Análise de textos didáticos de Matemática: um mapeamento e uma proposta metodológica fundada numa perspectiva hermenêutica

This article discusses some methodological possibilities for analyzing textbooks in Mathematics Education. Its starting point was a review - which allowed us to build a general map - of the production developed by consolidated Research Groups that deal with this theme in Brazil. This map allowed us to propose a complementary/alternative guide to analyse textbooks according to a hermeneutical approach.

Análise Narrativa em Trabalhos de História da Educação Matemática: algumas considerações

This paper presents some reflections on the use of narrative analysis as a possible approach to study the History of (Mathematics) Education, mainly to interpret historical situations and biographical data. Its perspective is linked to Walter Benjamin's ideas about the figure of the narrator and how the dialogue between narrator and historian can be seen. Following the perspective of another author, Benedito Nunes, we try to establish relations among narratives, fiction and historiography, also highlighting the ideas of Jorge Larrosa regarding the transmission of experiences. Finally, our focus is turned to Antonio Bolivar and his alternative statements about why and how analysis of investigations, in which narratives are the main source of data, can be done.

História na Educação Matemática – um estudo sobre trabalhos publicados no Brasil nos últimos cinco anos

In this paper we report a study on research in the field of History in Mathematics Education conducted in Brazil in the last five years. We evaluate studies that are theoretical or report experiences on the support found in history that can contribute to the situations of teaching and learning of mathematics, based on the Proceedings of Seminarios Nacionais de Historia da Matematica and Encontros Luso-Brasileiros de Historia da Matematica. Examining the interests, directions and focus of research in the field, we found that the vast majority of studies address specific issues of History of Mathematics, and the number of studies on History in Mathematics Education is still very low. We note that, in the last five years, the arguments in favor of the teaching potential of the History of Mathematics, which is very present in the speech of teachers and managers of public education, has not yet been materialized in experiments or investigations to promote this link effectively.

Efeito da época de colheita e da calagem no rendimento de sementes comercializáveis de amendoim cv. Botutatu

A field experiment was carried out to study the effects of liming and time of harvesting on peanut cv. Botutatu (Arachis hypogaea L.) seed yield and yield components in the period of July, 1991 to February, 1992, in São Manuel, State of São Paulo. The soil was a Dark Red Latosol (Hapludult, sandy loam), and the experimental design was a subplot replicated four times in completely randomized blocks. Lime levels (0.0 and 1.75 t/ha) were applied in the plots, and the subplots were nine weekly harvests, starting at 87 days after planting (DAP). There was no effect of lime on hulls or seed yield and on peanut yield components. The germination of seeds in hulls was incresead at each harvest and was lower at lime presence. The highest yield was observed at 129 DAP.

Efeitos da adubação com manipueira sobre o rendimento e qualidade dos frutos de tomate

The objective of this research was to evaluate the residue from cassava, known as manipueira, as an alternative for tomato (Lycopersicon esculentum) fertilization. This experiment was carried out in UNESP with the cultivar Rio Grande. The experimental design was a completely randomized blocks in a 3 × 3 factorial arrangement with five blocks. Treatments constituted the following: 1) witness; 2) 54 m3/ha of manipueira; 3) 108 m3/ha of manipueira; 4) half recommended mineral fertilization; 5) half recommended mineral fertilization + 54 m3/ha of manipueira; 6) half recommended mineral fertilization + 108 m3/ha of manipueira; 7) recommended mineral fertilization; 8) recommended mineral fertilization + 54 m3/ha of manipueira and 9) recommended mineral fertilization + 108 m3/ha of manipueira. Tomato yield, number of fruits per plant, fruit diameter and lenght, total soluble solids (TSS), total titratable acidity (TTA) and the ratio TSS/TTA were evaluated. The results obtained indicated that manipueira contributed significantly to yield and quality of pos-harvested tomato fruits.

Novos conversores retificadores Sepic ZCS-PWM, operando como abaixadores de tensao, com elevados rendimento e fator de potencia - um estudo comparativo

A comparative evaluation regarding a new zero-current-switching (ZCS) pulse width modulated (PWM) Sepic rectifier, operating in voltage step-down mode, employing two different techniques, in order to obtain high power factor and reduced total harmonic distortion (THD) at the input current, is presented. The methods are those in continuous-current mode operation, known as peak current mode control with slope compensation, and average-current mode control. The principle of operation, the theoretical analysis, a design example and the main experimental results are presented for both proposed control techniques.

Influência de cinco temperaturas de secagem no rendimento e composição do óleo essencial de citronela (Cymbopogon winterianus Jowitt)

The Influence of Drying Temperatures on the Yield Composition of Citronella (Cymbopogon winterianus Jowitt) essential oil. The studies were carried out to establish more precise parameters for citronella (C. winterianus Jowitt) post-harvest, and to optimize drying time and essential oil quantitative/qualitative yield. Five treatments were designed (30°C, 40°C, 50°C, 60°C and 70°C), with 14 repetitions of the drying process and 12 of the essential oil extraction. Drying at 60°C gave the best results for drying time (48 hours until weight stabilization), and also for extracted oil quantity (1.228 ± 0.127% over dry weight). Essential oil content showed high quantitative variations. The main compound found was neral, except in the 50°C treatment, where citronelal was the main compound.

Detecção de pistas de aeroporto em imagens orbitais utilizando morfologia matemática

The Brazilian Cartography presents great deficiency in cartographic products updating. This form, Remote Sensins techniques together Digital Processing Images - DPI, are contributing to improve this problem. The Mathematical Morphology theory was used in this work. The principal function was the pruning operator. With its were extracted the interest features that can be used in cartographic process updating. The obtained results are positives and showed the use potential of mathematical morphology theory in cartography, mainly in updating.

Rendimento de óleo essencial de Salvia officinalis L. sob ação de reguladores vegetais

This study aimed to evaluate the effect of different plant growth regulators on essential oil yield in Salvia officinalis L. plants. The experiment was held in a greenhouse and the experimental design was completely randomized, with 5 treatments and three replications. The Treatments consisted in the application of gibberellic acid (GA3), benzylaminopurine (BAP), 2-chloroethyl phosphonic acid (ethephon), and Stimulate at 2%, compared with control plants (water). Applications of plant growth regulators were performed in three consecutive periods, in turn, 15, 25 and 35 days after transplanting of seeding germinating in the light at 25°C. The dry mass yield of the aerial part and the oil essential content were determined 131 days after the transplant. The aerial part of the plants was dried in an oven at 35°C; after dry mass determination, the oil was extracted by hydrodistillation and its volume was determined. Plants treated with GA 3 and Stimulate showed increase in essential oil content, while plants treated with BAP and ethephon showed decrease in essential oil volume when compared with the control plants.