1,471 research outputs found
Ensino de Aritmética no livro didático da escola nova de Miguel Aguayo: reverberações do escolanovismo em Santa Catarina
https://aplicacoes.ifs.edu.br/periodicos/index.php/caminhos_da_educacao_matematica/article/view/90Este artigo é um recorte dos resultados da pesquisa de mestrado desenvolvida no Programa de Pós-Graduação em Educação Científica e Tecnológica (UFSC). De modo particular, analiso a oitava edição do manual didático “Didática da Escola Nova” de Alfredo Miguel Aguayo, evidenciando como os conteúdos de aritmética foram indicados e apresentados aos professores que ensinavam matemática nas escolas primárias. Procuro estudar o manual com base no contexto histórico-pedagógico do Brasil, e particularmente de Santa Catarina, na década de 1940. Os aportes teórico-metodológicos fundamentam-se nas reflexões acerca da história das disciplinas escolares e da cultura escolar. Os resultados sugerem que representações da aritmética escolar circularam em Santa Catarina por meio do manual de Aguayo e que estas foram apropriadas pelos representantes da educação no estado. Para Aguayo, o ensino de aritmética deveria ser sistematizado e racional, visando o cálculo e os problemas práticos
Effect of turbulent fluctuations on the drag and lift forces on a towed sphere and its boundary layer
The impact of turbulent fluctuations on the forces exerted by a fluid on a
towed spherical particle is investigated by means of high-resolution direct
numerical simulations. The measurements are carried out using a novel scheme to
integrate the two-way coupling between the particle and the incompressible
surrounding fluid flow maintained in a high-Reynolds-number turbulent regime.
The main idea consists in combining a Fourier pseudo-spectral method for the
fluid with an immersed-boundary technique to impose the no-slip boundary
condition on the surface of the particle. Benchmarking of the code shows a good
agreement with experimental and numerical measurements from other groups. A
study of the turbulent wake downstream the sphere is also reported. The mean
velocity deficit is shown to behave as the inverse of the distance from the
particle, as predicted from classical similarity analysis. This law is
reinterpreted in terms of the principle of "permanence of large eddies" that
relates infrared asymptotic self-similarity to the law of decay of energy in
homogeneous turbulence.
The developed method is then used to attack the problem of an upstream flow
that is in a developed turbulent regime. It is shown that the average drag
force increases as a function of the turbulent intensity and the particle
Reynolds number. This increase is significantly larger than predicted by
standard drag correlations based on laminar upstream flows. It is found that
the relevant parameter is the ratio of the viscous boundary layer thickness to
the dissipation scale of the ambient turbulent flow. The drag enhancement can
be motivated by the modification of the mean velocity and pressure profile
around the sphere by small scale turbulent fluctuations.Comment: 24 pages, 22 figure
Sphaleron damping and effects on vector and axial charge transport in high-temperature QCD plasmas
We modify the anomalous hydrodynamic equations of motion to account for
dissipative effects due to QCD sphaleron transitions. By investigating the
linearized hydrodynamic equations, we show that sphaleron transitions lead to
nontrivial effects on vector and axial charge transport phenomena in the
presence of a magnetic field. Due to the dissipative effects of sphaleron
transitions, a wavenumber threshold emerges characterizing the
onset of chiral magnetic waves. Sphaleron damping also significantly impacts
the time evolution of both axial and vector charge perturbations in a QCD
plasma in the presence of a magnetic field. Based on our analysis of the
linearized hydrodynamic equations, we also investigate the dependence of the
vector charge separation on the sphaleron transition rate, which may have
implications for the experimental search for the Chiral Magnetic Effect in
Heavy Ion Collisions.Comment: 19 pages, 9 figure
Analysis of the turbulent law of the wall through the finite scale Lyapunov theory
This work analyzes the turbulent velocity distribution in proximity of the
wall using the finite-scale Lyapunov theory just presented in previous works.
