection airfoil are analyzed and compared, and the impacts of different ACTE structure design parameters on aerodynamic characteristics are discussed. The airfoils mentioned above include two types (NACA0012 and NACA64A005.92). The computing results demonstrate that: compared with the conventional plane flap airfoil, the morphing wing using ACTE structures has the capability to improve aerodynamic characteristic and flow separation characteristic. In order to study the noise level of ACTE, flow field analysis using LES model is done to provide noise source data, and then the FW-H method is used to get the far field noise levels. The simulation results show that: compared with the conventional flap/aileron airfoil, the ACTE configuration is better to suppress the flow separation and lower the overall sound pressure level.

  12. On the shape optimization of flapping wings and their performance analysis

    Ghommem, Mehdi

    2014-01-01

    The present work is concerned with the shape optimization of flapping wings in forward flight. The analysis is performed by combining a gradient-based optimizer with the unsteady vortex lattice method (UVLM). We describe the UVLM simulation procedure and provide the first methodology to select properly the mesh and time-step sizes to achieve invariant UVLM simulation results under mesh refinement. Our objective is to identify a set of optimized shapes that maximize the propulsive efficiency, defined as the ratio of the propulsive power over the aerodynamic power, under lift, thrust, and area constraints. Several parameters affecting flight performance are investigated and their impact is described. These include the wingÊ1/4s aspect ratio, camber line, and curvature of the leading and trailing edges. This study provides guidance for shape design of engineered flying systems. © 2013 Elsevier Masson SAS.

  13. Two-stage heterotopic urethroplasty with usage of groin flap. Case report

    R. T. Adamyan

    2014-11-01

    Full Text Available The article is devoted to the issues of struggle with problems of the urogenital region, arising as a consequence iatrogeny, with the help of plastic surgery. The article provides the case report, which deals with a two-step treatment of the patient with complete loss of the part of the urethra and bladder neck due to iatrogeny. The first stage of surgical treatment is the development of the artificial urethra formation by the rotation groin flap with the axis blood supply. The second stage is connection private urethra with artificial, with a heterotopic location of the lower urinary tract.

  14. Complete Lower Lip Reconstruction with a Large Lip Switch Flap and a Composite Modiolus Advancement Flap

    Gudjon L. Gunnarsson, MD

    2017-12-01

    Full Text Available Summary:. Total loss of the lower lip is debilitating and poses a reconstructive challenge. Aiming to restore oral continence and function and also cosmetic appearance, a successful reconstruction has a huge impact on the quality of life for the individual patient. Early sources of local tissue rearrangement for lip reconstruction date back 3000 years, with earliest reports of lip switch procedures more than 2 centuries ago in Europe, when noma was still endemic in Europe, indicating that the anatomy was better understood by the barber surgeons of the past than we like to acknowledge. We are still faced with such challenging cases all over the world where resources are limited. Our current understanding of perforator anatomy and blood supply makes more frequent revisits to flaps of the past with modern advances. Innovative solutions are imperative for salvage, and old ideas tend to reappear when they prove to be useful. Herein, we describe in open access a new reconstructive method where we combined a large lip switch flap together with a composite advancement modiolus flap to reconstruct a whole lower lip and the donor defect of the upper lip all at once, a procedure that is simple to perform and works in settings where it is greatly needed.

  15. Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap.

    Ortega-Usobiaga, J; Llovet-Osuna, F; Katz, T; Djodeyre, M R; Druchkiv, V; Bilbao-Calabuig, R; Baviera, J

    2018-02-01

    To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Positioning the 5'-flap junction in the active site controls the rate of flap endonuclease-1-catalyzed DNA cleavage

    Song, Bo

    2018-02-09

    Flap endonucleases catalyze cleavage of single-stranded DNA flaps formed during replication, repair and recombination, and are therefore essential for genome processing and stability. Recent crystal structures of DNA-bound human flap endonuclease (hFEN1) offer new insights into how conformational changes in the DNA and hFEN1 may facilitate the reaction mechanism. For example, previous biochemical studies of DNA conformation performed under non-catalytic conditions with Ca2+ have suggested that base unpairing at the 5\\'-flap:template junction is an important step in the reaction, but the new structural data suggest otherwise. To clarify the role of DNA changes in the kinetic mechanism, we measured a series of transient steps - from substrate binding to product release - during the hFEN1-catalyzed reaction in the presence of Mg2+. We found that while hFEN1 binds and bends DNA at a fast, diffusion-limited rate, much slower Mg2+-dependent conformational changes in DNA around the active site are subsequently necessary and rate-limiting for 5\\'-flap cleavage. These changes are reported overall by fluorescence of 2-aminopurine at the 5\\'-flap:template junction, indicating that local DNA distortion (e.g., disruption of base stacking observed in structures), associated with positioning the 5\\'-flap scissile phosphodiester bond in the hFEN1 active site, controls catalysis. hFEN1 residues with distinct roles in the catalytic mechanism, including those binding metal ions (Asp-34, Asp-181), steering the 5\\'-flap through the active site and binding the scissile phosphate (Lys-93, Arg-100), and stacking against the base 5\\' to the scissile phosphate (Tyr-40), all contribute to these rate-limiting conformational changes, ensuring efficient and specific cleavage of 5\\'-flaps.

  17. Retention of a reconstructed nipple using a C-V flap with different layer thicknesses in the C-flap.

    Sowa, Yoshihiro; Itsukage, Sizu; Sakaguchi, Kouichi; Taguchi, Tetsuya; Numajiri, Toshiaki

    2018-04-01

    The C-V flap for nipple reconstruction is now one of standard surgical techniques. But decreased projection is still a problem. In recent years, it has been suggested that projection can be more easily maintained when raising of the C-flap is performed with a split thickness dermis. In this study, we examined whether decrease of projection can be prevented by raising of a C-flap with a split dermis rather than with full dermis. A total of 49 consecutive patients who underwent reconstruction of a nipple using the C-V flap technique were enrolled. The patients included 22 who underwent surgery using a C-flap with a full thickness dermis (Group F), and 27 who underwent surgery with raising of a flap with a split thickness dermis (Group S). The size of the reconstructed nipple was measured at 2 weeks, 6 months and 1 year postoperatively for comparison between Groups F and S. Partial necrosis of the C-flap end occurred in 4 subjects in only Group S. The decrease in projection after 1 year postoperatively in Group S was significantly lower than that in Group F. In contrast, the teat base size in Group F tended to be greater than that in Group S, suggesting a tendency for an expanded base using a flap with a full dermis. Our results indicated that it is recommended to use a C-flap with a split dermis for cases with high projection of the nipple on the contralateral side.

