Discontinuous tuning

Fig. 5.56a,b. Discontinuous tuning of lasers (a) part of the neon spectrum excited by a single-mode dye laser in a gas discharge with Doppler-limited resolution, which conceals the cavity mode hops of the laser (b) excitation of Na2 lines in a weakly collimated beam by a single-mode argon laser. In both cases the intracavity etalon was continuously tilted but the cavity length was kept constant... 

Basic process control system (BPCS) loops are needed to control operating parameters like reactor temperature and pressure. This involves monitoring and manipulation of process variables. The batch process, however, is discontinuous. This adds a new dimension to batch control because of frequent start-ups and shutdowns. During these transient states, control-tuning parameters such as controller gain may have to be adjusted for optimum dynamic response. 

We can also use the fact that the output voltage of a discontinuous mode converter at a given duty cycle depends on its inductance. So we can tune the slave buck-boost to have the required output level (at its expected maximum load current) by a careful choice of inductance. Within a valid range, this technique provides completely adjustable auxiliary output voltages, something we cannot normally expect from composite topologies based only on continuous conduction modes. 

The ramifications for a Gedanken experiment at T = 0 K are sketched in Fig. 4a, revealing the d.c. electrical conductivity for a macroscopic system such as Si P in which d, the average distance between one-electron centers, can be continuously tuned by changes in the composition of the system. For values of d below a critical distance, dc, i.e. d < <4) the system is metallic and the electronic wave-function is completely delocalized over the entire sample. For very large d d > dfj, we have an insulator with a valence electron wavefunction that is completely localized at the individual atomic sites. At a critical distance, d we then have, according to Mott, a first-order (discontinuous) metal-insulator transition. Thus, at r = 0 K one either has a non-metal or an insulator, for which the limiting (low temperature) d.c. electrical conductivity is zero, or a metal, with a finite conductivity at this base temperature. Whether the metal-insulator transition in Si P (Fig. 4a) is continuous or discontinuous is still a source of controversy. 

For a given sample and separation mechanism, the separation selectivity of the chromatographic system depends on the nature of both mobile as well as stationary phase. Interactions of solute with mobile and stationary phases may include a mixture of non-polar dispersive and various polar forces. The terms polar and non-polar have been commonly used to describe a property of both the solute, as well as mobile and stationary phases. These terms, however, should not be confused with selectivity. The separation selectivity of a stationary phase can be changed discontinuously by selection of a proper column packing (by its polarity or other parameters), or tuned continuously, synthesizing tailor-made phases or mixing stationary phases differing in polarity. ... 

Transmission Line Sections Discontinuities Impedance Transformers Terminations Attenuators Microwave Resonators Tuning Elements Hybrid Circuits and Directional Couplers Filters Ferrite Components Passive Semiconductor Devices... 

The algorithm was originally developed for use when the controller scan interval (ts) is signihcant compared to the process dynamics. This makes it suitable for use if the PV is discontinuous, such as that from some types of on-stream analysers. Analysers are a major source of deadtime. They may located well downstream of the MV and their sample systems and analytical sequence can introduce a delay. An optimally tuned PID controller would then have a great deal of derivative action. However this wUl produce the spiking shown in Figure 7.6. 

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