A high-sensitivity, low-cost, ultrathin, hollow fiber micro bubble structure was proposed; such a bubble can be used to develop a high-sensitivity strain sensor based on a Fabry-Perot interferometer (FPI). The micro bubble is fabricated at the fiber tip by splicing a glass tube to a single mode fiber (SMF) and then the glass tube is filled with gas in order to expand and form a micro bubble. Th...

A ferroelectric cathode is employed for the first time as the electron-beam source in a microwave amplifier tube. A PLZT 12/65/35 ferroelectric ceramic with a high dielectric constant ( 4000) is used in a form of a hollow cathode. The tube is operated in poor vacuum conditions (2 10 Torr) at room temperature, in a mechanism of a cyclotron-resonance maser amplifier. The device operates near the ...

To analyze the influence of tapered form two upper vertices a rectangular cube placed in channel and impact insertion hollow center obstacle, three-dimensional study was executed using K-ω SST turbulence model. Different models were presented to examine features flow with Reynolds number Re=4×104. The kinetic energy, 2D 3D time-averaged streamlines, trace-lines, streamwise velocity profiles, pr...

Hollow-core negative-curvature fibres have been the focus of current research, but how to reduce loss hollow-core is a serious problem. This paper proposes new structure fibres, that numerically simulated using finite-element method, and compared with simulation results conjoined-tube negative curvature (CTNCFs) nested anti-resonant nodeless (NANFs). The show that, LP01 mode can reach 0.003694 ...

Abstract: In this paper, the forming process of a central hub by radial-forward extrusion is analyzed by using the finite element software, ABAQUS. Radial-forward extrusion is used to produce hollow parts that generally feature a central hub with radial protrusions. Effective design factors such as mandrel diameter, die corner radius, die fillet radius, mandrel corner radius, tube wall thick...

During the passage of a tube from nostril to trachea certain difficulties may be encountered. The anterior nasal opening may be unusually narrow, there may be a septal deflection or spur, or an inferior turbinate;; may be tiresomely over-sized. On such occasions, of course, the effect of rotation of the tube is tested, the other nostril is tried, or a narrower^ tube used. However, a little beyo...

To the Editor:—In the face of difficult intubation, it is sometimes useful to insert a small-diameter introducer through the laryngeal aperture in the trachea and then pass the endotracheal tube over it. We report a modification of this technique using the Univent bronchial-blocker tube (Fuji System, Tokyo, Japan) in a patient with unanticipated difficult intubation. A 60-yr-old, 67-kg man with...

This paper investigates the propagation of an air finger into a fluid-filled, axially uniform tube of elliptical or rectangular cross section with transverse length-scale a and aspect ratio α. Gravity is assumed to act parallel to the tube’s axis. The problem is studied numerically by a finite-element-based direct solution of the freesurface Stokes equations. In rectangular tubes, our results f...