We investigate landscape evolution in a region of the Alps that has escaped glacial erosion during periodic glaciations of the last million years. The research is thus suited to investigate ...landscaping processes on a longer time scale at the eastern end of the Alps. Morphometric analysis reveals the presence of incised relict landscapes in several regions. In the Koralpe range topographic analysis is interpreted in terms of the relict landscape being present on both sides of the eastward tilted Koralpe block. This suggests that the relict landscape is younger than the tilting of the range, which is inferred to have taken place between 18 and 16Ma. In the Pohorje region, a relict landscape is developed across the contacts of a 19Ma pluton. We use apatite (U–Th)/He thermochronology to constrain the possible age of the Koralpe and Pohorje relict landscapes. The results indicate that the Pohorje massif had cooled below 70°C by about 15Ma suggesting that the relict landscape must be younger — consistent with the interpretation of the Koralpe range. These results suggest that many relict landscapes of the eastern Alps may have formed after 15Ma in a period of tectonic quiescence and erosion. However, in both ranges channel profile projections show that about 387±105m uplift and incision occurred subsequently. This incision is likely to have occurred during the last 6–5Ma in response to the uplift of the whole region. It testifies to a renewed and ongoing uplift event that is earlier than the glaciation periods but might easily be confused with impact of glacial erosion elsewhere in the eastern Alps.
•Morphologically, Koralpe and Pohorje ranges constitute incised relict landscapes.•Channel profile projection indicates an incision amount of c. 400m.•New apatite (U–Th)/He ages suggest that the relict landscape is <15Ma.
► Propose a high-order X-FEM approximation that can be easily extended to 3D. ► Uncouple geometry and approximation using two mesh octree approach. ► Use Nitsche’s method to obtain optimal ...convergence rates for material interfaces. ► Exponential convergence rates can be obtained for both free surfaces or material interfaces.
In this contribution, a strategy is proposed for uncoupling geometrical description and approximation with the X-FEM. The strategy is based on an uniform coarse mesh that defines a high order approximation of the mechanical fields and an adapted mesh that defines the geometrical features by means of levelsets. The connection between the geometry and the approximation is obtained by sharing the quadtree trees of the two meshes. Numerical examples involving level-set based parts, convergence studies, mechanical computations and numerical homogenization show good promise for this approach.
Summary
A novel integration scheme is proposed for fictitious domain finite element methods. It relies on the use of a surface tracking strategy based on anisotropic mesh adaptation. Thanks to an ...error estimator, the method builds iteratively an adapted anisotropic mesh that is refined near the geometrical interface and elongated in the direction of a small curvature. This strategy allows to decrease the integration cost, which can be problematic for high‐order fictitious domain methods. In addition, it opens the possibility for the creation of unfitted solid shell strategies that can be used for the treatment of thin structures. Numerical studies show that the method leads to promising results for both integration cost and behavior with respect to locking.
•A new approach (TLSV2) to couple damage mechanics and cohesive zone model (CZM) is proposed.•The mechanism relies on the Thick Level Set (TLSV1) approach to fracture.•Both the bulk and cohesive ...damages depend on a unique level set field.•A 1D equivalence between CZM, TLSV1 and TLSV2, is established.•Quick convergence rates of the TLSV2 can be observed, compared to the TLSV1.
This paper couples bulk damage modeling and cohesive zone modeling to get the benefits of both. Damage brings the directionality for the crack propagation as well as the possibility of crack branching while cohesive zone modeling allows for an explicit discrete crack modeling. The coupling is made easy through the Thick Level Set approach. The originality is that the coupling induces concurrent development of bulk and interface degradation.
Recent clinical success of epidermal growth factor (EGFR)-tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) have raised hopes that targeting other deregulated growth factor ...signaling, such as the hepatocyte growth factor/MET pathway, will lead to new therapeutic options for NSCLC. Furthermore, NSCLC present secondary EGFR-TKIs resistance related to exons 20 and 19 EGFR mutations or more recently to MET amplification. The aim of this study was to determine MET copy number related to EGFR copy number and K-Ras mutations in a targeted TKI naive NSCLC cohort.
We investigated 106 frozen tumors from surgically resected NSCLC patients. Genes copy number of MET and EGFR were assessed by quantitative relative real-time polymerase chain reaction and K-Ras mutations by sequencing.
MET is amplified in 22 cases (21%) and deleted in nine cases (8.5%). EGFR is amplified in 31 cases (29%). K-Ras is mutated in 11 cases (10.5%). As observed for EGFR amplification, MET amplification is never associated with K-Ras mutation. MET amplification could be associated with EGFR amplification. MET amplification is not related to clinical and pathologic features. MET amplification and EGFR amplification showed a trend toward poor prognosis in adenocarcinomas.
In EGFR-TKIs naive NSCLC patients, MET amplification is a frequent event, which could be associated with EGFR amplification, but not with K-Ras mutation. MET amplification may identify a subset of NSCLC for new targeted therapy. It will also be important to evaluate MET copy number to properly interpret future clinical trials.
Using thin reinforcements is a common way to strengthen structures, as in reinforced concrete for example. From a numerical point of view, dealing with these reinforcements is tedious, because of ...their diameter which is usually small compared to the characteristic dimensions of the structures, therefore requiring very fine meshes to represent them accurately. In this paper, a new approach allowing to mix a volumic and a lineic modeling of the reinforcements is proposed. Fine meshes with a volumic representation of the reinforcements are used in the zones of interest of the structure, whereas coarser meshes associated to lineic elements are used in the rest of the structure in order to decrease the computing times. A methodology to ensure the transition between both modeling is proposed, so that the results in the zones of interest are similar to the results that would be obtained with a full volumic representation of the reinforcements. The efficiency of the method is illustrated on several examples, involving linear elasticity and plasticity.
•Propose an approach to combine 3D and 1D models for reinforced structures.•The 3D X-FEM based model is used in the zones of interest.•The 1D truss-based model is used in the rest of the structure.•A method is proposed to mix these two models.•The method is shown to be efficient for both linear and nonlinear material behaviour.
The homogenization theory is a powerful approach to determine the effective thermal conductivity tensor of heterogeneous materials such as composites, including thermoset matrix and fibers. Once the ...effective properties are calculated, they can be used to solve a heat conduction problem on the composite structure at the macroscopic scale. This approach leads to good approximations of both the heat flux and temperature fields in the interior zone of the structure; however edge effects occur in the vicinity of the domain boundaries. In this paper, following an approach proposed for elasticity problems, it is shown how these edge effects can be accounted for. An additional asymptotic expansion term is introduced, which plays the role of a “heat conduction boundary layer” (HCBL) term. This expansion decreases exponentially and tends to zero far from the boundary. Moreover, the HCBL length can be determined from the solution of an eigenvalues problem. Numerical examples are considered for a standard multilayered material and for a unidirectional carbon-epoxy composite. The homogenized solutions computed with a finite element software, and corrected with the HCBL terms are compared to a heterogeneous finite element solution at the microscopic scale. The influences of the thermal contrast and the scale factor are illustrated for different kind of boundary conditions.
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