Core stream

Feind (F2) has shown that, in countercurrent flow of the film and gas stream, there is a zone at low gas velocities in which the film thickness is hardly altered by the gas stream. At larger gas flow rates the film thickness increases this point of initial increase of the film thickness occurs at lower gas Reynolds numbers as the film Reynolds number is increased, as might be expected. With countercurrent flow of liquid core streams, when the interfacial drag is much larger than with gas cores, Strang et al. (Sl3) and Treybal and Work (T16) have noted much larger increases in the film thicknesses. 

Core stream The core stream is the stream-within-a-stream that has been injected into the center of the sheath stream and is maintained there by the hydrodynamic considerations of laminar flow at increasing velocity. The core contains the sample particles that are to be analyzed in the flow cytometer. If the sample is injected too rapidly, the core stream widens and particles may be unequally illuminated. In addition, with a wide core stream, coincidence events are more likely. 

Event An event is the name given by flow cytometrists to what most people would call a cell. A flow cytometer associates all light signals that occur without a gap in time with a single event and stores the intensities of the light in association with that event in the data file. If cells (or other particles) are spaced appropriately in the core stream and do not coincide in the laser beam, then an event is the same as a cell or particle. If cells do coincide in the laser beam, then an event may be two or more cells. 

Figure 5.1 Tab/chevron mixing enhancement study for separate flow nozzles the plot above shows the resulting integrated mixing extent of core stream, 4> = (To — 0,fan)/(To...

When these ripples grow and eventually detach from the main liquid core/ stream, they are considered atomized. The morphology of these individual droplets is unique and their initial shape has a profound effect on their subsequent secondary atomization, discussed in the following section. 

Air Jet spinning n. A spinning system in which yarn is made by wrapping fibers around a core stream of fibers with compressed air. In this process, the fibers are drafted to appropriate sliver size, then fed to the air jet chambers where they are twisted, first in one direction, then in the reverse direction in a second chamber. They are stabilized after each twisting operation. 

Figure 10.33. Effect of varying the feed rate of the core stream on the average fiber diameter of the core/shell nanofiber with a fitc-BSA/polycaprolactone core and a PEG shell [131]...

Figure 7.9 shows the working principle of the formation of this type of liquid microlens with different lens curvatures in the expansion chamber achieved by tuning the flow rates of the three liquid streams. The configuration of the liquid lens was controlled hydrod)mamically through the flow rates of the three streams. The central, core stream had a flow rate of 14)- The other two (left and right) cladding streams had flow rates of Vai and respectively. 

Li et al. presented a similar design of a circular chamber for lens curvature, adjusted by the combined effects of pressure and electro-osmosis [17]. Figure 7.14 shows the concept. Two cladding streams (fluid 1 and fluid 3) were electrically conducting with high electro-osmotic mobility the core stream (core fluid 2) was non-conducting with low electro-osmotic mobility. 

The second step is to disperse the core material being encapsulated in the solution of shell material. The core material usually is a hydrophobic or water-knmiscible oil, although soHd powders have been encapsulated. A suitable emulsifier is used to aid formation of the dispersion or emulsion. In the case of oil core materials, the oil phase is typically reduced to a drop size of 1—3 p.m. Once a suitable dispersion or emulsion has been prepared, it is sprayed into a heated chamber. The small droplets produced have a high surface area and are rapidly converted by desolvation in the chamber to a fine powder. Residence time in the spray-drying chamber is 30 s or less. Inlet and outlet air temperatures are important process parameters as is relative humidity of the inlet air stream. 

BWRs operate at ca 7 MPa (70 bar) and 288°C. Some of the coolant passing through the core is converted into steam which is separated from the water with equipment inside the reactor vessel (see Eig. 2). The steam goes to the turbine generator while the water is recirculated back to the bottom of the core. A side stream is continuously purified using deminerali2ers and filters to control the water quality of the reactor water. EuU-flow condensate deminerali2ers... 

Air-Suspension Coa.ting. The Wurster process utilizes a cylindrical chamber in which the cores are suspended in a controlled stream of air. Film coatings are appHed by introducing the coating solution into the airstream, where the solvent evaporates quickly. The process is much quicker than film coating however, care must be taken to avoid destmction of the cores by attrition in the air stream. 

The fuel for the Peach Bottom reactor consisted of a uranium-thorium dicarbide kernel, overcoated with pyrolytic carbon and silicon carbide which were dispersed in carbon compacts (see Section 5), and encased in graphite sleeves [37]. There were 804 fuel elements oriented vertically in the reactor core. Helium coolant flowed upward through the tricusp-shaped coolant channels between the fuel elements. A small helium purge stream was diverted through the top of each element and flowed downward through the element to purge any fission products leaking from the fuel compacts to the helium purification system. The Peach... 

Another process, the Barton process, is based on molten lead. The core of such a device is the "Barton reactor", a heated pot that is partly filled with molten lead. It is continuously refilled by a fine stream of molten lead. Fine droplets of lead are produced by a fast rotating paddle that is partly immersed under the surface of the molten lead within the "Barton reactor". The surface of each droplet is transformed by oxidation into a shell of PbO by an airstream that simultaneously carries away the oxidized particles if they are small enough otherwise, they fall back into the melt and the process is repeated. Thus the airstream acts as a classifier for particle size. 

Weld line With moldings that include openings (holes), problems can develop. In the process of filling a cavity the flowing melt is obstructed by the core, splits its stream, and surrounds the core. The split stream then... 

Accumulation of metals in the core sampled in the northern Lagoon, relative to the industrial core, are about 5 times lower for mercury and comparable for the other two metals. Metals reaching this area of the Lagoon are carried by fresh water streams from the basin. A very high number of small productions, whose environmental impact has not yet been adequately evaluated, contribute to this pollution. 

The D-O events are far too rapid to be caused by insolation changes, and they most likely result from changes in ocean circulation. Their prominence and clarity in the Greenland cores relative to the Antarctic ones is due to the proximity of Greenland to the sites of deep-water formation in the North Atlantic and the tremendous amount of heat being delivered to them by the Gulf Stream (Broecker and Denton, 1989). 

Recent development of the use of reversed micelles (aqueous surfactant aggregates in organic solvents) to solubilize significant quantities of nonpolar materials within their polar cores can be exploited in the development of new concepts for the continuous selective concentration and recovery of heavy metal ions from dilute aqueous streams. The ability of reversed micelle solutions to extract proteins and amino acids selectively from aqueous media has been recently demonstrated the results indicate that strong electrostatic interactions are the primary basis for selectivity. The high charge-to-surface ratio of the valuable heavy metal ions suggests that they too should be extractable from dilute aqueous solutions. 

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