In a duct-flute such as the recorder, steady-state oscillations are controlled by two parameters, the blowing pressure and the frequency of the acoustic resonator. As in most feedback oscillators, the oscillation amplitude is determined by gain-saturation of the amplifier, and thus it cannot be controlled independently of blowing pressure and frequency unless the feedback loop is opened. In thi...

The study of acoustics is rooted in the origins of physics, yet the dynamics of flue-type instruments are still only qualitatively understood. Our group has developed a measurement system, the Acoustic VNA, which can precisely determine acoustic wave amplitudes of the lowest mode propagating in a cylindrical waveguide. I used the AVNA to study a musical oscillator, the tenor recorder. The recor...

Taguchi Method is explained in brief and one of the textile processes, called spinning process, is optimised by using Taguchi method for manufacturing optimum packing density of different technologies yarns. The effect of process variables like: lap hank, card draft, draft/doublings and drafts at speed frame, ring frame, rotor and air-jet spinning machine on packing density parameters of respec...

The purpose of this study was to investigate the effect of the structure of reactive dye on cotton ink-jet printing. Cotton fabric was printed upon with three commercial cellulosic reactive dyes which are based on the similar chromophore and possess different numbers of reactive and anionic groups. Colour yield and absorbed dye fixation of the printed cotton were evaluated at various pHs. The i...

introduction : the aim of this study was to examine and compare the apical sealing ability of ah26, ah plus and ah plus jet using a fluid filtration model. materials and methods : 70 single-rooted teeth were dissected from the cement-enamel junction. canals were prepared with protaper rotary system and manual k files and irrigated with 5.25% naocl and 17% edta. ten teeth were assigned as contro...

This paper examines the process of transition to turbulence within an accelerating planar liquid jet. By calculating the propagation and spatial evolution of disturbance wave packets generated at a nozzle where the jet emerges, we are able to estimate break–up lengths and break–up times for different magnitudes of acceleration and different liquid to air density ratios. This study uses a basic ...