objective: repair of an indirect restoration is usually preferred over its replacement. this study aimed to evaluate the effect of silane in different surface preparation techniques on the bond strength of direct to indirect composite resin.   methods: for this in vitro experimental study, 48 indirect composite cubes were fabricated, divided into 4 groups of 12 and subjected to the following pr...

In this work, we demonstrate that for ultrathin MOS gate oxides, the reliability is closely related to the SiO2/Si interfacial physical stress for constant current gate injection ( ) in the Fowler–Nordheim tunneling regime. A physical stress-enhanced bond-breaking model is proposed to explain this. The oxide breakdown mechanism is very closely related to the Si–Si bond formation from the breaka...

In this study, the bond stress distribution and bond–slip model of steel bars iron tailing sand recycled aggregate concrete (ITRAC) were investigated using central pullout tests on 33 ITRAC bonded specimens. The results show three failure modes for specimens: splitting, pullout, splitting–pullout. Compared with maximum strength nature (NAC), specimens increased by 23.12% 6.08–23.96%, respective...

background : nursing is one of the most stressful jobs. the present study aimed to determine the effect of a cognitive -behavioral stress management training program based on precede model on stress reduction among nurses. methods : in this quasi-experimental study, which was conducted in 2010, 58 female nurses in hamadan, northwest iran were enrolled in the study and were divided into two equa...

The resistance of reinforced concrete is mobilized through the composite action of two materials with different mechanical behaviors and physical features. Enabling the composite action requires a transfer mechanism between the concrete and the reinforcement which is referred to as bond. The bond model can be defined as a traction-slip relation tangent to the interface. The bond strength betwee...

The resistance of reinforced concrete is mobilized through the composite action of two materials with different mechanical behaviors and physical features. Enabling the composite action requires a transfer mechanism between the concrete and the reinforcement which is referred to as bond. The bond model can be defined as a traction-slip relation tangent to the interface. The bond strength betwee...

Abstract : The effect of a bond failure and its extent is studied on stress concentration in long fibers as well as stress distribution in short fibers and their surrounding matrix bays. The material is assumed to be a finite width hybrid composite lamina which is subjected to a tensile load of magnitude "P" at infinity. The surrounding matrix is assumed to take only shear (shear-lag theory). T...

In this work, we developed a bond-based cohesive peridynamics model (CPDM) and apply it to simulate inelastic fracture by using the meso-scale Xu-Needleman potential . By doing so, have successfully continuum mechanics with intrinsic stress/strain measures as well consistent built-in macro-scale constitutive relations. The main novelties of work are: (1) We shown that stress proposed nonlocal i...

Reviewing the research on reinforced reactive powder concrete’s bonding properties from three perspectives: test methods, influencing factors of and stress-slip constitutive relationship. For central pull-out test, steel bar bond stress state deviates actual engineering structure, beam is closer to situation. The relevant experimental at home abroad bond-slip model based are described in detail...

The objective of this study was to evaluate the influences of enamel shape and bracket base configuration on shear bond strength from a biomechanical point of view. To this end, shear bond test and stress analysis using finite element method (FEM) were performed. Results obtained from both tests were then comprehensively investigated. Maxillary incisors were prepared for plane specimens, while ...