Multiple-step forming

Analogously, for polyethyleneterephtalate, drawing procedures in multiple steps, with preliminary drawings at room temperature generating a mesomorphic form [127], have been suggested by several authors [128-130], in order to get high modulus and high tenacity fibers. 

In the past, only tablet dosage forms of enzymatic cleaners were available. They required soaking lenses in solutions prepared from a tablet for a period of 15 minutes to more than 2 hours before disinfecting the lenses. Although this process provided sufficient time for cleaning, it was a cumbersome process and required multiple steps. Complicated or cumbersome processes... 

If the forward and reverse reactions are nonelementary, perhaps involving the formation of chemical intermediates in multiple steps, then the form of the reaction rate equations can be more complex than Equations 5.33 to 5.36. 

Although the inhibition-based biosensors are sensitive, they are poor in selectivity and are rather slow and tedious since the analysis involves multiple steps of reaction such as measuring initial enzyme activity, incubation with inhibitor, measurement of residual activity, and regeneration and washing. Biosensors based on direct pesticide hydrolysis are more straightforward. The OPH hydrolyzes ester in a number of organophospho-rus pesticides (OPPs) and insecticides (e.g. paraoxon, parathion, coumaphos, diazinon) and chemical warfare agents (e.g. sarin) [53], For example, OP parathion hydrolyzes by the OPH to form p-nitrophenol, which can be measured by anodic oxidation. Rainina... 

Chemical transmission between nerve cells involves multiple steps 167 Neurotransmitter release is a highly specialized form of the secretory process that occurs in virtually all eukaryotic cells 168 A variety of methods have been developed to study exocytosis 169 The neuromuscular junction is a well defined structure that mediates the presynaptic release and postsynaptic effects of acetylcholine 170 Quantal analysis defines the mechanism of release as exocytosis 172 Ca2+ is necessary for transmission at the neuromuscular junction and other synapses and plays a special role in exocytosis 174 Presynaptic events during synaptic transmission are rapid, dynamic and interconnected 175... 

After multiple steps, an organic halide can be converted to a carboxylic acid. The organic halide converts to a Grignard reagent, which reacts with carbon dioxide and then acidification forms the acid. Figures 12-13 and 12-14 illustrate the steps in this process. 

An ionic liquid was fully immobilized, rather than merely supported, on the surface of silica through a multiple-step synthesis as shown in Fig. 15 (97). A ligand tri(m-sulfonyl)triphenyl phosphine tris(l-butyl-3-methyl-imidazolium) salt (tppti) was prepared so that the catalyst, formed from dicarbonylacetylacetonate rhodium and the ligand (P/Rh = 10), could be soluble in both [BMIMJBFq and [BMIM]PF6. The supported ionic liquid-catalyst systems showed nearly three times higher rate of reaction (rate constant = 65 min ) that a biphasic system for the hydroformylation of 1-hexene at 100°C and 1500 psi in a batch reactor, but the n/i selectivity was nearly constant the same for the two ( 2.4). Unfortunately, both the supported and the biphasic ionic liquid systems exhibited similar metal leaching behavior. 

The mechanism of transcription is identical for all forms of RNA and occurs in multiple steps. 

The pathway of transcription initiation is becoming much better defined (Fig. 26-6a). It consists of two major parts, binding and initiation, each with multiple steps. First, the polymerase binds to the promoter, forming, in succession, a closed complex (in which the bound DNA is intact) and an open complex (in which the bound DNA is intact and partially unwound near the... 

In general, the synthesis of [n]helicenes involves two key synthetic steps, i.e. connection and annelation. The most efficient approaches to [njhelicenes use multiple annelations, forming two or more rings in one synthetic step however, relatively few annelation reactions have been implemented effectively. 

Fig. 17.58. The mechanism of the McMurry reaction. A mixture of diastereomers of the dititanium(III) glycolate C is either directly generated via the initially formed Ti(in) ketyl B (variant 1) or in multiple steps (variant 2). At sufficiently high temperatures, C is then reduced to a mixture of diastereomers of the corresponding dititanium(III) glycolate G. The latter decomposes via homolytic cleavage of one of its C—0 bonds to furnish the radical intermediate H. If the only C—0 bond left in this radical also breaks homolytically—which partly occurs without ( ) prior rotation around the C-C(OTiCl) bond—the alkene is formed as an F,Z-mixture. Its composition may (somewhat) depend on the configuration of the dititanium(II) glycolate precursor G (cf. Figure 17.56).

For single separation duty, Diwekar et al. (1989) considered the multiperiod optimisation problem and for each individual mixture selected the column size (number of plates) and the optimal amounts of each fraction by maximising a profit function, with a predefined conventional reflux policy. For multicomponent mixtures, both single and multiple product options were considered. The authors used a simple model with the assumptions of equimolal overflow, constant relative volatility and negligible column holdup, then applied an extended shortcut method commonly used for continuous distillation and based on the assumption that the batch distillation column can be considered as a continuous column with changing feed (see Type II model in Chapter 4). In other words, the bottom product of one time step forms the feed of the next time step. The pseudo-continuous distillation model thus obtained was then solved using a modified Fenske-Underwood-Gilliland method (see Type II model in Chapter 4) with no plate-to-plate calculations. The... 

Using electron ionization, the molecular radical cation is formed in the source. This radical cation fragments into a radical and a cation with an even number of electrons or, through rearrangements or multiple steps, into a neutral molecule and a new odd-electron cation. The latter are often easily recognized in the spectrum because their mass is even in the absence of a nitrogen atom. 

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