Fracture analysis of glass/epoxy composites under different thermal cycling conditions is considered. Temperature difference, stacking sequence, fiber volume fraction and number of thermal cycles are selected as the experimental design factors. The Taguchi method is implemented to design of the experiment and an apparatus is developed for automatic thermal cycling tests. The tensile tests are d...

The nasal bone is among the most frequently broken facial bone due to all types of trauma and is the most frequently fractured facial bone due to motor vehicle collisions. This study reports the results of anterior-posterior impacts performed on male cadavers using a free-falling impactor with a flat impacting surface. The force at fracture onset was determined using an acoustic emission sensor...

This clinical study investigated the practical value of two methods for debonding brackets attached by the adhesive Concise to acid-etched enamel surfaces. Forty-two Ultratrimm Standard metal brackets and 42 Fascination ceramic brackets were collected from juvenile patients undergoing orthodontic treatment. All metal brackets were mechanically debonded by a conventional bracket removal plier, w...

[1] Water-rock interactions within variable aperture fractures can lead to dissolution of fracture surfaces and local alteration of fracture apertures, potentially transforming the transport properties of fractures over time. Because fractures often provide dominant pathways for subsurface flow and transport, developing models that effectively quantify the role of dissolution on changing transp...

Silicon dioxide has eight stable crystalline phases at conditions of the Earth's rocky parts. Many metastable phases including amorphous phases have been known, which indicates the presence of large kinetic barriers. As a consequence, some crystalline silica phases transform to amorphous phases by bypassing the liquid via two different pathways. Here we show a new pathway, a fracture-induced am...

The fracture strength of silicon nanowires grown on a [111] silicon substrate by the vapor-liquid-solid process was measured. The nanowires, with diameters between 100 and 200 nm and a typical length of 2 microm, were subjected to bending tests using an atomic force microscopy setup inside a scanning electron microscope. The average strength calculated from the maximum nanowire deflection befor...

Age-Although their ages ranged from five to thirteen years (average ten years), twenty-six of the children were aged nine years or older. Sex-There were eighteen boys and sixteen girls. Site of fracture-In seventeen cases the fracture was three to four millimetres distal to the epiphysial plate, representing a true fracture of the neck of the radius (Fig. 1). In seventeen cases the injury was a...

We report a brittle Mg-based bulk metallic glass which approaches the ideal brittle behavior. However, a dimple structure is observed at the fracture surface by high resolution scanning electron microscopy, indicating some type of "ductile" fracture mechanism in this very brittle glass. We also show, from the available data, a clear correlation between the fracture toughness and plastic process...

Fractures of the distal humerus involving the articular surface can be challenging. The complexity of these fracture patterns increases when the distal fracture is associated with a concomitant humeral shaft fracture with significant proximal extension. The combined exposure technique described here allows for consistent and controlled posterior humeral exposure proximally from the traverse of ...

nowadays, by complication of production mechanisms from reservoirs and depletion of most of the reservoirs in iran, secondary production has become more important. regarding the nature of iranian reservoirs and carbonate inherencies and diagenetic and tectonic effects on these reservoirs, we see heterogeneities in them which cause uncertainty in predictions and performance of these reservoirs. ...