Eucken

Damk5hler, G in 1937, Eucken-Jackob Der Chemie Ingenieur, III, Pait 1, p. 367. 

Damkdhler, G. 1937, Einfluss von Difilision, Stromung und Warmetransport auf die Ausbeute bei chemisch-techniscen Reaktionen. Kap. II , 2. in A, Eucken und M. Jakob, editors, Der Chemie-Ingenieur. Band III. 

The dipole moment of a molecule is another additive property since it arises from the difference in electronegativity of two atoms connected by a double bond. It should therefore be possible to associate a dipole moment with every linkage. Eucken and Meyer" have suggested the following moments for various linkages (in units of 10 e.s.cm)... 

In this equation, AH is not known, but Eucken (as quoted by von Stackelberg48) suggested, AH = 0, and comparison of experimental and calculated heats of hydrate formation30 certainly supports a low value of AH. The variation of the composition of a gas hydrate along the three-phase line ice-hydrate-gas will therefore be small. (The variation along the three-phase line hydrate-aqueous liquid-gas is larger, cf. Section III.C.(l).)... 

Measurements of the true specific heats at low temperatures have been carried out by Eucken, who worked in such a way that to a weighed quantity of the substance in the form of a block, or in a proper isolated vessel, a known quantity of heat was added by means of an electrically heated platinum spiral, the resistance of wThich at the same time served to measure the temperature. The quotient of the electrical energy spent by the rise of temperature gives the specific heat. The correction for cooling (in vacuum of 5 Jo mm.) amounted to 20 per cent., and for heat capacity of the apparatus 5 per cent., yet the results are stated to be accurate to 1 per cent. 

The method has been applied by Eucken to determine specific heats of gases (e.g., H2) at constant volume by enclosing them in small metallic vessels. 

At very low temperatures the rotational energy, being subject to the law of ergonic distribution, will vanish, and hence Cr will approach the value fR in the case of hydrogen the molecular heat has been experimentally found by Eucken (12) to have the value 2 98 in liquid air. 

Approximate values for the thermal conductivity of pure gases, up to moderate pressures, can be estimated from values of the gas viscosity, using Eucken s equation, Eucken (1911) ... 

The lack of hydrodynamic definition was recognized by Eucken (E7), who considered convective diffusion transverse to a parallel flow, and obtained an expression analogous to the Leveque equation of heat transfer (L5b, B4c, p. 404). Experiments with Couette flow between a rotating inner cylinder and a stationary outer cylinder did not confirm his predictions (see also Section VI,D). At very low rotation rates laminar flow is stable, and does not contribute to the diffusion process since there is no velocity component in the radial direction. At higher rotation rates, secondary flow patterns form (Taylor vortices), and finally the flow becomes turbulent. Neither of the two flow regimes satisfies the conditions of the Leveque equation. 

Das FRANCK-CoNDON-Prinzip (Condon 1928, vgl. auch Eucken I, 453) besagt ... 

Eucken, A. Lehrbuch der chemischen Physik. Leipzig Akadem. Verlagsges. 3. Auflage 1949. 

Eucken and Wicke (6) proposed a mechanism which necessitates the operation of several sites, and which can be pictured schematically as follows ... 

Landolt H, Bomstein R, Borschers H, Bartels J, Eucken A. 1960. LandolX-Bornstein Zahlenwerte und Funktionen aus Physik, Chemie, Astronomic, Geophysik, Technik. Berlin Springer. 

Reinkober, O. Die experimentellen Methoden der Ultrarotspektroskopie. In Eucken-Wolf, Hand- und Jahrbuch der chemischen Physik, Bd. 9/II. Leipzig 1934. 

Abb. 23. Stuart-Briegicb-Kalottenmodeli der HgO-Aggregate ira Eucken-Modcll... 

Abb. 24. Molenbriiche der einzelnen Aggregate Abb. 25. Freies OH itn HjO nach dem Eucken-Modell des HjO im Eucken-Modell berechnet... 

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