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A study of SnO2 nanowire FET devices: ambipolarity effect induced by UV Light exposure and their use as UV sensors
(Universidade Federal de São Carlos, 2021-03-18) Arantes, Adryelle do Nascimento; Chiquito, Adenilson José; https://lattes.cnpq.br/7087360072774314; https://lattes.cnpq.br/6444614628132115
In this work, SnO2 nanowires (NW) were grown by the Vapor-Liquid-Solid (VLS) method and used to build single NW FET devices. As-grown samples went through structural and morphological analysis and seven single NW devices were built, with a back-gated FET architecture, by direct photolithography. SnO2 NWs grown by VLS method presented the desired tetragonal structure and monocrystalline character, inspected by XRD and HRTEM techniques. In addition, the as-grown samples morphology of a NW with lengths of tens of micrometers and cross-section mostly displaying rectangular geometry were assured through SEM images. The device fabrication process by direct photolithography was proven to be efficient to build the back-gated FET architecture devices with great electrical contacts quality. Single SnO2NWFET’s transport properties were explored, where on/off ratio, mobility and carrier density parameters were extracted, resulting in values around 105, lower than 0.1 cm2/V and in the order of 1019/cm3, respectively. Schottky barrier heights were estimated, considering the gate bias as grounded and room temperature, and Φ_Bn values between 0.41 and 0.75 eV were found. Afterwards, different conditions were analyzed: the device (1) under positive gate bias (V_G>0) and no applied source/drain bias (V_DS=0); (2) V_DS>0 and V_G>0; (3) V_DS<0 and V_G<0 and (4) V_DS<0 , V_G<0 but under UV illumination. Regarding the latter, all devices presented UV induced ambipolary effect, where on/off states ratio with values of the same order were obtained and ranged from 1.1 to about 19.3. A simple band model to explain the observed behavior, i.e., describe how both types of carriers can contribute to the final current depending on the biasing was proposed. Ambipolarity is one of those effects that may direct its use for specific purposes, where a controllable separated unipolar mode can be achieved in one single device. Furthermore, the devices were tested as UV sensors and presented satisfactory results: as a UV photodetector, the acquired I_on⁄I_off ratio was found to be of the order of 〖10〗^4 for all devices investigated. In addition, rise time was found to range 0.56 s < τ_r< 0.63 s, whereas the decay time 0.54 s < τ_d< 0.75 s. According to those results, one can assure their huge feasibility as a UV sensor.
Contribuição dos estudos semióticos para a catalogação de histórias em quadrinhos
(Universidade Federal de São Carlos, 2021-03-18) Pavarina, Etefania Cristina; Zafalon, Zaira Regina; https://lattes.cnpq.br/1584935790390793; https://lattes.cnpq.br/0906483851923523
This research has proposed to study the contribution of semiotics to the cataloging of comic books. The comics stand out as an object of research, considering the alignment of questions and visual and verbal values, which are intrinsic to them, as well as the process of defining the context of the scenario involved in the story as important elements for the retrieval of information. Thus, the general objective is to evaluate the contribution of semiotics in the cataloging of comic books. The research, of an applied nature, has presented a qualitative approach and exploratory objectives. Systematic mapping of literature was adopted as a method for bibliographic research, and the Content Analysis was used to analyze the data. As a result, it is understood that semiotics and semiology might contribute to the cataloging of comic books, in theoretical-conceptual and methodological aspects. In this perspective, cataloging has been seen as a semiotic process that permeates all stages of Organization and Representation of Information in comics, from the representation process (thematic and descriptive) to the search and recovery by users. It is observed that the semiotic narrative, discursive and cultural currents might contribute to the cataloging of comic books, mainly in the processes of reading, description, and representation.
O livro didático do professor na pré-escola: uma análise das propostas pedagógicas a partir das políticas públicas educacionais
(Universidade Federal de São Carlos, 2021-03-18) Silva, Caroline Lurdes; Souza, Geraldo Tadeu; https://lattes.cnpq.br/3516168011612531; https://lattes.cnpq.br/4854690633680864
This monograph has the general objective of developing a critical look at the pedagogical proposals suggested for the preschool through the use of the teacher's textbooks. From the documental point of view, we studied the public educational policies Opinion CNE / CEB nº 20/2009, Resolution CNE / CEB nº 5/2009, National Curricular Guidelines for Early Childhood Education (DCNEI) and Common National Curricular Base (BNCC), from of which it was possible to understand the guidelines for teaching practices in the first stage of Basic Education and to problematize the role that the teacher and the child need to assume in the educational process during early childhood education. To think about the presence of the textbook in Early Childhood Education, we explored the National Book and Didactic Material Program (PNLD) through the edition of PNLD 2019, which selected teacher textbooks aimed at pre-school educators and teachers. Based on this assumption, pedagogical proposals analyzed by the didactic work Pé de brincadeira (CORDI, 2018) are analyzed, in view of the legal documents and their guidelines for the curricular organization in early childhood education. As a result of this research, we built a critical view of the possibilities that the textbook object can bring to the pre-school teacher as a source of continuing education and as an inspiring resource for pedagogical practices in the interaction with young children, enriching the teaching process-learning in early childhood education.
Inovação social para o envelhecimento ativo: iniciativas em Portugal e no município de São Carlos -SP
(Universidade Federal de São Carlos, 2021-03-18) Mello, Kemilly Bianca de; Pedro, Wilson José Alves; https://lattes.cnpq.br/8135701448186851; https://lattes.cnpq.br/8614808357673501
The idea of social innovation (SI) stands out today, but when linked to active aging, there is a very large gap in knowledge and practice, especially in Brazil. In the face of this unexplored theme, this research aims to identify and analize SI initiatives focused on active aging in the city of São Carlos-SP and north region of Portugal. This research used a theoretical-empirical methodology and a multi-case study aimed at identifying SI initiatives linked to active aging and quality of life. In addition, a study of the state of the art of SI and active aging was carried out to understand and update itself on the productions developed. The project referring to this research was approved by the Research Ethics Committee - CEP / UFSCar (Opinion nº 3,350,844). The results and discussions point to the existence of well-consolidated SI initiatives for active aging in Portugal, mainly due to the support for this demand in the country and on the European continent. In São Carlos, the initiatives identified, despite not calling themselves SI, aim to meet the demands associated with aging in an innovative way. In addition, this study shows the relevance of research on the theme of social innovation for active aging in the Brazilian context, since there is a lack of knowledge on this theme and there are no public policies for social innovation in Brazil. The final considerations, on the other hand, present reflections and possibilities to expand this theme for its diffusion and incentive to social transformations.