Regenerative Amplification

Examples of such situations are very numerous perhaps the best known example is the transition of the performance of an electronic circuit from regenerative amplification to the generation of oscillations. The parameter A in this case is the coefficient of mutual inductance between the anode and the grid circuits. As long as A < A0, the circuit functions as amplifier whose coefficient of amplification gradually... 

Dopamine Dl receptor activation enhances NMDA-mediated excitatory responses (Cepeda et al., 1993 Cepeda and Levine, 1998). The modulatory actions of dopamine on NMD A receptor mediated responses are reduced in Dl deficient mice (Levine et al., 1996a), supporting a specific role for Dl receptors in enhancement. However, this enhancement involves a complex interplay of actions both on the NMDA receptors and also on the voltage-sensitive calcium channels (VSCC). In particular, the activation of VSCC conductances on the distal dendrites contributes to the enhancement of NMDA currents by dopamine. This mechanism of enhancement involves increased regenerative amplification of synaptic responses by increased VSCC currents (Cepeda et al., 1993, 1998 Cepeda and Levine, 1998). Synaptic responses may also be increased directly by... 

Pulse Energy Issues, Laser Oscillator and Regenerative Amplification. 203... 

Rudd J V, Korn G, Kane S, Squier J, Mourou G and Bade P 1993 Chirped-pulse amplification of 55 fs pulses at a 1 kHz repetition rate in a TIAI203 regenerative amplifier Opt. Lett. 18 2044-6... 

Norris T B 1992 Femtosecond pulse amplification at 250 kHz with a Ti sapphire regenerative amplifier and application to continuum generation Opt. Lett. 17 1009-11... 

Figure 6 Block diagram of the two-color optical parametric amplifier (OPA) and IR-Raman apparatus. CPA = Chirped pulse amplification system Fs OSC = femtosecond Ti sapphire oscillator Stretch = pulse stretcher Regen = regenerative pulse amplifier SHGYAG = intracavity frequency-doubled Q-switched Nd YAG laser YAG = diode-pumped, single longitudinal mode, Q-switched Nd YAG laser KTA = potassium titanyl arsenate crystals BBO = /J-barium borate crystal PMT = photomultiplier tube HNF = holographic notch filter IF = narrow-band interference filter CCD = charge-coupled device optical array detector. (From Ref. 96.)...

Any rhythm can be comprehended as a sequence of two phases that merge and follow each other in an autonomous manner. The first phase, of amplification, corresponds here to the onset of a peak in cAMP synthesis. The second phase, of limitation, corresponds to the decrease in cAMP synthesis, once the maximum is passed. Autonomous oscillations occur because of the regenerative process that leads to the renewal of the self-amplification phase after cAMP has reached its minimum level. To understand the mechanism of oscillations is tantamount to identifying this regenerative process as well as those responsible for self-amplification and for its limitation. 

Rapid detection with fewer false alarms Mass production Moleculeu amplification technologies Nanocatalytic technologies rmd regenerative materieils... 

The amplifier system is composed of three logic subunits, a femtosecond pulse stretcher (Fig. 2.27), the titanium sapphire regenerative amplifier (Fig. 2.28) and a femtosecond pulse compressor (Fig. 2.29). To exploit the storage capability of titanium sapphire the system uses chirped-pulse amplification [264-266]. For this a seed pulse (80 fs, 5nJ) of the titanium sapphire oscillator is stretched to about 500 ps and then amplified. The stretched pulse can be safely amplified because the peak power has been significantly lowered, thereby avoiding any nonlinear effects that could result in damage to the... 

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