In a shell and tube heat exchanger, the failure of tube-to-tubesheet welds results in high-pressure water jet which erodes the refractory in front of the tubesheet. Finite element method was employed to simulate the welding process and post weld heat treatment (PWHT) to find the factors affecting the failure in tube-to-tubesheet weldments. Residual stresses in two different geometries of tube-t...

The mechanical behavior of freestanding gold membranes 0.5 micron thick with and without passivation layers was studied with a membrane deflection experiment. Membrane width was varied from 2.5 to 20 microns to investigate size effects. The presence of the passivation layer had the effect of reducing the membrane strength. Yield stress, as well as fracture strain and stress, were all found to b...

This dictionary, sponsored by the International Epidemiological Association, is due for revision, and we propose that this definition should be revised. It is unclear from the definition as currently worded how residual confounding differs from just confounding. Kleinbaum et al. (2) refer to residual confounding as both the lack of proper covariates and the effect of not sufficiently detailed i...

This paper deals with the effect of several residual stress profiles on the fatigue crack propagation in prestressing steel wires subjected to tension loading or bending moment. To this end, a computer program was developed to evaluate the crack front evolution on the basis of the Walker law. Results demonstrate that the absence of residual stresses makes the crack propagate towards a preferent...

Residual stresses in a surface layer determine many exploitation characteristics of machined surface. Depending on their kind and the type of applied loading, the influence of residual stresses can be negative or positive. Tensile residual stresses usually exert highly detrimental impact on several functional aspects such as strength, fatigue life, corrosion, wear resistance, etc., whereas comp...

The present paper concerns the nature of the relationship between auxin and the expansion of the plant cell. It will be shown that it is possible to separate in time the action of auxin on the cell from the act of cellular expansion by water uptake. The separation of auxin action from cell expansion is achieved as follows: auxin is first applied to tissue which is kept from expanding by a suita...

PURPOSE In this 10-year longitudinal study we evaluated the amount of mandibular residual ridge resorption for 2 groups of subjects with complete dentures, one group with porcelain artificial teeth and the other with acrylic resin teeth. METHODS One hundred and nine patients who had undergone ridge extension procedures with skin graft and prosthetic rehabilitation with porcelain or acrylic re...