External triggers

The external trigger input allows automatic inspections and ultrasonic imaging. The clock signal of an encoder or of stepper motors can be used as a trigger for the pulser. An internal software controlled divider allows different scan resolutions. 

The internal pulser generates an output voltage of 228 V with a rise time of lower than 6 ns, which provides high resolution for frequencies above 10 MHz. The external trigger input enables synehronization with manipulators. 

Both devices are externally triggered by an inductive sensor so that all measurements are carried out at the same disk position. 

In most tests, no external trigger was used. Explosions did or did not occur depending on the variables discussed above. In some tests, however, external shocks were used in an attempt to turn normal nonexplosive tests into explosive ones. 

These conclusions hold only for a free contact model. Contact in shock tubes or with external triggers are excluded. 

The way to improve LIBS analytical abilities is double pulse LIBS. It is conducted by using two pulses from the same laser source operated at a single wavelength. By utilizing a modified commercial laser, a proper external trigger circuit allows us to extract two laser pulses with adjustable delay from the same flash-lamp emission, and a relative time delay variable from a few to several tenths of microseconds. The experimental results show that such a technique... 

Formation of a signal in the signal-producing cell as a result of an external trigger... 

Air-pressure-driven active devices. Air-pressure-driven aerosolization is the concept employed in a number of devices currently in different stages of development with drugs for local or systemic action. These devices rely on a small patient-operated air pump. Air is compressed by mechanical means (piston or bellows) and is released on the external trigger given by the patient s inspiratory cycle. Because of the use of this air pump, these devices have an active aerosolization mechanism and are assumed to be less flow-rate-dependent than passive DPI devices. 

As well as sustained release, core/shell particles may be used also for triggered release applications. In this case, as with the microgel systems discussed earlier, an external trigger is used to cause some change in the properties of the shell polymer, which allows the active molecules to diffuse across the shell into the exterior. With many active materials there is an optimum dosage that is required in the exterior, e.g. with drugs. This... 

The experiments described reveal the potential of perimidinespirocyclohexa-dienones for the design of multiswitchable devices. Such molecular switching processes are considered to be crucial to the reversible modulation of a given physical property by means of a certain external trigger, in particular of light.31"33... 

Finally, we will consider briefly the formation of multilayer thin films by layer-by-layer deposition of hydrogen-bonded polymer pairs [51,52]. In this way a multilayer structure is obtained from potentially miscible polymer pairs. The stability of these films very much depends on the presence of hydrogen bonds, and pH may be used as an external trigger to erase the layered structure [53,54] and selectively dissolve one of the components [25-27]. This procedure allows for the preparation of microporous films not unlike the nanoporous films obtained by dissolution of the hydrogen-bonded side groups from self-assembled block copolymer-based comb-shaped supramo-lecules [15,17,18]. 

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