Stop time effect

After a shut-down in high vacuum of 10 Torr or better it was sometimes found that there is a brief increase in the friction. This disappears after a short period of operation . In other cases there may be a decrease in friction during a shutdown. The effect is known as the "stop time effect". Matsunaga s first investigation confirmed that the presence of contaminants was involved in this phenomenon, and showed that the friction increase on re-starting could be described by an equation based on a simple model of contaminant diffusion within the lubricant film. 

The transient increase in friction in vacuum known as the "stop time effect" has been discussed earlier. The extent of the transient increase depends on the... 

FIGURE 5.16 The effect of desensitization on stop-time mode measurements. Bottom panels show the time course of response production for a system with no desensitization, and one in which the rate of response production fades with time. The top dose response curves indicate the area under the curve for the responses shown. It can be seen that whereas an accurate reflection of response production is observed when there is no desensitization the system with fading response yields an extremely truncated dose-response curve. 

In projecting results of short-term trials over patients lifetimes, it is typical to present at least two of the many potential projections of lifetime treatment benefit. A one-time effect model assumes that the clinical benefit observed in the trial is the only clinical benefit received by patients. Under this model, after the trial has ended, the conditional probability of disease progression for patients is the same in both arms of the trial. Given that it is unlikely that a therapy will lose all benefits as soon as one stops measuring them, this projection method generally is pessimistic compared to the actual outcome. A continuous-benefit effect model assumes that the clinical benefit observed in the trial is continued throughout the patients lifetimes. Under this model, the conditional probability of disease progression for treatment and control patients continues at the same rate as that measured in the clinical trial. In contrast to the one-time model, this projection of treatment benefit most likely is optimistic compared to the treatment outcome. 

Because the literature on the effects of psychedelics frequently notes alterations in spatial perception, in size, and in the speed with which time passes, the conditions of no depth, expanded depth, blurred vision, clear and distinct vision, diminished size, enlarged size, fast time, slow time, and stopped time have been selected for inclusion here. Each of the time conditions involves an alteration of time by keying it to a metronome, as well as a verbal alteration of time. Interspersed through all the other conditions are control conditions, in which the subject is hypnotized, but no sugges-... 

The chromatographic stage is not interrupted and therefore no stop-start effects will create disturbances. The peaks are separated in the storage loops, and therefore the NMR measurement time is not limited and will not decrease the performance of other peaks. In complex chromatograms the chance of finding the peak(s) of interest is dramatically increased. As in the direct stop-flow mode, the static conditions provide stability and the best NMR conditions for the acquisition of all kinds of high-resolution ID and 2D NMR spectra. 

FIGURE 10.22 Electropherograms of the products following on-chip tryptic digestion of bovine insulin B-chain at 37°C. The flow in the reaction channel was stopped for different times to study the effect on the reaction. Control runs (see the flat curves) without insulin B-chain were performed in the continuous flow mode and in a flow with a stop time of 6 min. The arrows indicate the migration time of benzylamine, which was added as an EOF marker. All electropherograms are plotted on the same scale with an offset for clarity [1058]. Reprinted with permission from Elsevier Science. 

A more easily defined situation can be seen in production of Macintosh apples. These apples, which make up a very significant portion of the northeastern U.S. apple crop, are notorious for dropping off the tree as soon as they have reached maturity. Prior to the development of stop-drop chemicals, it was expected that at least 20-25% of the crop would go on the ground before harvest. The stop-drop programs of today can virtually eliminate this problem, spread the harvest over a longer period of time, and improve the quality of the fruit as it is sold fresh or as it comes out of long-term storages. The value of the stop-drop effect alone could be calculated to be at least 500 on a 300-box-per-acre yield. 

The contact time is the time during which the AHA is left to act before being neutralized and stopping its effect. It depends more on the appearance of erythema than on the... 

If the signal period is longer than the sum of the start-stop time and the TAC/ADC dead time (Fig. 7.82, left) the dead time ends before the next laser pulse. If a second photon is detected during this signal period it is lost. Consequently, the situation is exactly described by the classic pile-up effect. 

This effect is known as time dilation. Of course, for the passengers waiting at the tram stop and watching the eloek, its two ticks would be separated by exactly 1 second. If Einstein took his watch out of his waistcoat pocket and showed it to them through the window, they would be amazed. The seconds will pass at the tram stop, while Einstein s watch would seem to have stopped. This effect has been double-checked experimentally many times. For example, the meson lives such a short time (in the coordinate system associated with it), that when created by cosmic rays in the stratosphere, it would have no chance of reaching a surface laboratory before decaying. Nevertheless, as seen from the laboratory coordinate system, the meson s clock ticks very slowly and mesons are observable. 

Extensive work has been performed to establish effective clearances and safety distances in order to protect machine operators and others. Widely accepted safeguarding dimensions are defined by standard ANSI/ASME B15.1. Safety distances are an important consideration in the designation of machine safeguarding. Safety distances are a function of stopping time of machines and the speed at which a machine operator or observer can inadvertently move a body part into a hazard zone. Safety distance considerations are defined in standards and regulations such as OSHA publication 29CFR 1910 and ANSI standard ANSI B11.2... 

Answer by author Other than the length of time required to obtain a constant adsorption pressure after the adsorbate feed was stopped, no long time effects were investigated. No experiments were made on the speed of adsorption. 

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