  18. Positioning the 5'-flap junction in the active site controls the rate of flap endonuclease-1-catalyzed DNA cleavage

    Song, Bo; Hamdan, Samir; Hingorani, Manju M

    2018-01-01

    Flap endonucleases catalyze cleavage of single-stranded DNA flaps formed during replication, repair and recombination, and are therefore essential for genome processing and stability. Recent crystal structures of DNA-bound human flap endonuclease (hFEN1) offer new insights into how conformational changes in the DNA and hFEN1 may facilitate the reaction mechanism. For example, previous biochemical studies of DNA conformation performed under non-catalytic conditions with Ca2+ have suggested that base unpairing at the 5'-flap:template junction is an important step in the reaction, but the new structural data suggest otherwise. To clarify the role of DNA changes in the kinetic mechanism, we measured a series of transient steps - from substrate binding to product release - during the hFEN1-catalyzed reaction in the presence of Mg2+. We found that while hFEN1 binds and bends DNA at a fast, diffusion-limited rate, much slower Mg2+-dependent conformational changes in DNA around the active site are subsequently necessary and rate-limiting for 5'-flap cleavage. These changes are reported overall by fluorescence of 2-aminopurine at the 5'-flap:template junction, indicating that local DNA distortion (e.g., disruption of base stacking observed in structures), associated with positioning the 5'-flap scissile phosphodiester bond in the hFEN1 active site, controls catalysis. hFEN1 residues with distinct roles in the catalytic mechanism, including those binding metal ions (Asp-34, Asp-181), steering the 5'-flap through the active site and binding the scissile phosphate (Lys-93, Arg-100), and stacking against the base 5' to the scissile phosphate (Tyr-40), all contribute to these rate-limiting conformational changes, ensuring efficient and specific cleavage of 5'-flaps.

  19. Wisps in the outer edge of the Keeler Gap

    Tiscareno, Matthew S.; Arnault, Ethan G.

    2015-11-01

    Superposed upon the relatively smooth outer edge of the Keeler Gap are a system of "wisps," which appear to be ring material protruding inward into the gap, usually with a sharp trailing edge and a smooth gradation back to the background edge location on the leading side (Porco et al. 2005, Science). The radial amplitude of wisps is usually 0.5 to 1 km, and their azimuthal extent is approximately a degree of longitude (~2400 km). Wisps are likely caused by an interplay between Daphnis (and perhaps other moons) and embedded moonlets within the ring, though the details remain unclear.Aside from the wisps, the Keeler Gap outer edge is the only one of the five sharp edges in the outer part of Saturn's A ring that is reasonably smooth in appearance (Tiscareno et al. 2005, DPS), with occultations indicating residuals less than 1 km upon a possibly non-zero eccentricity (R.G. French, personal communication, 2014). The other four (the inner and outer edges of the Encke Gap, the inner edge of the Keeler Gap, and the outer edge of the A ring itself) are characterized by wavy structure at moderate to high spatial frequencies, with amplitudes ranging from 2 to 30 km (Tiscareno et al. 2005, DPS).We will present a catalogue of wisp detections in Cassini images. We carry out repeated gaussian fits of the radial edge location in order to characterize edge structure and visually scan those fitted edges in order to detect wisps. With extensive coverage in longitude and in time, we will report on how wisps evolve and move, both within an orbit period and on longer timescales. We will also report on the frequency and interpretation of wisps that deviate from the standard morphology. We will discuss the implications of our results for the origin and nature of wisps, and for the larger picture of how masses interact within Saturn's rings.

  20. Distal Based Sural Fascio-Cutaneous Flap: A Practical Limb Saviour for Wounds of War and Peace

    Tahirkheli, M. U. I.; Ellahi, I.; Dar, M. F.; Sharif, A.

    2016-01-01

    Objective: To determine the effect of mechanism of injury on wound healing, and on the viability and success of distally based sural flap when used for the coverage of defects of lower leg, ankle and foot. Study Design: Descriptive study. Place and Duration of Study: Department of Surgery, Combined Military Hospital, Peshawar and Khariyan, from January 2012 to December 2014. Methodology: Patients with soft tissue defects over the distal leg, ankle and foot were selected by purposive sampling technique and divided into 2 groups of 19 patients each. Group A(road traffic accidents) and group B (war injuries). Sural fascio-cutaneous flap was the reconstructive tool used in all the cases using single technique by the same surgical team; and time for recipient site preparation, size of the defect, graft survival, its healing time and complications, were studied. Result: The mean age of the 38 patients in the study was 28.2 ±13.4 years. There were 36 male and 2 female patients. The most common site of injury encountered was leg (n=20) followed by foot (n=11) and ankle (n=5). Maximum wound size seen in group A was 10 x 12 cm and in group B was 15 x 38 cm. Recovery was uneventful in 17/19 cases of group Awhile 7/19 in group B and with no graft failure. Superficial epidermolysis was seen in 2 and 8 cases in group A and B respectively while edge necrosis of the flap was observed in group B only (n=4). Healing time on average was 2 to 3 weeks in group A, and 4 to 5 weeks in group B. Conclusion: Soft tissue defects of the distal lower extremity as a result of war injuries and road traffic accidents have different dynamics in terms of wound size, time of wound healing, wound complications and functional outcome; but distal based sural flap has promising Result in both situations. (author)

  1. Competing edge networks

    Parsons, Mark; Grindrod, Peter

    2012-06-01

    We introduce a model for a pair of nonlinear evolving networks, defined over a common set of vertices, subject to edgewise competition. Each network may grow new edges spontaneously or through triad closure. Both networks inhibit the other's growth and encourage the other's demise. These nonlinear stochastic competition equations yield to a mean field analysis resulting in a nonlinear deterministic system. There may be multiple equilibria; and bifurcations of different types are shown to occur within a reduced parameter space. This situation models competitive communication networks such as BlackBerry Messenger displacing SMS; or instant messaging displacing emails.

  2. Anomalous Hydrodynamic Drafting of Interacting Flapping Flags

    Ristroph, Leif; Zhang, Jun

    2008-11-01

    In aggregates of objects moving through a fluid, bodies downstream of a leader generally experience reduced drag force. This conventional drafting holds for objects of fixed shape, but interactions of deformable bodies in a flow are poorly understood, as in schools of fish. In our experiments on “schooling” flapping flags, we find that it is the leader of a group who enjoys a significant drag reduction (of up to 50%), while the downstream flag suffers a drag increase. This counterintuitive inverted drag relationship is rationalized by dissecting the mutual influence of shape and flow in determining drag. Inverted drafting has never been observed with rigid bodies, apparently due to the inability to deform in response to the altered flow field of neighbors.

