Oxygen plasma treatment has been used extensively to bond polydimethyl siloxane to polydimethyl siloxane or glass in the rapid prototyping of microfluidic devices. This study aimed to improve the bonding quality of polydimethyl siloxane to passivated silicon using oxygen plasma treatment, and also to evaluate the bonding quality. Four types of passivated silicon were used: phosphosilicate glass...

Many fabrication processes for polymeric objects include melt extrusion, in which the molten polymer is conveyed by a ram or a screw and the melt is then forced through a shaping die in continuous processing or into a mold for the manufacture of discrete molded parts. The properties of the fabricated solid object, including morphology developed during cooling and solidification, depend in part ...

ABSTRACT: This paper describes analysis of deep beams subjected to two point loading with three different L/D ratios (1.5, 1.6, 1.71) using Non-linear Finite element method (ANSYS 9.0 software) in order to investigate the stress and strain distribution pattern at mid-section of the beam. In ANSYS 9.0 software, SOLID 65 and LINK 8 element represent concrete and reinforcing steel bars. Non-linear...

Directional arrays of branched microscopic setae constitute a dry adhesive on the toes of pad-bearing geckos, nature's supreme climbers. Geckos are easily and rapidly able to detach their toes as they climb. There are two known mechanisms of detachment: (1) on the microscale, the seta detaches when the shaft reaches a critical angle with the substrate, and (2) on the macroscale, geckos hyperext...

During agitated drying and mixing processes, particle beds are exposed to shear deformation. This leads to particle attrition, the extent of which is dependent on the prevailing stresses and strains in the bed. The distributions of shear stresses and strain rates within the bed are highly non-uniform, requiring attention to localised conditions. Therefore a narrow angular sector of the bed is d...

Organic nanoparticles of poly(styrene-co-maleimide) or SMI were synthesized in aqueous dispersion with a maximum concentration of 35 wt.% and are favorably applied in industrial coating processes. In order to evaluate the further processability and flow behavior of these nanoparticle dispersions, general rheological characterization under creep, oscillatory and rotational testing was done by ap...

Composites of concentric cylinders can fail by microcracks that span the thickness and length of one cylinder but arrest at the boundary to adjacent cylinders. This failure mode was analyzed by developing a new polar shear-lag analysis for stresses in a cross section of a concentric-cylinder composite. The analysis can accurately calculate stresses in each cylinder in the presence of microcrack...

In this study, a finite element (FE) model of a below-knee prosthesis of patellar tendon-bearing (PTB) design, and several altered variations of the model have been constructed. A load of approximately 1.5 times normal body weight (984 N) was applied at the heel of the model to simulate heelstrike conditions. The "base" model was then analyzed and revised iteratively until a model which provide...

Fiber suspension theory model parameters for use in the simulation of fiber orientation in complex flows are, in general, either calculated from theory or fit to experimentally determined fiber orientation generated in processing flows. Transient stress growth measurements in startup of shear flow and flow reversal in the shear rate range, γ = 1 to 10 s, were performed on a commercially availab...

Many industries such as oil, gas, aerospace, and automotive, use axisymmetric adhesively bonded single lap joints. Different materials are frequently mated using When composite adherents delaminate, the stress circulation inside adhesive layer significantly influenced. As a result, importance of considering stresses in presence considerable delamination is investigated this paper. To understand...