Über Wärmeinhalt und Gitterzustand verschieden aktiver Formen von CuO und über die Bildungswärme des Cu(OH)₂. XXXI. Mitteil. über aktive Stoffe von R. Fricke und Mitarbeitern

Evaluation of the Surface Area of Catalysts of Cubic Form by the Emanation Method.

“…Consequently, Heckter's experimental results have been recalculated (6) by application of the expression in which R is the range of recoil expressed in A., c is the constant of proportionality, d is the density of the solid substance expressed in gram-centimeters, A is a corrected average atomic weight of the solid expressed in gram-atoms, and B is the stopping power for alpha-particles (17) of each element composing the solid. 4 The constant of proportionality, c, for radon was found by this method to be 57 and for thoron 83. Thus the comparison factor, cR, between £'mfl(Ra) and EmR{Tn) in expression 2 is determined as 0.687.…”

“…Thus the comparison factor, cR, between £'mfl(Ra) and EmR{Tn) in expression 2 is determined as 0.687. The ranges of recoil, RRn and IfTn, for different substances which have been investigated by the emanation method have been found from expression 4 by the use of the corresponding constant of proportionality (3,6,21). In older papers (4,5,20,23) in which thoron alone was used to evaluate surface areas, the constant c = 52.1, given by Heckter, was applied for the calculation of the range of thoron recoil.…”

“…In Systems of Sodium Gum Arabic1 DAVID R. BRIGGS Minnesota Agricultural Experiment Station, St. Paul, Minnesota That an electrokinetic potential existing at the interface between the particle of a disperse phase and the dispersion medium might be expected to give rise to a marked increase in the viscosity of a system containing such particles was first postulated by Smoluchowski (11). He offered an equation to describe this effect, which was based upon the equation of Einstein (4) and upon an equation previously derived by himself (10), designed to describe the retardation effect of the charge on a spherical particle falling through a liquid. This latter effect had been observed and studied by Hardy (7).…”

“…The emanation method is applied extensively at present to the study of oxides and hydrates (4,5,8,9), but this paper presents work which developed from the use of the method in the study of industrial catalysts, for which it was found to be a very sensitive tool.…”