This study of two lemur species (Lemur catta and Propithecus v. verreauxi) in Madagascar combines observations of food procurement and initial food placement in the mouth with comparisons to food toughness and external properties. Food toughness was hypothesized to play a decisive role in determining food placement during ingestion. It was found that tougher foods are generally ingested on the ...

Solid lubricants are commonly found in applications where more traditional lubrication techniques are undesirable or precluded. Polytetrafluoroethylene (PTFE) is an attractive solid lubricant, but high wear rates limit its use. While nanofillers have been found, in some cases, to provide wear resistance without introducing other detrimental effects, the mechanisms of wear resistance remain uncl...

Delamination plays a pivotal role during normal development and cancer. Previous work has demonstrated that delamination and epithelial cell movement within the plane of an epithelium are associated with a change in cellular phenotype. However, how this positional change is linked to differentiation remains unknown. Using the developing mouse pancreas as a model system, we show that β cell dela...

A finite-element-based toolset has been developed to simulate arbitrary evolution of 3-D, geometrically explicit, interlaminar delaminations in composite structures. A new energy-based growth formulation uses the virtual crack extension (VCE) method to predict point-by-point growth along the delamination front. The VCE method offers an accurate and computationally efficient means to extract bot...

Dead cells in most epithelia are eliminated by cell extrusion. Here, we explore whether cell delamination in the amnioserosa, a seemingly stochastic event that results in the extrusion of a small fraction of cells and known to provide a force for dorsal closure, is contingent upon the receipt of an apoptotic signal. Through the analysis of mutant combinations and the profiling of apoptotic sign...

the basic trait in the ceramics is their high brittle or low fracture toughness, and the main criteria in the design and application is specifying the fracture toughness in ceramics. in this paper, a new method is proposed to determine the fracture toughness of ceramics, which is enhanced in lowering the cost of fracture toughness determination relative to the previous methods. hence due to the...

An experimental setup is designed to detect composite delamination damage based on ultrasonic infrared thermography. The ultrasonic infrared thermography system is composed by ultrasonic excitation system, infrared thermal imager and data acquisition system and two damaged composite plate specimens are produced in the experiment. The image processing methods including thresholding, filters, edg...

A sound knowledge of mechanical properties of rocks at high temperatures and pressures is essential for modelling volcanological problems such as fracture of lava flows and dike emplacement. In particular, fracture toughness is a scale invariant material property of a rock that describes its resistance to tensile failure. A new fracture mechanics apparatus has been constructed enabling fracture...

In this paper, effects of ply orientation of adjacent plies with (ϕ//θ) interfaces on mode II critical strain energy release rate (fracture toughness) of multidirectional (MD) laminate has been studied. Ply orientation of adjacent plies is one of the most important parameters affects the mode II critical strain energy release rate () in the initiation of the delamination. To  study this paramet...

Delamination is a type of representative damage in composite structures, severely degrading structural integrity and reliability. The identification of delamination is commonly treated as an issue of nondestructive testing. Differing from existing studies, a hybrid optimization algorithm HOA , combining particle swarm optimization PSO with simplex method SM , is proposed to identify delaminatio...