Mean kinetic temperature concept

In subsequent years, a number of guidance documents related to stability of pharmaceutical products have been issued. The guidance documents are based on the concept of climatic zones (1). There are four zones based on Mean Kinetic Temperature and Mean Annual Relative Humidity (RH) Zone I (temperate climate), e.g., Canada and Northern European, Zone 11 (subtropical), e.g., the United States and Southern Europe, Zone III (hot and dry), e.g.. Egypt and Zone IV (hot and humid), e.g., Brazil. The United States, Europe, and Japan are all in Zones I and II so the ICH guidelines are applicable for these zones. 

This study presents kinetic data obtained with a microreactor set-up both at atmospheric pressure and at high pressures up to 50 bar as a function of temperature and of the partial pressures from which power-law expressions and apparent activation energies are derived. An additional microreactor set-up equipped with a calibrated mass spectrometer was used for the isotopic exchange reaction (DER) N2 + N2 = 2 N2 and the transient kinetic experiments. The transient experiments comprised the temperature-programmed desorption (TPD) of N2 and H2. Furthermore, the interaction of N2 with Ru surfaces was monitored by means of temperature-programmed adsorption (TPA) using a dilute mixture of N2 in He. The kinetic data set is intended to serve as basis for a detailed microkinetic analysis of NH3 synthesis kinetics [10] following the concepts by Dumesic et al. [11]. 

In tie kinetic theory of gases, the concept of temperature is primarily a foreign element, since in fact the individual molecules are characterized by their velocity alone. But it suggests itself that we should define the absolute gas-temperature T in terms of the mean kinetic energy. This is usually done in accordance with the eq[uation... 

As seen from Fig. 10, the non-exponential drop in the intensity of fluorescence for Nh-inverse kinetic isotope effect is observed as distinct from the process of spontaneous deactivation, for which a normal isotopic effect (td > ih) is observed. Note that the possibility of the abnormal isotopic effect for electron tunneling reactions follows directly from the theoretical concepts set out in Chap. 3, Sect. 6. The mean values of the parameter / obtained from experiments with various concentrations of CC14 proved to be p = (0.240 0.010) M 1 for Nh d8 and j = (0.205 0.010) M l for Nh. As the effect of the nuclear motion on W R) must be reflected more in the value of ve than in that of ae it seems natural to connect the difference observed between the values of P for Nh and those for Nh-d8 with the change in the parameter ve. At the value of ae 1 A typical of tunneling reactions, the difference observed in the values of P corresponds to an approximately 2.5-fold increase of ve upon naphthalene deuteration. With an increase in temperature from 77 to 140 K, the parameter / remained virtually unchanged, although the time, t, for spontaneous deactivation was markedly reduced. Thus, tunneling reaction (14) proceeds via a non-activated mechanism. 

The slip flow near the boundary surface can be analyzed based on the type of fluids, i.e., gas and Newtonian and non-Newtonian liquids. The sUp flow in gases has been derived based on Maxwell s kinetic theory. In gases, the concept of mean free path is well defined. Slip flow is observed when characteristic flow length scale is of the order of the mean free path of the gas molecules. An estimate of the mean free path of ideal gas is /m 1/(Vlna p) where p is the gas density (here taken as the number of molecules per unit volume) and a is the molecular diameter. The mean free path / , depends strongly on pressure and temperature due to density variation. Knudsen number is defined as the ratio of the mean free path to the characteristic length scale... 

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