Solid Particle Effects in Centi-scale Slurry Bubble Columns

Both solid particles and column diameter affect the gas holdup and flow regimes in slurry bubble columns, but investigations of the combined effects are not to be found. This study shows the simultaneous impacts on the overall gas holdup and flow regime transitions and determines the dominant effects in slurry bubble columns on the centi-scale containing solid particle concentrations up to 20 vol %. Additional tomography measurements are presented to visualize the gas phase flow and the spatial gas phase distribution in the column.     

Mechanical Properties,Fatigue Life,and Electrical Conductivity of Cu–Cr–Hf Alloy after Equal Channel Angular Pressing

Structure, mechanical, and service properties of a Cu–Cr–Hf alloy after quenching, equal‐channel angular pressing (ECAP), and subsequent aging have been studied. The positive effects of ultrafine‐grained structure formation (grain/subgrain size of ≈200 nm) during ECAP and strengthening particles precipitation upon subsequent aging at 450 °C on the mechanical and fatigue properties of the alloy are shown. Ultrafine‐grained Cu–Cr–Hf alloy after aging shows increasing in the fatigue limit on the basis of 10⁷ cycles from 185 to 375 MPa relative to that of the initial coarse‐grained state. The alloy after ECAP and aging also exhibits sufficient elongation to failure (11.4%) and good electrical conductivity (78%IACS).     

Simplified isolation procedure for the 12 S globulin and the albumin fraction from rapeseed (Brassica napus L.)

A simplified procedure for the isolation of chromatographic homogeneous albumin and 12 S globulin from rapeseed is proposed. The method includes prepurification of the proteins by means of fractionating precipitation and dissolution with ammonium sulphate and single chromatography on Sephadex G-200. The most important advantages of the proposed technique are high yields of purified proteins and a simplification of isolation procedure by reducing the number of chromatographic runs.     

Application of the Jones calculus for a modulated double-refracted light beam propagating in a homogeneous and nondepolarizing electro-optic uniaxial crystal

The Jones matrix calculus is applied to an electro-optic crystal with uniaxial symmetry when the light beam is incident nearly normally on the crystal face. The approach allows one to treat refracted waves and rays that diverge in the crystal and are modulated by an external low-frequency field. The effect of partial interference of overlapping refracted beams is allowed for and calculated for the case of uniform intensity of the beam over its cross section. The method is employed to analyze optical systems containing an imprecisely cut and aligned electro-optic crystal plate.     

Effects of Willows (Salix brachycarpa) on Populations of Salicylate-Mineralizing Microorganisms in Alpine Soils

We used the substrate-induced growth-response (SIGR) method to quantify salicylate-mineralizing microbes and total microbial biomass in soils from under willows (Salix brachycarpa) and in surrounding meadows dominated by the sedge Kobresia myosuroides. Willows had a strong effect on the biomass of salicylate-mineralizing microbes in both years of this study. There were always higher biomass levels of salicylate mineralizers in soils from under Salix (4.6–10.1 g C/g) than under Kobresia (0.23–0.76 g/g). In contrast, total microbial biomass was not significantly different under these plant species in 1996 and was only higher under Salix on one date in 1997. These results show that the standing biomass and activity of salicylate-mineralizing microbes can be greatly enhanced by salicylate-producing plants in the field. Given this finding, it is unlikely that simple phenolic compounds like salicylate would persist for very long in soil beneath the plants that produce them.