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Twisted axially loaded rod with shear and compressibility

Summary Stability of a twisted and axially compressed elastic rod is analysed using the Euler method of adjacent equilibrium configuration. The constitutive equations of the rod are assumed in the form that takes into account both shear of the cross-sections and compressibility of the rod axis. It is shown that bifurcation points of the non-linear system of equations describing equilibrium are determined from the linearized system of equations. The influence of shear and compressibility on the critical values of twisting couple and compressive force is obtained. Moreover, the bifurcation pattern is examined by using the Liapunov-Schmidt method.     

There's more to touch than meets the eye: The salience of object attributes for haptics with and without vision.

The availability and salience of object attributes under haptic exploration, with and without vision, were assessed by 2 tasks in which Ss sorted objects that varied factorially in size, shape, texture, and hardness. In the directed-discrimination task, Ss were instructed to sort along a particular dimension. Although levels on all dimensions were easily discriminated, shape was relatively less so for haptic explorers without vision, as was hardness for those using vision and haptics. Size was least discriminable for both groups. In the free-sorting task, Ss were to sort objects by similarity. Three groups used haptic exploration only; these were differentiated by the experimenters' definition of object similarity: unbiased haptics, haptically biased haptics, haptics plus visual imagery. A 4th group used vision as well as haptics, with instructions like those of the unbiased haptics group. Results support the contention that the haptic and visual systems have distinct encoding pathways, with haptics oriented toward the encoding of substance rather the shape. This may reflect a direct influence of haptic exploratory procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dietary fibre of coconuts from a pacific atoll: Soluble and insoluble components in relation to maturity

Polysaccharide fractions were measured in coconuts at three stages of maturity, which corresponded to dietary usage in the Tokelau Islands of the South Pacific. Kernel was sequentially extracted with cold water (CW), hot water (HW) hot 0.5% ammonium oxalate (HOX), 1M H² SO⁴ and 72% H² SO⁴, and the monosaccharide compositions of the fractions determined. Total readily soluble fractions (CW+HW+HOX) were predominantly galactomannan, and decreased from 77% of the polysaccharide in the immature kernel to 8.8% of that in the mature kernel. Insoluble mannan increased during maturation to be the major polysaccharide component in mature kernel. This indicates that marked differences exist between the three stages of maturity examined, in the properties of their dietary fibre. The results suggest that in studies of diets in which coconut is a staple part, there is a need for careful definition of the coconut component with respect to maturity. Furthermore, they show the importance of using dietary fibre methods which are appropriate to the solubility characteristics of the indigestible polysaccharide.     

INTEGER analysis of two-dimensional polygonal objects

A consistent modelling scheme for digital images is presented, with the grey-level raster image as input and the list-oriented polygonal image as output. The output information consists of two parts: The metric of the polygonal object, represented by coordinates of marked positions, and the global topology, which takes the form of a two-dimensional topologic order. The central problem, which has to be solved, is to select a digital polygon, approximating a digital arc such that the essential feature of the arc is represented at a predefined precision level. The proposed algorithm uses simple incremental calculations of INTEGER quantities to solve the problem.     

Influence of various types of load-dependent supports on the stability of a compressible column model

Summary The nonlinear behaviour and static stability of a compressible elastic column whose flexural resistance changes as it is loaded is studied. A two-degree-of-freedom, compressible rod model of the column is analysed. Various types of load-stiffness relationships are considered. Post-buckling behaviour under static unidirectional loads is investigated. Singularities of the equilibrium paths of the column are classified according to the slenderness ratio of the column and the load-stiffness relationship of its support.On leave from Department of Mechanical Engineering, University of Toronto, 5 King's College Road Toronto, Ontario, Canada, M5S 1A4     

Analysis of ink flow in a mimeograph printer based on the mechanics of fluid-filled poroelastic solids

Summary To understand some main ink flow mechanisms in a mimeograph printer, the continuum mechanics theory of fluid-saturated porous solids is applied to analyze the ink flow through screens and a printing master, which are modeled by a fluid-filled poroelastic single layer. The layer is assumed to be pressed by a press roller from below and to be subjected from above to the hydrodynamic lubrication pressure induced between a printing drum and an ink roller. Nonlinear elasticity of the layer and dependence of the permeability on its deformation are taken into account. The numerical results show some important results: e.g., squeezing-out of the ink from the layer by the layer compaction by the press roller plays an important role, especially for the case where the compression duration is small in comparison with the characteristic time of the ink-filled poroelastic layer.