Gain, amplitude-dependent

The echo amplitude Ar of a reference reflector depends on the type, size (diameter) d f, and distance Sr,., of the reference reflector, and additionally on a possible attenuation in the reference block and finally the absolute gain setting of the instrument G f. In a combined DAC/DGS evaluation program we define the following ... 

Under the simplifying assumption that the reflexions are independent of each other, K, can be written as a product over reflexions for which experimental structure factor amplitudes are available. For each of the reflexions, the likelihood gain takes different functional forms, depending on the centric or acentric character, and on the assumptions made for the phase probability distribution used in integrating over the phase circle for a discussion of the crystallographic likelihood functions we refer the reader to the description recently appeared in [51]. 

If the density pc of the cell is known, then the acoustic velocity in the cell can be immediately deduced, since vc = Zc/pc. Since determination of acoustic velocity by this method depends on the measurement of relative amplitudes, the amplifiers and their gain controls must be accurately calibrated. The combination of reflection and transmission coefficients on the right-hand side of (9.4) can be expressed in terms of the acoustic impedances of the coupling fluid, the cell, and the substrate. 

The analysis of the stability of a control system which contains a non-linear element that can be characterised by a describing function N is facilitated by considering the non-linear element as a variable gain for which N depends upon the amplitude M of the input signal(40). The behaviour (in terms of frequency response) of linear elements in the control loop will be a function of frequency only. 

Note however, that the amplifier gain must be dynamically changed depending on signal amplitude, which leads to discontinuities. Kriz also points out the slew rate problems in the track and hold. His solution was to use a DC feedback loop with an analog integrator. 

Depending on samples, adjustment of RECEIVE GAIN and MODULATION AMPLITUDE may be necessary to display a well-defined signal. 

These results reveal that at low temperature the rate of diffusion of Ar and N2 into the intracrystalline pore structure is extremely slow. The increase in the adsorption with temperature is not thermodynamically controlled but is instead dependent on the molecules gaining enough kinetic energy to allow their passage through some of the 4A apertures. This process is probably assisted by enhanced vibrational amplitude of the oxygen ring structure. 

When chlorisondamine (>5 x 10 5M) was perfused over the locust isolated retractor unguis nerve-muscle preparation the neurally-evoked twitch contraction of the retractor unguis muscle was reduced in amplitude with 5 x lO H chlorisondamine the twitch was almost abolished. Part of this reduction in twitch amplitude was independent of the recent stimulation history of the retractor unguis muscle, unlike the remainder which was clearly dependent upon the stimulation frequency. Although it is not possible with this type of preparation to gain much insight into the site and mode of action of compounds such as chlorisondamine the results of these... 

---