  3. Application analysis on different suture of scleral flap in trabeculectomy

    Ning Liu

    2014-05-01

    Full Text Available AIM: To research the application of scleral flap suture in trabeculectomy. METHODS: Totally 114 primary angle-closure glaucoma patients, aged from 36-72 years old, were selected as the objects, and randomly divided into research group and control group. The two groups received different administration methods. Traditional sewing method of sclera flap was used in research group and improved sewing method of sclera flap was used in control group. RESULTS: There was statistical differences between postoperative intraocular pressure of the patients in the observation group and the control group after 1d; 2wk; 1, 3mo(PPP>0.05.CONCLUSION: It is safe and effective that the improved sewing method of sclera flap for trabeculectomy of acute angle-closure glaucoma, and it is a better method to avoid the occurrence of shallow anterior chamber than the traditional sewing method in the early stage after operation.

  4. Shape optimisation and performance analysis of flapping wings

    Ghommem, Mehdi; Collier, Nathan; Niemi, Antti; Calo, Victor M.

    2012-01-01

    optimised shapes produce efficient flapping flights, the wake pattern and its vorticity strength are examined. This work described in this paper should facilitate better guidance for shape design of engineered flying systems.

  5. A Novel Perforator Flap Training Model Using a Chicken Leg.

    Cifuentes, Ignacio J; Yañez, Ricardo A; Salisbury, Maria C; Rodriguez, José R; Varas, Julian E; Dagnino, Bruno L

    2016-04-01

    Living animal models are frequently used for perforator flap dissection training, but no ex vivo models have been described. The aim of this study is to present a novel nonliving model for perforator flap training based on a constant perforator in the chicken leg. A total of 15 chicken legs were used in this study. Anatomical dissection of the perforator was performed after its identification using ink injection, and in four of these specimens a perforator-based flap was raised. The anatomical dissection revealed a constant intramuscular perforator with a median length of 5.7 cm. Median proximal and distal vessel diameters were 0.93 and 0.4 mm, respectively. The median dissection time was 77.5 minutes. This study introduces a novel, affordable, and reproducible model for the intramuscular dissection of a perforator-based flap using an ex vivo animal model. Its consistent perforator and appropriate-sized vessels make it useful for training.

  6. Reconstruction of hand contracture by reverse ulnar perforator flap

    Cengiz Eser

    2016-04-01

    Full Text Available Hand burn scar contractures affect patients in aesthetic and functional aspects. After releasing these scars, the defects should be repaired. The reconstruction methods include primary suturation, Z plasty, skin grafting, local or free flaps, etc. All methods have their own advantages and disadvantages. One of the most useful flaps is the reverse ulnar perforator flap. We performed a two-staged procedure for repairing a post-burn contracture release defect in a 40-year-old male. In the first stage we applied reverse ulnar perforator flap for the hand defect, and ulnar artery and vein repair in the second stage. In conclusion, this two-staged procedure is a non-primary but useful option for hand and finger defects and prevents major vascular structure damage of the forearm. [Hand Microsurg 2016; 5(1.000: 40-43

  7. Effect of Frontal Gusts and Stroke Deviation in Forward Flapping Flight and Deconstructing the Aerodynamics of a Fruit Bat

    Viswanath, Kamal

    This dissertation broadly seeks to understand the effect different kinematic parameters, external forces, and dynamic wing conformation have on the fluid dynamics of flapping flight. The primary motivation is to better grasp the fundamental fluid phenomena driving efficient flapping flight in the Reynolds number regime of birds, bats, and man made fliers of similar scale. The CFD solver (GenIDLEST) used is a Navier-Stokes solver in a finite volume formulation on non-staggered structured multiblock meshes. It has the capability for both body-fitted moving grid simulations and Immersed Boundary Method (IBM) for simulating complex bodies moving within a fluid. To that purpose we investigate the response of a rigid flapping thin surface planar wing in forward flight, at Re=10,000, subjected to frontal gusts. Gusts are a common ecological hazard for flapping fliers, especially in crowded environments. Among the various temporal and spatial scales of gust possible, we look at the phasing and duration of very large spatial scale gusts and their impact on the unsteady fluid dynamics of flapping within a single flapping cycle. The gust is characterized by a step function with time scale much smaller than the flapping time period. Having the advantage of prescribing the motion, as well as the timing and duration of the gust, this allowed the observation of the effect of angle of attack (AOA) and wing rotation on the evolution of the Leading Edge Vortex (LEV) and, hence the instantaneous lift and thrust profiles, by varying the parameters. During the downstroke, frontal gusts accelerated the flow development resulting in early separation of existing LEVs and formation of new ones on the wing surface which influenced the force generation by increasing the lift and thrust. These phenomena underscored the importance of the unsteady vortex structures as the primary force generators in flapping flight. The effect of the gust is observed to be diminished when it occurs during rapid

  8. Degenerate band edge laser

    Veysi, Mehdi; Othman, Mohamed A. K.; Figotin, Alexander; Capolino, Filippo

    2018-05-01

    We propose a class of lasers based on a fourth-order exceptional point of degeneracy (EPD) referred to as the degenerate band edge (DBE). EPDs have been found in parity-time-symmetric photonic structures that require loss and/or gain; here we show that the DBE is a different kind of EPD since it occurs in periodic structures that are lossless and gainless. Because of this property, a small level of gain is sufficient to induce single-frequency lasing based on a synchronous operation of four degenerate Floquet-Bloch eigenwaves. This lasing scheme constitutes a light-matter interaction mechanism that leads also to a unique scaling law of the laser threshold with the inverse of the fifth power of the laser-cavity length. The DBE laser has the lowest lasing threshold in comparison to a regular band edge laser and to a conventional laser in cavities with the same loaded quality (Q ) factor and length. In particular, even without mirror reflectors the DBE laser exhibits a lasing threshold which is an order of magnitude lower than that of a uniform cavity laser of the same length and with very high mirror reflectivity. Importantly, this novel DBE lasing regime enforces mode selectivity and coherent single-frequency operation even for pumping rates well beyond the lasing threshold, in contrast to the multifrequency nature of conventional uniform cavity lasers.

  9. Investigation of piezoelectric flaps for load alleviation using CFD; Wind turbines

    Heinz, J.C.

