Motion, gating

A simple example of an area meter is a gate valve of the rising-stem type provided with static-pressure taps before and after the gate and a means for measuring the stem position. In most common types of area meters, the variation of the opening is automatically brought about by the motion of a weighted piston or float supported by the fluid. Two different cyhnder- and piston-type area meters are described in the ASME Research Committee on Fluid Meters Report, op. cit., pp. 82-83. 

A time-and-motion modeling mind-set can easily blinker analysis of how best to improve the value created by research. Truly useful simulations of drug discovery must go beyond simplistic assumptions about yields at stage gates and address the causes of failure, starting to quantify the common concept of pipeline quality. ... 

Figure 1. Schematic Diagram of the off-axis radiant heated reactor. A. cell body B. linear/rotary motion feedthrough C. transport rod D. projector bulb E. reflector F. insulated stainless steel enclosure G. air cooling port H. gas inlet I. gas outlet/pumping port J. chromel/alumel thermocouple K. high vacuum gate valve L, sample mount.

Fig. 6 Dynamic molecular motions can gate DNA-mediated charge transport. Two time constants (5 and 75 ps) are observed for hole transfer from photoexcited ethidium, tethered and intercalated near the end of a 14-base pair DNA duplex, to a base analog, 7-deazaguanine, in DNA. The 5 ps time constant, which is independent of distance between 10-17 A, is due to direct hole transfer, while the 75 ps time constant corresponds to reorientation of the ethidium before hole transfer. Adapted from [96]... 

The analogy drawn between -stacked solids and duplex DNA has provided a useful starting point for experiments to probe and understand DNA-medi-ated CT. As with the -stacked solids, the DNA base pair array can provide an effective medium for long range CT. Mechanistically, however, the differences between DNA and these solid state materials may be even more important to consider. Duplex DNA, as a molecular -stacked structure, undergoes dynamical motion in solution. The time-dependent and sequence-dependent structures that arise serve to modulate and gate CT. Indeed in probing DNA CT as a function of sequence and sequence-dependent structure, we may better understand mechanistically how CT proceeds and how DNA CT may be utilized. 

Physical security Security systems and architectural features that are intended to improve protection. Examples include fencing, doors, gates, walls, turnstiles, locks, motion detectors, vehicle barriers, and hardened glass. 

Figure 7. Guest molecules egress from hemicarcerands (Host) through conformational motions known as gating. Gate-opening occurs by (a) French door and (b)...

Treptow, W., Marrink, S.J., Tarek, M. Gating motions in voltage-gated potassium channels revealed by coarse-grained molecular dynamics simulations. J. Phys. Chem. B 2008, 112, 3277-82. 

In an attempt to combine band-Uke charge carrier motion realized in an -inevitably fragile - crystalline FET structure with structural robustness and flexibility, Sakanoue and Sirringhaus [167] prepared FETs using spin coated films of 6,13-bis(triisopropylsilylethynyl)(TIPS)-pentacene films in contact with a perfluorinated, low dielectric-constant polymer gate electrode. The (linear) hole mobility at room temperature is 0.8 cm /V s with tendency of an apparent band-like negative temperature coefficient of the mobility (d/i/dT < 0). 

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