Korrosionsuntersuchung

Ohne Zusammenfassung     

Ueber Dispergation verschiedener Zellulosearten auf mechanischem Wege und unter Einwirkung wässeriger Salzlösungen

Ohne Zusammenfassung Von nun an werde ich als meinen ersten Beitrag meine Abhandlung in der Koll.-Zeitschr.2, 141 (1913) bezeichnen, als zweiten Koll.-Zeitschr.29, 198 (1921), wobei zu bemerken ist, da? diese Abhandlung eine Uebersetzung meiner russischen Abhandlung ist, die 1913 in Nachr. d. St. Petersburg. Berginstit.4, 152 ver?ffentlicht wurde, und schlie?lich, als meinen dritten Beitrag zur Dispersoidologie der Zellulose bezeichne ich meine Abhandlung in der Koll.-Zeitschr.29, 197 (1921). Vgl. auch meine Abhandlungen: „Dispersoidological Investigations on Cellulose“, in Reports of the Imperial Industrial Research Institute of Osaka (Japan). Vol. IV, No. 7, August 1923.     

Rigid nitronyl-nitroxide-labelled anchoring molecules: syntheses, structural and magnetic investigations

The syntheses of two rigid organic molecular rods bearing a nitronyl-nitroxide radical and a terminal nitrogen-based functionality like a pyridine or a cyano group are reported. Both new paramagnetic molecules are fully characterized, including crystal structure analysis. Furthermore their magnetic behaviours in the crystalline state are investigated and their spin concentration corroborate their excellent purity. While the pyridine functionalized rod is synthesized by converting the corresponding benzaldehyde to the phenyl-nitronyl-nitroxide radical, the synthesis of the cyano functionalized rod demonstrates the accessibility of highly sophisticated spin-labelled molecules via cross-coupling reaction with a meta-iodo-phenyl-nitronyl-nitroxide moiety.     

Spin Axioms in Different Geometries of Relativistic Continuum Physics

The 24 components of the relativistic spin tensor consist of 3 + 3 basic spin fields and 9 + 9 constitutive fields. Empirically only three basic spin fields and nine constitutive fields are known. This empirem can be expressed by two spin axioms, one of them denying purely relativistic spin fields, and the other one relating the three additional basic fields and the nine additional constitutive fields to the known (and measurable) ones. This identification by the spin axioms is material-independent and does not mix basic spin fields with constitutive properties. The approaches to the Weyssenhoff fluid and the Dirac-electron fluid found in literature are discussed with regard to these spin axioms. The conjecture is formulated, that another reduction from six to three basic spin fields which does not obey the spin axioms introduces special material properties by not allowed mixing of constitutive and basic fields.     

Effect of impeller geometry on gas-liquid mass transfer coefficients in filamentous suspensions

Volumetric gas-liquid mass transfer coefficients were measured in suspensions of cellulose fibers with concentrations ranging from 0 to 20 g/L. The mass transfer coefficients were measured using the dynamic method. Results are presented for three different combinations of impellers at a variety of gassing rates and agitation speeds. Rheological properties of the cellulose fibers were also measured using the impeller viscometer method. Tests were conducted in a 20 L stirred-tank fermentor and in 65 L tank with a height to diameter ratio of 3:1. Power consumption was measured in both vessels. At low agitation rates, two Rushton turbines gave 20% better performance than the Rushton and hydrofoil combination and 40% better performance than the Rushton and propeller combination for oxygen transfer. At higher agitation rates, the Rushton and hydrofoil combination gave 14 and 25% better performance for oxygen transfer than two Rushton turbines and the Rushton and hydrofoil combination, respectively.