Oscillating time-temperature

Time-temperature superposition. Because of the relatively strong relaxations in the frequency range at room temperature (300 K), oscillation measurements were also performed at 345, 390 and 435 K in addition the D networks were measured at 265 K. 

For noninteracting control loops with zero dead time, the integral setting (minutes per repeat) is about 50% and the derivative, about 18% of the period of oscillation (P). As dead time rises, these percentages drop. If the dead time reaches 50% of the time constant, I = 40%, D = 16%, and if dead time equals the time constant, I = 33% and D = 13%. When tuning the feedforward control loops, one has to separately consider the steady-state portion of the heat transfer process (flow times temperature difference) and its dynamic compensation. The dynamic compensation of the steady-state model by a lead/lag element is necessary, because the response is not instantaneous but affected by both the dead time and the time constant of the process. 

If a film is heated by the continuous-operated or oscillated lasers, temperature overshoot takes place in ftie films of smaller values of CoX /a within a very short period of time. The effect of ftie laser heat source on ftie temperature distribution in the film becomes larger in the thin film. In other words, if ftie absorption coefficient, b, of the laser increases, ftie temperature is more dependent on the laser heat source in a ftiin film thMi in a ftiick film. Overshoot and oscillation of thermal wave depend on the frequency (o of the heat source time characteristics. 

Cationic polymerization is terminated by the presence of contaminants, including water. In experiments to note the combined effects of temperature and humidity on tack-free time, temperature of the substrate was controlled by means of the oscillating stage, as described above, and humidity was controlled by conducting the experiments in an environmental chamber. Results are shown in Table XI. 

FIGURE 6.1 Torque -time (temperature) curves obtained with the oscillating disc rheometer (ODR) and the moving disc rheometer (MDR). 

The oscillating force which is imposed on the specimen can be deconvoluted as the superposition of a number of excitations at different frequencies [47]. By summing the contributions from all frequencies the total material dissipation can be calculated. In analogy to time-temperature superposition, the glass transition activation energy can be determined through the use of results obtained at multiple frequencies. 

Thermal event start System delay time Temperature difference between set value and actual value Heating power Creep case Oscillating case Aperiodic limit... 

Two such processes are the excitation of either thermal crystal lattice oscillations (spin-lattice relaxation) and/or excitement of oscillation in the nuclear magnetic system (spin-spin relaxation). Both processes are characterized by constants 7T and T2 71 is the spin-lattice relaxation time and T2 is the spin-spin relaxation time. Valnes of 71 and T2 render an essential influence upon the form of resonance curves. On the other hand, the relaxation processes depend on the mobility of one atomic group or another in the substance. So, experimental measurement of the relaxation processes serves as a method of measurement of the dynamics of chemical conversions depending on time, temperature, chemical conversion particularity and other factors. 

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