Heating experiments, temperature

Temperature- and time-resolved SCTA techniques have major advantages over conventional TA techniques. Temperature-resolved SCTA can give information on reaction mechanisms that are not apparent from corresponding linear heating experiments. Temperature-resolved SCTA is also particularly advantageous for the in situ preparation of porous or finely divided solids by thermal decomposition and for the study of catalytic materials. Time-resolved SCTA is particularly useful in conjunction with an evolved gas analysis system whereby time resolution of evolved gases leads to their unambiguous identification. 

Ogawa, T., and Ikawa, K., High Temperature Heating Experiments on Unirradiated ZrC-Coated Fuel Particles, J. Nucl. Mater., 99(l) 85-93 (July 1981)... 

The blue color of 83 has been observed in numerous experiments. For example, a brilliant blue color occurs if a potassium thiocyanate melt is heated to temperatures above 300 °C [132] or if eutectic melts of LiCl-KCl (containing some sulfide) are in contact with elemental sulfur [132, 133], if aqueous sodium tetrasulfide is heated to temperatures above 100 °C [134], if alkali polysulfides are dissolved in boiling ethanol or in polar aprotic solvents (see above), or if borate glasses are doped with elemental sulfur [132]. In most of these cases mixtures of much 83 and little 82 will have been present demonstrating the ubiquitous nature of these radicals [12]. 

Additional experiments have shown that the formation of ammonium nitrate is a reversible process due to the observation that the catalyst recovers its original activity when heated at temperatures above 200 C [33,41],... 

A comparison of results for fire effluents from full scale and small scale fire tests has to be done in steps. A full scale fire is a developing event where temperature and major constitutions changes continously. A small scale fire test either take one instant of that developing stage and try model that or try to model the development in a smaller scale. On a priority one level rate of heat release, temperature, oxygen concentrations and the ratio of C02/C0 concentrations have to be similar for a comparison. The full scale fire experiments reaches a temperature of 900 C at the moment of flashover, while the small scale fire tests are reaching temperatures just above 400 °C for NT-FIRE 004 and the cone experiments. For the DIN 53436-method the temperature was set to 400 °C. 

We have been rather glib so far when using words such as heat and temperature , and will be more careful in future. Heat is merely one way by which we experience energy. Everything contains energy in various amounts, although the exact quantity of the energy is not only unknown but unknowable. 

As stated above, when probes with specific adsorption characteristics are used, additional chemical information can be extracted from adsorption-desorption experiments. Temperature-programmed desorption (TPD) in particular is often employed to obtain information about specific sites in catalysts [55,56], The temperature at which desorption occurs indicates the strength of adsorption, whereas either the amount of gas consumed in the uptake or the amount of desorption upon heating attests to the concentration of the surface sites. The most common molecules used in TPD are NH3 and C02, which probe acidic and basic sites, respectively, but experiments with pyridine, Oz, H2, CO, H20, and other molecules are often performed as well [57-59], As an example, the ammonia... 

To make cut pile carpets, two strands of BCF yarns are twisted together and heat-set with steam using a Superba heat setting machine at 135-145 °C or at 175-195 °C when heat-set with super-heated steam in a Suessen. An experimental design experiment [94] showed the higher the heat set temperature, then the lower is the bulk of the final carpet, but there is an increase in the tip definition and walk performance. The tufted carpets are then dyed with disperse dyes at atmospheric boil [95] in a continuous or a batch process. PTT carpets showed excellent resiliency in walk test experiments, equivalent to a nylon and much better than both PET and polypropylene, had lower static charge of <3.5 kV, and were resistant to coffee, mustard, betadine, red acid dyes and other stains [96],... 

Figure 11. Schematic representation of a laser heating experiment in the DAC. The IR laser beam is directed onto the absorbing sample immersed in a compression medium acting also as thermal insulator. The thermal emission of the sample is employed for the temperature measurement, while the local pressure is obtained by the ruby fluorescence technique (see next section).

Figure 12. Typical procedure to measure the sample temperature in a laser heating experiment. The experimental emission spectrum (thick line) htted according to Eq. (1) (thin line) gives a sample temperature of 3000 K.

The carriers of anomalous Ne-E (two forms of which were now known) and Xe-S were quickly identified. Neon-E(H), which is released at temperatures above 1200 °C in stepped heating experiments, and Xe-S were found to be carried in presolar silicon carbide (Tang and Anders, 1988). Neon-E(L), which is released below 900 °C, was found to be carried by presolar graphite (Amari et al., 1990). Once these presolar compounds were shown to be present in meteorites, studies were carried out to identify all of the different types of meteorites that carry presolar grains. Concentrated searches for other presolar phases were also initiated, and many new types of presolar grains have been found. This work is just beginning, however, and we cannot yet account for the majority of the presolar components that must have been present in the Sun s parent molecular cloud. 

The effect of the composition of the powder, in particular of the content of nitroglycerine upon the volume of gases, heat and temperature of explosion is illustrated by the figures in Table 165 (according to Brunswig) and by the curves in Fig. 185 (on the basis of another series of experiments by the same author). 

Measurements on cooling are often difficult to carry out, so that heating experiments are usually substituted. These may lead, however, to hysteresis phenomena if heating and cooling are not carried out at similar rates, or if annealing occurred close to the glass transition temperature before analysis. Figure 5 shows typical apparent heat... 

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