This theory is here applied to the steady boundary layer under the hypothesis
of moderate pressure gradient and fully developed flow along the streamwise
direction. The analysis gives an equation for the velocities correlation and
identifies the parameters of the expression of the average velocity through the
statistical properties of the velocity correlation functions. In particular,
the von K\'arm\'an constant, theoretically calculated, is about 0.4, and the
dimensionless Prandtl's length is in function of the Taylor-scale Reynolds
number. The study provides the average velocity distribution and gives also the
variation laws of the other variables, such as Taylor scale and Reynolds
stress. The obtained results show that the finite-scale Lyapunov theory is
adequate for studying the turbulence in the proximity of the wall.Comment: 29 pages, 8 figure
Performance-informed EEG analysis reveals mixed evidence for EEG signatures unique to the processing of time
Certain EEG components (e.g., the contingent negative variation, CNV, or beta oscillations) have been linked to the perception of temporal magnitudes specifically. However, it is as of yet unclear whether these EEG components are really unique to time perception or reflect the perception of magnitudes in general. In the current study we recorded EEG while participants had to make judgments about duration (time condition) or numerosity (number condition) in a comparison task. This design allowed us to directly compare EEG signals between the processing of time and number. Stimuli consisted of a series of blue dots appearing and disappearing dynamically on a black screen. Each stimulus was characterized by its duration and the total number of dots that it consisted of. Because it is known that tasks like these elicit perceptual interference effects that we used a maximum-likelihood estimation (MLE) procedure to determine, for each participant and dimension separately, to what extent time and numerosity information were taken into account when making a judgement in an extensive post hoc analysis. This approach enabled us to capture individual differences in behavioral performance and, based on the MLE estimates, to select a subset of participants who suppressed task-irrelevant information. Even for this subset of participants, who showed no or only small interference effects and thus were thought to truly process temporal information in the time condition and numerosity information in the number condition, we found CNV patterns in the time-domain EEG signals for both tasks that was more pronounced in the time-task. We found no substantial evidence for differences between the processing of temporal and numerical information in the time–frequency domain
The VISIR Implementation Process at IFSC - problems, obstacles and solutions
In recent year, the use of remote laboratories applied to teaching has been more frequent in several educational institutions around the world. The benefits on the learning process are easy to verify. In addition, remote laboratories bring in their application, operational advantages associated to component inventory, equipment maintenance, security, and others practical issues. Considering this, it is intuitive that the implantation of a remote laboratory and its use is easily recognized and accepted by the users, namely, students and teachers. This paper aims to present the obstacles and advantages observed in the implantation of the virtual laboratory VISIR (Virtual Instruments Systems in Reality) at Federal Institute of Santa Catarina - IFSC, as well as the obtained results.info:eu-repo/semantics/publishedVersio
Professional learning in moments of whole-class discussion in a Lesson Study
This article aims to present 1st cycle of basic education Portuguese teachers’ learning of teaching pupils between 6 and 7 years of age, when they plan, lead and reflect on the moment of whole-class discussion, during a lesson study in mathematics. It is a qualitative research, and data collection was carried out by non-participant observation with the elaboration of a logbook and audio and video recording of sessions. The results show that, when planning the whole-class discussion, the teachers became aware of the importance of planning teaching in detail, paying attention to the objectives that are intended to achieve and the role of the teacher in the whole-class discussion. When they conducted and reflected on the discussion, the teachers understood the need to act during the undertaking of the task, in order to support pupils in terms of mathematical language so that they could better communicate their reasoning to their colleagues.This article aims to present 1st cycle of basic education Portuguese teachers’ learning of teaching pupils between 6 and 7 years of age, when they plan, lead and reflect on the moment of whole-class discussion, during a lesson study in mathematics. It is a qualitative research, and data collection was carried out by non-participant observation with the elaboration of a logbook and audio and video recording of sessions. The results show that, when planning the whole-class discussion, the teachers became aware of the importance of planning teaching in detail, paying attention to the objectives that are intended to achieve and the role of the teacher in the whole-class discussion. When they conducted and reflected on the discussion, the teachers understood the need to act during the undertaking of the task, in order to support pupils in terms of mathematical language so that they could better communicate their reasoning to their colleagues
Um estudo da extensão do seno, cosseno e tangente no triângulo retângulo para funções de domínio real
TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Físicas e Matemáticas. Curso de Química.objetivou-se nesse trabalho fazer um estudo do seno, cosseno e tangente no triângulo retângulo e como funções trigonométricas com domínio real, bem como analisar a transição da Trigonometria no triângulo para as funções trigonométricas num livro didático de ensino médio, enfocando principalmente os exercícios. Como a Trigonometria é resultado de um processo histórico, sofrendo várias transformações ao longo dos séculos até apresentar-se no formato atual, também buscou-se fazer seu estudo histórico
Long-time behaviour and phase transitions for the McKean—Vlasov equation on the torus
We study the McKean-Vlasov equation ∂t% = β −1∆% + κ ∇·(%∇(W ? %)) , with periodic boundary conditions on the torus. We first study the global asymptotic stability of the homogeneous steady state. We then focus our attention on the stationary system, and prove the existence of nontrivial solutions branching from the homogeneous steady state, through possibly infinitely many bifurcations, under appropriate assumptions on the interaction potential. We also provide sufficient conditions for the existence of continuous and discontinuous phase transitions. Finally, we showcase these results by applying them to several examples of interaction potentials such as the noisy Kuramoto model for synchronisation, the Keller–Segel model for bacterial chemotaxis, and the noisy Hegselmann–Krausse model for opinion dynamics
LETRAMENTOS ACADÊMICOS EM FOCO: DISCUSSÕES DE CONTEXTO CURRICULAR DE APRENDIZAGEM ATIVA NA ENGENHARIA
Atualmente, o engenheiro se defronta com a demanda de atuar em práticas de linguagem que constituem o mundo da engenharia e são requisitos para que se torne membro efetivo nessa área do saber. Nesse contexto, este artigo objetiva discutir como se constituem práticas de letramento na formação acadêmica em contexto de aprendizagem ativa em engenharia. Para tanto, são analisadas entrevistas com estudantes e professores do Mestrado Integrado em Engenharia e Gestão Industrial (MIEGI) da Universidade do Minho, que tem parte de seu currículo organizado por projetos. Os dados são analisados sob as teorias do Círculo de Bakhtin, dos Novos Estudos do Letramento e da Aprendizagem Ativa. As análises sinalizam que currículos pautados em metodologias ativas empreendem práticas de letramento acadêmico de forma integrada às práticas de linguagem características do mundo profissional.Nº DOI: 10.5935/2179-0027.2018004
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