Tapered channel

Eig. 1. Parts of an extmder A, screw B, barrel C, heater D, thermocouple E, feed throat E, hopper G, thmst bearing H, gear reducer 1, motor , deep channel feed section K, tapered channel transition section and L, shallow channel metering section (15). 

The wodd s total capacity of grid-coimected electric power derived from wave energy is less than half a megawatt, distributed among several demonstration plants. The largest unit, the 350-kWe Tapered Channel plant in Norway, uses the hydropower approach. The plant was developed by Norwave AS and has operated continuously since 1986. Based on this durabiUty, two commercial orders were placed from other parts of the wodd. 

Norway built a wave energy station on the coast near Bergen in 1985. It combined an OWC with a Norwegian device called aTapchan (TAPered CHANnel). The waves move up a concrete slope where they fill a reservoir. As the water flows back to the ocean, it drives a turbine generator. 

Hence, for a constant channel depth we can determine the length of the channel required to melt the solid bed from eqn. (6.324). For a tapered channel of constant taper, eqn. (6.322) can be written as... 

In another report, an on-chip chamber containing a capture matrix was used for sample cleanup. A 2- dL unpurified sample is concentrated into a smaller volume ( 10 nL), and this yields a volumetric concentration factor of 200. Longer residence time can be achieved by using a doubly tapered chamber. Here, the electric field is 10-fold lower within the chamber than within the tapered channel. So, a high-field (fast) sample introduction is followed by a low-field (slow) sample flow past the capture matrix, increasing the residence time so that the binding kinetics are dominant over electromigration [971]. 

To increase the absorbance detection sensitivity, both a collimating lens and a detection slit have been used in a PDMS chip to reduce collection of scattered light [707], An improved S/N ratio was also obtained by using tapered channel waveguides as the collimators as well as the elliptical lens for absorbance detection [708],... 

The lubrication approximation facilitates solutions to flow problems in complex geometries, where analytical solutions either cannot be obtained or are lengthy and difficult. The utility of this approximation can well be appreciated by comparing the almost exact solution of pressure flow in slightly tapered channels to that obtained by the lubrication approximation. 

Finally, as pointed out earlier, extruder screws have tapered channel sections. The various shaped pressure profiles that can be obtained in simple non-parallel plate geometry explain the experimentally observed pressure profiles in screw extruders. For example, in a common metering screw (with a constant channel depth feed section, followed by a tapered section and a constant channel depth metering section), under normal conditions the pressure profile exhibits a maximum in the tapered section with the pressure dropping in the metering section to the die pressure. 

Without too much difficulty, we can extend the model to any screw design consisting of constant depth channels, and moderate tapers by using the taper correction factors of Eq. 6.4-4 separately for each section, and adding up the pressure drops (rises) according to Eq. 9.2.2. Thus, for a tapered channel, the drag and pressure flow terms are multiplied by the expressions 2/(1 + 0) and 2/ 0(l + CoX respectively, where 0 = Hq/H, with Hq... 

Comparing Eq. 9.3-32 to Eq. 9.3-30, we note that the length of melting in a tapered channel is always shorter than in a channel of constant depth. 

Fig. 1 Different methods for worm immobilization on a microfluidic platform (a) tapered channel array [21] (b) microvalves [26] and (c) suction channel array [27]...

Debbaut, B., Dooley, J., Flow of a Low Density Polyethylene In Straight and Tapered Channels Experiments and 3-D Finite Element Simulation, Xlll-th International Conference on Rheology, Cambridge, UK, 2, 170 (2000)... 

Refractive Index In a Cross Section of a Tapered Channel Waveguide... 

For melts which cause stringing, there are open nozzles with a mini-torpedo (Husky) located at the entrance to the taper channel, i.e., at the point where the sprue is broken away. 

Specimens can be exposed in the pressurizer, in holders in the line just beyond the pump outlet, and in the core. The specimens in the core inside the tapered-channel holder and in the annulus around it are exposed to the solution in which fissioning is taking place and to direct pile radiation. Duplicate specimens in the in-line holders are exposed to the same solution in the absence of the fissioning and direct pile radiation. As in the out-of-pile loops discussed previously, the tapered-channel coupon holders are used to study velocity effects. The core specimen holder is shown in place in Fig. 5-7. Figure 5-8 is a photograph of a core corrosion " pecimen assembly in which can be seen coupled coupons on a rod assembly, as well as coupons in the tapered-channel holder and stress specimens in the core annulus. Although not shown, impact and tensile specimens are also sometimes exposed in the core annulus. 

Tapered channel Straight channel across straight channel... 

For a tapered channel of constant taper, which is usually... 

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