Volume of melts

Since about 1965, efficient vacuum evaporators have been used in most plants. Second stage evaporators, where the ammonium nitrate is concentrated to more than 99%, are designed to retain only a small volume of melt, have short residence times, and are protected from overheating and contamination by sensitizers. Falling film units are especially suited for this appHcation. 

Mason JT, O Leary TJ. Effects of headgroup methylation and acyl chain length on the volume of melting of phosphatidylethanolamines. Biophys. J. 1990 58 277-281. 

Tables 6.13 and 6.14 list sets of internally consistent thermodynamic data for crystalline and liquid components, for use in equations 6.79 to 81. Although equations 6.80 and 6.81 are simply based on the Clausius-Clapeyron approach, Ghi-orso et al. (1983) use a semiempirical formulation for the volume of melt components. Its development is...

Water body Area Supply of Volume of melted... 

The plateau modulus is given by the usual formula for entangled polymers, Gq vksT, where v is the number of entanglement strands per unit volume of melt that is,... 

Numerical and analytical models of the vertical and lateral flow of hot, buoyant plume material beneath variable thickness continental lithosphere show that steep gradients at the lithosphere-asthenosphere boundary (LAB) strongly influence the distribution of plume material, and, consequently, the location and volume of melt. Cratonic keels deflect the plume material, with only minor thinning and heating of the mantle lithosphere beneath the cratons. 

The mould cavity must be filled completely without any flash occurring. The simplest control for mould filling uses limit switches on the screw travel. These actuate after the correct volume of melt has been injected, reducing the injection pressure to a lower holding value. However, any melt leakage past the screw non-return valve, or at the nozzle, causes the part mass to vary, with a consequent variation in the product dimensions. A better, more direct, control method uses a melt pressure transducer in the mould, which detects the rapid pressure rise, once the mould is full the... 

The process is illustrated schematically in Fig. 8.3. Polypropylene granules are fed into a continuously rotating screw of special design to permit nitrogen gas to be introduced to the melt. The screw feeds melt and gas into an accumulator where they are maintained under high pressure to keep the gas in solution . When sufhcient volume of melt has been accumulated (limit switch) a valve in the mould nozzle is opened and melt is forced into the cavity where, under reduced pressure, the nitrogen gas is free to expand. The nozzle valve closes and the accumulator continues to be charged with melt from the extruder barrel. 

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