222 research outputs found
Justifications-on-demand as a device to promote shifts of attention associated with relational thinking in elementary arithmetic
Student responses to arithmetical questions that can be solved by using arithmetical structure can serve to reveal the extent and nature of relational, as opposed to computational thinking. Here, student responses to probes which require them to justify-on-demand are analysed using a conceptual framework which highlights distinctions between different forms of attention. We analyse a number of actions observed in students in terms of forms of attention and shifts between them: in the short-term (in the moment), medium-term (over several tasks), and long-term (over a year). The main factors conditioning studentsÂŽ attention and its movement are identified and some didactical consequences are proposed
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Effect of different storage conditions on analytical and sensory quality of thermally processed milk based germinated Foxtail millet porridge
Foxtail millet porridge was prepared using germinated grains and milk and was evaluated for its storage stability after thermal processing at Ultra High Temperatures (UHT) of 142 oC for 5 s and Retort processing temperatures of 121.5 oC for 15 min. Various physical, chemical and microbial changes of the porridge were studied for a storage period of 180 days at 25 ± 1 oC. Using consumer perception and survival analysis, the predicted shelf life of the UHT treated and retort processed foxtail millet porridge samples stored at 25 ± 1 oC was found to be 186 ± 9 days and 245 ± 15 days, respectively. Also, data from consumer liking, profiling, physical, chemical and microbial parameters showed significant changes (p < 0.05) in the thermally treated packaged porridge samples over time. As the consumer overall acceptability decreased, the detection of positive attributes (Thick and uniformly coloured texture and appearance; grainy mouth texture; caramel taste and aroma) in the porridge decreased, while the detection of negative attributes (Uneven, decoloured, and curdled texture and appearance; sticky mouth texture; cooked, sour and off smell; cooked, sour and off taste) increased. The present study could establish a significant difference (p < 0.05) in the storage induced properties of UHT and retort processed porridge samples. The analytical evaluation of foxtail millet porridge found that UHT treated porridge was better in quality, but consumers preferred retort processed porridge
Mathematical talent in Braille code pattern finding and invention
The recognition of patterns and creativity are two characteristics associated with mathematical
talent. In this study, we analyzed these characteristics in a group of 37 mathematically talented
students. The students were asked to find the pattern the Braille code had been built upon and
reinvent it with the aim of making its mathematical language become more functional.
Initially, the students were unable to identify the formation pattern of Braille, but after
experiencing the difficulties that blind people face when reading it, they recognized the
generating element and the regularity. The results were in contrast with those of a control
group, and it is noted that the students with mathematical talent were more effective in using
visualization to identify the regularity of the pattern and their invention proposals were more
sophisticated and used less conventional mathematical content.This research is part of the R+D+I project EDU2015-
69,731-R (Spanish Government/MinEco and ERDF)
Quantitative imaging of concentrated suspensions under flow
We review recent advances in imaging the flow of concentrated suspensions,
focussing on the use of confocal microscopy to obtain time-resolved information
on the single-particle level in these systems. After motivating the need for
quantitative (confocal) imaging in suspension rheology, we briefly describe the
particles, sample environments, microscopy tools and analysis algorithms needed
to perform this kind of experiments. The second part of the review focusses on
microscopic aspects of the flow of concentrated model hard-sphere-like
suspensions, and the relation to non-linear rheological phenomena such as
yielding, shear localization, wall slip and shear-induced ordering. Both
Brownian and non-Brownian systems will be described. We show how quantitative
imaging can improve our understanding of the connection between microscopic
dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of
methodology. Submitted for special volume 'High Solid Dispersions' ed. M.
Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009);
22 pages, 16 fig
Relationships between students' conceptions of constructivist learning and their regulation and processing strategies
The present study investigated relationships between students' conceptions of constructivist learning on the one hand, and their regulation and processing strategies on the other hand. Students in a constructivist, problem-based learning curriculum were questioned about their conceptions of knowledge construction and self-regulated learning, as well as their beliefs regarding their own (in)ability to learn and motivation to learn. Two hypothesized models were tested within 98 psychology students, using a structural equation modelling approach: The first model implemented regulation and processing variables of the Inventory of Learning Styles [ILS, Vermunt (Learning styles and regulation of learning in higher education - towards process-oriented instruction in autonomous thinking, 1992)], the second model of the Motivated Strategies for Learning Questionnaire [MSLQ, Pintrich and de Groot (Journal of Educational Psychology, 82, 33-40, 1990)]. Results showed that structural relations exist between conceptions of constructivist learning and regulation and processing strategies. Furthermore, students who express doubt with regard to their own learning capacities are at risk for adopting an inadequate regulation strategy. A three-tiered structure of conceptual, controlling, and operational level appeared valid for the MSLQ variables, but not entirely for those of the ILS
Avaliação de argamassas colantes por reometria rotacional
As argamassas colantes sĂŁo produtos constituĂdos por areia natural ou artificial, ligantes (cimento) e aditivos quĂmicos que cumprem uma função de adesivo para assentamento de revestimentos em pisos e paredes. Atualmente, a avaliação em campo sobre a mistura do produto Ă© efetuada de forma empĂrica. O aplicador (pedreiro) determina, por meios de aspectos sensoriais, a facilidade ou a dificuldade de mistura, classificando a argamassa em pesada, leve, macia, de fĂĄcil ou de difĂcil mistura, etc. PorĂ©m, essas descriçÔes sĂŁo subjetivas e Ă© difĂcil de mensurar quantitativamente a aplicabilidade do produto, alĂ©m do que induzem a erros de avaliação, pois cada aplicador pode ter uma percepção diferente. O propĂłsito deste trabalho foi medir, atravĂ©s da reometria rotacional, duas composiçÔes para avaliar o comportamento de mistura e reolĂłgico de forma quantitativa. Foram utilizadas duas argamassas colantes de mercado do tipo ACI (Argamassa Colante do Tipo I) e ACIII (Argamassa Colante do Tipo III), as quais foram submetidas a ensaios de reometria rotacional, variando-se o teor de ĂĄgua. Os resultados desta pesquisa demonstram que o tempo de mistura de 150 s Ă© eficiente e suficiente para homogeneizar e estabilizar as argamassas testadas, e que a argamassa do tipo ACI apresenta maior dificuldade de mistura e resulta em uma suspensĂŁo com maior viscosidade e tensĂŁo de escoamento do que a argamassa ACIII. Este estudo mostra a aplicação e os resultados inĂ©ditos de reometria rotacional para avaliação do comportamento reolĂłgico de argamassas colantes. Essa transferĂȘncia do conhecimento visa ampliar os horizontes sobre os comportamentos dos materiais de construção civil para melhorar o desempenho de aplicação e avaliação da argamassa no estado fresco
Empowering Qualitative Research Methods in Education with Artificial Intelligence
Artificial Intelligence is one of the fastest growing disciplines, disrupting many sectors. Originally mainly for computer scientists and engineers, it has been expanding its horizons and empowering many other disciplines contributing to the development of many novel applications in many sectors. These include medicine and health care, business and finance, psychology and neuroscience, physics and biology to mention a few. However, one of the disciplines in which artificial intelligence has not been fully explored and exploited yet is education. In this discipline, many research methods are employed by scholars, lecturers and practitioners to investigate the impact of different instructional approaches on learning and to understand the ways skills and knowledge are acquired by learners. One of these is qualitative research, a scientific method grounded in observations that manipulates and analyses non-numerical data. It focuses on seeking answers to why and how a particular observed phenomenon occurs rather than on its occurrences. This study aims to explore and discuss the impact of artificial intelligence on qualitative research methods. In particular, it focuses on how artificial intelligence have empowered qualitative research methods so far, and how it can be used in education for enhancing teaching and learning
Sucrose in the concentrated solution or the supercooled âstateâ : a review of caramelisation reactions and physical behaviour
Sucrose is probably one of the most studied molecules by food scientists, since it plays an important role as an ingredient or preserving agent in many formulations and technological processes. When sucrose is present in a product with a concentration near or greater than the saturation pointâi.e. in the supercooled stateâit possesses high potentialities for the food industry in areas as different as pastry industry, dairy and frozen desserts or films and coatings production. This paper presents a review on critical issues and research on highly concentrated sucrose solutionsâmainly, on sucrose thermal degradation and relaxation behaviour in such solutions. The reviewed works allow identifying several issues with great potential for contributing to significant advances in Food Science and Technology.Authors are grateful for the valuable discussions with Teresa S. Brandao and Rosiane Lopes da Cunha during this research. Author M. A. C. Quintas acknowledges the financial support of her research by FCT grant SFRH/BPD/41715/2007
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