Merry-go-round system

Disadvantages of these continuous countercurrent systems are associated primarily with the complexity of the equipment required and with the attrition resulting from the transpoiT of the ion exchanger. An effective alternative for intermediate scale processes is the use of merry-go-round systems and SMB units employing only packed-beds with no movement of the ion-exchanger. 

Merry-go-round systems, 14 408 Mes, buffer for ion-exchange chromatography, 3 830t Mescaline, 2 84, 85 Mesh-belt furnace, 12 289 Mesh wick, 13 232... 

Analogous relationships are derived for SMB systems where each zone comprises a number of fixed beds operated in a merry-go-round sequence, as shown in Fig. 16-48. External flow velocities are calculated from Eqs. (16-209a) to (16-209d), replacing us with... 

Carbonyl a remains unaffected, excluding site exchanges by a merry-go-round of six CO groups, as proposed for Rli4(CO)i2. Since restricted axial-basal site exchanges are observed, this fluxional process may be called a change of basal face (Rh(l)-Rh(2>-Ir(l) to Rh(l)-Rh(2)-Ir(2)). This new process, which has a positive volume of activation [49], is also encountered in the following systems. 

Procedures. Continuous irradiations of halocarbon solutions were conducted with monochromatic radiation in a merry-go-round apparatus (12) or in a Schoeffel reaction chemistry system. Reactions were followed through analysis for remaining halocarbon or analysis of chloride ions produced by the photoreactions. Dark controls were used in all cases to correct for thermal production of chloride ions. Ferrioxalate actinometers were used to determine the irradiance (16). The irradiance at the photoreaction cell surface was typically about 10 nanoeinsteins/cm2,s. The Fe(II) concentrations were determined by using a modified version of the ferrozine procedure described by Stookey (17). Electronic absorption spectra were obtained by using a Shi-madzu model 265 spectrophotometer. 

The useful thing about this merry-go-round as far as the cell is concerned is that it provides that critical feature of all desirable energy-releasing systems - a way for the acetic acid molecule to be carefully picked to pieces so as to release its potential energy in small steps. The cycld, as we shall find, is of great importance not only as the final stage of glucose oxidation, but in the metabolism of many other substances as well. We shall later see how, in the breakdown of both fatty and amino acids, products are formed which can enter the cycle at one of several points, to be whirled round the merry-go-round and thus oxidized. 

In M4(CO)j2 systems, the merry-go-round and basal face change mechanisms, shown in reactions (4.18) and (4.19), have been identified. In the first case the unbridged intermediate is shown. For the second case, the... 

The NAG derivatives are irradiated at 0° in Pyrex vessels, with a 650-watt incandescent movie lamp source 10 cm from the samples. The mixtures are stirred and a merry-go-round is used for multiple samples. Judged by spectral changes in NAG-NOS after irradiation, 3-5 min is sufficient under these conditions. However, the kinetics should be checked for each experimental system. 

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