Beliefs, Intentions, Actions, & Reflections (BIAR): A New Way to Look at the Interactions of Students and Teachers

An accurate, nuanced capturing and characterization of student/teacher behavior inside and outside the classroom is a necessity in today’s education reform. In this paper, a new framework, called the BIAR (Beliefs, Intentions, Actions, and Reflections) Student-Teacher Interaction Model, is introduced. This tool incorporates the use of TDOP (Teaching Dimensions Observation Protocol) in classroom observations alongside student/faculty interviews, stimulated recall sessions, and electronic surveys. Once gathered, the data can be compared and rated for their degree of correlation. While the work in this project wasn’t aimed at making any specific claims about the practices of teachers or students, the introduction of the BIAR Model provides a structure for future work in this area

Avaliação da resistência à compressão e cor de cimentos LC3 Amazônicos / Compressive strength and color evaluation of Amazonian LC3 cements

O emprego de adições minerais como substituição parcial do clínquer no cimento Portland tem sido uma das principais estratégias para redução da emissão de CO2 por parte da indústria mundial do cimento. Contudo, a disponibilidade de escorias de alto forno e cinza volante não suprem a demanda. Na Amazônia, há grandes depósitos de caulins, todos consistituídos por concentrações expressivas de caulinta extremamente fina. Uma alternativa para a região seria o emprego destas adições ao cimento Portland, combinando com matérias-primas abundantes como calcário. Estes cimentos são denominados na literatura de LC3 e caracterizam-se por serem cimentos de baixa emissão de CO2. O objetivo deste trabalho foi avaliar as propriedades dos cimentos LC3 produzidos com elevadas incorporações de caulim calcinado e calcário. Os níveis de substituição das adiçoes minerais sobre a massa de cimento Portland comum foram de 45% e 60%. As variáveis investigadas foram massa específica, área superficial especifica Blaine, água de consistencia e tempos de pega inicial e final dos cimentos, além da cor proveniente das misturas em pasta e resistencias à compressão de argamassas. As incorporações das misturas metacaulim-calcário aumentaram a demanda de água e reduziram os tempos de pega em razão da elevada finura da caulinita. Entretanto, houve acrescimentos significativos de resistencia à compressão em comparação aos cimentos Portland comum e composto. Os resultados são promissores, mas requerem estudos mais aprofundados, principalmente no que tange aos aspectos de durabilidade frente à alta demanda de água destes cimentos

Caracterização e avaliação do índice de atividade Pozolânica do resído do beneficiamento do caulim para produção de cimentos de baixo impacto ambiental / Characterization and evaluation of the Pozzolanic activity index of kaolin processing waste for the production of low environmental impact cements

Durante os últimos anos, o mundo todo vem sofrendo com as variações ambientais causadas pelo aquecimento global. Um dos fatores preponderantes para o aumento das temperaturas da atmosfera e oceanos são as emissões produzidas a partir de processos de queima industrial. Com largo potencial ainda em atividade, a indústria do cimento é uma das que mais contribui para esse processo, fato que vem fomentando a busca por alternativas tecnológicas menos agressivas ao meio ambiente. Nesse contexto, este artigo apresenta as característica físico-químicas de uma potencial alternativa para cimentos de baixa emissão de CO2 potenciais alternativas: resíduo do beneficiamento do caulim. Após ensaios laboratoriais são apresentados resultados relevantes que mostram que o RBC apresentou um nível de pozolanicidade muito superior ao daquele requisitado por norma.

Community detection in graphs

The modern science of networks has brought significant advances to our understanding of complex systems. One of the most relevant features of graphs representing real systems is community structure, or clustering, i. e. the organization of vertices in clusters, with many edges joining vertices of the same cluster and comparatively few edges joining vertices of different clusters. Such clusters, or communities, can be considered as fairly independent compartments of a graph, playing a similar role like, e. g., the tissues or the organs in the human body. Detecting communities is of great importance in sociology, biology and computer science, disciplines where systems are often represented as graphs. This problem is very hard and not yet satisfactorily solved, despite the huge effort of a large interdisciplinary community of scientists working on it over the past few years. We will attempt a thorough exposition of the topic, from the definition of the main elements of the problem, to the presentation of most methods developed, with a special focus on techniques designed by statistical physicists, from the discussion of crucial issues like the significance of clustering and how methods should be tested and compared against each other, to the description of applications to real networks.Comment: Review article. 103 pages, 42 figures, 2 tables. Two sections expanded + minor modifications. Three figures + one table + references added. Final version published in Physics Report

