A-stage

The experiment was carried out by a continuously working Nd YAG-laser fabricated by NEC. The laser has a maximum output of 1200 W and is controlled by handling facility with a linear axle. A stage index fiber optical waveguide with a diameter of d=1000 pm was used for the control of the beam. The focusing optics consist of a focusing lens (f=l 16 mm) and a collimation lens (f=70 mm). 

The Bart reaction can be carried a stage further. For example, dichloro-phenylarsine, CjHjAsCl, when added to an excess of sodium carbonate solution, gives CjHjAsfONa) this solution, if similarly treated with benzenedia-zonium chloride, affords diphenylarsinic acid, (CjHjjjAsf. OjOH. 

Seeing the aromatic ketones in a and c we might have a Friedel-Crafts reaction in mind. Continue tiiese two a stage further. 

Stopping the polymer at this point requires the ratio of formaldehyde to phenol to be less than unity. Both methylene and ether bridges are known to be present. The reaction is either acid or base catalyzed, and branching is uncommon at this stage. The products are variously known as A stage resins, novolacs, or resole prepolymers. 

Copper. The recovery of copper [7440-50-8] Cu, from ore leach Hquors as a stage in the hydrometallurgical route to the pure metal is one of the... 

Initial operation at the Wilsonville pilot plant was ia SRC-I mode and later evolved iato a two-stage process (129) by operation ia NTSL mode. NTSL limitations described previously combiaed with high hydrogen consumptions resulted ia subsequent focus on a staged iategrated approach, which was to be the basis for all further studies at Wilsonville. 

Key resins used in the manufacture of laminates are made with formaldehyde (qv). The A-stage resins are manufactured to have low levels of free formaldehyde, less than one percent, and plant atmospheres as well as individual operators are monitored to be certain they are exposed to levels of formaldehyde that are below OSHA guidelines of 0.75 ppm (14). 

Neutralization usually follows equalization so that acidic and alkaline streams can be partially neutralized in the equalization basin. If the wastewater is always acidic, neutralization may occur at a stage prior to the stream reaching the equalization basin, so as to minimize corrosion in the equalization basin. 

However, this difference would not seem to be large enough to account for the very large differences in solvent losses that have been reported. Another factor may be that high solids coatings may reach a stage where solvent loss is controUed by diffusion rate much eadier than is the case in low solids coatings (8,43). 

Thus, the separative capacity of a stage is directiy proportional to the stage upflow as well as to the square of the separation effected. 

Figure 7 is a schematic representation of a section of a cascade. The feed stream to a stage consists of the depleted stream from the stage above and the enriched stream from the stage below. This mixture is first compressed and then cooled so that it enters the diffusion chamber at some predetermined optimum temperature and pressure. In the case of uranium isotope separation the process gas is uranium hexafluoride [7783-81-5] UF. Within the diffusion chamber the gas flows along a porous membrane or diffusion barrier. Approximately one-half of the gas passes through the barrier into a region... 

Foi a veiy liigli quality baiiiei (p oo), the separative capacity of a stage having a mixing efficiency of 100% and operating at a cut of one-half would be ... 

Continuous polymerization in a staged series of reactors is a variation of this process (82). In one example, a mixture of chloroprene, 2,3-dichloro-l,3-butadiene, dodecyl mercaptan, and phenothiazine (15 ppm) is fed to the first of a cascade of 7 reactors together with a water solution containing disproportionated potassium abietate, potassium hydroxide, and formamidine sulfinic acid catalyst. Residence time in each reactor is 25 min at 45°C for a total conversion of 66%. Potassium ion is used in place of sodium to minimize coagulum formation. In other examples, it was judged best to feed catalyst to each reactor in the cascade (83). 

It is possible for some projects to reach a stage at which repairs, replacements, etc., can exceed net earnings in a particular year. In this case the cumulative-discounted-cash-flow or net-present-value curve plotted against time has a genuine maximum. 

The nonequilibrium-model equations for the stage in Fig. 13-56 are as follows in residual form, where i = component (i = 1 to C), j = stage number (j = 1 to N), and V = a stage in another column that supplies an interlink. 

When chemical equilibrium is achieved qiiickly throughout the liquid phase (or can be assumed to exist), the problem becomes one of properly defining the physical and chemical equilibria for the system. It sometimes is possible to design a plate-type absorber by assuming chemical-equilibrium relationships in conjunction with a stage efficiency factor as is done in distillation calculations. Rivas and Prausnitz [Am. Tn.st. Chem. Eng. J., 25, 975 (1979)] have presented an excellent discussion and example of the correct procedures to be followed for systems involving chemical equihbria. 

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