Raising temperature alternately method

Raising temperature alternately method. The method of raising temperature is as follows. Steps of raising temperature slowly-constant temperature- are undertaken alternately in order to prevent rising rate of temperature from exorbitant. It is because both the reduction rate is very fast to cause too high concentration of water vapor and the reaction rate for formation ammonia on the reduced catalyst is very fast to cause too fast temperature rising due to the heat of reaction. 

An alternative method of raising the vapour pressure of a solvent is to increase the experimental temperature. The consequence should be both a decrease in the rate of degradation and an increase in the limiting degree of polymerisation (i. e. higher final R.M.M. value) as a result of the lower intensities of cavitational collapse at the higher temperatures (see Section 2.6.2). Tab. 5.5 and Fig. 5.16 [41] show these predictions are borne out in practice. 

The energy released by the combustion is sufficient to raise the temperature well above the melting point of iron, 1535 °C. One of the incentives for development of alternative methods of producing metals is the hope of finding less energy-intensive processes. 

An alternative method of overcoming the time delay of mixing is to use a relaxation method. An equilibrium mixture of reagents is preincubated and the equilibrium is perturbed by an external influence. The rate of return, or relaxation, to equilibrium is then measured. The most common procedure for this is temperature jump (Figure 4.6).13 A solution is incubated in an absorbance or fluorescence cell and its temperature is raised through 5 to 10°C in less than a microsecond by the discharge of a capacitor (or, in more recent developments, in 10 to 100 ns by the discharge of an infrared laser). If the equilibrium involves an... 

An alternative method is by sulphonation. Evans describes the following method for toluene. A measured quantity (about 50 c.c.) of toluene is added to 150 c.c. of 98 per cent, sulphuric acid in a 250 c.c. graduated cylinder. The cylinder is carefully shaken, so that the temperature does not exceed 4 and the stopper is lifted frequently to avoid excess pressure. The cylinder is allowed to stand for five minutes and vigorously shaken for three to four minutes. The liquid is transferred to a separating funnel, the neck of which is narrow and graduated in 1/100 c.c. The bottom outlet of the funnel is connected by a rubber tube with a mercury reservoir. By this means the acid can be raised until the paraffin layer is contained in the narrow neck. The volume is read after two to three hours. A correction for solubility of 0 6 of the percentage of paraffins found is allowed. 

For the determination of the ash, 10 g. of the picric acid is added in very small quantities to a heated crucible. The temperature it then raised to bum off carbon, and the residue is moistened with nitric acid, then with a little sulphuric add, and again ignited. An alternative method is to moisten the picric acid with concentrated sulphuric acid and heat it gradually. 

Sanyal and Cumming [1985] proposed an alternative method of determining the initial deformation temperature based on changes in the electrical resistivity of the ash as the temperature is raised. At a temperature where melting commences, ionic conduction markedly reduces ash resistivity. A plot of the log of resistivity against the reciprocal of the absolute temperature will show a discontinuity where melting commences. 

Method (I) E is suitable for many organic and biological materials and the alternative method (ii) is particularly flexible, since the increases in temperature and the lengths of the periods of refluxing can be altered to suit the type of sample being decomposed. Further, except for the periods during which the temperature is being raised, it needs no supervision. 

The most widely used method for the measurement of the constant pressure molar heat capacity of molten salts, Cp, was drop calorimetry, in which a sample preheated to some definite temperature imparted its heat to a fluid in the calorimeter, raising its temperature. The expected accuracy of the measurements was 1 %. An alternative method introduced more recently is differential scanning calorimetry, but it has a somewhat lower accuracy (uncertainty >2 %), due to the smallness of the samples employed. It turned out that Cp of molten salts varied generally hardly at all with the temperature as it was reported in [2], [175], and [202] and shown in Table 3.11. 

Properties of deposits Deposits are often more adherent, coherent and temperature-stable than those produced by alternative coating methods. Adhesion can be adversely affected by spurious reactions between the metal-gas and impurities in (e.g. as observed during the deposition of molybdenum on steel ) and also where the thermal coefficients of expansion of A/, and differ widely. The purity of reactants can affect that of A/,. crystal size is reduced by raising the reactant concentrations, or by lowering the plating temperature. 

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