Considerações sobre o papel da comunicação científica na educação em química

In the present work, we provide some considerations about the role of scientific communication in Chemistry Education. Such considerations may subsidize the development of communication in scientific language by Chemistry students. These considerations are based on information collected during a participatory research for the production of didactic material about scientific communication. The meetings were audio recorded and the contents of the participants' speeches were divided into categories. The category analysis supported the elaboration of the considerations.

El Papel de la motivación de los asesores y profesores en el proceso de asesoramiento = The figure of the motivation of the advisers and professors in the advice process

El escenario de asesoramiento colaborativo es un espacio sociocultural donde lo que se hace y se dice condiciona el tipo de interacción que se va a dar entre las personas que participan así como la actividad que llevan a cabo de manera conjunta. En este artículo vamos a reflexionar sobre el papel de la motivación de los profesores y asesores para mantener el asesoramiento así como en las posibilidades que tiene el asesor para crear y mantener un contexto que resulte motivante para asesor y asesorados

O papel governamental como ator essencial para a P&D de medicamentos: um estudo de casos

The importance of natural products as a source of new high value-added drugs has, no doubt, transformed Brazilian megadiversity into one of the country's most valuable and strategic assets. Thus the rational exploration of the Brazilian flora on an economic basis should be considered as part of a national development strategy. In this respect, governmental mechanisms to stimulate regulation on the access, bioprospection and industrial use of natural products represent a crucial issue. The aim of this paper is to show how the incentives and institutional arrangements that led to one of the greatest breakthroughs in the pharmaceutical industry, the development and commercialization of the anti-cancer agent Taxol, could be applied to the Brazilian case.

Formação de micelas mistas entre o sal biliar colato de sódio e o surfactante aniônico dodecanoato de sódio

Mixed-micelle formation between sodium chlolate (NaC) and the anionic surfactant sodium dodecanoate (SDoD) in Tris-HCl buffer solutions, pH 9.00, varying the molar fraction of the surfactants, was investigated by means of electrical conductivity and steady-state fluorescence of pyrene. The critical micelar concentration (cmc) was measured from the equivalent conductance versus the square root of the molar surfactant concentration plots and the regular solution theory (RST) was used to predict the mixing behavior. The I1/I3 pyrene ratio-surfactant concentration plots were used as an additional technique to follow the behavior and the changes in the micropolarity of the mixed micelles.

Del papel a la pantalla y del aula a la nube: ideas para dinamizar la expresión escrita en secundaria = From paper to the screen and from the classroom to the cloud: ideas to energise written expression at secondary level

The spread of sociocultural focuses and critical literacy studies, which offer an holistic perspective on communicative skills, has reached our country at a time when the commonest environment for writing is the internet, and information technologies have transformed writing with new channels, genres, forms of preparation and languages. Thanks to these changes, educational programmes now include new concepts of literacy related to knowledge and the use of digital environments. This paper explores the impact of introducing these new communicative environments to teaching written expression at secondary level and puts forward some ideas to link learning how to write to present communicative contexts and established practices. Without forgetting the achievements of recent decades, we need to bring about a series of changes to bring new learned writing practices to class and leave behind others we had championed as necessary when the goal was to move beyond exclusively linguistic or grammatical approaches

O papel dos sulfetos volatilizados por acidificação no controle do potencial de biodisponibilidade de metais em sedimentos contaminados de um estuário tropical, no sudeste do Brasil

Measurements of acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) were combined in order to verify the ecological hazard of contaminated sediments from the Santos-Cubatão Estuarine System (SE Brazil), which is located in one of the most industrialized areas in the Latin America. Intertidal sediments from the Morrão River estuary were collected seasonally in short cores. The redox conditions, organic matter contents and grain-size were the main controlling factors on SEM distribution. However, clear relationships among these variables and AVS were not observed. The molar SEM/AVS ratios were frequently > 1 especially in the summer, suggesting major metal bioavailability hazard in this humid hot season.

Previsão das propriedades físicas do papel kraft por espectroscopia no infravermelho próximo (NIR) e regressão por mínimos quadrados parciais (PLS)

The main objective of the present work is represented by the characterization of the physical properties of industrial kraft paper (i.e. transversal and longitudinal tear resistance, transversal traction resistance, bursting or crack resistance, longitudinal and transversal compression resistance (SCT (Compressive Strength Tester) and compression resistance (RCT-Ring Crush Test)) by near infrared spectroscopy associated to partial least squares regression. Several multivariate models were developed, many of them with high prevision capacity. In general, low prevision errors were observed and regression coefficients that are comparable with those provided by conventional standard methodologies.

Comparação entre um trocador aniônico de sal de amônio quaternário de quitosana e um trocador comercial na extração de fósforo disponível em solos

The present work aimed modify chemically the chitosan (QTS) surface to obtain a reticulate chitosan quaternary ammonium salt (SAQQR), and compare this anionic exchanger with an commercial ion exchanger in the extraction of available phosphorus in soils. The results showed that the two exchangers are identical, extracting similar and proportional quantities of available phosphorus in the studied soils, and the anionic exchanger of SAQQR provides a high chemical stability, not affected by the pH difference of soils.

