Produce Color Changes Research Articles

Energetic Heavy-Particle Detection by Photochromic Material

Mechanisms are discussed by which radiations can produce color changes in Fe-doped SrTi${\mathrm{O}}_{3}$. $\ensuremath{\alpha}$-particle and cosmic-ray ($\ensuremath{\pi}$-meson) absorption events have been detected by these crystals.

Literature Survey for Compounds in Urine and Saliva Suitable as a Basis for a Color Test for Ovulation

A search was made of the literature to find a compound in saliva or urine on which a color test for ovulation could be based. No such compound was found but a number of possibilities for research were indicated. Saliva has not been studied from the standpoint of cyclically occurring compounds. Color changes might be sought with ferric chloride and with starch paste with KI-I (Lugos solution) added and a color test might be developed for the known cyclic variation of citric acid. Ferric chloride and carbolic acids produce color changes in urine which might vary cyclically and variations in the rate of spontaneous alkalinization of urine should be investigated.

Coördination Properties of the Thiocyanato Radical.1 I. The Bonding of Silver and Mercury Ions by Thiocyanato Complexes of Cobalt(III) and Chromium(III)

Silver(I) and mercury(II) ions have been found to produce color changes in solutions of cis- and transdithiocyanatoamminecobalt(III) salts and in the corresponding salts of chromium(III) similar to those already known for mono- thiocyanatoamminecobalt(III) salts with silver(I) ion. The nature and stability of the interaction species occurring in the solutions have been studied spectrophotometrically using the method of continuous variations. The effects of acidity and ionic strength were found to be as expected from the hydrolytic nature of the sons and the Debye - Huckel theory. The effects of light and metal sons (viz., Ag(I) or Hg(II) upon the stability of solutions of STACo(NH/sub 3/)/ sub 5/NCS!(NO/sub 3/) /sub 2/ and STACr(NH/sub 3/)/sub 5/NCS!(NO/sub 3/)/sub 2/, respectively. have been compared. The nature of the reaction and the identity of type established between the cobalt and chromium series of complexes are used to infer that both series have the isothiocyanato structure. (auth)

Studies on Sweating: IV. A New Quantitative Method of Assaying Sweat-delivery to Circumscribed Areas of the Skin Surface

The limited number of procedures affording results in units of weight [Y. Kuno (l', G. E, Burch and collab. (2, a and b), J. S. Weiner (3)1 does not include any method which would be sufficiently convenient for extensive use under the ordinary conditions of a clinical laboratory. Quite recently E. Cohen (4) devised a quantitative method for determining the amount of palmar sweat by weighing a square of blotting paper before and 1) involves the risk of a weight loss through evaporation before the weighing is ended (4); 2) hardly eliminates the possibility of an admixture of fatty matter, or cellular and horny particles. In addition, the technic is still too inconvenient and time consuming for a great number of examinations within limited periods of time. In recent years we obtained accurate measurements by means of a special electrohygrometer, but its use was likewise hardly practicable for medical examinations on a large scale, since too much time was consumed by a single determination; moreover, the intricate construction of the apparatus necessitated frequent adjustments. The only procedure known to us for examining the degree of sweating which can be employed with relative ease, is the application of reagents which produce color changes in the presence of water. Their use also affords a most valuable means for direct examination of outpouring sweat, exclusive of insensible cutaneous perspiration. Until the present time, however, color indicators could be used only for approximations for which more or less arbitrary standards (5, 6) were chosen. Another handicap in the application of indicator-methods is the usually strong objection of both the subjects under test and those performing the examination, to the unavoidable discoloration of clothing, skin, etc., with staining products formed by the indicatorsubstances in use. Thus, the dark blue salt resulting from the reaction of ferric chloride with tannic acid in the presence of traces of water [method of J. J. Silverman and V. E. Powell (7)1 often causes irreparable damage to clothing and leaves stains on the skin which are removable only with difficulty. Similarly, though to a somewhat milder degree, the purple product of the starch-iodine reaction [methods of Minor (8), W. C. Randall (9), and othersl is apt to soil clothing. One of the greatest disadvantages of almost all the indicator-methods employed thus

OXIDATION AND REDUCTION OF GLASSES BY MEANS OF ELECTROLYSIS*

AbstractThe existing need for better understanding and influencing the state of oxidation of colored glasses led to an investigation of the possibilities of oxidizing or reducing a glass melt by means of electrolysis. A method was developed for the electrolytic oxidations of molten glass in which the anodic and cathodic reaction zones were separated by means of a refractory diaphragm. Low‐melting alkali‐borate and alkali‐phosphate glasses containing a minor addition of colorant were electrolyzed using voltages up to 10 volts. It was found that electrolysis could be used to lower the “gas content” of a glass as well as to produce color changes.