Single-stage development

Because the development of lead isotope ratios has occurred in two or more stages, the observed ratios may be greater than they would be in a single stage development because the lead has evolved in an integrated system with > about 9. Such lead is radiogenic in comparison... 

Table 1 shows the superiority of the single-stage development over the two-stage CM process. 

In the single-stage development, adding chemicals in two steps was found to be beneficial. Cotton gauze was first treated with alcoholic caustic soda for 15 minutes at 100°F [to swell cotton and increase accessible hydroxyl groups] before treating it in the same bath with alcoholic monochloroacetic acid for 4 to 5 hours at 155 +/- 3 F [refer to... 

The objective of the Zimm plot is to conduct all extrapolations on a single graph. The three-stage development of Fig. 10.14 is not typical, but it is intended to clarify the discussion. 

Hybrid Crystallization/Adsorption Process. In 1994, IFP and Chevron announced the development of a hybrid process that reportedly combines the best features of adsorption and crystallization (59,99). In this option of the Eluxyl process, the adsorbent bed is used to initially produce PX of 90—95% purity. The PX product from the adsorption section is then further purified in a small single-stage crystallizer and the filtrate is recycled back to the adsorption section. It is reported that ultrahigh (99.9+%) purity PX can be produced easily and economically with this scheme for both retrofits of existing crystallization units as well as grass-roots units. A demonstration plant was built at Chevron s Pascagoula refinery in 1994. 

P-type manifold—veiiical configuration. The P ring dryer (see Fig. 12-100) incorporates a single-stage classifier and was developed specifically for use with heat-sensitive materials. The undried material is reintroduced into a cool part of the dryer in which it recirculates until it is dry enough to leave the circuit. 

Operational Factors In industrial use, peiwaporation is a continuous-flow single-stage process. Multistage cascade devices are unusual. Peiwaporation is usually an adjunct separation, occasionally a principal one. It is used either to break an azeotrope or to concentrate a minor component. Large stand-alone uses may develop in areas... 

Vane compressors tend to be limited to low pressure service, generally less than 100 to 200 psi discharge. They are used extensively as vapor recovery compressors and vacuum pumps. Single-stage vane compressors can develop 27 in. Hg vacuums, two-stage compressors can develop 29.0 in. Hg, and three-stage compressors can develop even higher vacuums. 

Adiabatic Head Developed per Single-Stage Wheel. The head developed hy a single stage of compression, consisting of an impeller and diffuser, depends upon the design, efficiency, and capacity and is related to its speed. 

Another centrifugal pump classification is whether the pump is a single-stage pump (the pressure head is developed by a single impeller) or a multistage pump (the pressure head is developed by two or more impellers). 

The compound formed in the first step of the reaction between the solid components and the molten alkali metal carbonate can passivate the surface and prevent subsequent development of the interaction. This special property of M4Me04F, the compound formed in the first step, leads, in effect, to a single-stage interaction. 

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