We observe a new type of behavior in a shear-thinning yield stress fluid: freestanding convection rolls driven by vertical oscillation. The convection occurs without the constraint of container boundaries, yet the diameter of the rolls is spontaneously selected for a wide range of parameters. The transition to the convecting state occurs without hysteresis when the amplitude of the plate accele...

We report on spatially resolved measurements of the mechanical stress in drying polymer films. The technique is based on the deflection of a flexible membrane serving as the substrate. Assuming that the lateral tension of the membrane is the main source of its resistance to deformation, one can show that the local surface stress sigma f (x,y) is proportional to the vertical displacement of the ...

terminal heat stress in mediterranean climates like ahwaz is reduced wheat yield. in order to study effect of terminal heat stress on yield and yield components of 20 spring bread wheat cultivars, an experiment was conducted in ramin university of agricultural and natural resources, ahwaz in 2007-2008. the experimental design was stripe block design in randomized complete block design with thre...

the study of flow in compound channels with vegetated floodplains is essential to assessing the development of the stage-discharge relationship and sediment and pollutant transport. the present study experimentally investigated mean flow and turbulence characteristics in a prismatic compound channel. the experimental program consisted of vegetated and non-vegetated floodplains with different re...

In this study, the effect of the tube material on the thermal stress generated in a vertical shell and tube heat exchanger is investigated. Shell and tube heat exchangers are the most common heat exchangers used in industries. One of the most common failures in these exchangers in the industry is the tube failure at the junction of the tube to tubesheet. When the shell side and the tube side fl...

Measurements of the yield behaviour of a cohesive bulk solid in the Jenike shear tester are normally done in two steps. First, pre-shearing to a steady state yielding, and secondly, shearing under a lower normal stress to establish the shear stress at incipient failure. Due to the limited strain of the sample in this apparatus, the material must be consolidated in an earlier stage. This is done...

Linear elastic fracture mechanics predicts that joint orientation is controlled by the stress field in which the joints propagate. Thus joint sets are effective proxies for stress trajectories during joint growth. Complexity in joint orientation indicates stress trajectory variability, a phenomenon quantified using an eigenvalue method that measures dispersion of joint normal vectors (i.e. pole...

The mechanical behavior of three styrenic thermoplastic block copolymer elastomers with applied surgical sutures was studied by uniaxial tensile testing. The materials exhibited oriented cylindrical microstructure. Distinct macroscopic deformation mechanisms have been observed upon stretching of samples with vertical and horizontal orientation. Deformation progressed along the axis of the sutur...

This paper presents results from drained cyclic torsional shear tests on Toyoura sand and a residual soil under dry and saturated conditions. The relationships of shear strain,   z with shear stress,   z ; normalized shear stress, z z     / ; vertical strain, z  ; and equivalent shear modulus, Geq are compared. The investigation of granular decomposition with respect to its influence o...

In this paper, a simple cracked beam under vertical pressure is considered. Stress intensity factor, normal, and shear stresses (at the tip of the crack) are calculated with finite element software. Results are compared when there is contact between crack surfaces with different direction of pressure, and when there is no contact. Results show that stress intensity factors can be implemented fo...