Three-dimensional free surface modelling in an unstructured mesh environment for metal processing applications

In the casting of metals, tundish flow, welding, converters, and other metal processing applications, the behaviour of the fluid surface is important. In aluminium alloys, for example, oxides formed on the surface may be drawn into the body of the melt where they act as faults in the solidified product affecting cast quality. For this reason, accurate description of wave behaviour, air entrapment, and other effects need to be modelled, in the presence of heat transfer and possibly phase change. The authors have developed a single-phase algorithm for modelling this problem. The Scalar Equation Algorithm (SEA) (see Refs. 1 and 2), enables the transport of the property discontinuity representing the free surface through a fixed grid. An extension of this method to unstructured mesh codes is presented here, together with validation. The new method employs a TVD flux limiter in conjunction with a ray-tracing algorithm, to ensure a sharp bound interface. Applications of the method are in the filling and emptying of mould cavities, with heat transfer and phase change.

Lucrecio, "De rerum natura": Sentido y coherencia del prólogo

El prólogo del De rerum natura de Lucrecio (1.1-148) parece ser un tema gastado: ha sido tratado decenas de veces tanto por su excelente calidad como por los problemas que plantea. Pero esperamos poder dar un nuevo sentido y solución a ambos aspectos. En primer lugar, el himno a Venus no es una mera convención, sino que respira sentimiento religioso; Venus no personifica a la naturaleza, sino al placer y la felicidad y ni la hegemonía que se dice ejerce Venus, ni las plegarias que contiene el himno contradicen la teología epicúrea. Todavía más, nos parece que el himno constituye una auténtica epifanía religiosa muy propia de la teología epicúrea. En segundo lugar, suponiendo que el autor ha tomado como tema compartido los schemata o grados de dificultad de la intellectio retórica en el texto de 1.50-148, se intentan solucionar las dificultades de coherencia del texto.

Vannevar Bush e as matrizes discursivas de As we may think: por uma possível história da Ciência da Informação

MEDEIROS, A. L.; VANTI, Nadia. Vannevar Bush e as matrizes discursivas de As we may think: por uma possível história da Ciência da Informação. Informação & sociedade:Estudos. João Pessoa, v. 21, p. 31-39, 2011

Professor de dupla habilitação: (des)continuidades entre o 1º e 2ºciclos do ensino básico

Relatório de estágio apresentado à Escola Superior de Educação de Paula Frassinetti para a obtenção do grau de Mestre em Ensino do 1.º e 2.º Ciclo do Ensino Básico

Formação e profissionalidade: um estudo na formação inicial de professores do ensino básico em Moçambique

Visando analisar a Formação Inicial de Professores (FIP) do Ensino Básico em Moçambique, no intuito de captar como concorre para a construção da representação de profissionalidade na atividade docente, este estudo descritivo e interpretativo estrutura-se em duas dimensões complementares (extensiva e intensiva). Através dessas duas dimensões procurou-se explicitar os pontos críticos do objeto de estudo e produzir conhecimento sobre o mesmo. E, nessa linha, nas conclusões do estudo ficarão disponíveis possíveis contributos para a melhoria da sustentação e eficácia da formação inicial. Na dimensão extensiva, em função de descritores de profissionalidade associados ao reconhecimento social de uma atividade como profissional, definidos na literatura investigativa da sociologia das profissões e da educação, analisou-se a noção de profissionalidade que norteia a FIP. Essa análise foi desenvolvida com recurso ao estudo de documentos legais e curriculares, inquéritos por questionário a 289 formadores e por entrevista a 7 agentes-chave da formação de professores (gestores, académicos e formadores de professores). Na dimensão intensiva, concretizada num estudo multicaso (4 estudos de caso) envolvendo, essencialmente, 16 formadores de 4 instituições de formação de professores (polos), aprofundou-se a compreensão da visão de formadores de professores sobre profissionalidade, com recurso à observação de atividade docente e respetiva planificação, entrevistas semi-estruturadas a 4 gestores da Prática Pedagógica e estágio nesses polos, à luz do quadro teórico fundamentador dos caraterizadores de profissionalidade referenciais do estudo e dos resultados obtidos na dimensão extensiva. Os resultados do estudo denotam falta de sintonia entre o conceito de ensinar patenteado nos documentos e discursos dos agentes-chave da Formação de Professores (a indicar que ensinar é fazer aprender) e a prática letiva dos formadores, a denunciar que ensinar é entendido como expôr conteúdos/transmitir conhecimentos. Quanto aos caraterizadores de profissionalidade, discursivamente destacam-se como atributos reconhecidos ao professor: ser educador e profissional; possuir conhecimento específico para ensinar; ter a função e a responsabilidade de ensinar; ser inovador e investigador; e agir de acordo com o quadro deontológico associado à profissão. No entanto, estas representações entram em choque com a realidade, marcada por falta de poder dos professores sobre o currículo e sobre o conhecimento profissional, que não produzem nem controlam; baixas qualificações (possuem nível correspondente à 10ª classe); inexistência de um quadro deontológico específico e por uma prática docente dos formadores inscrita na racionalidade técnica e mais alinhada com uma dinâmica de funcionarização do que de profissionalização. Na esteira do isomorfismo pedagógico, da chamada naturalização das práticas de ensino, e da força da gramática escolar, o tipo de prática docente que marca a ação dos formadores tenderá a ser replicada pelos formandos quando professores. Aliás, os documentos curriculares parecem resumir o ser profissional ao facto de se possuir formação para professores. O estudo fundamenta a possibilidade de, nas políticas, se reforçar uma maior coerência entre discursos e práticas na visão de profissionalidade construída na FIP, aprofundar os pontos de descontinuidade detetados no estudo ou outros relevantes e trabalhar no sentido da clarificação do conceito de profissionalidade pretendida na Formação de Professores do Ensino Básico em Moçambique.

