Bei der Bestimmung der Reichert-Meissl'schen Zahl

Ohne Zusammenfassung     

Tests of drag-reducing polymer coated on a riblet surface

Experiments have been carried out at BMT where the drag reduction due to Hoechst U-groove riblets, a polymer coating, and the two combined were measured in a towing tank on a one-third scale model of the America's Cup winning yacht, Australia II. The results indicated that the riblet/polymer combination offered an overall improvement in drag reduction characteristics over either riblets or polymer coating alone, with a maximum reduction of 3.5% observed for a non-dimensional S ⁺=8. The qualitative behaviour of the drag reduction was similar to that recorded in earlier pipe flow experiments, employing an injection of polymer additive and 3M V-groove riblets, but contrary to that recorded in studies of an axisymmetric body, also coated with 3M riblets, in a drop tank filled with a polymer solution.     

Extractionsapparate

Ohne Zusammenfassung     

A Surrogate Modelling Approach Based on Nonlinear Dimension Reduction for Uncertainty Quantification in Groundwater Flow Models

Transport in Porous Media - In this paper, we develop a surrogate modelling approach for capturing the output field (e.g. the pressure head) from groundwater flow models involving a stochastic...     

Ein neues ternäres Rubidium-Eisen Oxid Darstellung von Rb6Fe2O6

A New Rubidium-Iron Ternary Oxide. Preparation of Rb₆Fe₂O₆ Dark red crystals, formed by the heating of mixtures of rubidium and iron oxides at 773 K, were identified as the new ternary oxide Rb₆Fe₂O₆ by means of chemical analysis and X-ray powder diffraction analysis. X-ray powder diffraction data and free energy of formation data are presented, the latter having been determined by equilibrium oxygen potential measurements in liquid rubidium using a Harwell electrochemical oxygen meter.     

The Structure of Gas Phase Tin Oxide Ions Generated by Laser Ablation: A Combined Fourier Transform Mass Spectrometry and Density Functional Theory Study

The radical ion series (SnO)⁺ _2-6, (SnO)^– _2-6, (SnO)_0-5Sn⁺ and (SnO)_1-6O^– have been generated by the high power laser ablation of SnO and SnO₂ targets positioned inside an ICR cell. In all ablation spectra obtained, and for any particular size Sn _x core, the tin-rich clusters (SnO) _x Sn⁺ were more abundant than the corresponding oxygen-equivalent clusters (SnO)⁺ _x , while the oxygen-rich clusters (SnO) _x O^– were always more abundant than the oxygen-equivalent clusters (SnO)^– _x . High yields of the ions (SnO)_1,3Sn⁺, (SnO)_3,6O^– and (SnO)^– ₆ suggest high stabilities for these species. Low energy CID studies revealed that loss of neutral (SnO) _x units is the preferred, and for most ions investigated the exclusive, dissociation pathway. Global minima for the smaller cations and anions are proposed on the basis of local density functional theory (DFT) calculations. Calculated dissociation energies for the neutral and charged clusters were found to compare well with effusion cell and FTICR results. DFT also predicts that, for any cluster with the same size Sn _x core, IE(SnO) _x x Sn and EA(SnO) _x O>EA(SnO) _x . A correlation between ion abundances and DFT heats of formation is evident, and the ground state geometries provide insight into the evolution of structural versus size trends. Without assistance from the calculations, erroneous conclusions regarding the structures of the experimentally-sampled clusters might have been drawn from the low energy CID results.     

Metal-containing cellulose: Some novel materials

This communication describes our preliminary studies of the preparation and characterisation of permeable cellulose films and filaments containing ca. 25% by weight metallic platinum, present as very small particles of colloidal dimensions dispersed throughout the cellulose matrix. The platinum (0)/cellulose displays high catalytic activity with respect to the decomposition of hydrogen peroxide.     

The possibility of normal shock waves on a body with convex surfaces in inviscid transonic flow

Zusammenfassung Es zeigt sich, dass in der Tat senkrechte Stosswellen an einem Körper mit konvexen Oberflächen bei reibungsfreier transsonischer Strömung auftreten können, wenn diese Strömung unmittelbar stromabwärts des Stosses eine Singularität besitzt und diese zur Singularität in der Strömung über eine Grenzfläche mit Krümmungsdiskontinuität ähnlich ist.     

PAMAM Dendrimers as Potential Agents against Fibrillation of α‐Synuclein,a Parkinson's Disease‐Related Protein

The effect of PAMAM dendrimers (generations G3, G4 and G5) on the fibrillation of α‐synuclein was examined by fluorescence and CD spectroscopy, TEM and SANS. PAMAM dendrimers inhibited fibrillation of α‐synuclein and this effect increased both with generation number and PAMAM concentration. SANS showed structural changes in the formed aggregates of α‐synuclein – from cylindrical to dense three‐dimensional ones – as the PAMAM concentration increased, on account of the inhibitory effect. PAMAM also effectively promoted the breaking down of pre‐existing fibrils of α‐synuclein. In both processes – that is, inhibition and disassociation of fibrils – PAMAM redirected α‐synuclein to an amorphous aggregation pathway.