Learning physics with Controllable Worlds : Perspectives for examining and augmenting physics students' engagement with digital learning environments

In this thesis I present a collection of case studies involving small groups of participants using ‘Controllable Worlds’—i.e., a particular class of physics digital learning environment (DLE) including simulations, ‘microworlds,’ and educational games that provides users with control over manipulable virtual environments. Throughout the thesis I employ and develop several perspectives for the interpretation, analysis, and instructional guidance of physics students’ engagement with DLEs. While this thesis focuses in particular on participants’ use of the 2D Newtonian software Algodoo and the PhET simulation My Solar System, I also contribute to a more general scholarly discussion on student interaction and technology use in physics education. One such contribution, which relates to my development of an overarching taxonomy for learning environments, is the theoretical distinctions between ‘constrained’ and ‘less-constrained’ DLEs and between DLEs with high and low degrees of ‘semi-formality.’ The work of this thesis is largely based on five peer-reviewed publications, the content of which can be organized into three broader themes. In Theme 1, called ‘Bridging the physical and formal,’ I incorporate the perspectives of semi-formalisms, modeling, Papertian constructionism/microworlds, and informal learning to examine the ways in which less-constrained DLEs such as Algodoo can mediate between the ‘physical world’ and ‘formal world’ of physics. In Theme 2, called ‘Embodiment and the making of meaning,’ I incorporate the perspectives of multimodal social semiotics, embodied cognition, and kinesthetic/embodied learning activities in order to form a multi-perspective analytic model for examining a pair of students’ embodied interactions against the backdrop of the PhET simulation My Solar System. In Theme 3, called ‘The responsive role of the teacher,’ I incorporate the perspectives of responsive teaching, the variation theory of learning, and the grounded theory family of methods in order to explore a teaching arrangement that combines less-constrained DLEs like Algodoo with the feedback of a responsive teacher. Especially as compared to PER work that aims to measure learning gains or conceptual mastery via assessment tools, I opt to focus instead on the mechanisms of meaning-making that occur between the ‘pre’ and ‘post.’ Thus, I am able to contribute to the theoretical picture of students’ meaning-making in digitally-rich physics learning environments. Across all of the studies in this thesis, I show how the use of technology like Controllable Worlds can lead to student behavior which is productive for physics teaching and learning in ways that may be altogether unexpected

Learning physics with Controllable Worlds : Perspectives for examining and augmenting physics students' engagement with digital learning environments

In this thesis I present a collection of case studies involving small groups of participants using ‘Controllable Worlds’—i.e., a particular class of physics digital learning environment (DLE) including simulations, ‘microworlds,’ and educational games that provides users with control over manipulable virtual environments. Throughout the thesis I employ and develop several perspectives for the interpretation, analysis, and instructional guidance of physics students’ engagement with DLEs. While this thesis focuses in particular on participants’ use of the 2D Newtonian software Algodoo and the PhET simulation My Solar System, I also contribute to a more general scholarly discussion on student interaction and technology use in physics education. One such contribution, which relates to my development of an overarching taxonomy for learning environments, is the theoretical distinctions between ‘constrained’ and ‘less-constrained’ DLEs and between DLEs with high and low degrees of ‘semi-formality.’ The work of this thesis is largely based on five peer-reviewed publications, the content of which can be organized into three broader themes. In Theme 1, called ‘Bridging the physical and formal,’ I incorporate the perspectives of semi-formalisms, modeling, Papertian constructionism/microworlds, and informal learning to examine the ways in which less-constrained DLEs such as Algodoo can mediate between the ‘physical world’ and ‘formal world’ of physics. In Theme 2, called ‘Embodiment and the making of meaning,’ I incorporate the perspectives of multimodal social semiotics, embodied cognition, and kinesthetic/embodied learning activities in order to form a multi-perspective analytic model for examining a pair of students’ embodied interactions against the backdrop of the PhET simulation My Solar System. In Theme 3, called ‘The responsive role of the teacher,’ I incorporate the perspectives of responsive teaching, the variation theory of learning, and the grounded theory family of methods in order to explore a teaching arrangement that combines less-constrained DLEs like Algodoo with the feedback of a responsive teacher. Especially as compared to PER work that aims to measure learning gains or conceptual mastery via assessment tools, I opt to focus instead on the mechanisms of meaning-making that occur between the ‘pre’ and ‘post.’ Thus, I am able to contribute to the theoretical picture of students’ meaning-making in digitally-rich physics learning environments. Across all of the studies in this thesis, I show how the use of technology like Controllable Worlds can lead to student behavior which is productive for physics teaching and learning in ways that may be altogether unexpected