Thermal activation, long-range ordering, and topological frustration of artificial spin ice

Frustrated systems, typically characterized by competing interactions that cannot all be simultaneously satisfied, are ubiquitous in nature and display many rich phenomena and novel physics. Artificial spin ices (ASIs), arrays of lithographically patterned Ising-like single-domain magnetic nanostructures, are highly tunable systems that have proven to be a novel method for studying the effects of frustration and associated properties. The strength and nature of the frustrated interactions between individual magnets are readily tuned by design and the exact microstate of the system can be determined by a variety of characterization techniques. Recently, thermal activation of ASI systems has been demonstrated, introducing the spontaneous reversal of individual magnets and allowing for new explorations of novel phase transitions and phenomena using these systems. In this work, we introduce a new, robust material with favorable magnetic properties for studying thermally active ASI and use it to investigate a variety of ASI geometries. We reproduce previously reported perfect ground-state ordering in the square geometry and present studies of the kagome lattice showing the highest yet degree of ordering observed in this fully frustrated system. We consider theoretical predictions of long-range order in ASI and use both our experimental studies and kinetic Monte Carlo simulations to evaluate these predictions. Next, we introduce controlled topological defects into our square ASI samples and observe a new, extended frustration effect of the system. When we introduce a dislocation into the lattice, we still see large domains of ground-state order, but, in every sample, a domain wall containing higher energy spin arrangements originates from the dislocation, resolving a discontinuity in the ground-state order parameter. Locally, the magnets are unfrustrated, but frustration of the lattice persists due to its topology. We demonstrate the first direct imaging of spin configurations resulting from topological frustration in any system and make predictions on how dislocations could affect properties in numerous materials systems.

Core-level photoemission investigations of the CDTE(100) and INSB(100) surface and interfacial structures

Photoemission techniques, utilizing a synchrotron light source, were used to analyze the clean (100) surfaces of the zinc-blende semiconductor materials CdTe and InSb. Several interfacial systems involving the surfaces of these materials were also studied, including the CdTe(lOO)-Ag interface, the CdTe(lOO)-Sb system, and the InSb(lOO)-Sn interface. High-energy electron diffraction was also employed to acquire information about of surface structure. A one-domain (2xl) structure was observed for the CdTe(lOO) surface. Analysis of photoemission spectra of the Cd 4d core level for this surface structure revealed two components resulting from Cd surface atoms. The total intensity of these components accounts for a full monolayer of Cd atoms on the surface. A structural model is discussed commensurate with these results. Photoemission spectra of the Cd and Te 4d core levels indicate that Ag or Sb deposited on the CdTe(l00)-(2xl) surface at room temperature do not bound strongly to the surface Cd atoms. The room temperature growth characteristics for these two elements on the CdTe(lOO)-(2xl) are discussed. The growth at elevated substrate temperatures was also studied for Sb deposition. The InSb(lOO) surface differed from the CdTe(lOO) surface. Using molecular beam epitaxy, several structures could be generated for the InSb(lOO) surface, including a c(8x2), a c(4x4), an asymmetric (lx3), a symmetric (lx3), and a (lxl). Analysis of photoemission intensities and line shapes indicates that the c(4x4) surface is terminated with 1-3/4 monolayers of Sb atoms. The c(8x2) surface is found to be terminated with 3/4 monolayer of In atoms. Structural models for both of these surfaces are proposed based upon the photoemission results and upon models of the similar GaAs(lOO) structures. The room temperature growth characteristics of grey Sn on the lnSb(lOO)-c(4x4) and InSb(l00)-c(8x2) surfaces were studied with photoemission. The discontinuity in the valence band maximum for this semiconductor heterojunction system is measured to be 0.40 eV, independent of the starting surface structure and stoichiometry. This result is reconciled with theoretical predictions for heterostructure behavior.

