Dynamics and rheology of a dilute suspension of dipolar nonspherical particles in an external field: Part 1. Steady shear flows

Suspensions of small nonspherical particles having dipolar moments exhibit non-Newtonian behavior under the influence of shear and external fields. Numerical methods are presented for calculating the rheological and rheo-optical properties of dilute suspensions of Brownian particles having permanent dipoles subject to time-dependent shear and external fields. The numerical methods employ the Galerkin method of weighted residuals to solve the differential equation for the particle orientation distribution function. The steady-state shear flow intrinsic viscosity of suspensions of particles with sufficiently extreme aspect ratio is predicted to exhibit a maximum value attained for intermediate shear rates at selected field orientations. These numerical results provide valuable insight into the coupling which occurs between the effects of rotary Brownian motion, the hydrodynamic resistance of nonspherical particles, and the external torque exerted on dipolar particles. The results are applicable to both suspensions of magnetic particles and electrically dipolar particles.     

Rapid screening of alkylphenol exposure in fish bile using an enzymatic peroxidase biosensor

This article deals with the development and novel application of an amperometric peroxidase biosensor for monitoring fish exposure to petroleum-related discharges, in particular, to alkyl phenols (AP) using fish bile as the main sample material. The biosensor consisted of a screen-printed electrode coupled with peroxidase immobilized by glutaraldehyde cross-linking. The sensor was optimized with regards to factors such as immobilization procedures, substrate selectivity, and matrix effects. The biosensor was used for the analysis of fish bile samples from Atlantic cod (Gadus morhua L.) exposed in the laboratory during a 2 week period to different petroleum related compounds. The biosensor could distinguish between bile samples of fish exposed to water containing high concentrations (a mixture of C₄–C₇) to moderate levels (mainly C₀–C₅) of alkylphenols and that of the control group.     

Zur Bestimmung von Aetzalkalien neben kohlensauren Alkalien und Schwefelalkalien

Ohne Zusammenfassung     

Synthesis and purification of the allofarnesenes

The eight isomers of allofarnesene (3,7,11-trimethyl-2,4,6,10-dodecatetraene) were prepared using Wittig reactions. The four E-4 isomers could be separated using GC but the unstable Z-A isomers required HPLC on silver nitrate impregnated silica gel for analysis. Purified samples of each isomer were prepared for spectral studies. The configuration of the pseudoionone (6,10-dimethyl-3,5,9-undecatriene-2-one) starting materials was also studied, confirming previous results.     

Bivalent polyether ionophores: Synthesis and biological evaluation of C2-symmetric salinomycin dimers

Efficient methods for the synthesis of C₂-symmetric dimers of salinomycin joined at either the C1 or C20 positions are reported. Similarly to the native structure, the C20-O-terephthalate dimer displayed activity in the low μM range against a series of cancer cell lines, while dimers joined at the C1 position were essentially inactive.     

Analysis of the Kω spectrum

We present results of a spin-parity analysis of the Kω system from threshold to 1.52 MeV based on 12 500 events of the type K^?p→K^?π⁺π^?π^op at 7.3 GeV/c. We also present evidence for a possible resonant state decaying into Kω at a mass 1710 ± 15 MeV and width 110 ± 50 MeV.