    2010-03-15

    Cost efficient wind power generation demands for large wind turbines with a long lifetime. These demands place high interests on sophisticated load control techniques such as deformable trailing edge flaps. In this work a previously tested prototype airfoil was investigated by using the 2D incompressible RANS solver EllipSys2D. The prototype was built with a Risoe-B1-18 airfoil where piezoelectric actuators THUNDER TH-6R were attached at the trailing edge to realize a movable flap. The results of the simulation were compared to measurements of the previous wind tunnel test and comprehensive steady state computations were conducted to gain information about the general airfoil properties. The model was subsequently used to investigate aero-servo-elastic effects on the 2D airfoil section exposed to a fluctuating inflow. It is explained how a fluctuating inflow was simulated with EllipSys2D and how the CFD solver was coupled with a 3 DOF structural model and with two different control algorithms. Control 1 used the measured AOA in front of the LE as input, Control 2 used the pressure difference between suction and pressure side as input. The model showed a substantial load reduction potential for the present prototype airfoil. For a wind step from 10 m/s to 10.5 m/s the standard deviation of the structural deflection normal to the rotor plane could be reduced with up to 98 % (Control 1) and 96 % (Control 2). A 4 s turbulent inflow with TI=2.2 % could be reduced with up to 81 % (Control 1) and 82 % (Control 2). For a 12 s inflow with TI=2.4 % the standard deviation could be reduced with up to 68 % (Control 1) and 67 % (Control 2). The influence of possible time lags inside the control loop on the reduction potential of the prototype was also investigated. For a 12 s inflow with a tripled turbulence intensity of TI=7.7 % the prototype airfoil could still reach a reduction of up to 54 %. For an extended flap range of -6 to +6 degrees the reduction could be returned to 66

  10. Surgeon-Based 3D Printing for Microvascular Bone Flaps.

    Taylor, Erin M; Iorio, Matthew L

    2017-07-01

    Background  Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods  Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results  Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions  Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence  Level IV. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. An international comparison of reimbursement for DIEAP flap breast reconstruction.

    Reid, A W N; Szpalski, C; Sheppard, N N; Morrison, C M; Blondeel, P N

    2015-11-01

    The deep inferior epigastric artery perforator (DIEAP) flap is currently considered the gold standard for autologous breast reconstruction. With the current economic climate and health cutbacks, we decided to survey reimbursement for DIEAP flaps performed at the main international centres in order to assess whether they are funded consistently. Data were collected confidentially from the main international centres by an anonymous questionnaire. Our results illustrate the wide disparity in international DIEAP flap breast reconstruction reimbursement: a unilateral DIEAP flap performed in New York, USA, attracts €20,759, whereas the same operation in Madrid, Spain, will only be reimbursed for €300. Only 35.7% of the surgeons can set up their own fee. Moreover, 85.7% of the participants estimated that the current fees are insufficient, and most of them feel that we are evolving towards an even lower reimbursement rate. In 55.8% of the countries represented, there is no DIEAP-specific coding; in comparison, 74.4% of the represented countries have a specific coding for transverse rectus abdominis (TRAM) flaps. Finally, despite the fact that DIEAP flaps have become the gold standard for breast reconstruction, they comprise only a small percentage of all the total number of breast reconstruction procedures performed (7-15%), with the only exception being Belgium (40%). Our results demonstrate that DIEAP flap breast reconstruction is inconsistently funded. Unfortunately though, it appears that the current reimbursement offered by many countries may dissuade institutions and surgeons from offering this procedure. However, substantial evidence exists supporting the cost-effectiveness of perforator flaps for breast reconstruction, and, in our opinion, the long-term clinical benefits for our patients are so important that this investment of time and money is absolutely essential. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons

  12. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles

    Sutthiphong Srigrarom; Woei-Leong Chan

    2015-01-01

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

  13. Free tissue transfer versus pedicled flap reconstruction of head and neck malignancy defects.

    O'Neill, J P

    2012-02-01

    BACKGROUND: With the advent of microsurgery the pedicled flap is considered by many to be an outdated surgical option. AIMS: To explore the relationship between flap survival and pre-morbid risk factors, conduct a comparative analysis of flap and systemic morbidities and complete a cosmesis and functionality assessment for oral and oropharyngeal reconstruction patients. METHODS: 114 patients, over a 13-year period, who had a one-stage reconstructive procedure employing the pectoralis major myocutaneous flap (PMMF) or radial forearm-free flap (RFFF). RESULTS: Variables, including age, smoking and radiation exposure were not statistically significant predictors of flap survival probability. Atelectasis was a significant post-op finding of RFFF patients. Flap dehiscence of >50% was a significant morbidity of PMMF. No statistical difference in cosmetic deformity, diet and socialisation was noted. CONCLUSIONS: Pectoralis major myocutaneous flap remains an enduring and safe flap; however, the RFFF has markedly improved speech performance over the PMMF.

  14. A retrospective study: Multivariate logistic regression analysis of the outcomes after pressure sores reconstruction with fasciocutaneous, myocutaneous, and perforator flaps.

    Chiu, Yu-Jen; Liao, Wen-Chieh; Wang, Tien-Hsiang; Shih, Yu-Chung; Ma, Hsu; Lin, Chih-Hsun; Wu, Szu-Hsien; Perng, Cherng-Kang

    2017-08-01

    Despite significant advances in medical care and surgical techniques, pressure sore reconstruction is still prone to elevated rates of complication and recurrence. We conducted a retrospective study to investigate not only complication and recurrence rates following pressure sore reconstruction but also preoperative risk stratification. This study included 181 ulcers underwent flap operations between January 2002 and December 2013 were included in the study. We performed a multivariable logistic regression model, which offers a regression-based method accounting for the within-patient correlation of the success or failure of each flap. The overall complication and recurrence rates for all flaps were 46.4% and 16.0%, respectively, with a mean follow-up period of 55.4 ± 38.0 months. No statistically significant differences of complication and recurrence rates were observed among three different reconstruction methods. In subsequent analysis, albumin ≤3.0 g/dl and paraplegia were significantly associated with higher postoperative complication. The anatomic factor, ischial wound location, significantly trended toward the development of ulcer recurrence. In the fasciocutaneous group, paraplegia had significant correlation to higher complication and recurrence rates. In the musculocutaneous flap group, variables had no significant correlation to complication and recurrence rates. In the free-style perforator group, ischial wound location and malnourished status correlated with significantly higher complication rates; ischial wound location also correlated with significantly higher recurrence rate. Ultimately, our review of a noteworthy cohort with lengthy follow-up helped identify and confirm certain risk factors that can facilitate a more informed and thoughtful pre- and postoperative decision-making process for patients with pressure ulcers. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All

  15. Unsteady Aerodynamics of Flapping Wing of a Bird

    M. Agoes Moelyadi

    2013-04-01

    Full Text Available The unsteady flow behavior and time-dependent aerodynamic characteristics of the flapping motion of a bird’s wing were investigated using a computational method. During flapping, aerodynamic interactions between bird wing surfaces and surrounding flow may occur, generating local time-dependent flow changes in the flow field and aerodynamic load of birds. To study the effect of flapping speed on unsteady aerodynamic load, two kinds of computational simulations were carried out, namely a quasi-steady and an unsteady simulation. To mimic the movement of the down-stroke and the upstroke of a bird, the flapping path accorded to a sinus function, with the wing attitude changing in dihedral angle and time. The computations of time-dependent viscous flow were based on the solution of the Reynolds Averaged Navier-Stokes equations by applying the k-e turbulence model. In addition, the discretization for the computational domain around the model used multi-block structured grid to provide more accuracy in capturing viscous flow, especially in the vicinity of the wing and body surfaces, to obtain a proper wing-body geometry model. For this research, the seagull bird was chosen, which has high aspect ratio wings with pointed wing-tips and a high camber wing section. The results include mesh movement, velocity contours as well as aerodynamic coefficients of the flapping motion of the bird at various flapping frequencies.

