Pressure tube, schematic representation

Fig. 9.6. Schematic representation of die BEST system (Brnker Biospin see also [21]). 1, Bottle with transport liquid 2, dilutor 402 single syringe (5mL) with 1100 iL tube 3, dilutor 402 3-way valve 4, sample loop (250-500 pL) 5, 6-way valve (standard version) loading sample 6, 6-way valve (standard version) injecting sample 7, injection port 8, XYZ needle 9, rack for sample vials 10, rack for recovering vials 11, rack for washing fluids and waste bottle (3 glass bottles) 12, external waste bottle 13, flow probe with inner lock container 14, inert gas pressure canister for drying process.

The model is based on the schematic representation of the commercial reactor shown in Figure le. The wafers are supported concentrically and perpendicular to the flow direction within the tube. The heats of reaction associated with the deposition reactions are small because of the low growth rates obtained with LPCVD ( 2 A/s). Furthermore, at high temperatures (1000 K) and low pressures (100 Pa), radiation is the dominant heat-transfer mechanism. Therefore, temperature differences between wafers and the furnace wall will be small. This small temperature difference eliminates the need for an energy balance. Moreover, buoyancy-driven secondary flows are unlikely. In fact, because of the rapid diffusion, the details of the flow field... 

Figure 14.4 Schematic representation of an apparatus for FVP As with all high vacuum work, care must be taken. After all of the substrate has passed through the hot tube, turn off the furnace and allow to cool to room temperature (still under vacuum). Then turn off the pump and admit nitrogen to atmospheric pressure. Remove the traps to a fume cupboard and allow to warm to room temperature, and work up in the usual way. If the desired product is unstable towards air, water, or is simply very reactive, then a more sophisticated pyrolysis system might be required, and more elaborate work up procedures used.

Figure 13.14 Schematic representation of pressure flow in a capillary tube.

The flow of liquid caused by electro-osmosis displays a pluglike profile because the driving force is uniformly distributed along the capillary tube. Consequently, a uniform flow velocity vector occurs across the capillary. The flow velocity approaches zero only in the region of the double layer very close to the capillary surface. Therefore, no peak broadening is caused by sample transport carried out by the electro-osmotic flow. This is in contrast to the laminar or parabolic flow profile generated in a pressure-driven system, where there is a strong pressure drop across the capillary caused by frictional forces at the liquid-solid boundary. A schematic representation of the flow profile due... 

Fig. 4.20 A schematic representation of two different approaches to high-pressure NMR (a) a pressurizable sample tube, and (b) a dedicated pressurizable NMR probe.

A schematic representation of the most advanced set-up, based on the latest scientific findings, the MPTl from LAUDA, is shown in Fig. 5.12. The air coming from a micro-compressor flows first through the flow capillary. The air flow rate is determined by measuring the pressure difference at both ends of the flow capillary with the electric transducer PSl. Thereafter the air enters the measuring cell. The excess air pressure in the system is measured by a second electric sensor PS2. In the tube which leads the air to the measuring cell, a sensitive microphone is placed. 

The compartments indicated in Figure 5.57a are a schematic representation of reverse osmosis process. In practice, the reverse osmosis process is conducted in a tubular configuration system (Figure 5.57b). Raw waste water flows under high pressure (greater than osmotic pressure) through an inner tube made... 

Schematic representation of a pressure tube of the RBMK-1000 reactor. The pressure tube contains two fuel elements (above and below). A fuel element consists of a bundle of 18 fuel rods. The pressure tube houses the stream of cooling water. The sketch is not to scale the diameter of the pressure tube is 88 mm, its length is a total of 22 m, of which 9 m are above the core and 5 m are below and contain no fuel. The pressure tube is surrounded by graphite, which serves as a moderator for the neutrons. The number of such pressure tubes forming the reactor core is 1,661 (GRS 1987 GRS 1996)...

The maximum bubble pressure technique is the most useful technique for measuring adsorption kinetics at short times, particularly if a correction for the so-called "dead time , x, is made. The dead time is simply the time required to detach the bubble after it has reached its hemispherical shape. A schematic representation of the principle of maximum bubble pressure is shown in Fig. 3.7, which shows the evolution of a bubble at the tip of a capillary. The figure also shows the variation of pressure p in the bubble with time. At t = 0 (initial state), the pressure is low (note that the pressure is equal to 2y/r since r of the bubble is large, p is small). At t = x (smallest bubble radius that is equal to the tube radius) p reaches a maximum. At t = x, (detachment... 

The most common flow reactor consists of a quartz flow tube inside a furnace a schematic representation of a flow tube is shown in Figure 3.2. The reactor is split into temperature zones, thereby estabUshing a temperature gradient across the flow tube. A carrier gas is introduced at the high-temperature end, while pumping occurs at the low-temperature end. The source materials are placed in a crucible upstream (zone A) from the nanowire collection (zone B), which is maintained at a lower temperature than zone A. The temperature and pressure in zone A must be balanced such that subUmation or vaporization of the source materials is fadli-tated. The geometry and temperature differential of the flow reactor lead to the condensation of source materials on the substrate. The temperature in zone B... 

Fig. 14.2 Schematic representation of a classical displacement calorimeters [69]. (a annular heater b Peltier cooling unit c inlet valve d injection tube e stirrer,/ thermistor g stirrer gland h solution outlet i inlet valve control j outlet to pipette k by-pass outlet.) and of b modified calorimeter [19] a pressure transducer b gas injection device c calorimeter d pipette e carbon dioxide reservoir tank)...

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