TPR times

Blood pressure (BP) is a product of the total peripheral resistance (TPR) times the cardiac output (CO). The CO is equal to the heart rate (HR) times the stroke volume (SV). The autonomic (neural) system helps regulate the BP through feedback control involving the baroreceptors, the cardiovascular centers in the brain stem, and the PANS and SANS, which act in an opposing but coordinated manner to regulate the pressure. 

A simulated TPR process was carried out during this study, whereby the tool lid was opened approximately 1.5 mm for a three second duration. TPR was applied at various time intervals throughout the evaluation. Two mechanical clasps affixed to the top and bottom halves of the tool precisely controlled the gap opening. These clasps were manually opened and closed at the desired TPR time interval. 

Figure 1.15 Initial FTC versus TPR Time - Cushion Formulation...

Delta of Initial to Final FTC vs. TPR Time Cushion Formulalion... 

Back formulations V, VI, VII and VIII found in Table 1.3, were all run at TPR times of 70-150 seconds and no TPR. Collapsed foam was encountered at TPR times of 70 seconds for all formulations. FTC values for the back control formulation V had an initial FTC value of 138 N/323 cm at a 90 TPR and 160 N/323 cm at a 100 second TPR time. Formulations VI, VII and VIII produced a maximum initial FTC value at a 90 and 100 second TPR of 138 N/323 cm. Control formulation V and experimental formulations VI, VII and VIII provided acceptable FTC values at 90 and 100 second TPR times (Figures 18 and 19). No significant difference in FTC was realised with these formulations at these TPR times. The foam quality at this TPR range was also very good. When TPR times were increased to 120 seconds for control formulation V, initial FTC increased to 645 N/323 cm. Experimental formulations VI, VII and Vin maintained acceptable initial... 

Physical properties were evaluated for all the formulations found in Tables 1.2 and 1.3 with TPR being applied at various times throughout the moulding cycle as previously discussed. Additionally, physical properties were evaluated with no TPR being applied. The 90 second TPR time was chosen to be the minimum time to perform TPR for all formulations. Physical property pads were produced at this TPR time. Extended TPR... 

Tables 1.6 and 1.7 provide the physical property comparison for all formulations I-Vin at a 90 second TPR time. The data clearly demonstrates that physical properties are maintained, and in several cases improved, compared to the control formulations. For example, airflow can be improved by as much as 20% as compared to both cushion and back control formulations, when using Dabco BL-53 and experimental silicone surfactants...

Tables 1.8 and 1.9 illustrate the physical properties for selected formulations at TPR times of 130 and 150 seconds. Control physical properties were not evaluated at these extended TPR times since the control formulations I and V had visual surface distortions and severe scalloping. The data in Tables 1.8 and 1.9 demonstrate that the TPR window can be extended by using these newly developed additives without negative impact to the physical properties. In fact, the data indicates that several of the physical properties for the experimental formulations exceed the control formulation properties at the 90 second TPR time. For example, airflow measurements are improved when utilising the extended TPR times. Improvements are greater than 10% with the Dabco BL-53 catalyst and experimental silicone surfactant combinations. Additional improvements are also observed with wet set and 50% humid aged compression set values.

Fig. 1.80.3. Course of the freeze drying after the product has been frozen as per Fig. 1.80.1 (bottom). Nomenclature as in Figs. 1.80.1 and 1.80.2. The rise of T is different. The optima) time frame for the change from MD to SD can not be estimated from the Tpr plot (Fig. 7 from [ 1.631).

After 3 days, cooling of the shelves was terminated and the temperature of the bones rose to -15 °C. The operation pressure in the plant was always 0.1 mbar or less. The first 3 days can be saved, since at Tpr -35 °C / s is approx. 0.2 mbar. The amount of water sublimated during these 3 days was small compared with the amount sublimated thereafter at Tpr -15 °C, since ps 1,5 mbar. From the third day on, seven times more water/unit time can be sublimated than in the previous days. Therefore it is recommended to rise from the beginning to -15 °C. The ice temperature at the sublimation front Tkc, established under these conditions, can be measured by BTM, as shown in Section 1.2.1. 

Tsh has been increased to +40 °C, but only until Tpr reached +25 °C, at which time Tsh was reduced to +30 °C. By this step the total drying time is reduced by 15 %. 

In temperature programmed reduction one follows the degree of reduction of the catalyst as a function of time, while the temperature increases at a linear rate. We follow the theoretical treatment of the TPR process as given by Hurst et al. [1] and by Wimmers et al. [8]. Formally, one can write the rate expression for the reduction reaction in (2-1), under conditions where the reverse reaction from metal to oxide can be ignored, as... 

The AES results indicate that the aniline coverage is more than two times greater than the maximum coverage based on van der Waals radii. The TPR results show this species is too stable to be a condensed multilayer. Hence, we conclude that aniline polymerized forming a very stable polymer layer. In addition, the absence of infrared bands corresponding to C=C stretches or ring vibrations indicated that the poly(aniline) film was formed with the phenyl rings parallel to surface. The infrared results also indicated that the poly(aniline) film had N-H bonds which were oriented perpendicular relative to the surface. 

Catalytic reactions of methanol on an Mo(112)-(lX2)-0 surface under a constant flow of CH3OH and 02 (10 6—10 5 Pa) were monitored as a function of reaction time by the temperature-jump method. Total amounts of the products are summarized in Table 8.3. When only CH3OH was fed, the reaction rate exponentially decayed with reaction time. After the reaction ceased in both conditions, the surfaces were covered with nearly 1 ML of C(a) (Table 8.3) and the sharp (1X2) LEED subspots of the surface before the reaction almost disappeared due to an increase in background intensity. As shown in Table 8.3, the selectivity of the reaction at 560 K is similar to that obtained by TPR (Table 8.2). The C(a) species formed with 26% selectivity cover the surface, resulting in the exponential decay of the reaction rate. O(a) species are also formed on the surface but they are desorbed as H20 by reaction with hydrogen atoms. It should be noted that neither C(a) nor a small amount of O(a) change the selectivity in this case. 

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