The cold climate is a favorable parameter for the development of tension cracks and decrease of rock brittleness. Therefore, this paper attempts to investigate the Hamekasi porous limestone in order to predict the brittleness indices during freeze-thaw cycles. The freeze–thaw test was executed for one cycle including 16 h of freezing, and 8 h of thawing. The geo mechanical properties and brittl...

RATIONALE Previous studies have shown that an increase in inspiratory pressure during nasal intermittent positive pressure ventilation (IPPV) does not result in increased effective minute ventilation (E) due to glottic interference. STUDY OBJECTIVES To test the consequences of increases in negative pressure ventilation (NPV) on V(E). MATERIAL AND METHODS Eight healthy awake subjects underwe...

There has been an emerging interest in stretchable power sources compatible with flexible/wearable electronics. Such power sources must be able to withstand large mechanical strains and still maintain function. Here we report a highly stretchable H3PO4-poly(vinyl alcohol) (PVA) polymer electrolyte obtained by optimizing the polymer molecular weight and its weight ratio to H3PO4 in terms of cond...

China has done R&Ds on the fabrication technology for ITER first wall (FW). The FW materials, such as the vacuum-hot-pressing (VHP) Be and ITER-grade CuCrZr alloys, have been developed in China. The Be plate showed good physical and mechanical properties, similar to S65C. The effect of fabrication process on mechanical strength of CuCrZr alloy was studied. Several FW qualification (FWQ) mock-up...

We continuously monitored the microstructure of a rat-tail tendon during stretch/relaxation cycles. To that purpose, we implemented a new biomechanical device that combined SHG imaging and mechanical testing modalities. This multi-scale experimental device enabled simultaneous visualization of the collagen crimp morphology at the micrometer scale and measurement of macroscopic strain-stress res...

AIM Silver colloidal nanoparticles have been incorporated into acrylic resins to induce antimicrobial properties. However, as additives, they can influence the mechanical properties of the final product. Mechanical properties are also dependent on different curing cycles. The aim of this study was to evaluate flexural strength of a denture base resin incorporated with different concentrations o...

Clinical cases show that zirconia restoration could happen fracture by accident under overloading after using a period of time. The purpose of this study is to research mechanical behavior and predict lifetime of dental zirconia ceramics under cyclic normal contact loading with experiments. Cyclic normal contact loading test and three point bending test are carried on specimens made of two bran...

In this paper we generalize previous work in which the fixed points of dynamical systems were used to construct obstacle-avoiding, goalattracting trajectories for robots to more complex attractors such as limit cycles in the form of closed planar curves. Following the development of a formalism for dealing with a mechanical system, some of whose coordinates are constrained to follow the traject...