Stress imaging in patients with diabetes; routine practice?

Ventricular Dysfunction & Heart Failur

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

A cohesive XFEM model for simulating fatigue crack growth under mixed-mode loading and overloading

\u3cp\u3eStructures are subjected to cyclic loads that can vary in direction and magnitude, causing constant amplitude mode I simulations to be too simplistic. This study presents a new approach for fatigue crack propagation in ductile materials that can capture mixed-mode loading and overloading. The extended finite element method is used to deal with arbitrary crack paths. Furthermore, adaptive meshing is applied to minimize computation time. A fracture process zone ahead of the physical crack tip is represented by means of cohesive tractions from which the energy release rate, and thus the stress intensity factor can be extracted for an elastic-plastic material. The approach is therefore compatible with the Paris equation, which is an empirical relation to compute the fatigue crack growth rate. Two different models to compute the cohesive tractions are compared. First, a cohesive zone model with a static cohesive law is used. The second model is based on the interfacial thick level set method in which tractions follow from a given damage profile. Both models show good agreement with a mode I analytical relation and a mixed-mode experiment. Furthermore, it is shown that the presented models can capture crack growth retardation as a result of an overload.\u3c/p\u3

A new method for fatigue life prediction based on the Thick Level Set approach

\u3cp\u3eThe last decade has seen a growing interest in cohesive zone models for fatigue applications. These cohesive zone models often suffer from a lack of generality and applying them typically requires calibrating a large number of model-specific parameters. To improve on these issues a new method has been proposed in this paper based on the Thick Level Set approach. In this concept, material degradation due to cyclic loading is the result of interaction between damage evolution and fracture mechanics. The Thick Level Set formulation has been extended to interface elements, in order to allow for separation of strain energy in the bulk and energy required for surface creation. Global fracture parameters, derived from a free energy description governing the interface elements, are used as input for the empirical crack growth rate relation (Paris’ equation). It must be emphasized that in contrast to existing fatigue models, the Thick Level Set approach does not require the definition of a damage evolution law. Instead, damage is updated automatically by a continuously moving damage front. It is shown that applicability is not limited to fatigue behavior of linear elastic materials; elastic-plastic materials such as steels can be analysed as well. The sensitivity of model parameters is investigated and discussed and the practical relevance is explored for standard test configurations.\u3c/p\u3

A framework for automatic annotation of web pages using the Google Rich Snippets vocabulary

One of the latest developments for the Semantic Web is Google Rich Snippets, a service that uses Web page annotations for displaying search results in a visually appealing manner. In this paper we propose the Automatic Review Recognition and annOtation of Web pages (ARROW) framework, which is able to identify reviews on Web pages and to annotate them using RDFa attributes. The ARROW framework consists of four steps: hotspot identification, subjectivity analysis, information extraction, and page annotation. We evaluate an implementation of the framework by using various Web sites. Based on the evaluation we conclude that our framework is able to properly identify the majority of reviews, reviewed items, and review dates