Hugo Fricke

XXXIII. The theory of electrolytic polarization

Synopsis C p designates the polarization capacity, R p the polarization resistance, and ψ the phase angle defined by tan ψ = C p ωR p (ω: angular frequency of alternating current). V(x)dq represents the value of the counter-electromotive force x seconds after a quantity dq of electricity has passed through the electrolytic cell. The following equations are derived: Thus, when C p varies inversely as the mth power of the frequency the phase angle ψ is constant and its value stated by equation (6). For many electrodes, C p varies inversely as a power of the frequency, at all frequencies, or over an extended frequency range. For such electrodes equation (6) is found to represent the experimental findings with satisfactory accuracy. Relationships derived from the theories of Warburg and Kruger are represented by equation (6) as special cases. Surveying existing experimental data, it is found that equation (6) generally holds quite closely even when m, is not independent of the frequency.

Chemical Reactions of Organic Compounds with X‐Ray Activated Water

Gas free solutions of carbon monoxide, alcohols, aldehydes, ketones and acids were irradiated in the concentration range 10 μM to 1 M, between pH=1 to 13 and the reactions studied principally by gas analysis and potentiometric acid analysis. One organic component systems and, to a more limited extent, two organic component systems were investigated. To obtain significant results, foreign organic matter must be strictly excluded from the low concentration solutions and the methods used to accomplish this are described. Organic impurities in the water can be detected by irradiating the water with x‐rays and measuring the evolved hydrogen and carbon dioxide. The reactions cannot be briefly abstracted, but oxidation and condensation reactions with the evolvement of gaseous hydrogen are important in the effect of the rays. Carbon dioxide was produced from certain acids, particularly strongly from those having an oxygen containing group in the α‐position. No liberation of carbon monoxide, hydrocarbons or oxygen...

The Reduction of Oxygen to Hydrogen Peroxide by the Irradiation of Its Aqueous Solution with X‐Rays

Irradiation with x‐rays produces no chemical change in air‐free water. With oxygen present, hydrogen peroxide is formed due to a primary activation of the water. The initial production of hydrogen peroxide is independent of the oxygen pressure, from 4 to 70 cm Hg and is dependent on the hydrogen ion concentration according to: H2O21000r×1000 cc=[2.2+2.2[109.6−pH1+109.6−pH]10−6N.

Studies of Reactions Induced by the Photoactivation of the Water Molecule. I

Unbuffered gas free solutions of methyl alcohol have been irradiated with ultraviolet light in the wave‐length range longer than 1850A and it is found that reactions involving the methyl alcohol occur, induced by the photoactivation of the water molecule. Gas free water itself is not changed by the irradiation. Products initially obtained in the water‐photosensitized reaction are hydrogen as the only gas and a small amount of formaldehyde accounting for 10 to 20 percent of the hydrogen produced. The direct photoactivation of the methyl alcohol leads to its decomposition according to CH3OH+(hv) = CH2 : O+H2. The spectral limit for the water‐photosensitized reaction is in the neighborhood of 2000A.

Application of a High‐Speed Electronic Computer in Diffusion Kinetics. II. Depletion Effect in the Spherical One‐Radical One‐Solute Model

The earlier computations [D. A. Flanders and H. Fricke, J. Chem. Phys. 28, 1126 (1958)] on the Spherical One‐Radical One‐Solute model were extended by taking account of the transient dilution of the solute which occurs during the reaction. Although the drop in concentration of the solute near the center of the reaction zone may be considerable, its effect on the fraction of radicals combining with the solute is only of the order of one percent under the most unfavorable conditions likely to be encountered when the model is applied to γ‐irradiated aqueous solutions.

Radiographs of Insects

FINDING no record that radiographs of insects were ever made, last summer we took several hundred radiographs of some forty different species of insects. The X-ray tube, constructed in the laboratory, was of lithium glass, and furnished with a very thin window allowing rays of sufficient softness to be used. 3500 volts was the lowest potential with which this tube could be run, and with this potential the venation of wings was shown very distinctly. During the whole work, potentials ranging from this lower limit to 15,000 volts have been used, according to the size of the insect. The insect was placed directly on the photographic film, which was of the type manufactured by the Eastman Kodak Company for dental work.