Helical ribbons with pitch angles of either 11 degrees or 54 degrees self-assemble in a wide variety of quaternary surfactant-phospholipid/fatty acid-sterol-water systems. By elastically deforming these helices, we examined their response to uniaxial forces. Under sufficient tension, a low pitch helix reversibly separates into a straight domain with a pitch angle of 90 degrees and a helical dom...

In this work, the aerodynamic performance and optimization of a vertical-axis wind turbine with high tip-speed ratio are theoretically studied on basis two-dimensional airfoil theory. By dividing rotating plane into upwind downwind areas, relationship among angle attack, azimuth, pitch angle, is derived using quasi-steady model, loads then obtained. applying polynomial approximation to function...

This paper describes the modeling of the various components in a pitch controlled wind energy system and the design of the pitch controller, and discusses the response of the pitch-controlled system to wind velocity variations. The investigated pitch control system was observed to have a large output power variation and settling time. The pitch function provides full control over the mechanical...

Progress in aircraft designs heavily depend on Automatic Flight Control System (AFCS). In this work a fuzzy sliding mode controller is designed as a supervisory controller in aircraft pitch control systems and different control strategies to model a pitch controller based on design a pitch angle control in autopilot are invistigated. A performance evaluation based on time response specification...

The purpose of this investigation was to create a flatfoot model and reconstruct the deformity with a novel static medial ligamentous complex (MLC) and to evaluate its ability to correct talar head subluxation and the radiographic flatfoot deformity. Four pairs of matched cadaveric specimens were sectioned to create a severe flatfoot model. Cyclic preconditioning and axial loading was applied t...

Nomenclature C = chord length, m C T = thrust coefficient f = flapping frequency, Hz h tip = plunge amplitude at the wing tip, m k = ωC∕U ∞ , reduced frequency l span = wingspan, m Re = U ∞ C∕ν, Reynolds number r z = z-directional distance away from the wing tip, m S wing = wing area, m 2 St = fh tip ∕U ∞ , Strouhal number U ∞ = freestream velocity, m∕s ν = kinematic viscosity of fluid, m 2 ∕s ...

The cosmic noise absorption (CNA) is compared with the precipitating electron flux for 19 events observed in the morning sector, using the high-resolution data obtained during the conjugate observations with the imaging riometer at Poker Flat Research Range (PFRR; 65.11 N, 147.42 W), Alaska, and the low-altitude satellite, NOAA 12. We estimate the CNA, using the precipitating electron flux meas...