To minimize the flow-dependent effects caused by an endotracheal tube during impedance measurements, we recorded pressure inside the tube at its distal end. We used a commercial endotracheal tube with a lumen built into its wall with the opening located near the outlet of the tube. We characterized the effect of the tube by means of an effective transfer function (H). We measured H from 0.25-32...

In the present paper the heat exchange performance of a counter flow double-tube condenser for a ternary refrigerant mixture R407C, composed ofHFC32/HFC125/HFC134a, is calculated using a prediction method developed by the present authors. The axial distributions of vapor and liquid bulk mass fraction, temperature, heat flux, mass flux, etc., are obtained for both a smooth tube and a microfin tu...

This paper reports the thermal performance of a new cylindrical solar collector based on an experimental investigation with this difference that instead of the collector tube with absorbent coating, coil into a spiral copper tube is placed in the center of the collector. The spiral shape of the tube, heat transfer without disruption or increase the heat transfer area, is increasing. In this cas...

A novel fluid power actuator called Flat Ring Tube (FRT) is introduced in this paper. The mechanism of FRT is so simple that it only needs a urethane flat tube and water pressure power source. No valves or switches are required. Applying constant water pressure results in periodic oscillation of the tube. The frequency is proportional to the flow rate of water and inversely proportional to the ...

The low frequency noise from heat recovery steam generator (HRSG) makes dominant contribution to the noise on the boundary of plant, which generation mechanism is investigated in this presentation. The non-stationary flow field and aeroacoustic noise is studied with hybrid numerical simulation, which is comprised of CFD method based on Large Eddy Simulation (LES) and acoustic analogy by using F...

Concerns about the work of breathing imposed by the endotracheal tube have led clinicians to routinely use pressure support to overcome this resistive component. More recently, ventilator manufacturers have introduced systems to automatically overcome endotracheal tube resistance, regardless of tube diameter or patient demand for flow. Despite the theoretical advantages, neither method appears ...

The Rotary-Draw Bending (RDB) process is a distinguished process employed for the precision cold bending of a hollow tube with small radius bends using Numerical Control (NC) machines. This research presents an analytical model based on the power law hardening model for the RDB processing of rectangular thin tubes. Based on the constraints of the tube in the dies and its thinness, the plane str...

tellurium nanostructures have been prepared by physical vapor deposition method in a tube furnace. the experiments were carried out under argon gas flow at a pressure of 1 mbar. tellurium powder was evaporated by heating at 350°c and 430°c and was condensed on substrates at 110–250°c, in the downstream of argon gas flow. the products were characterized by field emission scanning electron micros...

Three-dimensional CFD simulations are carried out to investigate heat transfer and fluid flow characteristics of a four-row plain fin-and-tube heat exchanger using the Commercial Computational Fluid Dynamics Code ANSYS CFX 12.0. Heat transfer and pressure drop characteristics of the heat exchanger are investigated for Reynolds numbers ranging from 400 to 2000. Fluid flow and heat transfer are s...