Einfluß der Expansion auf die Kontraktion hinter Staurändern

Zusammenfassung Es wird nachgewiesen, da? die Durchflu?gleichung für zusammendrückbare Medien (Gase, D?mpfe) bei Staur?ndern einer Berichtigung bedarf, welche die Volumenausdehnung des Strahles im Kontraktionsquerschnitt berücksichtigt. Die berichtigte Formel wird durch Versuche sehr genau best?tigt.     

MECHANISM OF PLASTICITY FROM COLLOID STANDPOINT1

Introduction .—Brief statement of present conceptions of the colloid chemists. Theory .—Plasticity is caused by the, enveloping film of colloidal material which surrounds the clay grains, this film being of opposite polarity to the grain proper. Addition of electrolyte acting as deflocculant causes outer layer of film to be attracted to ion of same polarity as clay particle, thus reducing effective diameter and increasing polarity of plasticity inducing particles. Particles which were held by surface forces of “particles in contact” are no longer in contact and are actually repelling each other due to like and increased polarity. A flocculating ion drives action in opposite direction causing an increase in depth of colloid film thereby increasing surface in actual contact and decreasing repulsive force of plasticity inducing particles. Transport numbers as well as polarity are governing factors in ions of electrolytes. Measurements .—Touch method is proven to be unreliable. Desirability of a unit of measurement. Plea for a unit of colloidality and standard method for measurement.