Thermal environment corrected effective temperature

Nitrous oxide and ozone were subjected to infra-red radiation at different temperatures and with different frequencies. These are very divergent types of gas reactions. The decomposition of nitrous oxide was carried out in a quartz vessel at high temperatures, and in a vessel containing a fluorite window at lower temperatures. The radiation density in the infrared was increased by means of an arc lamp. With the reaction vessel at 883°K., the upper limit of the effective increase is approximately 2.5mu. At this wave-length the input from the external source, after due correction for absorption and unequal emission, is several times that available from the immediate thermal environment. No change in reaction velocity was found. In the case of ozone, the upper limit can be... 

Heat transfer in micro-channels occurs under superposition of hydrodynamic and thermal effects, determining the main characteristics of this process. Experimental study of the heat transfer in micro-channels is problematic because of their small size, which makes a direct diagnostics of temperature field in the fluid and the wall difficult. Certain information on mechanisms of this phenomenon can be obtained by analysis of the experimental data, in particular, by comparison of measurements with predictions that are based on several models of heat transfer in circular, rectangular and trapezoidal micro-channels. This approach makes it possible to estimate the applicability of the conventional theory, and the correctness of several hypotheses related to the mechanism of heat transfer. It is possible to reveal the effects of the Reynolds number, axial conduction, energy dissipation, heat losses to the environment, etc., on the heat transfer. 

The studies of Criddle et al. [17] on carrot and tomato cell cultures outlined basic procedures for isothermal heat rate measurements of plant tissues. Samples are placed in an ampule, sealed to prevent any water vapor loss, placed in the calorimeter at the desired temperature and the heat rates recorded directly. Figure la shows the type of thermogram obtained. There is an initial rapid change in recorded heat rate while sample and ampules are thermally equilibrated. Following equilibration, (about 45 min in this example) the amplitude of the thermal signal is corrected for baseline values obtained with empty ampules to yield the sample metabolic heat rate. Temperature may then be adjusted to new values to establish temperature coefficients of heat rate or the ampules may be opened and the sample environment modified before the ampule is resealed and re-equilibrated for evaluation of effects of the modification on plant activities. Because plants are ectotherms that live in a variable temperature environment, temperature dependence studies using sequential i.sothermal mea.surements are essential for characterization of plant physiological properties. 

---