Coupled accelerator

Wennrich et al. [167] investigated the capabilities of coupling accelerated solvent extraction with water as the extraction solvent and solid-phase microextraction to determine chlorophenols in polluted soils. Subcritical water extraction was performed using a commercially available accelerated solvent extractor. This system solves the problem of the analytes partitioning back to the soil matrix, which can occur in straightforward subcritical water extraction because in the Wennrich et al. method [167] the aqueous phase and the soil are separated under the extraction conditions. 

In the manufacture of trisazo dyes, good yield and purity during final coupling are often obtained only in the presence of pyridine or other bases as coupling accelerators [10], Intermediate isolation and separation of impurities prior to continuation of coupling are also frequently necessary. 

A typical transition from the passive to the active state, as measured with a potential probe and a rotating Ag ring electrode, is reproduced in Fig. 53. The accelerated motion of the interface immediately leaps to the eye. It is, according to the explanation given in Section III.l, a consequence of nonlocal coupling. Accelerated fronts were found to be the characteristic feature in aU passive to active transitions. By contrast, during the much slower transitions from the active to the passive state, often only faint spatial variations were observed, but no sharp interfaces between... 

The inductively coupled plasma [19] is excited by an electric field which is generated by an RF current in an inductor. The changing magnetic field of this inductor induces an electric field in which tire plasma electrons are accelerated. The helicon discharge [20] is a special type of inductively coupled RF discharge. 

From Newton s second law, noting that more than one force may influence each mass, where a is the acceleration a = =. For the coupled masses... 

The coupling of 1,8-diiodonaphthalene (25) with acenaphthylene (26) affords acenaphth[l,2-a]acenaphthylene (27). It should be noted that the reaction involves unusual trans elimination of H—Pd—1[32], This tetrasubstituted double bond in 11 reacts further with iodobenzene to give the [4, 3, 3]propellane 28 in 72%. This unusual reaction may be accelerated by strain activation, although it took 14 days[33]. 

In the total synthesis of the naturally occurring big molecule of palytoxin, which has numerous labile functional groups, this coupling is the most useful for the creation of E, Z-conjugated diene part 653. In this case, thallium hydroxide as a base accelerates the reaction 1000 times more than KOH[523]. Even TECOj can be used instead of a strong base in other cases[524]. 

Since the charge becomes coupled with the oscillating field, q undergoes a periodic acceleration which we represent by ap. Next we borrow a relationship from electromagnetic theory to describe the field produced by an oscillating dipole such as the molecule we have described ... 

Excitation of smooth muscle via alpha-1 receptors (eg, in the utems, vascular smooth muscle) is accompanied by an increase in intraceUular-free calcium, possibly by stimulation of phosphoUpase C which accelerates the breakdown of polyphosphoinositides to form the second messengers inositol triphosphate (IP3) and diacylglycerol (DAG). IP3 releases intracellular calcium, and DAG, by activation of protein kinase C, may also contribute to signal transduction. In addition, it is also thought that alpha-1 adrenergic receptors may be coupled to another second messenger, a pertussis toxin-sensitive G-protein that mediates the translocation of extracellular calcium. 

Imidazole-4,5-dicarboxylic acids, coupling, 5, 403 decarboxylation, 5, 434 1-substituted synthesis, 5, 468 synthesis, 5, 362, 402, 484 Imidazole-4,5-dione, l-alkyl-2-phenyl-synthesis, 5, 129, 479 Imidazole-2,4-diones tautomerism, 5, 370 Imidazole-4,5-diones tautomerism, 5, 370 Imidazole-2,4-dithione, 5,5-diphenyl-tautomerism, 5, 370 Imidazole-2,4-dithiones tautomerism, 5, 370 Imidazolepropanol synthesis, 5, 486 Imidazoles accelerators epoxy resins, 1, 407... 

Steel coated with tin (tinplate) is used to make food containers. Tin is more noble than steel therefore, well-aerated solutions will galvanically accelerate attack of the steel at exposed areas. The comparative absence of air within food containers aids in preserving the tin as well as the food. Also the reversible potential which the tin-iron couple undergoes in organic acids serves to protect exposed steel in food containers. 

Severe corrosion by turbulent mill coolant was found generally throughout a rolling-oil system. Hose couplings were severely wasted in as little as 8 weeks (Fig. 7.23A and B). Turbulence caused by high-velocity flow through nozzles accelerated attack. Attack at bends, elbows, intrusive welds, and discharge areas was also severe. 

Corrosion tests of metals under static conditions reveal nothing relating to erosion-corrosion susceptibilities. It is entirely possible that a metal tested under static conditions will fail in service when sufficient fluid velocity produces erosion-corrosion. Similarly, it has been observed that galvanic corrosion between coupled, dissimilar metals may be accelerated or even initiated under flow conditions when little or no galvanic corrosion is observed under static conditions (see Chap. 16, Galvanic Corrosion ). 

Turbulence and high fluid velocities resulting from normal pump operation accelerated metal loss by abrading the soft, graphitically corroded surface (erosion-corrosion). The relatively rapid failure of this impeller is due to the erosive effects of the high-velocity, turbulent water coupled with the aggressiveness of the water. Erosion was aided in this case by solids suspended in the water. 

This type of switching provides very smooth acceleration. This is an advantage of electrolyte switchings over other conventional types of switchings. It exerts no kicks and calls for no special coupling arrangement to transmit the power smoothly to the drive if the requirement of the drive is to be precise and to have a smoother acceleration. 

Let us use a fluid coupling and start the motor lightly, similar to Figure 8.3. The revised accelerating torque and approximate clutching sequence of the coupling is illustrated in Figure 7.22. 

Figure 8.3 Smoother and quicker acceleration of heavy-duty loads with the use of a delayed-action coupling...

To date a number of reactions have been carried out in ionic liquids [for examples, see Dell Anna et al. J Chem Soc, Chem Commun 434 2002 Nara, Harjani and Salunkhe Tetrahedron Lett 43 1127 2002 Semeril et al. J Chem Soc Chem Commun 146 2002 Buijsman, van Vuuren and Sterrenburg Org Lett 3 3785 2007]. These include Diels-Alder reactions, transition-metal mediated catalysis, e.g. Heck and Suzuki coupling reactions, and olefin metathesis reactions. An example of ionic liquid acceleration of reactions carried out on solid phase is given by Revell and Ganesan [Org Lett 4 3071 2002]. 

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