Degradação de paracetamol empregando tecnologia oxidativa avançada baseada em fotocatálise heterogênea usando irradiação artificial e solar

In this work, the oxidation and mineralization of paracetamol, based in an advanced oxidative process promoted by heterogeneous photocatalysis, was evaluated. The action of two photocatalysts (titanium dioxide, and a composite based on the association between titanium dioxide and zinc phthalocyanine dye) was studied. First of all, experiments in laboratory scale were performed using as radiation font a 400 W high pressure mercury lamp. The mineralization of paracetamol, promoted by both photocatalysts, was evaluated working with 4L of solution containing 10 mg L-1 of paracetamol and 100 mg L-1 of photocatalyst. To find the best experimental conditions, the influence of hydrogen peroxide concentration and pH was evaluated for the reactions. The best results for the reactions in laboratory scale was obtained using 33,00 mg L-1 of hydrogen peroxide in natural pH (6,80). Under these conditions, 100% oxidation was reached in just 40 minutes of reaction using TiO2 P25, while the mineralization was 78%. Using the composite, the mineralization was 63% in 2 hours of reaction and a oxidation of almost 100% was reached after 60 minutes. A CPC reactor (compound parabolic concentrator) was employed in the expanded work scale, using the sun as irradiation source. In this case the experiments were performed using 50 L of aqueous solution containing 10 mg L-1 of paracetamol and 100 mg L-1 of photocatalyst. The assays were done at pH 3,00 and natural pH (6,80). The used concentration of hydrogen peroxide was 33,00 mg L-1, adopted after laboratory scale studies. The reaction at pH 3,00 shows to be more advantageous, since under natural pH (6,80), the use of deionized water was necessary to prepare the solutions, probably because the deleterious action of carbonate ions, known hydroxyl radical scavengers. Using solar irradiation, the reaction mediated by the composite was more efficient when compared with the assays under laboratory scale since the composite presents the advantage of promoting a better use of visible radiation. Under these conditions, the mineralization increased from 40% to 56% under pH 3,00. At natural pH the oxidation occurred more slowly and the mineralization decreased from 56% to 50%. Thus, the use of pH 3,00 will be more interesting in real scale applications, even if it is necessary the pH correction before the discard of the treated effluent to the environment.

Oficina educomunicativa de produção de vídeos: construção de significados sobre problemas socioambientais

This research aims to analyze the meaning making by Elementary Education students from public schools of Uberlândia (Minas Gerais, Brazil) about the social and environmental problems of their surroundings as of audiovisual reading and expression skills. The theoretical framework is based on constructivism, through the study of contributions about: cognitive development; meaningful learning; cognitive processes and types of knowledge; principles of learning with technology; educommunication focused on critical media literacy; and critical environmental education. The study object is a video production workshop organized in nine meetings, from September to November 2015, attended by 15 students. The following data collection instruments were used: the materials produced by the participants, specifically guided critical media literacy, agenda, script and final video; researcher observations from his role as a mediator; and focal interviews. The analysis was divided into two axes: procedural knowledge – technical skills of critical media literacy and production; and conceptual and metacognitive knowledge – representation of social and environmental problems and metacognitive skills of critical media literacy. Data were coded in the form of a skill evaluation rubric and also in the form of graphs. Thus, despite the time constraints, it is inferred that the workshop helped students to deepen their understanding about the discussed content, which is reinforced by observing in the graphs how the constant progressive differentiation of more inclusive concepts occurred along the meetings. It is further considered that the workshop contributed to the students reflect on their way of learning through critical use of techniques of media literacy and production, which can be seen from the satisfactory learners performance in most elements evaluated by the rubrics, as well as from the success in identifying interlocutors, values and actions in the read and built texts, something revealed by the graphs.

Intervenção mediacional e hábitos alimentares: um estudo de crianças com síndrome de Down

The inadequacy about eating habits have been established as a serious problem nowadays. It is a multifactorial and difficult to handle, given their different nuances and causes. A population particularly exposed to the bad eating habits arising harm are individuals with Down syndrome, both with regard to the aspects inherent to the individual's own condition, regarding eating misfits, making it the weight control a necessary measure for a proper development. Thus, this study aimed to develop and evaluate a proposal based nutrition education from the assumptions of mediated learning, with children three to four years with Down syndrome. The participants were five children, four girls and a boy. Also included his parents and / or guardians. The data collection procedure involved the use of eight playful workshops with children and nutritional evaluation of those five meetings with parents and three home visits with each participating family. We tried to build with these children and their families a nutritional education to contribute to their daily choices of eating. Using listening, observation and questionnaire, besides playful interventions, it was observed that the first meaning of the act of eating is built in the family and reinforced by their social life. Overall, our sample characteristics seem to agree with the literature. During the intervention, the children showed attention, but little understanding of the content. With mothers, the results were different, with reflections on the inadequate power both the type of food offered, and quantity and so this offer is performed, conducted along the interventions changes in your lifestyle, such as perception of influence they had on their children in the formation of their eating habits, as well as less frequent intake of soft drinks and sweets. Nutritional interventions and mediations conducted with the mothers is that they seem to be effective strategies to combat obesity. Face of what was discussed, we see the importance of implementing intervention measures in combating and preventing overweight or obese since childhood, particularly with children with Down syndrome. One should prevent childhood obesity with educational and informative measures from birth, with family and with each child, through the primary health care and schools.