Intermixer

In a flask the chemist mixes 50g piperonal into 200mL glacial acetic acid, then adds 45mL nitroethane and 17g ammonium acetate. The solution is then refluxed 4 hours and takes on the color of yellow to yellow-orange. After 4 hours and cooling, yellowish crystals of p-nitropropene will spontaneously form. If not, the solution can be diluted with 50ml of dHjO and chilled in an ice bath for an hour to form the crystals with some slushy glacial acetic acid and water intermixed. The mass of crystals is broken up and plopped into a Buchner funnel to be vacuum filtered. The filter cake is washed with a little extra acetic acid or water. All of the filtrate is saved. 

Discredited Synthetics. There are several materials that have in the past been considered to be synthetics, but were found on closet examination not to deserve such a designation, being merely imitations. Examples include imitation coral, lapis la2uli, and turquoise, all made by ceramic processes. This same point has been raised (17) with respect to synthetic opal, which does contain some substances not present in natural opal and somewhat less water. However, the composition of natural opal is quite variable and is usually intermixed with significant amounts of rock-derived materials hence the synthetic designation is usually retained. 

Marl, an impure, soft, earthy, carbonate rock, contains varying amounts of clay and sand intermixed in a loosely knit crystalline stmcture. 

Planeta-iy Type. Paddles or whips of various configurations are mounted in an off-center head that moves around the central axis of a bowl or vessel. Material is mixed locally and moved inward from the bowl side, causing intermixing. This mixer handles dry materials or pastes. 

Although a great number of compound semiconductor devices make use of epitaxy to form the cote vertical stmcture of the device, ion implantation (qv) is a powerful tool in creating both horizontal and vertical modifications to a device. Ion implantation can be used to dope a semiconductor either fi- or / -type by using appropriate species. Implantation can also be used to render a region semi-insulating or to initiate multilayer intermixing. 

Intermixing. In some fabrication sequences it is desirable to cause the interdiffusion of semiconductor supedattices. This effect causes a... 

J) The extreme fineness of iadividual clay particles, which may be of colloidal size ia at least one dimension. Clay minerals are usually platy ia shape, and less often lathlike and tubular or scroU shaped (13). Because of this fineness clays exhibit the surface chemical properties of coUoids (qv) (14). Some clays possess relatively open crystal lattices and show internal surface colloidal effects. Other minerals and rock particles, which are not hydrous aluminosihcates but which also show colloidal dimensions and characteristics, may occur intimately intermixed with the clay minerals and play an essential role. 

For most rapid mixing, in addition to diffusive (fine-scale) mixing, there should be a means by which large groups of particles are intermixed. This can be accomphshed by either the convective or the shear mechanism. A ribbon mixer illustrates the former, whereas a plain tumbler gives the latter. 

The entire internal surface was covered with a layer of dark greasy deposit and slime intermixed with reddish-brown oxides (oxides were dark immediately upon removal from systems) (Figs. 3.19 and 3.20). Analysis showed tubercular contents were fairly acidic. 

Calcium carbonate makes up the largest amount of deposit in many cooling water systems (Fig. 4.16) and can be easily detected by effervescence when exposed to acid. Deposits are usually heavily stratified, reflecting changes in water chemistry, heat transfer, and flow. Corrosion may be slight beneath heavy accumulations of fairly pure calcium carbonate, as such layers can inhibit some forms of corrosion. When nearly pure, calcium carbonate is white. However, calcium carbonates are often intermixed with silt, metal oxides, and precipitates, leading to severe underdeposit attack. 

Figure 4.30S As in Fig. 4.30A. Note the light-colored deposits intermixed with bluish-green corrosion products.

Slime is a network of secreted strands (extracellular polymers) intermixed with bacteria, water, gases, and extraneous matter. Slime layers occlude surfaces—the biological mat tends to form on and stick to surfaces. Surface shielding is further accelerated by the gathering of dirt, silt, sand, and other materials into the layer. Slime layers produce a stagnant zone next to surfaces that retards convective oxygen transport and increases diffusion distances. These properties naturally promote oxygen concentration cell formation. 

Sulfides are intermixed with iron oxides and hydroxides on carbon steels and cast irons. The oxides are also produced in the corrosion process (Reaction 6.6). Although theoretical stoichiometry of 1 to 3 is often suggested between sulfide and ferrous hydroxide, empirically the ratio of iron sulfide to ferrous hydroxide is highly variable. Sulfide decomposes spontaneously upon exposure to moist air. Additionally, corrosion-product stratification is marked, with sulfide concentration being highest near metal surfaces. 

If force P is greater than zero, the particle will be in motion relative to the continuous phase at a certain velocity, w. At the beginning of the particle s motion, a resistance force develops in the continuous phase, R, directed at the opposite side of the particle motion. At low particle velocity (relative to the continuous phase), fluid layers running against the particle are moved apart smoothly in front of it and then come together smoothly behind the particle (Figure 14). The fluid layer does not intermix (a system analogous to laminar fluid flow in smoothly bent pipes). The particles of fluid nearest the solid surface will take the same time to pass the body as those at some distance away. 

In either laminar or turbulent flow, rotational eireulation of a proeessed material around its own hydraulie eenter in eaeh ehannel of the mixer eauses radial mixing of the material. All proeessed material is eontinuously and eompletely intermixed, virmally eliminating radial gradients in temperature, veloeity, and material eomposition. 

Maximum mixedness (Individual molecules are tree to move about and intermix). 

Frye, C. D., and Edidin, M., 1970. The rapid intermixing of cell surface antigens after formation of monse-hnman heterokaryons. of Cell... 

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