POTASH–SODA–LIME FELDSPAR EUTECTIC STUDY*

An investigation was made of the fusion behavior of the potash feldspar, soda feldspar, and soda-lime feldspar system, all materials being of commercial grade. The potash feldspar had a pyrometric cone equivalent of cone 9½, the soda feldspar, cone 6½, and the soda-lime feldspar deformed at cone 11½. Mixtures varying according to the triaxial diagram were made in the form of pyrometric cones. These were fired in groups along with standard Orton cones. The 30% commercial potash feldspar-70% commercial soda feldspar mixture reached 6 o'clock deformation when standard Orton cone 6 showed 2 o'clock deformation. The mixture of 62½% commercial potash feldspar with 37½% soda-lime feldspar reached 6 o'clock deformation when cone 7 showed 1 o'clock deformation, the deformation of the cone 9½ potash feldspar being reduced 3 cones by the addition of the proper percentage of the cone 11½ soda-lime feldspar. There was an increase in deformation temperatures (no indication of eutectic) in the plagioclase series, soda feldspar to soda-lime feldspar. The mixture of 30% commercial potash feldspar, 60% commercial soda feldspar, 10% soda-lime feldspar showed 6 o'clock deformation when cone 6 showed 1 o'clock deformation, this being the lowest temperature at which any member of the system showed 6 o'clock deformation.     

An accelerated stability test using the peroxide value as an index

Summary A quick stability test for lard is described which depends on the peroxide content for identification of the rancid point. By its use ordinary samples of lard can be evaluated for stability in a working day. Oleo oil also is being tested by this method. It is applicable to edible fats and oils and hydrogenated shortenings. Typical peroxide curves for various fats and oils are shown. The effect of copper in accelerating oxidative rancidity is discussed.     

Die Expansionsberichtigung der Kontraktionsziffer von Blenden

Ohne Zusammenfassung Vergleich der verschiedenen N?herungsans?tze mit neuen exakten L?sungen der ebenen Gasstr?mung     

A PRELIMINARY STUDY OF THE RESISTANCE TO ABRASION OF CERAMIC GLAZES,ITS CONTROL AND METHODS OF DETERMINATION1

Two test methods, one using an Ingersoll glarimeter to obtain results of a high degree of accuracy, and the other simpler “alternate method” for plant control, are described in detail. Tests on commercial hotel chinaware showed the average resistance of foreign ware was higher than that of the domestic and the variation from the average was, in general, less. Experimental glazes were prepared to study the effect on resistance, of: (1) varying SiO₂ and Al₂O₃ content, (2) glaze thickness, and (3) firing treatment. Data obtained are insufficient to justify definite conclusions regarding the effect of varying SiO₂ and Al₂O₃, but do show the resistance of well-matured glazes to be inversely proportional to thickness, a decrease in resistance as the tendency to matt increases, a markedly increased resistance by the higher glost fire. That type of body affects resistance less than do glaze composition and temperature of glost fire.     

THE EFFECT OF STEAM ON THE TRANSVERSE STRENGTH OF FIRECLAY BRICKS1

In connection with an investigation of checker brick for carbureters of water-gas machines, it was considered desirable to find out whether or not fireclay brick suffered an appreciable decrease in transverse strength when exposed to the action of steam at a high temperature. Except for occasional references to the “destructive action” of steam, no information on this score was found in the literature. This paper describes experiments in which standard straight bricks at 11,00°C were subjected to the action of steam at the same temperature and the resulting change in transverse strength measured. No significant decrease in strength due to the action of steam alone was found.