69 research outputs found
Interconexão Entre Pintura, Vida e Religião: A Obra Mural Sacra Moderna de Emeric Marcier
No full textThis article aims to provide us with an overview of the contribution, given to the mural art in Brazil, by the Jewish Romanian painter, converted to Catholicism and naturalized Brazilian, Emeric Marcier, author of extensive work mural, with the theme of religion, performed between the years of 1946 and 1960. Marcier was part of the first generation of Jewish artists who immigrated to Brazil. He lived, initially, in Rio de Janeiro and then he moved to Barbacena, Minas Gerais.Este artigo pretende nos fornecer um panorama da contribuição, prestada à Arte Mural Brasileira, pelo pintor judeu romeno, convertido ao catolicismo e naturalizado brasileiro, Emeric Marcier, autor de extensa obra mural, com a temática religiosa, executada entre os idos anos de 1946 e 1960. Marcier fez parte da primeira geração de artistas judeus que imigrou para o Brasil. Residiu, inicialmente, no Rio e Janeiro e, depois, na cidade de Barbacena, Estado de Minas Gerais.
Radiation Hydrodynamics Scaling Laws in High Energy Density Physics and Laboratory Astrophysics
No full textaccepted paperInternational audienceIn this paper, radiating fluids scaling laws are studied. We focus on optically thin and optically thick regimes which are relevant for both astrophysics and laboratory experiments. By using homothetic Lie groups, we obtain the scaling laws, the similarity properties and the number of free parameters which allow to rescale experiments in the two astrophyscial situations
Scaling laws for radiating fluids: the pillar of laboratory astrophysics
No full textInternational audienceIn this paper, we derive the scaling laws for different radiating fluids. The studied regimes are relevant for both laboratory astrophysics and High Energy Density Physics. Using Lie groups theory, we obtain scaling laws, the similarity properties and the number of free parameters to rescale experiments
On the number of circuit–cocircuit reversal classes of an oriented matroid
No full textInternational audienceThe first author introduced the circuit–cocircuit reversal system of an oriented matroid, and showed that when the underlying matroid is regular, the cardinalities of such system and its variations are equal to special evaluations of the Tutte polynomial (e.g., the total number of circuit–cocircuit reversal classes equals t(M;1,1), the number of bases of the matroid). By relating these classes to activity classes studied by the first author and Las Vergnas, we give an alternative proof of the above results and a proof of the converse statements that these equalities fail whenever the underlying matroid is not regular. Hence we extend the above results to an equivalence of matroidal properties, thereby giving a new characterization of regular matroids
Magyar szentek énekei egy XIX. századi horvát kéziratos énekes könyvben
No full textThe author analyses a Croatian Catholic hymn-book written in 1852. At that time Hungary and Croatia lived in personal union. As the result of the coexistence for 800 years several Croatian village-names contain the names of Hungarian saints (St. Stephen, St. Ladislas, St. Emeric, St. Elisabeth, St. Margaret etc.). The writer of this 19th century Hymn-book noted down the chants in the dialect along the River Mura. The book contains songs about St. Stephen, St. Emeric, St. Elisabeth and St. Martin
Invariance concepts and scalability of two-temperature astrophysical radiating fluids
No full textInternational audienceIn this work, we present a classification of laboratory astrophysics experiments. We introduce different invariance concepts in order to build scaling laws and to determine the astrophysical relevant of laboratory experiments. Finally we present an analysis of the two-temperature radiating fluid scalability
Analytical solutions of specific classes of astrophysical radiating shocks
No full textIn this paper we study specific classes of radiating shocks which are widely spread in astrophysical environments. We present more general solutions of their structure and proceed to the analytical determination of physical quantities
Similarity Properties and Scaling Laws of Radiation Hydrodynamic Flows in Laboratory Astrophysics
No full textInternational audienceThe spectacular recent development of modern high-energy density laboratory facilities which concentrate more and more energy in millimetric volumes allows the astrophysical community to reproduce and to explore, in millimeter-scale targets and during very short times, astrophysical phenomena where radiation and matter are strongly coupled. The astrophysical relevance of these experiments can be checked from the similarity properties and especially scaling laws establishment, which constitutes the keystone of laboratory astrophysics. From the radiating optically thin regime to the so-called optically thick radiative pressure regime, we present in this paper, for the first time, a complete analysis of the main radiating regimes that we encountered in laboratory astrophysics with the same formalism based on the Lie-group theory. The use of the Lie group method appears as systematic which allows to construct easily and orderly the scaling laws of a given problem. This powerful tool permits to unify the recent major advances on scaling laws and to identify new similarity concepts that we discuss in this paper and which opens important applications for the present and the future laboratory astrophysics experiments. All these results enable to demonstrate theoretically that astrophysical phenomena in such radiating regimes can be explored experimentally thanks to powerful facilities. Consequently the results presented here are a fundamental tool for the high-energy density laboratory astrophysics community in order to quantify the astrophysics relevance and justify laser experiments. Moreover, relying on the Lie-group theory, this paper constitutes the starting point of any analysis of the self-similar dynamics of radiating fluids
Numerical modeling of accretion column in polars
No full textInternational audienceUsing powerful lasers, we are now able to produce in laboratory relevant regimes of density, temperature and velocity to create a diagnosable exact scaled model of magnetic cataclysmic variables accretion column. We present here preliminary results of a numerical modeling of these astrophysical objects which will allow us to precise the experimental setup of future experiments
Modal analysis of bottom founded offshore wind structures via the creation of a finite element model
No full textOne way to implement a wind turbine in the sea is to use lattice structures. Since these structures are placed offshore, they must be able to withstand all kinds of loads. It is essential that the eigenfrequencies of the support structure do not correspond to the passing frequencies of the blades and any other dynamic actions. To avoid this the natural frequencies of the structure should be estimated during the design and the objective of this MSc study is the development of an easy to use finite element model to perform the modal analysis of an offshore wind support structure. It was built based on relevant inputs, defining the possible design of the lattice structure. Based on these parameters, the model can be adjusted and a high number of designs can be tested easily. The model is built in Matlab and consists of several modules, each one representing a different part of the design. The user has access to a main script to enter all necessary inputs. Then the program starts and a second function takes over. This second function is divided into five parts. The first, the definition of the geometry, creates the nodes and elements composing the structure. The second part concerns the creation of matrices characterizing the model. Each element is associated with two matrices: a local element mass matrix and a local element stiffness matrix. Each is computed in a local frame of reference, then rotated and assembled into two global matrices, representing the complete structure. Then, the equivalent stiffness characterizing the soil-piles interaction is calculated in the third part. Depending on the pile size and the soil properties, the equivalent stiffness is determined. Once the matrices completely describe the model, eigenvalues and mode shapes are calculated in the fourth part. The fifth part of the function is the plotting of the structure.The functionalities of the Matlab tool have been validated and thoroughly checked. Firstly, by comparing the analytical and numerical results of a simplified structure (a clamped beam), and secondly using a complete structural model by comparing the outputs of the program with the outputs of the professional software “Bladed”. All key results are verified. From these verifications, it can be concluded that the characterizing matrices of the structure are correctly defined and that the model correctly represents the modal behaviour of a lattice structure. The tool is ready to be used for sensitivity studies to verify which parameters most affect the natural frequencies. The model can also be used as a pre-design tool to quickly obtain and test different scenarios for an offshore wind support structure. Nevertheless, the tool has some limitations such as the restricted number of possible designs/configurations, the assumption that the transition piece is a rigid body, the use of the p-y curves that can overestimate the stiffness of the soil, the non-linearity of the system that does not take into account the variation in time. Recommended future work may address these issues
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