  16. Temporalis myo-osseous flap: an experimental study

    Antonyshyn, O.; Colcleugh, R.G.; Hurst, L.N.; Anderson, C.

    1986-01-01

    The present paper investigates the anatomy and vascularization of the temporalis myo-osseous flap. This is a calvarial bone flap that employs temporalis muscle and its distal pericranial extension as a pedicle. In six human cadavers the flap was raised as an island on the anterior deep temporal artery after transecting the zygomatic arch and coronoid process. Maximal mobilization was thus obtained, allowing rotation of the flap into the mouth for intraoral reconstruction. The arc of rotation and potential surgical applications were noted. A comparative study of the temporalis myo-osseous flap and free calvarial bone graft was then conducted in a rabbit model. Vascularization of the calvarial bone flap was confirmed by technetium scintigraphy performed on the first postoperative day. The uptake of fluorochrome labels immediately after transfer verified the adequacy of the periosteal circulation in maintaining viability and new osteoid formation throughout the full thickness of calvarial bone. The transplantation of free calvarial bone grafts was followed by necrosis of most cellular elements. This was demonstrated by an absence of fluorochrome uptake up to 19 days postoperatively and a predominance of empty lacunae and nonviable marrow

  17. Prefabricated fibula free flap with dental implants for mandibular reconstruction.

    Pauchet, D; Pigot, J-L; Chabolle, F; Bach, C-A

    2018-03-02

    Free fibula transplant is routinely used for mandibular reconstruction in head and neck cancer. Dental rehabilitation, the objective of mandibular reconstruction, requires the use of dental implants as supports for fixed or removable dentures. Positioning of fibular bone grafts and implants determines implant osseointegration and the possibilities of dental rehabilitation. Prefabrication of a fibula free flap with dental implants prior to harvesting as a free flap can promote implant osseointegration. The position of the implants must then be precisely planned. Virtual surgery and computer-assisted design and prefabrication techniques are used to plan the reconstruction and then reproduce this planning by means of tailored fibula and mandible cutting guides, thereby ensuring correct positioning of fibular bone fragments and implants. The prefabricated fibula free flap technique requires two surgical procedures (prefabrication and flap transfer) and precise preoperative planning. Prefabricated fibula free flap with dental implants, by improving the quality of osseointegration of the implants before flap transfer, extends the possibilities of prosthetic rehabilitation in complex secondary mandibular reconstructions. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  18. Use of various free flaps in progressive hemifacial atrophy.

    Baek, Rongmin; Heo, Chanyeong; Kim, Baek-kyu

    2011-11-01

    Romberg disease is an uncommon condition manifested by progressive hemifacial atrophy of the skin, soft tissue, and bone. Facial asymmetry with soft tissue deficiency in Romberg disease causes a significant disability affecting the social life and can bring about many psychological problems. The aim of surgical treatment is cosmetic amelioration of the defect. Several conventional reconstructive procedures have been used for correcting facial asymmetry. They include fat injections, dermal fat grafts, filler injections, cartilage and bone grafts, and pedicled and free flaps. We report our experiences with 11 patients involving 11 free flaps with a minimum 1-year follow-up. All patients were classified as having moderate to severe atrophy. The average age at disease onset was 4.5 years; the average duration of atrophy was 5.2 years. No patients were operated on with a quiescent interval of less than 1 year. The average age at operation was 20.1 years, ranging from 10 to 55 years. Reconstruction was performed using 4 groin dermofat free flaps, 4 latissimus dorsi muscle free flaps, and 3 other perforator flaps. To achieve the finest symmetrical and aesthetic results, several ancillary procedures were performed in 4 patients. These procedures included Le Fort I leveling osteotomy, sagittal split ramus osteotomy, reduction malarplasty and angle plasty, rib and calvarial bone graft, correction of alopecia, and additional fat graft. All patients were satisfied with the results. We believe that a free flap transfer is the requisite treatment modality for severe degree of facial asymmetry in Romberg disease.

  19. Island Latissimus Dorsi Muscle Flap and a Perforator Flap in Repairing Post-Gunshot Thoracic Spine CSF Fistula: Case Presentation

    Nangole F. Wanjala

    2015-01-01

    Full Text Available Persistent posttraumatic CSF fluid leakage may present a challenge to manage. Failure to address the leakage may result in complications such as meningitis, septicemia, radiculopathy, muscle weakness, and back pains. While the majority of the leakages may be managed conservatively, large dura defects as a result of gunshot wounds or motor vehicle accidents are best managed by surgical interventions. This may range from primary closure of the defect to fascial grafts, adhesive glues, and flaps. We present our experience with the use of flaps in a patient who had sustained such wounds in the thoracic spine. An island latissimus dorsal flap and a perforator fasciocutaneous flap were used to close the defect. Postoperatively the patient recovered well and the wounds healed without any complications.

  20. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles

    Sutthiphong Srigrarom

    2015-05-01

    Full Text Available In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings are able to produce sufficient lift to fly. The differences in the flapping aerodynamics were also detailed. Experiments on different wing designs and materials were conducted and a paramount wing was built for a test flight. The first prototype has a length of 46.5 cm, wing span of 88 cm, and weighs 161 g. A mechanism which produced a flapping motion was fabricated and designed to create flapping flight. The flapping flight was produced by using a single motor and a flexible and light wing structure. A force balance made of load cell was then designed to measure the thrust and lift force of the ornithopter. Three sets of wings varying flexibility were fabricated, therefore lift and thrust measurements were acquired from each different set of wings. The lift will be measured in ten cycles computing the average lift and frequency in three different speeds or frequencies (slow, medium and fast. The thrust measurement was measure likewise but in two cycles only. Several observations were made regarding the behavior of flexible flapping wings that should aid in the design of future flexible flapping wing vehicles. The wings angle or phase characteristic were analyze too and studied. The final ornithopter prototype weighs only 160 g, has a wing span of 88.5 cm, that could flap at a maximum flapping frequency of 3.869 Hz, and produce a maximum thrust and lift of about 0.719 and 0.264 N respectively. Next, we proposed resonance type flapping wing utilizes the near

  1. A lining vomer flap for palate pushback in unilateral cleft palate repair.

    Clavin, H D; Owsley, J Q

    1978-01-01

    A combinaation vomer mucoperiosteal flap and nasal floor mucoperiosteal flap is described which is used to achieve nasal coverage in unilateral cleft palate patients requiring pushbacks. A posteriorly based readily accessible vomer flap is raised on the cleft side and used as nasal lining for the palatal mucoperiosteal flap on the non-cleft side. On the cleft side, a symmetrically sized nasal floor flap is easily elevated under direct vision and used to cover the nasal aspect of the corresponding mucoperiosteal palatal flap.

