Zouain N.,COPPE |
Pontes I.,Federal University of Pernambuco |
Vaunat J.,University of Barcelona
European Journal of Mechanics, A/Solids | Year: 2010
Energy and dissipation pseudo-potentials are employed to derive constitutive relationships, in the context of thermodynamic concepts, for the widely used Modified Cam-Clay (MCC) model for soil mechanics. A variational formulation of the MCC evolution equations is proposed in this paper. Since plastic collapse of MCC soils cannot be embedded in the classical limit analysis theory, finding the critical amplification of the load that produces plastic collapse is formulated in the form of a system of equations and inequalities. Then, a mixed minimization principle is proposed for the plastic collapse analysis of MCC soils. This principle is obtained by the application of the variational formulation for the flow law introduced in the first part of the article. © 2009 Elsevier Masson SAS. All rights reserved.
Vidal A.,Federal University of Campina Grande |
Soares J.,Federal University of Campina Grande |
Medeiros L.,PETREC |
Borges I.,Federal University of Campina Grande |
And 2 more authors.
3rd EAGE/SBGf Workshop 2016: Quantitative Seismic Interpretation of Lacustrine Carbonates | Year: 2016
X ray digital rock physics is a nondestructive technique, that enable the rock physic properties quantification and characterization. The method is based on the x ray absorption from each material, depending on the material density and the chemical components. Tomography methods are commonly used by medicine, but their application is coming together with geosciences since their discovery. The cross sections coming from the gray scale can be edited by many ways, depending on the study object. The sections integrations obtained by this method, allows a 3D projection by the material used. The image processing is made by computer systems to obtain qualitative and quantitative results quickly and efficiently.Through this stage develops a job that was applied to computed microtomography technique of X-ray mainly focused on the pores tortuosity study in carbonate rocks from Santana Formation, Araripe Basin. In this way, assist in the investigation of potential reservoirs. The data obtained by this technique is integrated and compared with petrophysical analyzes in a laboratory.
Fiel J.C.B.,Brazilian Military Institute of Engineering |
Da Silva F.C.,COPPE |
Martinez A.S.,COPPE |
Leal L.C.,Oak Ridge National Laboratory
Annals of Nuclear Energy | Year: 2014
The purpose of this work is to describe, by means of Chebyshev polynomials, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and U92235 enrichment. The cross-section data analyzed are fission, scattering, total, transport, absorption and capture. The parameterization enables a quick and easy determination of problem-dependent cross-sections to be used in few group calculations. The methodology presented in this paper will allow generation of group cross-section data from stored polynomials to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by the proposed methodology when compared with results from the SCALE code calculations show very good agreement. © 2014 Published by Elsevier Ltd.
On February 2 and 3, 2016, the High Performance Computing for Energy (HPC4E) project officially launches with a kick-off meeting for partners at Barcelona Supercomputing Center (BSC). Coordinated by BSC and running from December 1, 2015 to November 30, 2017, the project has been granted €2 million in funding by the EU’s Horizon 2020 research and innovation program. HPC4E brings together European and Brazilian partners that include both companies within the energy sector, such as REPSOL, TOTAL, Iberdrola and Petrobras, as well as the following research centres: BSC, CIEMAT, Inria, University of Lancaster (ULANC), COPPE, LNNC, ITA, Universidad Federal do Rio Grande do Sur and Universidad Federal de Pernambuco. Energy is one of the current priorities for EU-Brazil cooperation. The main objective is to develop high-performance simulation tools that go beyond the state of the art to help the energy industry respond to both future energy demands and carbon-related environmental issues. This objective follows the societal challenges defined for H2020 program and the Strategic Energy Technology Plan (SET-Plan) of the EU. HPC4E aims to achieve the Energy and Climate targets for 2020 and beyond on reducing greenhouse gases, increasing the proportion of energy from renewable sources and improving energy efficiency. In particular, the HPC4E project focuses on three different levels of the energy chain for different energy sources: With the participation of the most important HPC e-Infrastructures in Europe and Brazil, the project will exploit significant joint resources and expertise. The Computer Applications in Science and Engineering (CASE) department of Barcelona Supercomputing Center (BSC) will play a crucial role in the development of new HPC simulation