XIII International Conference on Computational Plasticity. Fundamentals and Applications -COMPLAS XIII

ABSTRACT Landslides can cause major economic damage and a large number of casualties as it is possible to see from past events occurred all over the world. Being able to predict these kind of hazards would then suppose the achievement of great benefits. Here a model that combines a depth integrated description of the soil-pore fluid mixture together with a set of 1D models dealing with pore pressure evolution within the soil mass is presented. In this way, pore pressure changes caused by vertical consolidation, changes of total stresses resulting from height variations and changes of basal surface permeability can be taken into account with more precision. The mathematical model is based on the Biot-Zienkiewicz equations, from where a depth averaged model is derived. Concerning the material behaviour, the approach used is the one suggested by the Perzyna viscoplasticity, which has been extensively used in the past to model solid behaviour prior to failure. Three different yield criterion are considered in the framework of Perzyna's model: a Von Mises, a Mohr Coulomb and a Cam Clay yield criterion. The obtained results lead to a good agreement with the results achieved using classical rheological models. Then, a simple shear rheological model is derived, providing the basal friction needed in depth integrated models. The Smoothed Particle Hydrodynamics (SPH) has been the numerical technique chosen to spatially discretised the depth integrated equations of the mathematical model. The SPH technique has been enriched by adding a 1D finite differences grid associated at each SPH node in order to improve the description of pore water profiles in the avalanching soil. The purpose of this work is to apply the SPH depth integrated numerical model, together with the sub-model that predicts the evolution of the pore water pressure inside the landslide, to simulate the propagation phase of the Aberfan flowslide occurred in 1966. REFERENCES [1] M. Pastor, M

Análisis de requerimientos y determinación preliminar de la potencia de actuación para el TVC de un vehículo lanzador con tobera flexible

En los vehículos lanzadores se requiere de un sistema de control de dirección del vector de empuje (TVC) que permita desarrollar un vuelo a lo largo de una trayectoria programada, así como también compensar las perturbaciones que se presenten durante la fase propulsiva. Existen distintos mecanismos para lograr este objetivo, siendo uno de los más utilizados el basado en modificar la dirección de la tobera de empuje. En el caso de combustibles sólidos, la tobera incluye una junta flexible conformada mediante la unión de un elastómero con aros de acero que posibilita ajustar la orientación del eje de empuje, mediante un actuador lineal montado de manera conveniente entre la tobera y la estructura del vehículo, el que provoca la deformación elástica de la junta. Se abordará la problemática de utilizar un actuador electromecánico (AEM), basado en tecnología de un motor eléctrico sin escobillas (brushless), para conformar el sistema de control de orientación de una tobera flexible. Dichas toberas imponen fuertes requerimientos operativos a los sistemas de actuación, debido a los elevados valores de rigidez y rozamiento que presentan. En lo metodológico se ha procedido formulando el modelo matemático mecánico, con el que se llevó a cabo la simulación numérica de funcionamiento empleando software especializado de acuerdo a los requerimientos impuestos para determinar a priori las potencias requeridas para los diferentes casos de maniobras planteados. Luego, en las condiciones de peor caso, se pasó a optimizar la relación de transmisión teniendo asimismo en cuenta los requerimientos de respuesta en frecuencia para condiciones de funcionamiento lineal.www.caim2014.unne.edu.arFil: Salomone, Javier E. Centro de Investigaciones Aplicadas. Departamento Sistemas Electromecánicos; Argentina.Fil: Pedroni, Juan P. Centro de Investigaciones Aplicadas. Departamento Sistemas Electromecánicos; Argentina.Fil: Jazni, Jorge E. Centro de Investigaciones Aplicadas. Departamento Sistemas Electromecánicos; Argentina.Fil: Dutto, Esteban A. Centro de Investigaciones Aplicadas. Departamento Sistemas Electromecánicos; Argentina.Fil: Cova, Walter J. D. Centro de Investigaciones Aplicadas. Departamento Sistemas Electromecánicos; Argentina.Fil: Lagier, Santiago. Centro de Investigaciones Aplicadas. Departamento Sistemas Electromecánicos; Argentina.Ingeniería Aeroespacia

