Didactic Experiment Research Articles

Uso de scanner em espectrofotometria de absorção molecular: aplicação em experimento didático enfocando a determinação de ácido ascórbico

Quantitative analysis of colored substances is generally performed using a spectrophotometer for detection of radiation. However, the combination of digital images and mathematical conversion of colors is an alternative for quantitative procedures based on colored chemical reactions. This work proposes a didactic experiment using a scanner for determination of ascorbic acid in medicines based on the formation of the Prussian blue complex. Results were in good agreement with a conventional spectrophotometer method and the procedure is attractive for instrumental analysis undergraduate courses.

Prego voador: um desafio para estudantes de eletromagnetismo

Neste trabalho apresentamos um experimento didático de baixo custo, produzido por um aluno de uma disciplina do curso de licenciatura em Física da Universidade Federal Fluminense, que tem sua ênfase no estudo dos movimentos - inesperados - de materiais ferromagnéticos sob a ação de campos magnéticos produzidos por um solenóide. O experimento, incluindo material utilizado, montagem e procedimentos, é mostrado em detalhe. São apresentadas, na forma de uma discussão, as várias tentativas de explicação para os movimentos obtidos. Objetiva-se a capacitação de professores em sustentar uma discussão com seus alunos.

Empleo del tratamiento matricial en el curso de óptica: sistema de lentes

En la enseñanza del curso de óptica, en la Licenciatura en Física, los estudiantes poseen conocimientos y habilidades operacionales de programas de cómputo, además de conocimientos de Álgebra Lineal, sobre la operación con matrices y determinantes. El método matricial, se emplea ampliamente en el análisis de fenómenos ópticos, aprovechando que muchos sistemas ópticos son susceptibles de ser descritos satisfactoriamente en la aproximación de modelos lineales. En el presente trabajo se describe el experimento didáctico realizado con la integración de conocimientos de Álgebra, Computación y óptica aplicados a la solución, por medio del método matricial, del diseño de un triplete de Cooke usado en cámaras fotográficas. Se obtiene un buen aprovechamiento por los estudiantes que logran profundizar en el tema lográndose la integración de los conocimientos propuesta inicialmente.

Análise de imagem em química analítica: empregando metodologias simples e didáticas para entender e prevenir o escurecimento de tecidos vegetais

A simple and didactic experiment was developed for image monitoring of the browning of fruit tissues caused by the enzyme polyphenol oxidase. The procedure, easy and inexpensive, is a valuable tool to teach and demonstrate the redox reaction between the enzyme and the natural polyphenols. To obtain the browning percentage for apple, pear and banana, digital photographs were employed, and the images were analyzed by means of Monte Carlo methods and digital analysis programs. The effects of several experimental conditions were studied, such as pH, light, temperature and the presence of oxygen or anti-oxidants. It was observed that each fruit presented a different condition that better minimized the oxidation process. The absence of oxygen and the application of a bissulphite solution were sufficient to keep the quality of all fruits tested.

A Didactical Experiment as Teacher Education Curriculum : Based on an ANalysis of the Process of Change in Perceptions by University Students and Teacher

A Didactical Experiment as Teacher Education Curriculum : Based on an ANalysis of the Process of Change in Perceptions by University Students and Teacher

Decomposição térmica do bicarbonato de sódio: do processo Solvay ao diagrama tipo Ellingham

A didactic experiment based on the thermal decomposition of sodium bicarbonate using a reagent found in the marketplace is proposed. The reaction products are identified by qualitative tests and stoichiometric calculations. The thermal stability of carbonates and the influence of lattice energies are discussed, emphasizing periodic trends in the alkali and alkaline earth families. The industrial importance of the reaction is also explored.

Teaching physics in Romania: new requirements call for new methods

The place and size of physics within academic teaching in Romania have obviouslychanged, and reform of the academic training system is underway. This paperreports on a didactical experiment conducted at the University of Craiova, one ofthe most representative higher education institutions in Romania, testing theefficiency of some evaluation methods applied to the teaching process of physics.This process functions under the actual conditions in which the academic teachingtakes place.

AN EXPERIMENT AT TOR VERGATA UNIVERSITY OF ROME (ITALY)

An interdisciplinary didactic experiment was conducted during 2002 at the Tor Vergata University of Rome (Italy). Four seminars (open to all undergraduates) were held, each involving eight 45-minute sessions and worth four credits (a three-year first degree requires 180 credits overall). The topics of the seminars were ‘Order and Disorder’, ‘Similar and dissimilar’, ‘Time’ and ‘An anatomy of emotions and a language of organs’. The 14 instructors involved belong to the Arts and Sciences faculties. About a hundred students overall enroled in the seminars.

Preparação de compostos de alumínio a partir da bauxita: considerações sobre alguns aspectos envolvidos em um experimento didático

Aluminum metal and aluminum compounds have many applications in several branches of the industry and in our daily lives. The most important raw material for aluminum and its manufactured compounds is bauxite, a rock constituted mainly by aluminum hydroxides minerals. In this work, a didactic experiment aiming the preparation of alumina and potassium alum starting from bauxite is proposed for undergraduate students. Both compounds are of great commercial, scientific and historical interest. The experiment involves applications of important chemical principles such as acid-base and precipitation. Some chemical properties and uses of aluminum compounds are also illustrated.

