Uncoating

It is known that even condensed films must have surface diffusional mobility Rideal and Tadayon [64] found that stearic acid films transferred from one surface to another by a process that seemed to involve surface diffusion to the occasional points of contact between the solids. Such transfer, of course, is observed in actual friction experiments in that an uncoated rider quickly acquires a layer of boundary lubricant from the surface over which it is passed [46]. However, there is little quantitative information available about actual surface diffusion coefficients. One value that may be relevant is that of Ross and Good [65] for butane on Spheron 6, which, for a monolayer, was about 5 x 10 cm /sec. If the average junction is about 10 cm in size, this would also be about the average distance that a film molecule would have to migrate, and the time required would be about 10 sec. This rate of Junctions passing each other corresponds to a sliding speed of 100 cm/sec so that the usual speeds of 0.01 cm/sec should not be too fast for pressurized film formation. See Ref. 62 for a study of another mechanism for surface mobility, that of evaporative hopping. 

Caffeine is extracted from beverages by a solid-phase microextraction using an uncoated fused silica fiber. The fiber is suspended in the sample for 5 min and the sample stirred to assist the mass transfer of analyte to the fiber. Immediately after removing the fiber from the sample it is transferred to the gas chromatograph s injection port where the analyte is thermally desorbed. Quantitation is accomplished by using a C3 caffeine solution as an internal standard. 

Caffeine in coffee, tea, and soda is determined by a solid-phase microextraction using an uncoated silica fiber, followed by a GC analysis using a capillary SPB-5 column with an MS detector. Standard solutions are spiked with G3 caffeine as an internal standard. 

The abihty of organically modified ceramics based on alumina, zkconia, titania, or siUca (and mixtures of each) to function as abrasion-resistant coatings has also been studied (62). Eor example, polycarbonate, when coated with an epoxy—aluminosihcate system, experiences a significant reduction in the degree of hazing induced by an abrader, as compared to uncoated polycarbonate. 

In a vacuum, uncoated molybdenum metal has an unlimited life at high temperatures. This is also tme under the vacuum-like conditions of outer space. Pure hydrogen, argon, and hehum atmospheres are completely inert to molybdenum at all temperatures, whereas water vapor, sulfur dioxide, and nitrous and nitric oxides have an oxidizing action at elevated temperatures. Molybdenum is relatively inert to carbon dioxide, ammonia, and nitrogen atmospheres up to about 1100°C a superficial nitride film may be formed at higher temperatures in the latter two gases. Hydrocarbons and carbon monoxide may carburize molybdenum at temperatures above 1100°C. 

Copper and nickel can be alloyed with zinc to form nickel silvers. Nickel silvers are ductile, easily formed and machined, have good corrosion resistance, can be worked to provide a range of mechanical properties, and have an attractive white color. These alloys are used for ornamental purposes, as sHverplated and uncoated tableware and flatware in the electrical iadustry as contacts, connections, and springs and as many formed and machined parts (see Electrical connectors). 

Sugar coating is time-consuming, requires skilled operators, and increases the tablet weight, sometimes to twice that of the uncoated core. 

For prolonged action therapy, granular-sized encapsulated particles, ie, beads, are used and can be both uncoated or coated. The uncoated beads provide the initial dose the others are made to dissolve at various rates depending on the coating type and thickness. 

Silk (qv) suture is made from the threads spun by the silkworm Bombjx mori. The fiber is composed principally of the protein fibroin and has a natural coating composed of sericin gum. The gum is usually removed before braiding the silk yams to make sutures in a range of sizes. Fine silk sutures may be made by simply twisting the gum-coated silk yams to produce the desired diameter. White silk is undyed. Silk is either dyed black with logwood extract or blue with D C Blue No. 9. The suture may be uncoated or coated either with high molecular weight polydimethylsiloxane or with wax. 

Steel [52013-36-2] suture is made from 316-L stainless steel wire. The suture may be monofilament, known as fixation wire, or multifilament twisted wires. The steel is heat-treated to improve ductility. The multifilament strands are either uncoated, or coated with Tefion (polytetrafiuoroethylene) or Tefion-fiuorinated ethylene—propylene copolymer. 

Both amantadiae and rknantadiae have been found to reduce the duration of influenza A-iaduced fever and malaise, and to lessen viral shedding. Prophylactic treatment has been recommended for high risk patients (95). It has been suggested that, ia the presence of amantadine, the influenza vims attaches normally to cells, but once iaside the ceU the vims fails to initiate repHcation. Thus amantadine appears to inhibit the initiation of transcription at an early stage between uncoating and viral-specific RNA synthesis (96). 

The Sierra product line contains secondary and minor elements. Sierrablen products, ie, blends of Osmocote with uncoated nutrients for quicker... 

Blended with uncoated nutrients. Also contains IBDU. 

Flexible PCBs are produced in large quantities, usually consisting of polyester, polyimide, and polyimide—Teflon films. Both foil-laminated and uncoated versions are available. A modem complex multilayer board after final fabrication is shown in Figure 2. 

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