Urban Catalyst: Continuing the Legacy of Massachusetts Avenue

This thesis proposes a reconnection of Massachusetts Avenue to the Anacostia River waterfront in Washington, DC. An intervention at the site of Reservation 13 will reconcile a difficult urban edge and reunite the neighborhood of Lincoln Park with the river. It also addresses the discontinuity of the avenue to the southeast and proposes the development of a bridge between the Western bank and ultimately Randle Circle. Along this reconciled corridor will be a series of architectural interventions that serve to promote community involvement. Ultimately this thesis is about generating an urban continuity and the cultural vibrancy and understanding that such a connection would foster.

O Modelo de gestão participativa do Plano Nacional do Turismo (PNT-2003/2007): a atuação do CONETUR/RN

To implement policies and plans at the tourist sector involve disposition to the establishment of parceries among government and private initiative, space to the action of studious, researchers and professionals of several areas of knowledge and formation, able of to give new courses no only at the tourism, but to the economy how a every, seen which the tourism had a effect multiplicator, reaching 52 sectors of the economy. At this sense, the Brazil came pruning for a new phase of politic actuation at the touristy activity. Until the year 2002, the tourism politic in the Brazil no had detail, because herself treated of isolated actions and many without continuity. However, at to start 2003, several actions were developed in order to contribute for the national touristy planning. The principal was the creation of Ministério do Turismo, accompanied of the formulation and implementation of the Plano Nacional do Turismo (2003/2007). This work pretend to understand the implementation at the Rio Grande do Norte of the model of participative administration extolled by Plano Nacional do Turismo. The your centre detail the action of the Conselho Estadual de Turismo do Rio Grande do Norte (CONETUR), to promote the participation at the tourism public policies. The bibliographical research contemplated diverse sources in order to compile knowledge of credential authors in the quarrel of inherent subjects to the participation and to the tourism public policies, especially at the Brazil. A qualitative perspective the case study was adapted as research method and for attainment of the data interviews with the members of the Conselho had been carried through beyond consultation the referring documents the dynamics of functioning of the Conselho. The principal actuations of the CONETUR, the directives tourism public policies already made and directed to implementation, the type of participation at made decision, the principal difficulties of the implementation of the participative administration model of the Plano Nacional do Turismo and the degree of participation of the members of the Conselho at the reunions had been identified. The results had shown that exist some difficulties at the implementation of the participation at the Conselho Estadual de Turismo do Rio Grande do Norte, knowledge of the Conselheiros of CONETUR function, the presence of bodies which doesn t directly connected at the touristy activity; the absence of time of the Conselheiros to be presents at reunions; the discontinuity of the presidency of the Conselho; among others. So, the CONETUR show himself how a Conselho with participative characteristics, but with some adapted needs.

Understanding the tsunami with a simple model

In this paper, we use the approximation of shallow water waves (Margaritondo G 2005 Eur. J. Phys. 26 401) to understand the behaviour of a tsunami in a variable depth. We deduce the shallow water wave equation and the continuity equation that must be satisfied when a wave encounters a discontinuity in the sea depth. A short explanation about how the tsunami hit the west coast of India is given based on the refraction phenomenon. Our procedure also includes a simple numerical calculation suitable for undergraduate students in physics and engineering.

