Facing Emerging Risks in Carbon Sequestration Networks. A Comprehensive Source Modeling Approach.

Tackling risks in emerging infrastructures is a key point in making them acceptable and safer. Carbon Sequestration pipeline networks, as part of the Carbon Capture and Storage chains, are linked to the handling of large amounts of CO2 and may be subjected to failures and ruptures. This results in large pressurized and multiphase releases of CO2 that behaves as a denser-than-air and asphyxiant gas. The lack of a comprehensive modelling approach in this sense makes employed risk safety procedures often unreliable and lacking. In this work, a comprehensive modelling approach, based on self-collected experimental data, is proposed with the aim of filling existing gaps. Results well match experimental data and the modelling procedure allows for the estimation of characteristic parameters linked to heat transfer phenomena and the incidence of geometry and operative conditions on the release evolution. The occurrence of the solid phase and the applicability of the isothermal hypothesis is discussed showing that specific geometric and operative conditions are required

Associations of clock genes polymorphisms with soft tissue sarcoma susceptibility and prognosis

BACKGROUND: Dysfunction of the circadian clock and polymorphisms of some circadian genes have been linked to cancer development and progression. We investigated the relationship between circadian genes germline variation and susceptibility or prognosis of patients with soft tissue sarcoma. PATIENTS AND METHODS: We considered the 14 single nucleotide polymorphisms (SNPs) of 6 core circadian genes that have a minor allele frequency >\u20095% and that are known to be associated with cancer risk or prognosis. Genotyping was performed by q-PCR. Peripheral blood and clinic-pathological data were available for 162 patients with liposarcoma or leiomyosarcoma and 610 healthy donors. Associations between the selected clock genes polymorphisms and sarcoma susceptibility or prognosis were tested assuming 3 models of inheritance: additive, recessive and dominant. Subgroup analysis based on sarcoma histotype was performed under the additive genetic model. Multivariate logistic regression and multivariate Cox proportional hazard regression analyses were utilized to assess the association between SNPs with patient susceptibility and survival, respectively. Pathway variation analysis was conducted employing the Adaptive Rank Truncated Product method. RESULTS: Six out of the 14 analyzed SNPs were statistically significantly associated with susceptibility or prognosis of soft tissue sarcoma (P <\u20090.05). The present analysis suggested that carriers of the minor allele of the CLOCK polymorphism rs1801260 (C) or of PER2 rs934945 (T) had a reduced predisposition to sarcoma (26% and 35% respectively with the additive model) and liposarcoma (33% and 41% respectively). The minor allele (A) of NPAS2 rs895520 was associated with an increased predisposition to sarcoma of 33% and leiomyosarcoma of 44%. RORA rs339972 C allele was associated with a decreased predisposition to develop sarcoma assuming an additive model (29%) and leiomyosarcoma (36%). PER1 rs3027178 was associated with a reduced predisposition only in liposarcoma subgroup (32%). rs7602358 located upstream PER2 was significantly associated with liposarcoma survival (HR: 1.98; 95% CI 1.02-3.85; P\u2009=\u20090.04). Germline genetic variation in the circadian pathway was associated with the risk of developing soft tissue sarcoma (P\u2009=\u20090.035). CONCLUSIONS: Genetic variation of circadian genes appears to play a role in the determinism of patient susceptibility and prognosis. These findings prompt further studies to fully dissect the molecular mechanisms

Explicit F.E. formulation with modified linear tetrahedral elements applied to high speed forming processes

International audienceWe will adapt a recent explicit FE formulation with modified linear tetrahedral elements for high speed metal forming simulation. This formulation both enables the use of efficient adaptive non structured meshers, and tackles the locking effect in quasi-incompressible cases. We implement this formulation for the infinitesimal elastic plastic case. The anti-locking modification effect will be underlined on two 3D bench marks: an elastic compression test and an elastic-plastic bar impact test

Numerical modelling of laser rapid prototyping by fusion wire deposit

International audienceA finite element model has been developed to simulate an innovative laser rapid prototyping process. Several numerical developments have been implemented in order to simulate the main steps of the rapid prototyping process: injection, heating, phase change and deposit. The numerical model also takes into account different phenomena: surface tension in the liquid state, asborptivity and plasma effects during materiallaser interaction. The threedimensional model is based on the lagrangian approach used in the Forge® finite element software. The thermal model coupled with materiallaser model is compared and gives good agreements. Simulations of the rapid prototyping are compared with experimental results

An enhanced Lemaitre model formulation for materials processing damage computation

The original publication is available at www.springerlink.comInternational audienceThe Lemaitre damage model is now widely used to deal with coupled damage analyses for various mechanical applications. In this article, different extensions of the model are presented and discussed to deal with complex multiaxial configurations--such as multi-stages bulk forming processes. A specific treatment is done to account for compressive damage growth, and a stress triaxiality cut-off value is considered to avoid any damage evolution below a critical negative triaxiality. The damage potential is also modified to deal with highly ductile materials, and the plastic strain is split into a negative part and a positive part to differentiate damage growth for compressive states of stress and for tensile states of stress. Finally, an anisotropic damage approach based on the comparison between grain flow orientation and principal loading directions is defined. A combination of these extensions is achieved within a single Lemaitre formulation. Application on different examples show the robustness and accuracy of the model defined in this paper

Simulation des assemblages par déformation. Vers une approche intégrée de l'assemblage dans la phase de dimensionnement