algorithms and tools capable of taking advantage of future exascale HPC capabilities for the energy sector. José María Cela, European HPC4E coordinator and CASE director, says: “The energy sector is one of the sectors that can most benefit from the possibilities provided by HPC. We could not improve current energy production systems if we didn’t have supercomputers. If HPC is already considered necessary for research and innovation, the next generation of supercomputers will be even more important.” Reduction of the cost of electricity generated by wind farms by mitigating risks related to the design and operation of large-scale wind turbines through enhanced knowledge of wind conditions. Better quantification of the wind energy potential, and provision of data and models that can improve spatial planning tools and operations, ensuring an effective and efficient deployment of wind power. Increasing the contribution of sustainable resources to produce fuels for transportation and energy production. Bioenergy will play a crucial role in the achievement of the 2020 targets. It currently provides more than two-thirds of the renewable energy in the EU, and is expected to account for more than half the EU's renewable energy in 2020 and for about 11 percent of the total EU energy consumption. The potential impacts for the oil and gas industry include: Energy needs worldwide will increase yearly until 2020 and far beyond. The International Energy Agency (IEA) 2014 report estimates that the global energy demand is set to grow by 37 percent by 2040. Energy scarcity (or inefficient usage) can lead to higher prices, which will have a critical impact on the economy, as emphasized by the Energy Challenge in the European Commission Horizon 2020 work program (the Energy Challenge is designed to support the transition to a reliable, sustainable and competitive energy system), and by the priorities of the Brazilian Ministry of Science and Technology. Different governmental programs both in EU and Brazil have been started to promote and improve the efficient use of energy, e.g. EERA, ESFRI Energy and KIC Energy in EU and the “National Strategy on Science, Technology and Innovation 2012-2015” in Brazil. Barcelona Supercomputing Center (BSC) is the national supercomputing centre in Spain. BSC specialises in high performance computing (HPC) and its mission is two-fold: to provide infrastructure and supercomputing services to European scientists, and to generate knowledge and technology to transfer to business and society. BSC is a Severo Ochoa Center of Excellence and a first level hosting member of the European research infrastructure PRACE (Partnership for Advanced Computing in Europe). BSC also manages the Spanish Supercomputing Network (RES). With more than 27,000 employees and a presence in more than 40 countries, Repsol is one of the world’s leading integrated energy companies. Repsol is a global and integrated company, present along the entire value chain. The company’s diverse global asset portfolio allows it to participate in areas with the greatest energy resources worldwide. It is vertically integrated and operates in all areas of the oil and gas industry, including exploration and production, refining, distribution and marketing, petrochemicals, power generation and trading. Iberdrola has undergone a wide-ranging transformation over the last 10 years, which has enabled it to advance through the ranks to become the number one Spanish energy group, one of the Spanish main companies on the Ibex 35 by market capitalization, the world leader in renewable energies, and one of the world's top power companies. The company has established itself as a global leader within the sector, becoming one of the leading operators in the UK, one of the largest electricity utilities in the United States, the main private energy generator for Mexico and as the electricity supplier with the most customers in Brazil.
Leite A.C.,COPPE |
Zachi A.R.L.,CEFET RJ |
Lizarralde F.,COPPE |
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2011
This work addresses the 3D visual servoing problem for robot manipulators in the presence of uncertainties in the camera-robot system parameters. From a fixed and uncalibrated camera, the cartesian motion is decomposed into a 2D motion on a plane orthogonal to the optical axis and a 1D motion parallel to this axis. An adaptive visual servoing scheme based on a kinematic approach is developed for image-based look-and-move systems to allow both depth and planar tracking of a reference trajectory, without using image velocity and depth measurements. A cascade control strategy based on direct/indirect adaptive method is applied to consider the uncertain robot kinematics and dynamics in the presented solution. The stability properties and the convergence analysis are discussed from the Lyapunov-passivity formalism. Simulation results are shown to illustrate the performance of the proposed control scheme. © 2011 IFAC.