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Desenvolvimento de biocompósitos de Poli (ácido láctico)/biocargas para impressão 3d de scaffolds para engenharia de tecidos ósseos
(Universidade Federal de São Carlos, 2020-08-11) Backes, Eduardo Henrique; Passador, Fabio Roberto; https://lattes.cnpq.br/0152213852695153; Pessan, Luiz Antonio; https://lattes.cnpq.br/8276650236213537; https://lattes.cnpq.br/6407713491620749
As life expectancy increases worldwide, there is an increased need for orthopedic procedures to repair bone defects resulting from trauma. In this context, new surgical procedures and bone repair materials, such as scaffolds and temporary models for bone regeneration have been developed. In this doctoral dissertation, the development of printable biocomposites composed of poly(lactid acid) (PLA)/bioactive fillers envisioning bone tissue engineering was investigated as an alternative for scaffold fabrication that supports bone growth and could be manufactured to fit the specifics of individuals. During the development of PLA/biofiller composites, an intense investigation was carried out on the processing, rheological and thermal characteristics and molecular properties and their correlation with the characteristics needed for manufacturing and printing filaments with bioactive properties. PLA filaments and PLA/hydroxyapatite (HA) and PLA/b-tricalcium phosphate (TCP) biocomposites were produced by twin screw extrusion, and scaffolds with the biomimetic bone structure were 3Dprinted from the filaments. The scaffolds were characterized by compression tests and presented compressive properties similar to those of human bone. Bioactivity and biocompatibility were analyzed using simulated body fluid and cell line tests, respectively. The scaffolds were able to originate the formation of calcium phosphates within seven days, indicating an adequate environment to support cell growth, and tests with cell lines showed that biocomposite scaffolds are capable of supporting cell growth and differentiation. In summary, PLA/HA and PLA/TCP biocomposite scaffolds with high biocompatibility and bioactivity properties were developed. The use of 3D printing enables the manufacturing of an infinite number of shapes that are suitable to repair bone defects.
Otimização do processo de secagem de concretos refratários
(Universidade Federal de São Carlos, 2020-08-11) Bezerra, Breno Parente; Luz, Ana Paula da; https://lattes.cnpq.br/3470395641242374; Pandolfelli, Victor Carlos; https://lattes.cnpq.br/7369376873984839; https://lattes.cnpq.br/3571098419382941
The drying step of hydraulic-bonded refractory castables is usually carried using conservative and long heating schedules, in order to preserve the microstructure of dense ceramic linings and inhibit explosive spalling risks, due the steam pressurization resulting from the intense water vapor release observed 110°C. Therefore, alternatives to minimize pressurization and/or to enhance the refractories’ explosion resistance may lead to significant energy savings and lower downtime of industrial processes. In this context, this work aimed to evaluate additives that are able to modify the castables’ permeability and prevent their explosion when exposed to fast drying schedules. Commercial additives (Emsil-Dry - ED and RefPac Mipore 20 - MP), alternatives ones (aluminum lactate - LA and calcium lactate - LC) and low melting point polymeric fibers (PP – polypropylene, PLA – polylactic acid, EVA – copolymer ethylene vinyl acetate, and PCL - polycaprolactone) were selected as drying agents. High-alumina castable formulations (with and without additives) containing calcium aluminate cement (CAC) or hydratable alumina (AB) have been designed according to the Andreasen packing model and, subsequently, extensive experimental tests (flowability, cold flexural strength, apparent porosity, permeability measurements, explosion resistance tests, etc.) were carried out to infer the properties and performance of such materials. The obtained results showed that MP, LA or LC additives change the hydration sequences of the used binders (CAC or AB) and that the performance of the polymeric fibers was improved by oxidative effects and their morphological transformations during heating. Except PLA-fibers, the other selected additives (ED, MP, LA, LC, PP, PCL, or EVA) were effective in adjusting the microstructure of CAC-bonded castables. On the other hand, AB-bonded refractory compositions exhibited high explosion resistance by adding MP, PP-fibers, or blends of LA+CAC or LC+CAC.
