Filament configurations

There are two filament configurations used in thermal ionization singlefilament and multifilament multifilament configurations can have two or three individual filaments. All these configurations are illustrated in Fig. 1.4. The choice... 

In the single-filament configuration, the same surface serves both to evaporate and to ionize the sample. It is more efficient than multifilament configurations... 

The unexpected results of Sablani et al. [17] (i.e., less turbulence with smaller spacer thickness) may be best explained by an excellent paper by Schwinge et al. [82], The latter employed computational fluid dynamics (CFD) in a study of unsteady flow in narrow spacer-filled channels for spiral-wound membrane modules. The flow patterns were visualized for different filament configurations incorporating variations in mesh length and filament diameter and for channel Reynolds numbers, Re y, up to 1000. The simulated flow patterns revealed the dependence of the formation of... 

Hause G, Hause B, van Lammeren AAM 1992. Microtubular and actin filament configurations during microspore and pollen development in Brassica napus cv. Topas. Canadian Journal of Botany 70 1369 -1376. 

To overcome the effect of temperature on the conventional resistors in the design of Figure 6.9, one can control the temperature of the resistors or use resistors at very low temperatures. The four-filament configuration shown in Figure 6.10 replaces each fixed resistor with a filament cell for improved stability. 

In general, nonabsorbable sutures can retain their tensile strength longer than 2 months [113]. The synthetic polymers used to make nondegradable sutures include polypropylene (PP), polyamides, polyesters such PET and polybutylene terephthalate (PBT), and polyether-ester based on poly(tetramethylene glycol), 1,4-butanediol, and dimethyl terephthalic acid [114]. The base polymer and filament configuration for common nonabsorbable sutures are summarized in Table 8.2. 

Kevlar fibre surface structure is primarily and directly observed in the filament configuration by the tapping... 

Quench. Attempts have been made to model this nonisotherma1 process (32—35), but the complexity of the actual system makes quench design an art. Arrangements include straight-through, and outside-in and inside-out radial patterns (36). The optimum configuration depends on spinneret size, hole pattern, filament size, quench-chamber dimensions, take-up rate, and desired physical properties. Process continuity and final fiber properties are governed by the temperature profile and extension rate. 

For most hydrardic pressure-driven processes (eg, reverse osmosis), dense membranes in hoUow-fiber configuration can be employed only if the internal diameters of the fibers are kept within the order of magnitude of the fiber-wall thickness. The asymmetric hoUow fiber has to have a high elastic modulus to prevent catastrophic coUapse of the filament. The yield-stress CJy of the fiber material, operating under hydrardic pressure, can be related to the fiber coUapse pressure to yield a more reaUstic estimate of plastic coUapse ... 

Bicomponent technology has been used to introduce functional and novelty effects other than stretch to nylon fibers. For instance, antistatic yams are made by spinning a conductive carbon-black polymer dispersion as a core with a sheath of nylon (188) and as a side-by-side configuration (189). At 0.1—1.0% implants, these conductive filaments give durable static resistance to nylon carpets without interfering with dye coloration. Conductive materials such as carbon black or metals as a sheath around a core of nylon interfere with color, especially light shades. 

Hybrid Processes. There are also hybrid processes that have evolved to meet specific product needs. As an example, automotive leaf springs utilize a filament winding system to prepare impregnated fiber bundles that are then compression molded to final configuration. 

Possible modes of regulation of filament assembly may be anticipated from the basic properties of actin. We have shown that the tightly bound divalent metal ion (Ca or Mg ) interacts with the P- and y-phosphates of ATP bound to actin, and that the Me-ATP bidentate chelate is bound to G-actin in the A configuration. The nature of the bound metal ion affects the conformation of actin, the binding kinetics of ATP and ADP, and the rate of ATP hydrolysis. 

Figure 49-3. Schematic representation of the thin fiiament, showing the spatiai configuration of its three major protein components actin, myosin, and tropomyosin. The upper panei shows individual molecules of G-actin. The middle panel shows actin monomers assembled into F-actin. Individual molecules of tropomyosin (two strands wound around one another) and of troponin (made up of its three subunits) are also shown. The lower panel shows the assembled thin filament, consisting of F-actin, tropomyosin, and the three subunits of troponin (TpC, Tpl, andTpT).

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