There are many pairs of related western and eastern avian taxa in North America, and for many of these, little is known about their interactions in sympatry. One example is provided by MacGillivray’s warblers Oporornis tolmiei and mourning warblers Oporornis philadelphia. There have been occasional reports of range contact and hybridization between these forms, but recent authors have doubted t...

When small explants from early gastrulae of Xenopus laevis are allowed to develop in a buffered salt solution there is a considerable difference between the patterns of differentiation obtained from different dorsoventral levels of the marginal zone. These patterns of differentiation correspond to the fates of the different regions in the course of normal development. They are not altered if se...

A high-resolution finite element model is developed using the MSC.Marc software package to investigate local bond behavior and the modeling of this behavior. In the model, interaction between concrete and steel is treated geometrically as contact between two separate bodies. Concrete is modeled as a homogenous material. A multiple, fixed, smeared crack model is used to simulate response in tens...

This paper presents finite element analysis of the strength of roadheaher conical picks. Failure forms of conical picks are investigated, and the FE model of conical pick is established based on ANSYS. The static analysis is carried out according to the load calculated by empirical formula and the deformation map and stress distribution are obtained. The results show that the maximum stress of ...

Automatic hydraulic press is widely used for pressing ceramic wall and floor tiles, the four columns of its frame withstand the all work force when it works, so the columns are the key compartments of the frame, and its work performance has an important impact on the structural performance of the entire automatic hydraulic press. Took the column thread connection of 32.8MN automatic hydraulic p...

Plastic zone evolution in Al–2 wt% Si metal films on silicon and sapphire substrates was studied using nanoindentation and atomic force microscopy (AFM). AFM was used to measure the extent of plastic pileup, which is a measure of the plastic zone radius in the film. It was found that the plastic zone size develops in a self-similar fashion with increasing indenter penetration when normalized by...

INTRODUCTION As fractures of the supraorbital region are far less common than midfacial or orbital fractures, a study was initiated to investigate whether fist blows could lead to fractures similar to those often seen in the midface. METHODS A detailed skull model and an impactor resembling a fist were created and a fist blow to the supraorbital region was simulated. A transient finite elemen...

Metal deposition at the tool flank wear-land during machining is a common phenomenon, especially in machining aluminum alloys and annealed teels. The cause of metal deposit has not been studied and the characteristics of the wear-land and deposit contact are not completely known. In his study, a turning test was conducted using tungsten carbide (WC) tools with pre-generated wear-land to machine...

in this paper, a three-dimensional finite element model has been developed to simulate the laser-tig hybrid welding (hlaw) of stainless steel 1.4418 with thickness of 4 mm. transient temperature profile and dimensions of the fusion zone and heat affected zone (haz) during welding process are calculatedusing finite element method (fem) and were solved in the abaqus/standard software.the heat sou...