Comparing the characteristics of front and back domestic gardens in Hobart, Tasmania, Australia

In Australia, suburban front gardens have been said to be for show, while back gardens have been thought to be used more productively. This pattern may have changed as a result of a change in the ways that western suburbanites use and value their gardens. In 107 gardens in 10 suburbs of Hobart, Tasmania, Australia, data on the floristic composition, structural characteristics and some use attributes were collected from front and back yards. The floristic data were used to classify the yards into types, many of which preferentially occurred in either front or back. Back yards preferentially containing food plant taxa, and had a larger proportion of lawn, dogs and chicken coops, while front yards preferentially contained showy and screening plant taxa, and had relatively high small shrub cover. However, in a large proportion of properties, the garden type in the front yard was the same as the type in the back yard. In another large proportion of properties the front yard was gardened more intensively than the back, indicating a desire to impress, but the back yard was not used for productive purposes. These gardens preferentially occurred in the older suburbs, while gardens that were showier in the back than the front were negatively correlated with the unemployment rate. In a relatively small proportion of properties showy gardens were located in the front yard, while productive gardens were located in the back yard. The prevalence of these gardens had no relationships with suburb characteristics. The wide variety of garden types, and of their combinations in back and front yards, both within and between suburbs, indicate a complexity not reducible to simple aphorisms.     

Rheological characterisation of cake batters generated by planetary mixing: Elastic versus viscous effects

Studies of cake batter rheology have focused on viscous behaviour. We demonstrate that elastic effects dominate at the shear rates used in commercial mixers. The development of batter structure was investigated for two flour types using two bench-scale planetary mixers with known shear rate profiles (Kenwood-KM250, maximum 100 s⁻¹; Hobart-N50, 500 s⁻¹). These wet foams (air volume fraction 0.39-0.45) showed shear-thinning behaviour at low shear rates (0.1-10 s⁻¹), with apparent viscosity dependent on air volume fraction. Simple shear thinning behaviour ceased, for foams, above 10-20 s⁻¹: for slurries (air volume fraction, 0.11-0.15) the limit approached 100 s⁻¹. Elastic effects, predominantly arising from the bubble phase, therefore dominate cake batter behaviour at the shear rates experienced in commercial mixers. Filament thinning extensional rheometry confirmed the VE behaviour of batters. These results indicate that visco-elastic analyses are likely to be the most appropriate probe of microstructure in cake batters.     

O. Hobart Mowrer.

Portrait. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

荷伯特城市滨水区开发研究

该文以萨利文海湾总体规划为基础，提出了荷伯特滨水空间改造所涉及的两大核心概念——即“硬质”的城市空间形态方面的“层”概念和“软质”的城市活动方面的概念，并通过荷伯特滨水区改造的具体实施内容加以分析论证。吸取荷伯特滨水区改造中有关“层”级界面和社会活动方面的理念，对于提高我国滨水环境开发建设水平具有普遍的现实意义。     

Modelling of shear rate distribution in two planetary mixtures for studying development of cake batter structure

The shear rate experienced by a fluid near the wall of a planetary mixer when agitated by a wire whisk tool has been estimated using a simple geometrical analysis. The bowl and whisk geometries were measured for a Kenwood KM250 and a Hobart N50 mixer which are in widespread use in domestic and laboratory installations. The shear rate is shown to be a maximum at the bowl wall. This value is relatively uniform over a large fraction of the wall height, except for a small volume near the base and the region above the maximum width of the mixer. The shear rate profile is sensitive to the vertical positioning of the agitator within the bowl. For standard manufacturer speed settings, the range of maximum shear rates was estimated to be 100-500 s⁻¹ in the Hobart and 20-100 s⁻¹ in the Kenwood.