LHC main dipole magnet circuits: sustaining near-nominal beam energies

Crossing the Franco-Swiss border, the Large Hadron Collider (LHC), designed to collide 7 TeV proton beams, is the world's largest and most powerful particle accelerator the operation of which was originally intended to commence in 2008. Unfortunately, due to an interconnect discontinuity in one of the main dipole circuit's 13 kA superconducting busbars, a catastrophic quench event occurred during initial magnet training, causing significant physical system damage. Furthermore, investigation into the cause found that such discontinuities were not only present in the circuit in question, but throughout the entire LHC. This prevented further magnet training and ultimately resulted in the maximum sustainable beam energy being limited to approximately half that of the design nominal, 3.5-4 TeV, for the first three years of operation (Run 1, 2009-2012) and a major consolidation campaign being scheduled for the first long shutdown (LS 1, 2012-2014). Throughout Run 1, a series of studies attempted to predict the amount of post-installation training quenches still required to qualify each circuit to nominal-energy current levels. With predictions in excess of 80 quenches (each having a recovery time of 8-12+ hours) just to achieve 6.5 TeV and close to 1000 quenches for 7 TeV, it was decided that for Run 2, all systems be at least qualified for 6.5 TeV operation. However, even with all interconnect discontinuities scheduled to be repaired during LS 1, numerous other concerns regarding circuit stability arose. In particular, observations of an erratic behaviour of magnet bypass diodes and the degradation of other potentially weak busbar sections, as well as observations of seemingly random millisecond spikes in beam losses, known as unidentified falling object (UFO) events, which, if persist at 6.5 TeV, may eventually deposit sufficient energy to quench adjacent magnets. In light of the above, the thesis hypothesis states that, even with the observed issues, the LHC main dipole circuits can safely support and sustain near-nominal proton beam energies of at least 6.5 TeV. Research into minimising the risk of magnet training led to the development and implementation of a new qualification method, capable of providing conclusive evidence that all aspects of all circuits, other than the magnets and their internal joints, can safely withstand a quench event at near-nominal current levels, allowing for magnet training to be carried out both systematically and without risk. This method has become known as the Copper Stabiliser Continuity Measurement (CSCM). Results were a success, with all circuits eventually being subject to a full current decay from 6.5 TeV equivalent current levels, with no measurable damage occurring. Research into UFO events led to the development of a numerical model capable of simulating typical UFO events, reproducing entire Run 1 measured event data sets and extrapolating to 6.5 TeV, predicting the likelihood of UFO-induced magnet quenches. Results provided interesting insights into the involved phenomena as well as confirming the possibility of UFO-induced magnet quenches. The model was also capable of predicting that such events, if left unaccounted for, are likely to be commonplace or not, resulting in significant long-term issues for 6.5+ TeV operation. Addressing the thesis hypothesis, the following written works detail the development and results of all CSCM qualification tests and subsequent magnet training as well as the development and simulation results of both 4 TeV and 6.5 TeV UFO event modelling. The thesis concludes, post-LS 1, with the LHC successfully sustaining 6.5 TeV proton beams, but with UFO events, as predicted, resulting in otherwise uninitiated magnet quenches and being at the forefront of system availability issues.

Extraposition in English and Spanish: A comparative study

451 p.

Patologías podales infecciosas y no infecciosas en vacas lecheras

Las cojeras son una de las mayores causas de problemas en el bienestar animal de las vacas lecheras, y tienen diferentes orígenes: infecciosas (dermatitis digital, flemón digital); o lesiones causadas por discontinuidad en el crecimiento del cuerno de las pezuñas (hemorragias, úlcera podal, enfermedad de la línea blanca). Los factores de riesgo que inducen estas afecciones son multifactoriales y no siempre son detectables, difieren según el establecimiento, así como su prevalencia / incidencia. La prevención y la detección precoz mantiene estas patología tengan un impacto menor sobre las economía en la producción lechera.

Ontologia do espaço : critica da critica da entificação social do ser enquanto pressuposto a uma teoria espacial interpenetrada a “ontologia do ser social”, de Gyorgy Lukacs

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, Programa de Pós Graduação em Geografia, 2015.

L'éthique et sa place dans la nature

Une des questions centrales de la métaéthique est celle de savoir si les propriétés morales sont des propriétés naturelles ou non-naturelles. Ce mémoire fait valoir que nous ferions bien de remettre en question une constellation d’arguments en faveur du non-naturalisme moral : l’argument de la question ouverte, l’intuition normative et l’argument du gouffre. L’influent argument de la question ouverte de Moore, d’abord, ne soutient le non-naturalisme que s’il commet une pétition de principe. L’intuition normative commet ou bien le sophisme d’inférer sur la base de sa différence spécifique qu’une chose n’appartient pas à un genre donné, ou bien sous-estime la panoplie de propriétés naturelles qui possèdent les caractéristiques censées être distinctives des propriétés morales et normatives. L’argument du gouffre, quant à lui, sous-estime l’ubiquité du fossé logique et conceptuel censé marquer une discontinuité métaphysique profonde entre les domaines normatif et naturel.