Laser-induced phase separation of silicon carbide

Understanding the phase separation mechanism of solid-state binary compounds induced by laser-material interaction is a challenge because of the complexity of the compound materials and short processing times. Here we present xenon chloride excimer laser-induced melt-mediated phase separation and surface reconstruction of single-crystal silicon carbide and study this process by high-resolution transmission electron microscopy and a time-resolved reflectance method. A single-pulse laser irradiation triggers melting of the silicon carbide surface, resulting in a phase separation into a disordered carbon layer with partially graphitic domains (???2.5 nm) and polycrystalline silicon (???5 nm). Additional pulse irradiations cause sublimation of only the separated silicon element and subsequent transformation of the disordered carbon layer into multilayer graphene. The results demonstrate viability of synthesizing ultra-thin nanomaterials by the decomposition of a binary system.open

Research On The Legal Issues Of Domestic Enterprises For Overseas Stock Market Listing ——From The Perspective Of VIE Agreements

2011年发生的“支付宝股权转移事件”引发了各界对我国境内公司以协议控制模式在境外上市法律问题的广泛关注。协议控制模式最初是为规避外商投资产业准入政策而设计，其合法性至今还存有很大的争议。本文从相关概念的界定入手，介绍了境内企业以协议控制模式在境外上市的操作方式，分析了导致协议控制模式存在和发展的法律动因及其存在的问题，在此基础上，对如何解决其存在的问题提出了几点建议。 本文分为引言、正文、结论三部分。其中正文共分为四章： 第一章从相关概念的界定入手，对协议控制上市模式进行分析。 第二章分析了境内企业以协议控制模式境外上市的法律动因主要是：规避外资行业准入政策；规避商务部关联并购的审批程...The Alipay’s transfer of ownership in 2011 draws public attention to legal defects of domestic enterprises for overseas stock market listing by VIE agreements . VIE agreements aims to avoid industry access policy to foreign merchants at first, which arouse controversy about its legitimacy until now. This paper begins to illustrates the conception of VIE agreements, followed by the operating ways a...学位：法律硕士院系专业：法学院法律系_法律硕士(JM)学号：1302009115033

Cornelia-de Lange syndrome-associated mutations cause a DNA damage signalling and repair defect

Cornelia de Lange syndrome is a multisystem developmental disorder typically caused by mutations in the gene encoding the cohesin loader NIPBL. The associated phenotype is generally assumed to be the consequence of aberrant transcriptional regulation. Recently, we identified a missense mutation in BRD4 associated with a Cornelia de Lange-like syndrome that reduces BRD4 binding to acetylated histones. Here we show that, although this mutation reduces BRD4-occupancy at enhancers it does not affect transcription of the pluripotency network in mouse embryonic stem cells. Rather, it delays the cell cycle, increases DNA damage signalling, and perturbs regulation of DNA repair in mutant cells. This uncovers a role for BRD4 in DNA repair pathway choice. Furthermore, we find evidence of a similar increase in DNA damage signalling in cells derived from NIPBL-deficient individuals, suggesting that defective DNA damage signalling and repair is also a feature of typical Cornelia de Lange syndrome

Checkpoint kinase inhibitor AZD7762 strongly sensitises urothelial carcinoma cells to gemcitabine

Background: More effective chemotherapies are urgently needed for bladder cancer, a major cause of morbidity and mortality worldwide. We therefore explored the efficacy of the combination of gemcitabine and AZD7762, a checkpoint kinase 1/2 (CHK1/2) inhibitor, for bladder cancer. Methods: Viability, clonogenicity, cell cycle distribution and apoptosis were assessed in urothelial cancer cell lines and various non-malignant urothelial cells treated with gemcitabine and AZD7762. DNA damage was assessed by ?H2A.X and 53-BP1 staining and checkpoint activation was followed by Western blotting. Pharmacological inhibition of CHK1 and CHK2 was compared to downregulation of either CHK1 or CHK2 using siRNAs. Results: Combined use of gemcitabine and AZD7762 synergistically reduced urothelial carcinoma cell viability and colony formation relative to either single treatment. Non-malignant urothelial cells were substantially less sensitive to this drug combination. Gemcitabine plus AZD7762 inhibited cell cycle progression causing cell accumulation in S-phase. Moreover, the combination induced pronounced levels of apoptosis as indicated by an increase in the fraction of sub-G1 cells, in the levels of cleaved PARP, and in caspase 3/7 activity. Mechanistic investigations showed that AZD7762 treatment inhibited the repair of gemcitabine-induced double strand breaks by interference with CHK1, since siRNA-mediated depletion of CHK1 but not of CHK2 mimicked the effects of AZD7762. Conclusions: AZD7762 enhanced sensitivity of urothelial carcinoma cells to gemcitabine by inhibiting DNA repair and disturbing checkpoints. Combining gemcitabine with CHK1 inhibition holds promise for urothelial cancer therapy