Simultaneous feeding

Laboratory colonies of worker ants were fed sugar-water containing l-C14-acetate, 2-C14-acetate, or in a carefully controlled simultaneous feeding, 1-C14- or 2-C14-mevalonate. After an appropriate period, the ants were frozen and extracted with methylene chloride and the terpene aldehydes (citronellal and citral) isolated by thin-layer chromatography. These were then converted into their dini-... 

Fig. 7.69. Simultaneous feed-forward control of overhead and bottoms compositions in the face of variations in feed composition...

Starch slurry make-down systems are designed to prepare a uniform suspension, using batch or continuous systems. In modem paper mills, automated batch or continuous systems are used. Water content and bulk density will affect the flow of dry starch.90 In the batch slurry system, weighed increments of starch are drawn from the silo and periodically added to a measured quantity of water in the make-up tank. The suspension is screened and automatically pumped to a larger storage tank on demand by a level transmitter. Continuous make-down of starch slurry is accomplished by simultaneously feeding starch and water at controlled rates into the slurry make-down tank. The dry starch is metered with a volumetric screw feeder. The slurry is screened before dispersion by batch or continuous cooking. 

It was possible also to incorporate unnatural precursors into the alkaloids of Dolichothele sphaerica (164,165,168,169). On feeding of 3-aminoethyl-pyrazole, the alkaloid 3-(Ar-isovalerylaminoethyl)pyrazole (112) was produced, and A -isocaproylhistamine was obtained by the simultaneous feeding of 4-methylpentanoic acid (isocaproic acid) and of 4(5)-aminoethy-... 

In the semibatch runs of VAc miniemulsion (or macroemulsion) plus neat VEOVA, with simultaneous feeding of VAc miniemulsion (or macroemulsion), the neat vinyl versatate was injected into the polymerization system two (for the feedrate of 0.6 ml/min) or three (for 0.3 ml/min) times during each sampling interval. Copolymer composition was determined by NMR, MWD by GPC, Tg by DSC, and PSD by dynamic light scattering. 

The chlorination reaction rate can be limited either by chemical kinetics or ethylene mass transfer, depending on ethylene partial pressure, agitation, catalyst composition, and temperature. If the ethylene partial pressure, and/or agitation rate are low, the transfer rate of ethylene to the catalyst solution will be too small to satisfy the kinetic capabilities of the catalyst, and the system will be mass-transfer limited. As either or both ethylene partial pressure and agitation are increased, the mass transfer rate will increase, and eventually ethylene can be supplied to the system at a rate equal to, or in excess of, the kinetic rate capabilities, and the reaction system will be limited kinetically from this point. The mass transfer and kinetic-limiting regimes have been delineated, and simultaneous feed operations were normally made under conditions where chlorination kinetics—not ethylene mass transfer—was controlling. 

Ammonium uranyl carbonate (AUC) process This process was developed in the 1960 s in the Federal Republic of Germany. It comprises the simultaneous feeding of uranium(Vl) fluoride, carbon dioxide and ammonia into an aqueous ammonium carbonate solution at 70°C, whereupon tetra-ammonium tricarbonato-dioxo-uranate (ammonium uranyl carbonate) precipitates out ... 

Intermittently or continuously feeding material to or withdrawing material from a batch reactor converts it into a semi-batch reactor. Note, we either feed material to or withdraw material from the reactor we do not do both simultaneously. If we simultaneously feed material to and withdraw material from a reactor, then we operate the reactor as a continuous stirred tank reactor (CSTR). 

To measure accurately the (full) correlation function for longer times, the second output channel of one of the discriminators in Fig. 15 is used to simultaneously feed a digital logarithmic correlator. This device covers the time range from microseconds up to thousands of seconds whereby its minimum time resolution strongly depends on the after pulsing characteristics of the phototube. By employing the two... 

This copolymerization provided a one-pot, two-stage method by the simultaneous feeding of two monomers. 

For the case of crystal growth from the constant liquid-phase volume with simultaneous feeding of the melt with starting material, it can be demonstrated that the expression (14.14) turns into j = const, resulting in the feasibility to calculate separately the mass-transfer parameters due to evaporation and due to crystallization. 

For fed-batch (simultaneous feed and reagent) operation of a vertical well-mixed vessel ... 

Celanese remained active in this area and produced some interesting technology in the mid-1990s. Many of these involved blends in which both components were anisotropic (Section 5.4), but Makhija et al. describe a technique for LCP/isotropic thermoplastic blends in which components are fed sequentially into a mixing die to give additional control over the morphology. Either the LCP or the isotropic polymer can be first, followed by the other component. In some cases solid polymer is fed into an extruded stream of melt. The patent gives numerous examples of PET first vs. LCP first vs. simultaneous feed, and shows improved mechanical properties. 

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