Uma conversa na escola: o diálogo e a mídia

The dialogue represents an essential condition for the complete realization of the Communication. In Paulo Freire we find a concept of dialogue which expresses itself, fundamentally, in two dimension: on one hand, in the confluence of subjectivities; on the other, in action. Dialogue would not be, therefore, a thinking for , but a thinking with . On the other hand, the media, here understood as synonym of technical media of information and expression is spread all over society as synonym of communication media. In this direction, this paper intends to check if the media allows the dialogue, in the heart of the Freirean concept of communication. We start from the premise that it is not possible to come to an answer if we continue to accept the theoretical approach which polarizes the process of communication between emitter and receptor. By using elements of the ethnomethodology such as the analysis of the conversation and the reflexivity, we dived in the school everyday life of educators and students of an elementary level public school in the city of Natal, capital of Rio Grande do Norte, in order to, through some experiences with the media, corroborate Paulo Freire's ideas, stating the mediation made by the world and seeking a bias for the use of the media to enable a more dialogic education

Síntese, caracterização e estudo da associação em meio aquoso de copolímeros responsivos de carboximetilcelulose-g-Jeffamine®

This thesis presents the synthesis, characterization and study of the associative behaviour in aqueous media of new responsive graft copolymers, based on carboxymethylcellulose as the water-soluble backbone and Jeffamine® M-2070 e Jeffamine® M-600 (commercial polyetheramines) as the thermoresponsive grafts with high cloud point temperatures in water. The synthesis was performed on aqueous medium, by using 1-ethyl-3- (3-(dimethylamino)-propyl)carbodiimide hydrochloride and N-hydroxysuccinimide as activators of the reaction between carboxylategroupsfrom carboxymethylcellulose and amino groups from polyetheramines. The grafting reaction was confirmed by infrared spectroscopy and the grafting percentage by 1H NMR. The molar mass of the polyetheramines was determined by 1H NMR, whereas the molar mass of CMC and graft copolymers was determined by static light scattering. The salt effect on the association behaviour of the copolymers was evaluated in different aqueous media (Milli-Q water, 0.5M NaCl, 0.5M K2CO3 and synthetic sea water), at different temperatures, through UV-vis, rheology and dynamic light scattering. None of the copolymers solutions, at 5 g/L, turned turbid in Milli-Q water when heated from 25 to 95 °C, probably because of the increase in hydrophibicity promoted by CMC backbone. However, they became turbid in the presence of salts, due to the salting out effect, where the lowest cloud point was observed in 0.5M K2CO3, which was attributed to the highest ionic strength in water, combined to the ability of CO3 2- to decrease polymer-solvents interactions. The hydrodynamic radius and apparent viscosity of the copolymers in aqueous medium changed as a function of salts dissolved in the medium, temperature and copolymer composition. Thermothickening behaviour was observed in 0.5M K2CO3 when the temperature was raised from 25 to 60°C. This performance can be attributed to intermolecular associations as a physical network, since the temperature is above the cloud point of the copolymers in this solvent.