Evaluation of the interaction between a new and the existing underground structures is one of the important problems in urban tunneling. In this work, using FLAC3D, four numerical models of single- and twin-tube tunnels in urban areas are developed, where the horizontal distance between the single- and twin-tube tunnels are varied. The aim is to analyze the effects of the horizontal dista...

It is reported in this article that Si nanowires can be employed as a positive template for the controllable electrochemical deposition of noble metal tube. The deposited tube exhibits good crystallinity. Scanning electron microscope and transmission electron microscope characterizations are conducted to reveal the growth process of metal tube, showing that the metal tube grows quasi-radially o...

The effective medium approach to radial fixed bed dispersion models, in which radial dispersion of mass is superimposed on axial plug flow, is based on a constant effective dispersion coefficient, DT. For packed beds of a small tube-to-particle diameter ratio (N), the experimentally-observed decrease in this parameter near the tube wall is accounted for by a lumped resistance located at the tub...

This paper describes the small-diameter monitored drift-tube detector construction at University of Michigan as a contribution to ATLAS Muon Spectrometer upgrade for high-luminosity Large Hadron Collider CERN. Measurements first 30 chambers built show that drift tube wire position accuracy meets specification 20 microns. The positions platforms alignment and magnetic field sensors are all insta...

We report the synthesis of aligned arrays of millimeter long carbon nanotubes (CNTs), from benzene and ferrocene as the molecular precursor and catalyst respectively, by a one-step chemical vapor deposition technique. The length of the grown CNTs depends on the reaction temperature and increases from ~85 µm to ~1.4 mm when the synthesis temperature is raised from 650 to 1100 °C, while the tube ...

Abstract Numerical simulation of the motion a Taylor gas bubble in heated small-diameter tube is carried out. Two models are used to describe dependence surface tension on temperature. In first model, decreases with temperature, and second, it increases, which corresponds pure water an aqueous surfactant solution. It shown that derivative sign affects thickness liquid film around bubble.

We present a new type of piezoelectric nanopositioner called KoalaDrive which can have a diameter less than 2.5 mm and a length smaller than 10 mm. The new operating principle provides a smooth travel sequence and avoids shaking which is intrinsic to nanopositioners based on inertial motion with sawtooth driving signals. In scanning probe microscopy, the KoalaDrive can be used for the coarse ap...

In this study, artificial neural networks have been used to model the effects of four important parameters consist of the ratio of the length to diameter, the ratio of the cold outlet diameter to the tube diameter, inlet pressure, and cold mass fraction on the cooling performance of counter flow vortex tube. In this approach, experimental data have been used to train and validate the neural net...

BACKGROUND Using a too big or a too small size of an endotracheal tube in pediatric patients would result in tracheal injury or insufficient ventilation. Determining the appropriate endotracheal tube size is important because using an inappropriate size can cause complications. This study was performed to predict the appropriate endotracheal tube size by measuring the transverse diameter of the...

J INTRODUCTION Tube feeding has been practiced for more than 400 years (1). In addition to feeding, gastrointestinal (GI) access can be used for decompression in cases of enteral obstruction. Temporary access can be achieved with a nasogastric (NG), oral gastric (OG), nasojejunal (NJ), or oral jejunal (OJ) feeding tube. These tubes can be placed “blindly” at the bedside, with the use of image g...