Pulse Stream generator

One of the first Pulse Stream generators was the 100 kW test rig situated in the Humber estuary, which currently feeds power into a chemicals company on the banks of the river. The shells of the blades of one of these Pulse Stream 100 tidal generators were manufactured in glass fibre/epoxy polymer composites the spar was fabricated in carbon fibre/epoxy polymer composites. The spar, which is thick compared with the shell, was manufactured by the infusion technique, but for subsequent generators the prepreg technique will be used to make the spars. Figure 10.8 shows the Pulse Stream 100 tidal generator. 

This circuit is actually a clever use of the timer characteristic of the 555 as long as the pulse spacing is less than the timing interval generated by R2 and Cl. Therefore, this circuit not only detects missing pulses, but variations in duty cycle, variations in frequency, and even a terminated pulse stream. Figure 6.8 shows the breadboard in detection... 

The general arrangement of an hplc system is fairly simple, as shown in Fig. 9.17. Solvent is pumped from a reservoir through a piston pump which controls the flow rate. From the pump the solvent passes through a pulse damper which removes some of the pulsing effect generated in the pump and also acts as a pressure regulator. In between the pulse damper and the column there is an injection valve which allows the sample to be introduced into the solvent stream. 

Step functions, pulses, and square waves can be generated with a low volume, chromatographic-type 4-way valve. We have found that the desired two gas mixtures are best made up and stored in cylinders rather than made continuously by blending two streams. At the time of the switch, there is a momentary stopping of the flow, and this usually results in a change in composition if the mixture is made by the continuous blending of two streams. By this method one or more spurious peaks are added to the desired step function. Naturally these are trivial for slow responses, but important for fast ones. 

Chemical equilibria are frequently temperature dependent, and we should not expect that the organic phase trapped in the quenched catalyst will always be identical to that existing immediately prior to the quench. However, the organic material in the quenched catalyst should be sufficiently related to its antecedents that inferences about structures present at higher temperatures will be possible. Another advantage of the pulse-quench reactor that proved useful is the fact that products are removed from the catalyst bed in this experiment. This has proven useful for the observation of hydrolytically unstable species which form in reactions that also generate water (16). In sealed ampoules or rotors, the water can not escape the catalyst bed in the pulse-quench reactor, the water is swept out in the gas stream. Most of the experiments that motivated the calculations in this contribution were performed using "conventional" sealed-rotor methods, but the pentamethylbenzenium study (vide infra) would not have been possible without the pulse-quench reactor. 

Our system works by focusing a laser beam into a stream of seawater and then measuring the fluorescent emission and the scattered laser radiation from the irradiated small-spot volume. As the irradiated spot moves through the water, the particles crossing the volume generate optical pulses whose peak height correlates with particle size. The concentration of the particles is also obtained from the counts, the measured volume, the flow speed, and the period of measurement. 

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