Search results for "Mesh"
showing 10 items of 885 documents
Endoventricular patch plasty improves results of LV aneurysmectomy.
1993
From May 1985 to December 1991 52 patients were operated upon for postischemic left ventricular aneurysm (LV-A). Between May 1985 and July 1989 25 patients (group I) with a mean age of 59 (46-72) years underwent conventional aneurysmectomy with direct closure of the left ventricle (LV) and a mean of 1.9 (0-3) additional bypass grafts (54% triple-vessel disease). The hospital mortality was 8% (2/25) and the late mortality during a median follow-up time of 34 months was 28% (7/25) with a 4-year survival of 66%. Improvement in the quality of life (NYHA from 2.6 to 2.1, P = 0.078) and global left ventricular ejection fraction (EF) (from 35 to 38%) proved to be unsatisfactory in conjunction with…
Introducing a novel mesh following technique for approximation-free robotic tool path trajectories
2017
Abstract Modern tools for designing and manufacturing of large components with complex geometries allow more flexible production with reduced cycle times. This is achieved through a combination of traditional subtractive approaches and new additive manufacturing processes. The problem of generating optimum tool-paths to perform specific actions (e.g. part manufacturing or inspection) on curved surface samples, through numerical control machinery or robotic manipulators, will be increasingly encountered. Part variability often precludes using original design CAD data directly for toolpath generation (especially for composite materials), instead surface mapping software is often used to gener…
The era of reference genomes in conservation genomics
2022
Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics.
Shortcut to Adiabaticity in the Lipkin-Meshkov-Glick Model
2015
We study transitionless quantum driving in an infinite-range many-body system described by the Lipkin-Meshkov-Glick model. Despite the correlation length being always infinite the closing of the gap at the critical point makes the driving Hamiltonian of increasing complexity also in this case. To this aim we develop a hybrid strategy combining shortcut to adiabaticity and optimal control that allows us to achieve remarkably good performance in suppressing the defect production across the phase transition.
Measurement and Modeling of the Origins of Starvation in Congestion Controlled Mesh Networks
2008
Significant progress has been made in understanding the behavior of TCP and congestion-controlled traffic over multi- hop wireless networks. Despite these advances, however, no prior work identified severe throughput imbalances in the basic scenario of mesh networks, in which one-hop flows contend with two-hop flows for gateway access. In this paper, we demonstrate via real network measurements, test-bed experiments, and an analytical model that starvation exists in such a scenario, i.e., the one-hop flow receives most of the bandwidth while the two- hop flow starves. Our analytical model yields a solution consisting of a simple contention window policy that can be implemented via mechanism…
Resveratrol as a Chemopreventive Agent: A Promising Molecule for Fighting Cancer
2006
International audience; Resveratrol (3,4',5 tri-hydroxystilbene) is a phytoalexin produced in hudge amount in grapevine skin in response to infection by Bothrytis cinerea. This production of resveratrol blocks the proliferation of the pathogen, thereby acting as a natural antibiotic. Numerous studies have reported interesting properties of trans-resveratrol as a preventive agent against important pathologies i.e. vascular diseases, cancers, viral infection or neurodegenerative processes. Moreover, several epidemiological studies have revealed that resveratrol is probably one of the main microcomponents of wine responsible for its health benefits such as prevention of vaso-coronary diseases …
Early Cambrian origin of modern food webs: evidence from predator arrow worms.
2007
7 pages; International audience; Although palaeontological evidence from exceptional biota demonstrates the existence of diverse marine communities in the Early Cambrian (approx. 540-520 Myr ago), little is known concerning the functioning of the marine ecosystem, especially its trophic structure and the full range of ecological niches colonized by the fauna. The presence of a diverse zooplankton in Early Cambrian oceans is still an open issue. Here we provide compelling evidence that chaetognaths, an important element of modern zooplankton, were present in the Early Cambrian Chengjiang biota with morphologies almost identical to Recent forms. New information obtained from the lowermost Cam…
Numerical Simulation of Friction Stir Welding by Natural Element Methods
2008
In this work we address the problem of numerically simulating the Friction Stir Welding process. Due to the special characteristics of this welding method (i.e., high speed of the rotating pin, very large deformations, etc.) finite element methods (FEM) encounter several difficulties. While Lagrangian simulations suffer from mesh distortion, Eulerian or Arbitrary Lagrangian Eulerian (ALE) ones still have difficulties due to the treatment of convective terms, the treatment of the advancing pin, and many others. Meshless methods somewhat alleviate these problems, allowing for an updated Lagrangian framework in the simulation. Accuracy is not affected by mesh distortion (and hence the name mes…
Unconditionally stable meshless integration of time-domain Maxwell’s curl equations
2015
Grid based methods coupled with an explicit approach for the evolution in time are traditionally adopted in solving PDEs in computational electromagnetics. The discretization in space with a grid covering the problem domain and a stability step size restriction, must be accepted. Evidence is given that efforts need for overcoming these heavy constraints. The connectivity laws among the points scattered in the problem domain can be avoided by using meshless methods. Among these, the smoothed particle electromagnetics, gives an interesting answer to the problem, overcoming the limit of the grid generation. In the original formulation an explicit integration scheme is used providing, spatial a…
Meshless Simulation of Friction Stir Welding
2007
This paper encompasses our first efforts towards the numerical simulation of friction stir welding by employing a Lagrangian approach. To this end, we have employed a meshless method, namely the Natural Element Method (NEM). Friction Stir welding is a welding process where the union between the work pieces is achieved through the extremely high deformation imposed by a rotating pin, which moves between the two pieces. This extremely high strain is the main responsible of the difficulties associated with the numerical simulation of this forming process. Eulerian and Arbitrary Lagrangian-Eulerian (ALE) frameworks encounter difficulties in some aspects of the simulation. For instance, these ap…