Unit operations, control INDEX

Refractive index detectors are not as sensitive as uv absorbance detectors. The best noise levels obtainable are about 1CT7 riu (refractive index units), which corresponds to a noise equivalent concentration of about 10-6 g cmT3 for most solutes. The linear range of most ri detectors is about 104. If you want to operate them at their highest sensitivity you have to have very good control of the temperature of the instrument and of the composition of the mobile phase. Because of their sensitivity to mobile phase composition it is very difficult to do gradient elution work, and they are generally held to be unsuitable for this purpose. 

The extraction vessel outlet valve can be controlled either manually from the control unit or automatically by the phase boundary detector unit. The operation of this detector is based on the difference in refractive index between the organic and aqueous phases, and has been described elsewhere [34]. 

Accesses to arrays and ports are automatically converted to functional unit calls. For example, suppose we have an FU named mm, described in Vhdl as an array (thus it is represented as a memory device in hardware, the array index being the address). Assignments to ram in the initial description would then be replaced by WRITE requests, and if ram was used as an operand in some operation, this would be replaced by a READ function. For our control-flow-dominated target domain, we have chosen to realize the memory access as implied by the Vhdl description. No memory-oriented loop optimizations, as addressed in chapter 7 and 8, are foreseen here. 

Papermakers operate their process to optimise production, quality, and cost objectives. Therefore, it may be necessary to monitor and control surface deposition to allow for an appropriate period of operation prior to maintenance and cleaning. During this period of operation, deposits accumulate throughout the whitewater loop in the process. A stream of whitewater is continuously pumped through the OFM, so deposition measurements can be made. The unit of measure is the fouling index . The fouling index is measured every hour so that trends can be established. These trends can be used for the following objectives ... 

---