Caracterização cromatográfica de compostos orgânicos presentes nos resíduos sólidos provenientes de indústria de reciclagem de papel e sua aplicação na produção de briquetes de carvão vegetal

Recycling of paper in industrial scale has become an established practice worldwide. In this work, organic compositions of three different kinds of sludge generated in recycle paper industry were studied, and the incorporation of one of those sludge in briket was also investigated. The characterization of organic compounds in sludge samples and briket was performed using Gas Chromatography coupled with Mass Spectrometry after a Soxhlet extraction. Different chemical classes were identified in each type of sludge, but just the sludge composed by cellulose residue did not presented polyaromatic hydrocarbons. Four formulations of sludge incorporated with charcoal for briket production were evaluated.

Influencia de variables de formulación en la viscosidad de emulsiones de surfactante aniónico-aceite-agua

Phase transition and viscosity behavior of emulsified systems were studied after modifying their physicochemical formulation. Effects of concentration and nature of salts and n-alcohols, and water/oil relation on the rheological properties of emulsions were also studied. Pre-equilibrated systems were emulsified according to an agitation procedure, and the viscosity (cP) was measured at different shear rates ranging from 1 to 300 s-1. The phase behavior, as well as the emulsion type based on electrolytic conductivity, was observed. Several interpretations of the flow and viscosity curves of emulsions were made through the estimation of rheological parameters such as consistency index "k" and behavior index "n".

Determinação simultânea de carbamazepina, fenitoína e fenobarbital em sangue seco em papel por cromatografia líquida de alta eficiência

Carbamazepine, phenobarbital and phenytoin were determined in dried blood spots (DBS) by high performance liquid chromatography, after extraction of 8 mm DBS using a mixture of acetonitrile and methanol. Analytes were separated by reversed-phase chromatography, with a run time of 17 minutes. Intra-assay and inter-assay precisions were in the 5.3 to 8.4% and 3.3 to 5.2% ranges, respectively. Accuracy was in the 98.8 to 104.3% range. The method had sensitivity to detect all analytes at levels below minimum therapeutic concentrations. The analytes were stable at 4 ºC and room temperature for up to 12 days and at 45 ºC for 9 days. The method was applied to 14 paired clinical samples of blood serum and DBS.

MOTIVAÇÃO PARA A CARREIRA DOCENTE E CONSTRUÇÃO DE IDENTIDADES: O PAPEL DOS PESQUISADORES EM ENSINO DE QUÍMICA

This research aims to identify the reasons that lead students to pursue a specific course of chemistry teacher training, i.e., their perspectives on the course and the teaching career, and if they are motivated by trainers to become basic education (BE) teachers. It was concluded that most students did not want to be teachers of BE. They identified through the social context of the course that the teachers focused on the area of chemistry teaching sought to motivate them for this career, whereas the teachers of these specific areas of chemistry encouraged them to seek other career opportunities.

O papel das vivências no Aufbau

Este artigo faz a análise de alguns aspectos do sistema de constituição do Logische Aufbau der Welt (A construção lógica do mundo) de Rudolf Carnap, tendo em vista duas possíveis interpretações da base autopsicológica escolhida pelo autor, ou seja, das vivências. Alguns autores, como Michael Friedman e Moulines, vêem o Aufbau como sendo um sistema estrutural cujas formas não são determinadas pelas experiências básicas - pelas vivências. Outros, como, por exemplo, Stegmüller, afirmam que as estruturas, as definições do Aufbau, resultam de relações que podem ser estabelecidas entre estas. Acompanhando os argumentos desses intérpretes e a proposta epistemológica do próprio Carnap, sustento a necessidade de pensar a base autopsicológica, as vivências, como determinantes das relações estruturais do Aufbau.

Método do rolo de papel toalha modificado para a detecção de Sclerotinia sclerotiorum em sementes de feijão

O mofo branco do feijoeiro, causado pelo fungo Sclerotinia sclerotiorum (Lib.) de Bary, é uma das principais doenças da cultura. O patógeno pode ser disseminado por sementes infectadas, que têm um importante papel na infestação de novas áreas de plantio e no estabelecimento da doença no início do ciclo da cultura. Este trabalho apresenta uma adaptação do método do rolo de papel toalha, originalmente desenvolvido para a detecção de Colletotrichum lindemuthianum, com o objetivo de detectar a presença de S. sclerotiorum em sementes de feijão. Neste método, as sementes foram incubadas por 7 dias a 20 ºC em rolos de papel toalha para germinação, sendo mantidas sob condições de 100% de umidade relativa. Após esse período, as plântulas infeccionadas e as sementes mortas, circundadas por micélio característico de S. sclerotiorum, foram transportadas para caixas tipo gerbox, sobre duas folhas de papel de filtro umedecido. Após 3 a 4 dias de incubação a 20 ºC e sob regime de 12 horas de luz por 12 horas de escuro, os escleródios foram observados nas sementes e plântulas. O método foi relativamente rápido, simples e barato, além de apresentar a vantagem de possibilitar a detecção simultânea de S. sclerotiorum e de outros importantes patógenos transmitidos por sementes de feijão, como C. lindemuthianum, Macrophomina phaseolina e Rhizoctonia solani.