  2. Cheating on the edge.

    Lee Alan Dugatkin

    2008-07-01

    Full Text Available We present the results of an individual agent-based model of antibiotic resistance in bacteria. Our model examines antibiotic resistance when two strategies exist: "producers"--who secrete a substance that breaks down antibiotics--and nonproducers ("cheats" who do not secrete, or carry the machinery associated with secretion. The model allows for populations of up to 10,000, in which bacteria are affected by their nearest neighbors, and we assume cheaters die when there are no producers in their neighborhood. Each of 10,000 slots on our grid (a torus could be occupied by a producer or a nonproducer, or could (temporarily be unoccupied. The most surprising and dramatic result we uncovered is that when producers and nonproducers coexist at equilibrium, nonproducers are almost always found on the edges of clusters of producers.

  3. Challenges in edge modeling

    Schneider, R.

    2007-01-01

    Fluid models like B2, UEDGE or EDGE2D are the working horses for scrape-off layer physics, both for design and experimental support. The concept of a numerical tokamak, aiming at a predictive code for ITER, triggers the need to re-assess the available tools and their necessary extensions. These additional physics issues will be summarized from a personal point-of-view. Depending on the specific problem, several complexity levels of scrape-off layer models will be needed. Therefore, a hierarchy of tools is necessary, which will be discussed. Furthermore, the experience existing in other scientific fields with multi-scale problems and modeling should be used. Here, the coupling of different length and time scales are in particular of interest for fusion problems. (author)

  4. Edge remap for solids

    Kamm, James R.; Love, Edward; Robinson, Allen C; Young, Joseph G.; Ridzal, Denis

    2013-12-01

    We review the edge element formulation for describing the kinematics of hyperelastic solids. This approach is used to frame the problem of remapping the inverse deformation gradient for Arbitrary Lagrangian-Eulerian (ALE) simulations of solid dynamics. For hyperelastic materials, the stress state is completely determined by the deformation gradient, so remapping this quantity effectively updates the stress state of the material. A method, inspired by the constrained transport remap in electromagnetics, is reviewed, according to which the zero-curl constraint on the inverse deformation gradient is implicitly satisfied. Open issues related to the accuracy of this approach are identified. An optimization-based approach is implemented to enforce positivity of the determinant of the deformation gradient. The efficacy of this approach is illustrated with numerical examples.

  5. Playing on the edge

    Cermak-Sassenrath, Daniel

    2018-01-01

    and specific ways. For instance, gambling for money, party and drinking games, professional play and show sports, art installations, violent and military propaganda computer games, pervasive/mobile gaming, live-action role playing, festivals, performances, and games such as Ghosting and Planking. It is argued......Everything gets more interesting, challenging, or intense the closer it gets to the edge, and so does play. How edgy can play become and still be play? Based on Huizinga’s notion of play, this chapter discusses how a wide range of playful activities pushes the boundaries of play in different...... that in concert with a number of characteristics that mark an activity as play, play is essentially a subjective perspective and individual decision of the player. Huizinga calls this attitude the play spirit, which informs a player’s actions and is in turn sustained by them. Edgy digital or mobile games do...

  6. Competing edge networks

    Parsons, Mark; Grindrod, Peter

    2012-01-01

    We introduce a model for a pair of nonlinear evolving networks, defined over a common set of vertices, subject to edgewise competition. Each network may grow new edges spontaneously or through triad closure. Both networks inhibit the other's growth and encourage the other's demise. These nonlinear stochastic competition equations yield to a mean field analysis resulting in a nonlinear deterministic system. There may be multiple equilibria; and bifurcations of different types are shown to occur within a reduced parameter space. This situation models competitive communication networks such as BlackBerry Messenger displacing SMS; or instant messaging displacing emails. -- Highlights: ► A model for edgewise-competing evolving network pairs is introduced. ► Defined competition equations yield to a mean field analysis. ► Multiple equilibrium states and different bifurcation types can occur. ► The system is sensitive to sparse initial conditions and near unstable equilibriums.

  7. Soft tissue reinforcement interposition flaps in hypospadias repair

    Singh R

    2007-01-01

    Full Text Available Purpose: To discuss the role and mechanism of action of soft tissue reinforcement interposition flaps (STRIFs in hypospadias repairs (reinforced hypospadiac urethroplasties. Materials and Methods: Between 2000-2005, 120 consecutive hypospadiacs (distal 85, mid 20, proximal 15, who underwent primary reinforced urethroplasties employing different types of STRIFs, were retrospectively analyzed. The STRIFs were highly vascular soft tissue pedicled flaps (devoid of epithelium interposed between neo-urethras and the covering skin to reinforce the neo-urethras against fistula formation. The STRIFs were harvested, without much donor site deformity, from: preputial skin, penile skin and scrotal skin by de-epithelialization. Those from Buck′s fascia, corpus spongiosum and tunica vaginalis are STRIFs without epithelium anyway, therefore do not need de-epithelialization. Redo urethroplasties and micropenises were not included. Seven patients were excluded because they had incomplete follow-up. The remaining 113 (distal 84, mid 17, proximal 12 were followed up for nine to 40 months for number, size, location, spontaneous closure and persistence of urethro-cutaneous fistula (UCF, and other complications with regard to the severity of hypospadias, method of neourethral re-construction, types of STRIFs employed and skin cover used. A total of 158 STRIFs and 124 skin covers were used in 113 hypospadiac urethroplasties. Results: The first surgery was curative in 74 (65% of 113 patients. In the remaining 39 (35%, various complications included 12 urethro-cutaneous fistulas (UCFs, 10 urethral strictures, six cases each of penile torsion and meatal stenosis and five cases each of superficial necrosis and poor cosmesis. Of these 39 patients, 25 (64% recovered with conservative treatment and 14 (36% required re-operation, i.e. UCFs and strictures in four cases each and penile torsion, meatal stenosis and dog-ears in two cases each. All the 12 UCFs were single

