Hindered external motions

Pray what is motion, by which Fire acts, but a mechanical affection or mode of matter Are there not certain laws of motion, which are every day found out or better explain d This state or mode of matter is called impetus or vehcity, and it is not a part of matter, but an effect of an impression or impulse given from an external or moral agent, which impulse continues till it meets with an obstacle hence a projection made, when there is no medium or attraction to resist, wou d be perpetual, let it proceed from what cause we please now tho fire is a natural agent, that has receiv d its impulse from the Almighty Hand, this does not hinder us from finding out its properties, nor from calhng its properties mechanical. 

To summarize this subsection, we have shown that, in principle, a unidirectional motion of a functional molecular group can be induced by LCT fields. Quantum calculations revealed that it is possible to trigger a rotational dynamics in one or the other direction. The quantum dynamics is very much alike to that of a swarm of classical trajectories. This proves that the intuitive picture of a single-particle orbit driven out of the potential wells is valid. In particular, a change of the field strength triggers a hindered rotation that can be timed to move the then freely rotating particle selectively in the counterclockwise or clockwise direction. We have not addressed the role of the overall molecular orientation with respect to the direction of the external field... 

The speed of kinesin calculated as a function of the external force showed that applied forces influence the kinesin motion in a rather complicated way (Figure 3.2, left panel) The speed of kinesin shows a maximum at an intermediate external load ( 5pN) and even larger external load slows down the kinesin walking speed, consistent with the experimental results of Carter and Cross [51]. A hindering force slows down the speed of kinesin in the force range of 0 to about 8pN (for [ATP] = 1 mM), without changing the direction of the net motion and the stall force appears to be insensitive to the ATP concentration, which decreases from about 8pN at 5mM of ATP to 7 pN at 5 pM of ATP. 

However, a complete set of molecular energy levels needed for calculation of the partition function (Eq. (1.16)) is not available in most cases. The arising problem can be simplified through the approximation that the different types of motion such as vibration, rotation, and electronic excitations are on a different timescale and therefore are unaffected by each other and can be treated as decoupled motions. This leads to a separation of Q into factors that correspond to separate partition functions for electronic excitations, translation, vibration, external molecular rotation, and hindered and free internal rotation ... 

A chain molecule as part of a thermoplastic body is in thermal contact with other chains and — at room temperature — constantly in motion. The atoms vibrate and take part in the more or less hindered rotations of groups and even of chain segments. With no external forces acting all molecular entities try to approach — and fluctuate around — the most stable positions attainable to them. The action of external forces causes — or maintains — displacements of the chain from those positions and evokes retractive forces. Let us consider a chain or a bundle of chains in thermal contact with the surrounding and at constant volume. The condition of thermodynamic stabihty of such a system is that the free energy... 

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