In order to replicate the fracture behavior of the intact human skull under impact it becomes necessary to develop a material having the mechanical properties of cranial bone. The most important properties to replicate in a surrogate human skull were found to be the fracture toughness and tensile strength of the cranial tables as well as the bending strength of the three-layer (inner table-dipl...

background: the ability of mineral trioxide aggregate (mta) to strengthen the tooth structure has been studied with contradictory results, and there is a lack of data in the case of calciumenriched mixture (cem) cement as a novel endodontic biomaterial. the aim of the present study was to evaluate the reinforcing effect of mta and cem cement on simulated immature teeth. materials and methods: t...

The propensity of the transition of fracture type in either brittle or ductile cracked solid under mixed-mode I and III loading conditions is investigated. A fracture criterion based on the competition of the maximum normal stress and maximum shear stress is utilized. The prediction of the fracture type is determined by comparing smax=rmax at a critical distance from the crack tip to the materi...

Composite materials utilizing the sandwich structure are a basic family of materials and possess a highly increasing use in modern industrial applications. Since the traditional approach to structural design and material selection tends to be replaced by the Fracture mechanics approach, it is worth understanding the way that the Fracture mechanics approach is applied. The traditional approach t...

BACKGROUND Early detection of a high-risk patient following hip fracture surgery is of paramount clinical importance. American Society of Anesthesiologists (ASA) grading is an easy and efficient index in predicting a worse outcome. The red cell distribution width (RDW) and handgrip strength, are gaining interest as a prediction tool as well. Accordingly, the objective of this study was to inves...

Osteoporosis has been previously defined in 1993 as a disease characterized by low bone mass and microarchitectural deterioration of bone tissue leading to enhanced bone fragility and a consequent increase in fracture risk. This definition has been revised in 2001 as a skeletal disorder characterized by compromised bone strength with an increased risk of fracture. The reason for the revision is...

With a hexagonal monolayer network of carbon atoms, graphene has demonstrated exceptional electrical and mechanical properties. In this work, the fracture of graphene sheets with Stone-Wales type defects and vacancies were investigated using molecular dynamics simulations at different temperatures. The initiation of defects via bond rotation was also investigated. The results indicate that the ...

in this study, al/al2o3 composites with two different particle sizes of 1 µm and 0.3 µm were produced via accumulative roll bonding (arb). the microstructure evolution, mechanical properties and fracture behavior of the composites were investigated. results show that higher arb cycles are required to achieve a uniform distribution of particles in the composite with 0.3 µm particle size. during ...

background : in anterior endodontically treated teeth a better esthetic can be achieved by using all-ceramic post -core restorations instead of metal post systems. maximum retention and fracture resistance of the post are the criteria upon which selection of a post system is based. the aim of this study was to evaluate the fracture resistance and retention of two all-ceramic post and core syste...