Numerical modeling of the behavior of fire and smoke within proposed building atria have revealed the possible presence of violent fire whirls or fire tornadoes induced by an inadvertent combination of ventilation and exhaust openings. Such fire vortexes can accelerate combustion up to ten times that seen during conventional fires, rapidly move fire and debris across available evacuation routes...

The paper gives an analytical approximation to the viscous damping coefficient due to the motion of a gas between a pair of closely spaced fluctuating plates in which one of the plates contains a regular system of circular holes. These types of structures are important parts of many microelectromechanical devices realized in MEMS technology as microphones, microaccelerometers, resonators, etc.T...

topological analysis has been performed on the total electron density of the two forms of ozonemolecule,c2v and d3h ,to investigate the nature of chemical bonds ,molecular structure , atomiccharges and electrical properties. while these concepts have been completely discussed usingclassical models the emphasize in this work is based on quantum theory of atoms in molecules(qtaim). because the d3...

the phase transformation phenomenon due to the crystallographic change of shape memory alloys subjected to mechanical or thermal loading is very complicated. regarding the thermo-mechanical coupling effects in shape memory alloys, in case of high  loading rates, heat generation/absorption during the forward/reverse transformation, will lead in temperature-dependent variation and consequently af...

During the design stage, realistic life time predictions for components help to reduce test cycles and allow for an optimization with respect to both production and repair costs (see e.g. Schuëller et al. 1996). Accurate predictions of the mean life time and its standard deviation can be obtained from a fracture mechanics approach that takes the uncertainties in the material parameters into acc...

Orthodontic tooth movement is a physiologic response to externally applied forces; the motive forces are primarily mechanical. The optimal application of orthodontic force enables maximum movement of teeth with minimal irreversible damage of the periodontal ligament (PDL), alveolar bone, and teeth. Since arch wires are the main force system in orthodontics, it is important in clinical practice ...

1 TA236 (Figure 2) is based on a patent pending design that optimizes the combination of these critical components. Specifically, the analyzer incorporates a noncontact direct drive motor to deliver reproducible forces (stresses) over a wide dynamic range of 0.001–18 N; an air bearing shaft support and guidance system to provide frictionless continuous travel over 25 mm for evaluating large sam...

Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoplasticity model. In this article, mechanical prope...