Le rôle d'une mémoire didactique des élèves, sa gestion par le professeur

This issue presents two ways of reading the data from a didactic experiment about teaching "the division" at school. This dialog allows the emergence of its management characteristics, as the experiment permits the creation of a collective memory of the didactic system that pupils call for on their own initiative. The various functionalities of these phenomenons within the creation process of numerical knowledge are analyzed through the concept of schema as presented in the Theory of the Conceptual Fields, as this theory could not explain teacher's work.

Polifosfatos em detergentes em pó comerciais

A didactic experiment is proposed in order to identify inorganic phosphates in home laundry detergents by ascending paper chromatography. Chemical principles related with hard water are also investigated. The role of polyphosphates in detergent formulations is discussed and the softening of hard water by sodium tripolyphosphate is illustrated. Several chemical concepts, related to the daily experience of the students, can be explored in post-lab discussions.

A simple real‐time process control experiment using serial communication

AbstractMicrocomputers introduced process control to a new era. A simple and didactic experiment, used to control the temperature of an equipment, is described. Features of this experiment include the use of two computers connected by serial ports and allowing students to build the controller and to disturb the process. © 2001 John Wiley & Sons, Inc. Comput Appl Eng Educ 9: 101–104, 2001

A simple real time process control experiment using serial communication

The development and the low cost of microcomputers introduced process control into a new era. Currently many analog and on-off controllers are being replaced by simple softwares. In this paper a simple and didactic process control experiment will be described. Basically it consists of the temperature control of equipment (an oven) using two microcomputers connected by their serial ports. Experiment features introduction of the practical side of the process control, using a distributed control system (DCS). It also allows the student to interact with the process and build the controller himself.

Plane wave interference: A didactic experiment to measure the wavelength of light

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Designing a learning sequence about a pre‐quantitative kinetic model of gases: the parts played by questions and by a computer‐simulation

Empirical studies in physics and chemistry education have shown some of the limits of a general constructivist view of the teaching‐‐learning process. In our opinion, we need more specific constructivist models of learning, which would take into account the distinctive epistemological features of the scientific field concerned. The dynamic process that we planned is founded upon some distinctive features of theories about the structure of matter: their philosophical and non‐empirical foundations, their character as a hypothetical model, their character of mechanical analogy. This learning process can be seen as a search for an analogy between the properties of a sample of gas and the properties of a set of particles moving under rules derived from the kinetic theory of gases. The didactic experiment is based upon the use of a computer simulation. It includes a first phase of interviews. The second phase of experimentation in the classroom gives some quantitative information in usual classroom teaching‐learning conditions. The analysis of the data allowed us on the one hand to assess the short‐term and long‐term effectiveness of this learning process and on the other hand to discuss the hypotheses underlying the choice of phenomena and questions we formulated in order to design the didactical situations.

Didactic experiment of a one-dimensional process of solidification from nuclei at random to linear polycrystal. Part II: comparison of experiment with theory

A filament of isotactic polypropylene, 15 μm diameter, is used to prove the theoretical predictions for a one-dimensional (1-D) process of solidification from nuclei at random to a linear polycrystal. The theoretical predictions were made in 1983. The agreement between theory and experiment is very good.

Didactic experiment of a one-dimensional process of solidification from nuclei at random to a linear polycrystal. Part I: Nuclei, nuclei distances, and grain lengths

We show theexperimental verification of a didactic model which is named “one-dimensional (1D) process of solidification (crystallization) from nuclei at random to linear polycrystal”.

A complexity architecture for information technologies: A three-year didactic experiment

One medium-term strategy for helping in the management of complexity is the introduction of a conceptual complexity component in the very centre of university curricula. In very few areas is the growth of complexity as evident as in the information technologies (ITs), the focus of the work presented in the current paper. We have therefore developed an integrated way of tackling the specific field of information technologies by means of an approach to complexity. The content of this paper describes the guidelines of our research effort, placing an emphasis on informatics. Concepts of complexity based on the system metaphor have been substantially drawn upon in this exercise and are thus presented in some detail. Also described is a didactic experiment conducted by the author and designed to provide a new and integrating approach to University curricula for future professionals. The students' “discovery” of complexity is the focal point of the experiment. The findings of this effort are encouraging and call for the continuation and expansion of this experiment.

Het Belang Van Taalkunde Voor de Toegepaste Taalkunde

Applied Linguistics is generally regarded as a multidisciplinary field in which didactics, psychology and linguistics participate. It is remarkable that within the context of foreign language teaching the focus is mainly on the didactic experiment and on the construction of psycholinguistic hypotheses. Yet for a linguistic-didactic experiment to be relevant, insight in what is to be taught, viz. language,is necessary. Many variants of language teaching could have been avoided with a better linguistic insight. Moreover, a better linguistic understanding in applied linguis-tics leads to a better distinction between the views of linguists on language didactics and psycholinguistics and the descriptions of language they give. In this paper the relation between grammar and vocabulary is discussed. It is argued that this distinction is based more on definition than on reality. Stressing the importance of the role of vocabulary does not imply denying or minimising the importance of grammar. On the contrary, the traditional task division in linguistics between grammar and lexicology has led to a sterile grammatical description. Recent tendencies in linguistics now show a more integrated description of grammar and vocabu-lary. Finally, with regard to the didactically important problem of vocabu-lary selection, some remarks are made concerning the difference between selection on the basis of linguistic properties and selection on the basis of usually arbitrary non-linguistic idiosyncrasies of words and the influence of this on teaching material. This is illustrated with examples from language courses.