Impulse theory

The results of these experiments can only be explained by the impulse theory. According to this theory a particle can be removed from a lattice site when the displacement energy Ej (the sum of the covalent or electrostatic binding energies) is delivered by momentum transfer from the incident particles. The maximum fraction of the energy transfenable from an incident particle is ... 

Chapter 4.3. discusses the explained theory for choosed examples. For several cracks the output is pre-calculated by using the impulse response and compared with measurement data. 

Methods from the theory of LTI-systems are practicable for eddy-current material testing problems. The special role of the impulse response as a characteristic function of the system sensor-material is presented in the theory and for several examples. 

Due to its importance the impulse-pulse response function could be named. .contrast function". A similar function called Green s function is well known from the linear boundary value problems. The signal theory, applied for LLI-systems, gives a strong possibility for the comparison of different magnet field sensor systems and for solutions of inverse 2D- and 3D-eddy-current problems. 

Walsh A M and Loring R F 1989 Theory of resonant and nonresonant impulsive stimulated Raman scattering Chem. Phys. Lett. 160 299-304... 

A final comment on the interpretation of stochastic simulations We are so accustomed to writing continuous functions—differential and integrated rate equations, commonly called deterministic rate equations—that our first impulse on viewing these stochastic calculations is to interpret them as approximations to the familiar continuous functions. However, we have got this the wrong way around. On a molecular level, events are discrete, not continuous. The continuous functions work so well for us only because we do experiments on veiy large numbers of molecules (typically 10 -10 ). If we could experiment with very much smaller numbers of molecules, we would find that it is the continuous functions that are approximations to the stochastic results. Gillespie has developed the stochastic theory of chemical kinetics without dependence on the deterministic rate equations. 

Another theory for the action of stimulant diugs in ADHD involves effects on nonstiiatal monoamine systems. Frontal cortical dopamine, norepinephrine, and serotonin are clearly important in cognitive functioning and impulse control. These neurotransmitters directly modulate reward-related behaviors associated with the striatal dopamine system. Moreover, the amygdala may be pharmacologically influenced leading to enhanced... 

These apparently paradoxical phenomena have been explained by Andronov 4 from the physical point of view, a major point being that at the two nonanalytic points impulsive inputs of energy occur which compensate for the continuous dissipation of energy on the analytic arcs of convergent spirals33 (compare with the theory of clocks of Section 6.9). 

The theory, due to Clausius, that in the thermoelectric current, as in other electric currents, the electricity alone moves, under the impulse of the constantly maintained potential differences at the junctions. 

The curve marked ion-dipole is based on the classical cross-section corresponding to trajectories which lead to intimate encounters (9, 13). The measured cross-sections differ more dramatically from the predictions of this theory than previously measured cross-sections for exothermic reactions (7). The fast fall-off of the cross-section at high energy is quite close to the theoretical prediction (E 5 5) (2) based on the assumption of a direct, impulsive collision and calculation of the probability that two particles out of three will stick together. The meaning of this is not clear, however, since neither the relative masses of the particles nor the energy is consistent with this theoretical assumption. This behavior is, however, probably understandable in terms of competition of different exit channels on the basis of available phase space (24). 

Topie and age group Experiments and phenomena Historie theories as impulses... 

Most findings for emotional functioning are also consistent with this theory. Mood states become more positive until arousal, including the caffeine component, crosses threshold, then deteriorate with further arousal increments. Happiness similarly increases, then decreases as arousal rises. Data on such arousal-relevant personality dimensions as extraversion and impulsivity clearly support the inverted-U hypothesis. What this suggests, then, is that many of the effects of caffeine are mediated by its effect on arousal and its interaction with other arousal agents. Such a finding... 

To understand the chemical-imbalance theory, it will be helpful to first review some basic aspects of how the brain functions. The human brain contains about ioo billion nerve cells called neurons. Each neuron is like an electrical wire with many branches. When a neuron fires, electrical impulses travel along its length from one end to the other. When an impulse reaches the end of a branch, it may stimulate the next neuron, influencing whether or not it fires. 

What was the scientific basis for these chemical-imbalance theories As I noted above, norepinephrine and serotonin are now known to be neurotransmitters - chemicals that transmit nerve impulses from one neuron to another. But in the 1950s knowledge of neurotransmission was sketchy at best. The presence of norepinephrine in the nervous system was not demonstrated until 1954, and evidence that dopamine functions as a neurotransmitter was not reported until 1958. As late as i960 the idea that neurotransmission is largely chemical in nature, though advocated by a group of largely British scientists, was not yet widely accepted.10... 

A second theory of phantom pain suggests that second-order neurons in the dorsal horn of the spinal cord become hyperactive. Spontaneous firing of these neurons causes transmission of nerve impulses to the brain and the perception of pain. 

In Bohr s theory, only estimates of maximum and minimum impact parameters are necessary. Better computations are required for determining the transverse distribution of lost energy or the effect of secondary electrons. The minimum impact parameter according to classical mechanics is ze2/mv2 from angular momentum consideration in quantum mechanics, it is h /mv. In practice, the larger of these two is taken. Also, the impulse approximation used by Bohr for the maximum impact parameter is not an absolute rule energy transfer beyond bmax falls off exponentially (Orear et al., 1956 Mozumder, 1974). 

Alchemical thinking helped lead the Society to interpret the implications of modem atomic theory in a way that emphasized the unity of matter (and even of energy) that saw oneness, rather than disunity and distinctness, as a major substratum of atomic theory and that pushed to spiritualize this principle. This grasping for ever simpler and more basic unity is, of course, not so uncommon an impulse in twentieth-century physics. (Consider unified field theories, and even the Theory of Everything in more recent physics.) Alchemy allowed the scientists and Hermeticists of the Alchemical Society to re-enchant science by positing the origins of the modem scientific push for unity in ancient Hermetic spirituality. 

Norepinephrine-Blocking Medications. There is some evidence that exaggerated norepinephrine activity plays a part in the affective instability, aggression, and impulsivity seen in a variety of psychiatric illnesses including the personality disorders. This may in fact explain why the TCAs, which tend to increase norepinephrine activity, have not proved helpful for BPD. Based on this theory, beta blockers, which interfere with norepinephrine activity at the beta-adrenergic receptor, may help in the treatment of impulsivity and aggression in those with BPD. 

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