Time-temperature indicator, evaluation

A temperature of 1750 F. (or 2000 F.) is reached in 1 minute on the coating surface and maintained for 0.5 hour. The pyrometers indicate the temperature differential (insulative ability of the fire-retardant coating) between the name temperature and the bare metal temperature. Results should be recorded on a graph indicating time vs. temperature and evaluated on a relative basis. 

In DIE, temperature-versus-time curves indicate the progress of the reaction. Kinetic processes can be evaluated (usually for reactions having half-reaction times greater than 5 sec), and from the total temperature change, heats of reaction can be evaluated. The general equation for a DIE curve is... 

The comparison of these different indexes (Table 10.4) shows the difficulty of evaluating the viticultural potential of an area based solely on a temperature criterion, even when corrected for light exposure time. These indices are, however, useful in choosing early- or late-ripening grape varieties to plant in a new vineyard. 

Since creep is considered as a key weaknesses of pressure sensitive adhesives, various specific test methods and standards have been developed to evaluate the creep resistance of pressure sensitive adhesives like, for example, in the European Standard EN 1943 ( Self adhesive tapes-Measurement of static shear adhesion ), FINAT (Federation Internationale des Fabricants et Transformateurs d Adhesives et ThermocoUants sur Papier et autres Supports), test method FTM 8 (Resistance to shear from a standard surface), or the Pressure Sensitive Tape Councils test method PSTC 107 (International Standard for Shear Adhesion of Pressure Sensitive Tape) by either monitoring the time- and load-dependent displacement of an adhesive specimen under shear load or simply recording the time to failure. The result of the so called SAFT-test ( Shear Adhesion Failure Temperature ) indicates the temperature at which a sample that has been subjected to an environment with steadily rising temperature under static shear load has failed. 

BaTiOj Kinetic Analysis. The BaTiOj kinetic analysis was performed using the as-produced anatase precursor (i.e., without drying or washing), whereas the as-received hydrous Ti gel was suspended in C02-free deionized water before introduction to the Ba(OH)2 solution. Reactions were performed with a 1.1 1 Ba Ti molar ratio and 0.2M Ba(OH)2 concentration at 75 C by addition of the Ti and Ba precursor suspensions into the hot sealed Teflon reactor under argon atmosphere. The time zero designation indicates the extraction time of the first sample upon stabilization at the desired solution temperature. Quantitative evaluation of the fractional crystallinity and observation of microstructural evolution were performed by XRD and HRTEM, respectively. 

For the tin pest reaction, the time exponent, n, is 3 [60]. Using the data in Ref. 52, it is approximated that a 40% volume fraction transforms after 1.5 years at —18°C, which yields a calculated value of K= 5.7 x lO sec when substituted into Eq. (2). It was also noted in Ref. 52 that tin pest was evident after 0.58 years. This results in approximately 2% of the volume transformed based on the previously calculated value of K. These time-temperature transformation reaction kinetics yield the classic S-shaped curves when the volume fraction transformed is plotted against the log of time. On that basis, it would require approximately 8.4x 10 min to transform 50% of a 99.5Sn-0.5Cu alloy. Other measurements of reaction kinetics in pure tin [56] are given in Table 6 which indicates that the time to transform a 50% volume fraction at — 15°C is 72 min. This difference, a factor of 10,000, is due to several parameters alloy additions, surface condition, residual stress, and prior thermal history. This very large difference in reaction rate illustrates the difficulty encountered when a tin-based solder is evaluated for use in microelectronic assemblies. Fig. 14 depicts the effect of temperature on the growth rate of the white-to-gray tin transformation. The maximum growth rate occurs at —40°C and decreases by a factor of 10 as the temperature approaches 0°C [56]. 

The influence of incubation temperature on liposome uptake by CVl cells was examined. The cells were ineubated with either the pol5mier-modified or the unmodified EYPC liposomes containing a fluorescent lipid, NBD-PE, at 37 or 42°C for 3 h. The amount of liposomal lipid associated with the cells after the incubation was evaluated from the fluorescence intensity of NBD-PE in the cells (Fig. 6). For the unmodified liposome, approximately the same amount of liposome was taken up by the cell at both temperatures, indicating that temperature does not affect the liposome uptake in this temperature region. In the case of the polymer-modified liposome, the amount of liposome taken up by the cell at 37°C was slightly lower than that of the unmodified liposome at the same temperature. However, at 42°C the amount became two times higher than that of the unmodified liposome. In... 

The effectiveness of a number of crude oil dispersants, measured using a variety of evaluation procedures, indicates that temperature effects result from changing viscosity, dispersants are most effective at a salinity of approximately 40 ppt (parts per thousand), and concentration of dispersant is critical to effectiveness. The mixing time has little effect on performance, and a calibration procedure for laboratory dispersant effectiveness must include contact with water in a manner analogous to the extraction procedure otherwise, effectiveness may be inflated [587]. Compensation for the coloration produced by the dispersant alone is important only for some dispersants. 

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