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Síntese eletroquímica e caracterização de filmes finos de Sb2Se3
(Universidade Federal de São Carlos, 2017-12-05) Costa, Magno Barcelos; Mascaro, Lucia Helena; https://lattes.cnpq.br/9130022476352844; https://lattes.cnpq.br/2725856250417886
Due to the environmental appeal, the shortage of raw material and the chemical complexity of some systems employed at photovoltaic devices, interest has been growing for semiconductors composed of abundant, low toxicity and less costly elements. Among these, the Sb2Se3 has gained attention, because besides having all the mentioned characteristics, it presents good photovoltaic properties. The present work presents the electro-obtaining of Sb2Se3 thin films, as well as the exploratory study of its properties from the effects of the thermal treatment (TT), the electrodeposition parameters and the addition of Fe2+ as a dopant to its photoelectrocatalytic activity in the reduction reaction of H+. The films were prepared by potentiostatic co-electrodeposition on FTO in a bath composed of K(SbO)C4H4O6 and SeO2 in 0.5 mol L-1 Na2SO4/H2SO4 – pH 2.0. After obtaining, they were submitted to different TT conditions under atmosphere of Se(vapor)/N2. Cyclic voltammetries were used to evaluate the electrochemical process of each separate element and the binary system. For the study of the electrodeposition parameters, the concentrations of the Sb and Se precursors (SbO+ and H2SeO3, respectively), the total deposition charge and the type of the supporting electrolyte were evaluated. Finally, the study of the addition of Fe2+ in the bath allowed to evaluate its effect under different concentrations of the dopant. Thus, through the morphological-structural analysis, band-gap and photoelectrocatalytic activity, it was possible to reach the optimized condition of obtaining Sb2Se3 films. Of all the proposed TT conditions, the one submitted to 300 °C for 3 h showed better results, exhibiting good optoelectronic property and photoactivity, with band gap of 1.08 eV and average photocurrent of 168.15 μA cm-2, respectively. With the study of the electrodeposition parameters allowed to reach the following optimized condition: bath with 2.5 mmol L-1 K(SbO)C4H4O6 and 2.0 mmol L-1 SeO2 in 0.5 mol L-1 Na2SO4/H2SO4 – pH 2.0, and deposition total charge of 600 mC, besides of the applied potential of -0.6 V vs. Ag/AgCl/Cl-(sat. KCl). In the doping study, the incorporation of Fe2+ caused low influence on the band gap of the films and on their morphological-structural properties. In the film obtained from the deposition bath composed of 5% Fe, it presented a similar photocurrent to the non-doped film, however, with carrier density in an order of magnitude three times higher, i.e., 1,0 x 10^19 cm-3, showing an important characteristic for a high efficiency and fill factor in the case a photovoltaic device was installed.
Comunicação alternativa para crianças com paralisia cerebral não verbais : programa de intervenção para contextos de vida diária
(Universidade Federal de São Carlos, 2017-12-05) Manzini, Mariana Gurian; Martinez, Claudia Maria Simões; https://lattes.cnpq.br/1371315095038350; https://lattes.cnpq.br/9552939271499545
Introduction: Children with complex communication needs benefit from rehabilitation programs directed to the orientation and instrumentalization of the user, the family and the school. Objective: To elaborate, implement and analyze the effectiveness of an individualized alternative communication program for children with nonverbal cerebral palsy applied together in three of their daily life contexts: school, residential and clinical. Method: The participants were: 03 children diagnosed with cerebral palsy with their respective interlocutors from the contexts already mentioned: teachers, family members and therapists. The research was carried out at the children's school, at the residence of the participants and at an outpatient school unit linked to a university. To reach the objectives of the research was the design of multiple probes by situations (clinical, home and school) involving 2 phases probing and intervention. The instruments for data collection used were: Protocol of characterization of the participants, Interview script with the interlocutors on the communicative abilities of the child, Protocol for selection of the figures, Road map to analyze the perception of the interlocutors on the implementation of the supplementary communication and / or alternative and Questionnaire of social validity. The data collection and analysis were structured in 5 phases: Phase 1 Initial Survey: Knowledge of the characteristics of the participants and the initial repertoire, Phase 2, 3, 4 Intervention: Theoretical, practical training and preparation of the alternative communication resource and Phase 5 Final Score: Final Score of the acquired skills. Results: The results demonstrated: (1) demand for improvements in the communication of the interlocutors (of the 3 contexts) for failing to recognize the needs and desires of the children needing alternative resources to make this communication meaningful and effective; (2) lack of repertoire of participants' input in relation to alternative communication; (3) that the Multiple Probe Design allowed to carry out a planned intervention, in order to guarantee control of the variables; (4) acquisition of new communicative skills by the children and (5) that from the instrumentalization of the participants the act of "changing a pictographic figure by its corresponding object" took place, which made it possible for the child and the interlocutors to use the alternative communication features with independence, functionality and low level of help. Conclusion: The implementation of an individualized alternative communication program aimed at the interlocutors of children with nonverbal cerebral palsy in three of their development contexts favored the increase of the communicative abilities of these children and promoted changes in the behavior of children in the three contexts (school, clinic and house). Through the results, the research revealed that the Alternative Communication Program was effective in the intervention strategies adopted.