The rα structure, chemical shift anisotropy, and the abnormal orientation of methyldichlorophosphine from the NMR spectrum

NMR studies of methyldichlorophosphine have been undertaken in the nematic phase of mixed liquid crystals of opposite diamagnetic anisotropies. The rα structure is derived. The proton chemical-shift anisotropy has been determined from the studies without the use of a reference compound and without a change of experimental conditions. It is shown that the molecule orients in the liquid crystal with positive diamagnetic anisotropy in such a way that the C3 symmetry axis of the CH3P moiety is preferentially aligned perpendicular to the direction of the magnetic field, unlike other similar systems. This is interpreted in terms of the formation of a weak solvent-solute molecular complex. The heteronuclear indirect spin-spin coupling constants are determined. The sign of the two-bond JPH is found to be positive.

Breakage of viscoelastic drops in turbulent stirred dispersions

The existing models of drop breakage in stirred turbulent dispersions are applicable only to purely viscous dispersed phases. In their present form, they are found to underpredict the diameters of the largest stable drops formed when a viscoelastic fluid is dispersed into a Newtonian liquid. In purely viscous fluids, the turbulent stresses are opposed both by the stresses due to interfacial tension and the viscous stresses generated as the drop deforms. In viscoelastic fluids, drop deformation produces additional retractive elastic stresses which also oppose turbulent stresses. As the deformation rates are large, the retractive stresses can be large in magnitude. Assuming that these additional stresses decay with time, a model of viscoelastic drop breakage in turbulent stirred dispersions has been developed. The new model quantitatively predicts the dmax of viscoelastic fluids. The model, however, does not predict the observation that when the time constant of the fluid becomes large (λ > 0.5 s), the fluid can not be dispersed into droplets up to agitator speeds of about 10 rps in our equipment.

Painted portrait of Roeschen Dux nee Abraham Portraits Women

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Tombstone of David Benjamin; Strangriede Cemetery (R 84.7); Hannover Cemeteries Tombs

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Tombstone of H. Solomon; Strangriede Cemetery (R 83); Hannover Cemeteries Tombs

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Tombstone of Frederike Benjamin nee Salamon; Strangriede Cemetery (R 83); Hannover Cemeteries Tombs

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Tombstone of Herz Benjamin (Naftali); Strangriede Cemetery (R 83.12); Hannover Cemeteries Tombs

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Tombstone of Max Molling; Strangriede Cemetery (R 29.10); Hannover Cemeteries Tombs

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Tombstone of Marianne Benjamin nee Sussmann; Strangriede Cemetery (R 83.9); Hannover Cemeteries Tombs

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Tombstone of Arthur Molling; Strangriede Cemetery (R 26.05); Hannover Cemeteries Tombs

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Tombstones of Frederike Benjamin nee Salamon and her husband David Benjamin; Strangriede Cemetery (R 84.6 and R 84.7); Hannover Cemeteries; Tombs

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Tombstone of Jeanette Molling nee Benjamin; Strangriede Cemetery (R 26.06); Hannover Cemeteries Tombs

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Detail of tombstone of Arthur Molling; Strangriede Cemetery (R 26.05); Hannover Cemeteries Tombs

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Tombstones of Sophie Molling and Max Molling (center in shadow); Strangriede Cemetery (R 29.09 and R 29.10); Hannover Cemeteries Tombs

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Tombstones of Joseph Benjamin and Marianne Benjamin nee Sussmann; Strangriede Cemetery (R 83.8 and R 83.9); Hannover Cemeteries Tombs

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