  8. Cannula-Assisted Flap Elevation (CAFE): a novel technique for developing flaps during skin-sparing mastectomies.

    Grant, Michael D

    2015-02-01

    One of the most challenging procedures in breast surgery is the skin-sparing mastectomy (SSM). Various techniques and incisions have evolved that characterize this procedure; however, what is common in all of them is the smaller the incision, the more difficult it is to develop the skin flaps. A procedure was developed that incorporates the use of liposuction cannulas (without suction) to create the skin flaps. The technique and results are described in this manuscript. From October of 2012 to April 2014, 289 mastectomies (171 patients) were performed using the CAFE procedure on women of all shapes and sizes. Postoperatively, no problems were experienced with flap viability using this technique. The main difference in side effects between the CAFE technique and other standard techniques for developing flaps in SSMs was more bruising than normal, but this resolved rapidly. The results for use of this technique were consistently impressive. The learning curve for this procedure is very short, especially for those who perform SSMs using sharp technique (scissors). Residents and fellows became proficient with the CAFE technique in a relatively short amount of time. Plastic surgeons were pleased with the cosmetic outcomes of their reconstructions that follow this type of mastectomy. Patients were extremely satisfied with their reconstructions as well. Incorporating the use of liposuction cannulas (without suction) makes the creation of flaps for SSM a relatively simple and rapid method. It is especially useful to assist in developing skin flaps with even the smallest of skin incisions.

  9. High Precision Edge Detection Algorithm for Mechanical Parts

    Duan Zhenyun

    2018-04-01

    Full Text Available High precision and high efficiency measurement is becoming an imperative requirement for a lot of mechanical parts. So in this study, a subpixel-level edge detection algorithm based on the Gaussian integral model is proposed. For this purpose, the step edge normal section line Gaussian integral model of the backlight image is constructed, combined with the point spread function and the single step model. Then gray value of discrete points on the normal section line of pixel edge is calculated by surface interpolation, and the coordinate as well as gray information affected by noise is fitted in accordance with the Gaussian integral model. Therefore, a precise location of a subpixel edge was determined by searching the mean point. Finally, a gear tooth was measured by M&M3525 gear measurement center to verify the proposed algorithm. The theoretical analysis and experimental results show that the local edge fluctuation is reduced effectively by the proposed method in comparison with the existing subpixel edge detection algorithms. The subpixel edge location accuracy and computation speed are improved. And the maximum error of gear tooth profile total deviation is 1.9 μm compared with measurement result with gear measurement center. It indicates that the method has high reliability to meet the requirement of high precision measurement.

  10. High Precision Edge Detection Algorithm for Mechanical Parts

    Duan, Zhenyun; Wang, Ning; Fu, Jingshun; Zhao, Wenhui; Duan, Boqiang; Zhao, Jungui

    2018-04-01

    High precision and high efficiency measurement is becoming an imperative requirement for a lot of mechanical parts. So in this study, a subpixel-level edge detection algorithm based on the Gaussian integral model is proposed. For this purpose, the step edge normal section line Gaussian integral model of the backlight image is constructed, combined with the point spread function and the single step model. Then gray value of discrete points on the normal section line of pixel edge is calculated by surface interpolation, and the coordinate as well as gray information affected by noise is fitted in accordance with the Gaussian integral model. Therefore, a precise location of a subpixel edge was determined by searching the mean point. Finally, a gear tooth was measured by M&M3525 gear measurement center to verify the proposed algorithm. The theoretical analysis and experimental results show that the local edge fluctuation is reduced effectively by the proposed method in comparison with the existing subpixel edge detection algorithms. The subpixel edge location accuracy and computation speed are improved. And the maximum error of gear tooth profile total deviation is 1.9 μm compared with measurement result with gear measurement center. It indicates that the method has high reliability to meet the requirement of high precision measurement.

  11. Rate-determining Step of Flap Endonuclease 1 (FEN1) Reflects a Kinetic Bias against Long Flaps and Trinucleotide Repeat Sequences.

    Tarantino, Mary E; Bilotti, Katharina; Huang, Ji; Delaney, Sarah

    2015-08-21

    Flap endonuclease 1 (FEN1) is a structure-specific nuclease responsible for removing 5'-flaps formed during Okazaki fragment maturation and long patch base excision repair. In this work, we use rapid quench flow techniques to examine the rates of 5'-flap removal on DNA substrates of varying length and sequence. Of particular interest are flaps containing trinucleotide repeats (TNR), which have been proposed to affect FEN1 activity and cause genetic instability. We report that FEN1 processes substrates containing flaps of 30 nucleotides or fewer at comparable single-turnover rates. However, for flaps longer than 30 nucleotides, FEN1 kinetically discriminates substrates based on flap length and flap sequence. In particular, FEN1 removes flaps containing TNR sequences at a rate slower than mixed sequence flaps of the same length. Furthermore, multiple-turnover kinetic analysis reveals that the rate-determining step of FEN1 switches as a function of flap length from product release to chemistry (or a step prior to chemistry). These results provide a kinetic perspective on the role of FEN1 in DNA replication and repair and contribute to our understanding of FEN1 in mediating genetic instability of TNR sequences. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Analytical model and stability analysis of the leading edge spar of a passively morphing ornithopter wing.

    Wissa, Aimy; Calogero, Joseph; Wereley, Norman; Hubbard, James E; Frecker, Mary

    2015-10-26

    This paper presents the stability analysis of the leading edge spar of a flapping wing unmanned air vehicle with a compliant spine inserted in it. The compliant spine is a mechanism that was designed to be flexible during the upstroke and stiff during the downstroke. Inserting a variable stiffness mechanism into the leading edge spar affects its structural stability. The model for the spar-spine system was formulated in terms of the well-known Mathieu's equation, in which the compliant spine was modeled as a torsional spring with a sinusoidal stiffness function. Experimental data was used to validate the model and results show agreement within 11%. The structural stability of the leading edge spar-spine system was determined analytically and graphically using a phase plane plot and Strutt diagrams. Lastly, a torsional viscous damper was added to the leading edge spar-spine model to investigate the effect of damping on stability. Results show that for the un-damped case, the leading edge spar-spine response was stable and bounded; however, there were areas of instability that appear for a range of spine upstroke and downstroke stiffnesses. Results also show that there exist a damping ratio between 0.2 and 0.5, for which the leading edge spar-spine system was stable for all values of spine upstroke and downstroke stiffnesses.

  13. Cutting Edge Localisation in an Edge Profile Milling Head

    Fernandez Robles, Laura; Azzopardi, George; Alegre, Enrique; Petkov, Nicolai

    2015-01-01

    Wear evaluation of cutting tools is a key issue for prolonging their lifetime and ensuring high quality of products. In this paper, we present a method for the effective localisation of cutting edges of inserts in digital images of an edge profile milling head. We introduce a new image data set of

  14. Long anterior urethral stricture: Reconstruction by dorsally quilted penile skin flap

    Mohammad Sayed Abdel-Kader

    2013-01-01

    Conclusion: Free penile skin flaps offer good results (functional and cosmetic in long anterior urethral stricture. Meticulously fashioned longitudinal, circular or spiral penile skin flaps could bridge urethral defects up to 15 cm long.

