Referate

Ohne Zusammenfassung     

Veränderung der Resonanzkurve eines Saitengalvanometers durch Parallelkondensator

Ohne ZusammenfassungHerr Professor Dr. Schering, der Leiter des Elektrotechnischen Institutes, ermöglichte es uns, die erforderlichen Versuche in seinem Institut auszuführen. Dafür sprechen wir ihm unseren Dank aus und danken außerdem ihm sowie Herrn Dr.-Ing. Potthof für verschiedene Anregungen.     

Referate

Ohne Zusammenfassung     

EFFECT OF ADDING ALUNITE TO REFRACTORY CLAYS

Four grades of alunite ore were mixed with four grades of fire clays, and the mixtures were formed into modulus of rupture test bars. These were fired to cone 13–14. Specimens were tested for bulk density and modulus of rupture after the initial firing and after reheating to 1400°C. and 1600°C. Softening temperatures of the mixtures were also determined. In general, small quantities (not exceeding 20%) of alunites improved fired characteristics, including decreasing the reheat shrinkage and increasing the P.C.E. The purity of both raw materials was the determining factor. Excessive additions of alunite, particularly to the low-grade clays, caused bloating as a result of the evolution of sulfur gases from the alunite.