background the forced oscillation technique (fot) is a non-invasive means of measuring respiratory resistance and reactance. we tested our hypothesis that endotracheal intubation would cause more substantial preoperative increases in fot parameters than a supraglottic airway device (sgd). methods forty patients requiring general anesthesia and mechanical ventilation for transurethral bladder tu...

In the Large Helical Device (LHD), the installation of a pair of ion cyclotron range of frequencies (ICRF) antennas from upper and lower ports is planned. These antennas are geometrically symmetrical and located side by side. By changing the current phase on the straps, the wave number parallel to the magnetic field line can be controlled. However, antenna impedances will also be changed and re...

This report concerns the inference of geometric and mechanical airway characteristics based on information derived from a single transient planar wave recorded at the airway opening. We describe a new method to simultaneously measure upper airway area and respiratory input impedance by performing dual analysis of a single pressure wave. The algorithms required to reconstruct airway dimensions a...

Alternating current impedance measurements have been made on several single marine eggs over the frequency range from 1 to 2500 kilocycles per second. The eggs were placed in the center of a short capillary made by heating the end of a 2 mm. thin walled glass tube until it nearly closed, and electrodes were placed in the sea water on each side of the egg. When it is assumed that the membrane co...

This study seeks to explain mechanisms responsible for the contour of pressure and flow waves and the pattern of vascular impedance in human systemic arteries. Pulsatile pressure and flow were recorded from the ascending aorta of seven patients undergoing open heart surgery and from the ascending aorta and other arteries of 17 patients at diagnostic catheterization. Ascending aortic pressure/fl...

The behavior of the longitudinal and transverse wakefields of short bunches in an -accelerating cavity has been examined. Computations of short time wakefields have been carried out using. T. Weiland’s computer program TBCI,l which integrates Maxwell’s Equations in the time domain. We present also our version of the diffraction model of the high frequency impedance of the cavity, a model origin...

A model for calculating the acoustic characteristics of 3-D vocal tract con guration is presented. A mode-matching technique and an impedance transformation are used to calculate the higher-order modes in this model where both propagative and evanescent higher-order modes are considered. A cascaded structure of rectangular acoustic tubes is introduced as an approximation of the real vocal tract...

The concept of the surface impedance is applicable to the case, when obstacles on the surface of a vacuum chamber are small compared to characteristic dimensions of the problem. We apply this concept to the calculation of a synchronous mode that can propagate in a tube with slightly corrugated walls. We also show that such a mode can propagate in a pipe with a rough surface, or a perforated pip...

Imperialist competitive algorithm (ICA) and particle swarm optimization (PSO) are two approaches for determining the solution of any objective function, but they use different strategies. Therefore, a comparison of their performance is required. The comparison is made on the basis of test functions, and then both techniques are applied to an eddy current non-destructive evaluation system to rec...

A mathematical analysis has been presented to study the effect of a mild stenosis on blood flow characteristics with the representation of blood by couple stress fluid. The equations governing the flow of the proposed model are solved and closed form expressions for the blood flow characteristics, namely, dimensionless resistance to flow and wall shear stress at maximum height of the stenosis a...