  15. Non-invasive tissue oximetry following unilateral DIEP-flap reconstruction: A pilot evaluation

    N.P.A. Vranken

    2017-06-01

    Conclusion: Continuous non-invasive tissue oxygen saturation is suitable for postoperative monitoring of DIEP-flaps, and StO2 pattern may aid in early identification of vascular compromise in DIEP-flaps.

  16. [The influence of estradiol on histomorphology of skin flaps with ischemia reperfusion injury].

    Jianlong, Wu; Ruixing, Hou; Guangliang, Zhou; Jihui, Ju

    2015-09-01

    To study the influence of estradiol on histomorphology of skin flaps with ischemia reperfusion injury. 48 adult male Wistar rats aged 12-14 weeks old, were randomly divided into control group (group I), ischemia-reperfusion group (group II), saline group (group III), estradiol group (group IV). Superficial epigastric artery axial flap, 3 cm x 6 cm in size, was made in the left lower quadrant abdominal of each rat. Flap model with ischemia-reperfusion injury was established by using the nondestructive micro vascular clamp to clamp the superficial epigastric artery. The general condition of the flap was observed after operation. At 7 days after operation, the survival rate of the flap was detected, the flaps were harvested to receive histology and ultrastructural observation. The neutrophils level of the superficial epigastric vein were tested. 7 days after operation, the survival rate of the flap in group IV was significantly higher than that in group II, III (P organization structure in flap.

  17. Paralytic Ectropion Treatment with Lateral Periosteal Flap Canthoplasty and Introduction of the Ectropion Severity Score

    Steven F. S. Korteweg, MD

    2014-05-01

    Conclusions: The ESS is a useful instrument to score the severity of paralytic ectropion. The periosteal flap canthoplasty is an effective procedure, with durable results in paralytic ectropion patients. The same periosteal flap can be used in a revision procedure.

  18. Anterior chamber gas bubble emergence pattern during femtosecond LASIK-flap creation.

    Robert, Marie-Claude; Khreim, Nour; Todani, Amit; Melki, Samir A

    2015-09-01

    To characterise the emergence pattern of cavitation bubbles into the anterior chamber (AC) following femtosecond laser-assisted in situ keratomileusis (LASIK)-flap creation Retrospective review of patients undergoing femtosecond LASIK surgery at Boston Laser, a private refractive surgery practice in Boston, Massachusetts, between December 2008 and February 2014. Patient charts were reviewed to identify all cases with gas bubble migration into the AC. Surgical videos were examined and the location of bubble entry was recorded separately for right and left eyes. Five thousand one hundred and fifty-eight patients underwent femtosecond LASIK surgery. Air bubble migration into the AC, presumably via the Schlemm's canal and trabecular meshwork, occurred in 1% of cases. Patients with AC bubbles had an average age of 33±8 years with a measured LASIK flap thickness of 96±21 μm. The occurrence of gas bubbles impaired iris registration in 64% of cases. Gas bubbles appeared preferentially in the nasal or inferior quadrants for right (92% of cases) and left (100% of cases) eyes. This bubble emergence pattern is significantly different from that expected with a random distribution (p<0.0001) and did not seem associated with decentration of the femtosecond laser docking system. The migration of gas bubbles into the AC is a rare occurrence during femtosecond laser flap creation. The preferential emergence of gas bubbles into the nasal and inferior quadrants of the AC may indicate a distinctive anatomy of the nasal Schlemm's canal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Clap-and-fling mechanism in a hovering insect-like two-winged flapping-wing micro air vehicle.

    Phan, Hoang Vu; Au, Thi Kim Loan; Park, Hoon Cheol

    2016-12-01

    This study used numerical and experimental approaches to investigate the role played by the clap-and-fling mechanism in enhancing force generation in hovering insect-like two-winged flapping-wing micro air vehicle (FW-MAV). The flapping mechanism was designed to symmetrically flap wings at a high flapping amplitude of approximately 192°. The clap-and-fling mechanisms were thereby implemented at both dorsal and ventral stroke reversals. A computational fluid dynamic (CFD) model was constructed based on three-dimensional wing kinematics to estimate the force generation, which was validated by the measured forces using a 6-axis load cell. The computed forces proved that the CFD model provided reasonable estimation with differences less than 8%, when compared with the measured forces. The measurement indicated that the clap and flings at both the stroke reversals augmented the average vertical force by 16.2% when compared with the force without the clap-and-fling effect. In the CFD simulation, the clap and flings enhanced the vertical force by 11.5% and horizontal drag force by 18.4%. The observations indicated that both the fling and the clap contributed to the augmented vertical force by 62.6% and 37.4%, respectively, and to the augmented horizontal drag force by 71.7% and 28.3%, respectively. The flow structures suggested that a strong downwash was expelled from the opening gap between the trailing edges during the fling as well as the clap at each stroke reversal. In addition to the fling phases, the influx of air into the low-pressure region between the wings from the leading edges also significantly contributed to augmentation of the vertical force. The study conducted for high Reynolds numbers also confirmed that the effect of the clap and fling was insignificant when the minimum distance between the two wings exceeded 1.2c (c = wing chord). Thus, the clap and flings were successfully implemented in the FW-MAV, and there was a significant improvement in the

  20. Flapping and flexible wings for biological and micro air vehicles

    Shyy, Wei; Berg, Mats; Ljungqvist, Daniel

    1999-07-01

    Micro air vehicles (MAVs) with wing spans of 15 cm or less, and flight speed of 30-60 kph are of interest for military and civilian applications. There are two prominent features of MAV flight: (i) low Reynolds number (10 4-10 5), resulting in unfavorable aerodynamic conditions to support controlled flight, and (ii) small physical dimensions, resulting in certain favorable scaling characteristics including structural strength, reduced stall speed, and low inertia. Based on observations of biological flight vehicles, it appears that wing motion and flexible airfoils are two key attributes for flight at low Reynolds number. The small size of MAVs corresponds in nature to small birds, which do not glide like large birds, but instead flap with considerable change of wing shape during a single flapping cycle. With flapping and flexible wings, birds overcome the deteriorating aerodynamic performance under steady flow conditions by employing unsteady mechanisms. In this article, we review both biological and aeronautical literatures to present salient features relevant to MAVs. We first summarize scaling laws of biological and micro air vehicles involving wing span, wing loading, vehicle mass, cruising speed, flapping frequency, and power. Next we discuss kinematics of flapping wings and aerodynamic models for analyzing lift, drag and power. Then we present issues related to low Reynolds number flows and airfoil shape selection. Recent work on flexible structures capable of adjusting the airfoil shape in response to freestream variations is also discussed.