International audienceL'augmentation de structures multimatériaux dans de nombreuses industries conduit à une utilisation de plus en plus importante des procédés d'assemblage. Nous nous intéressons ici plus particulièrement aux procédés d'assemblage ponctuels par déformations plastiques tels que les différentes familles de rivetage ou encore de clinchage. Dans l'industrie automobile par exemple, la volonté permanente d'alléger la " caisse en blanc " conduit à l'utilisation de plus en plus fréquente de métaux légers tels que les alliages d'aluminium, ou encore de tôles polymères composite. Le point de soudure, majoritairement utilisé pour l'assemblage de tôles de carrosserie, n'est alors plus adapté. Les techniques de rivetage autopoinçonneur ou encore de clinchage représentent alors des solutions idéales, alliant facilité de pose, tenue mécanique appropriée et assemblage propre (absence de fumée, de projections, de bruit, d'eau)

Modélisation numérique du laminage à pas de pèlerin de tubes ODS en vu de limiter les risques d'endommagement

National audiencePour les Réacteurs à Neutrons Rapides au sodium, les matériaux de gainage de référence pour les très forts taux de combustion sont les nuances ferritiques/martensitiques ODS. Ces matériaux présentent en effet des bonnes propriétés en fluage, en résilience et en résistance à l'oxydation. Toutefois la présence des oxydes ODS font de ces nuances des matériaux très difficiles à mettre en forme. Classiquement le tube de gainage est mis en forme à froid à partir d'une ébauche tubulaire par une succession de passes de laminage à pas de pèlerin et de traitements thermiques. Dans le cadre de cette étude la modélisation numérique du procédé de laminage dans une configuration de type HPTR a été entreprise. Le modèle prend en compte toute la complexité des phénomènes physiques, mécaniques ainsi que le modèle de comportement du matériau pour simuler les déformations élastoplastiques cycliques qui apparaissent au cours de la mise forme des tubes minces. La modélisation de la cinématique du procédé a déjà été réalisée. L'utilisation de capteurs numériques pour suivre le chemin de déformation de la matière lors du procédé permet d'estimer la nature et l'amplitude des déformations cycliques subies

A node-nested Galerkin multigrid method for metal forging simulation

International audienceA node-nested Galerkin multigrid method is developed to solve systems provided by mixed formulations of 3D metal forming problems. An algebraic approach is used where operators are built on node-nested coarse meshes obtained by an automatic coarsening algorithm. This blackbox multigrid preconditioner is developed within the PETSc library. It is plugged to the FORGE3® finite element software. The linear rate of convergence and the very high efficiency of the resulting multigrid solver are evaluated for large scale problems with nonlinear behaviour

Basal cell carcinoma: 10-year experience with electrochemotherapy

BACKGROUND: Electrochemotherapy (ECT), by combining manageable cytotoxic agents with short electric pulses, represents an effective palliative skin-directed therapy. The accumulated evidence indicates that ECT stands out as a safe and well-tolerated alternative treatment for patients with multiple or large basal cell carcinoma (BCC), who are not suitable for conventional treatments. However, long-term data and shared indications are lacking. METHODS: In this observational study, we retrospectively analyzed 84 prospectively collected patients with multiple, recurrent or locally advanced BCC who were not candidate for standard therapies and received bleomycin-based ECT according to the European Standard Operative Procedures of ECT, from 2006 to 2016. RESULTS: Disease extent was local, locally advanced and metastatic in 40 (48%), 41 (49%) and 3 (3%), respectively. Forty-four (52%) individuals had multiple BCCs. Grade 3 skin toxicity after ECT was observed in 6% of cases. Clearance rate was 50% (95% CI 39-61%). Primary presentation (p = 0.004), tumor size <3 cm (p < 0.001), well-defined borders (p = 0.021), absence of tumor ulceration (p = 0.001), non-aggressive BCC histology (p = 0.046) and age 6469 years were associated with higher complete response rate. In patients with local BCC, the clearance rate was 72.5 and 85% after one or two ECT cycles, respectively. In the laBCC group, 32 patients (78%) achieved an objective response. Five-year recurrence rate for local and laBCC was 20 and 38%, respectively (p 64 0.001). CONCLUSIONS: One or two ECT cycles with bleomycin may be a valuable palliative treatment in well-selected patients with multiple BCCs and favorable tumor features. Validation of predictive factors will be imperative to match patients with optimal ECT treatment modalities. Management of laBCC with ECT warrants further investigation. Trial registration ISRCTN14633165 Registered 24 March 2017 (retrospectively registered)

Finite Element Modeling of Tube Piercing and Creation of a Crack

From the issue entitled "Proceedings of the 11th ESAFORM Conference on Material Forming, Lyon (France), 23-25 April 2008, edited by P. Boisse, F. Morestin, E. Vidal-Sallé, LaMCoS, INSA de Lyon)" - http://esaform2008.insa-lyon.fr/proceedings/MS06/p_Ch_571.pdfInternational audienceA 3D simulation of Mannesmann tube piercing is performed using the finite element software Forge 2005®. The sensitivity of the simulation results to numerical methods and physical parameters is discussed. Advanced numerical schemes and refined time discretizations are required to obtain correct descriptions of the material flow. In this study, one concentrates on the stress state and damage development before the material comes in contact with the plug. Indeed, the crack is to appear prior to the action of the plug. The description of the material behaviour is found to be a key information to predict the crack development. Predictions based on a modified Lemaitre damage law and a normalised Latham and Cockroft criterion are compared