Um estudo da mobilidade acadêmica internacional em cursos de graduação da Universidade Federal de São Carlos no âmbito dos programas AUGM, BRACOL, BRAMEX e acordos bilaterais de cooperação
(Universidade Federal de São Carlos, 2020-08-11) Forim, Andréia Businaro; Rigolin, Camila Carneiro Dias; https://lattes.cnpq.br/2388584081961836; https://lattes.cnpq.br/3852615165970172
The internationalization of higher education institutions is an increasingly recurrent theme in the context of academic discussions because, in addition to being an impacting force in higher education, it is one of the most important challenges facing the 21st century. International academic mobility, a phenomenon that moves a significant number of students across borders, is the most visible face of the Internationalization of Higher Education. The activities associated with internationalization go far beyond the cross-border mobility of students, as it also encompasses curriculum development, international cooperation, staff development, among other aspects. In this scenario, this research aimed to assess international academic mobility in undergraduate courses at the Federal University of São Carlos, within the framework of the programs AUGM, Bracol, Bramex and bilateral cooperation agreements, from 2016 to 2019. Academic mobility international is one of the most successful mechanisms in preparing students to work and live in a globalized world, as well as in the acquisition or consolidation of transversal skills such as foreign language skills, independence, initiative, flexibility, intercultural understanding, sensitivity understanding, beyond international awareness. The present research adopted the survey methodology. It has a quantitative approach, and based on the objectives is descriptive. Data collection was carried out through documentary research and the application of a questionnaire to undergraduate students who participated in international academic mobility in the period from 2016 to 2019. The results obtained were analyzed and discussed based on the proposed objectives, confronting them with the literature. The analysis of the results was made through the Average Ranking (RM) of the Likert items within each category. Among the results of this study, it can be inferred that although the international academic mobility at UFSCar is expanding, from the weak spots detected through the questionnaire, it is possible to implement improvement actions to increase the number of academic mobility incoming and outgoing. It was also found that Latin America has developed its international academic mobility, notably through AUGM, however, it still needs to be improved, aiming to attract students from all areas of knowledge. The study also sought to offer subsidies for several institutional actions through the indicators presented. Limitations and suggestions for future studies are presented in the final considerations.
Cultura, poder e meio ambiente: sociologia dos trânsitos identitários de uma comunidade rural
(Universidade Federal de São Carlos, 2020-08-11) Oliveira, Priscila Silveira de; Martins, Rodrigo Constante; https://lattes.cnpq.br/6617183095074852; https://lattes.cnpq.br/6102996140263032
This thesis sought to understand representations of the rural and meanings attributed to the community life of the residents of a neighborhood in the city of Botucatu called Demétria, which arose from a pioneer experience in the development of biodynamic agriculture in Brazil. Currently, the role of biodynamic agriculture in this context is very small, with only two farmers linked to the biodynamic movement. However, the neighborhood remains with a strong identity linked to Waldorf pedagogy due to the presence of the Aitiara school and also to the principles of Anthroposophy. Our hypothesis was the existence of different social uses of the rural as a category of thought as well as different social uses regarding the identifications around Waldorf pedagogy and Anthroposophy that are linked to class, ethnic and racial differences. Interviews were conducted with residents using a semi-structured questionnaire. From the meanings attributed by the residents of the neighborhood, it was possible to understand a community that recognizes itself from the notion of socio-environmental rural and that emerges linked to a Brazilian social phenomenon at first urban, namely, the logic of condominium in which the closed residential condominium is elevated to a hegemonic way of life paradigm in the Brazilian national imaginary. Thus, our work presents different moments historically in the formation of the neighborhood, namely: the construction of Estância Demétria and the construction of the Waldorf school “Aitiara” and coming from first fixed and intermittent residents, linked to the process of building an identity associated with anthroposophy and building a community; a second moment, when agricultural production ceases to have a preponderant role in territorial organization, the arrival of new residents and the growth of the neighborhood present new identifications, the rural as landscape, nature and idyllic space, and the Aitiara school become the nuclei of these discursive practices. It is the period that establishes and expands frontiers between Demétria and the city of Botucatu. A third moment, which extends to the present day in which, the great growth of the neighborhood and the number of residents, presents Demetria very heterogeneous, the “demetrian” identity and a sense of community become more and more associated with condominium logic. At that moment, sustainable consumption and the relations with this space as a “commodity”, promote the growing real estate speculation in the neighborhood and reveal influences of the neoliberal ideology regarding the identifications to the rural and socio-environmental issue. In this regard, we seek to analyze the transformations, challenges and potentialities for identity issues in late capitalism, notably regarding the potentialities of the emergence of environmental sustainability as a new identity paradigm in the face of the emergence of the neoliberal subject.
Espectro do Laplaciano de Dirichlet-Neumann em faixas estreitas
(Universidade Federal de São Carlos, 2020-08-11) Bello, Diana Carolina Suarez; Verri, Alessandra Aparecida; https://lattes.cnpq.br/8794549732815622; https://lattes.cnpq.br/1880261381430298
Let $\Omega_\varepsilon$ be a thin strip in $\mathbb{R}^2$ and $-\Delta_{DN}^{\Omega_\varepsilon}$ the Dirichlet-Neumann Laplacian in $\Omega_\varepsilon$. In this work, we study the spectral problem of $-\Delta_{DN}^{\Omega_\varepsilon}$. The asymptotic behaviour for the non-decreasing sequence of numbers $\{\lambda_j(-\Delta_{DN}^{\Omega_\varepsilon})\}_{j=1}^{\infty}$ given by Max–Min Principle will be obtained, under the condition that $\Omega_\varepsilon$ is thin enough. Furthermore, we study the spectral properties of the Dirichlet-Neumann Laplacian in a thin strip of a fixed width.