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Desenvolvimento de compósito de HDPE verde com hidroxiapatita e união com Ti6Al4V através de sobremoldagem por injeção
(Universidade Federal de São Carlos, 2023-10-10) Morozo, Mario Augusto; Fiori, Márcio Antônio; https://lattes.cnpq.br/8793913102689273; https://orcid.org/0000-0002-4292-2068; Canto, Leonardo Bresciani; https://lattes.cnpq.br/7287108960864123; https://orcid.org/0000-0002-4138-005X; https://lattes.cnpq.br/9885777352903049
This thesis addresses the development of a composite of green high-density polyethylene (G-HDPE) and hydroxyapatite (HA), compatibilized with high-density polyethylene functionalized with maleic anhydride (HDPE-g-MAH). It further explores the hybridization of this nanocomposite onto a Ti6Al4V - ELI alloy through injection overmolding, focusing on biomedical applications. The study involved the synthesis (precipitation in aqueous medium) and characterization (XRD, XRF, particle size distribution, and SEM) of hydroxyapatite, extrusion and injection molding, mechanical (tensile and impact), thermal (DSC), microscopical (SEM), and in vitro biological characterization of the composites. The results were evaluated using design of experiments (DOE), analysis of variance (ANOVA), and Tukey test. The composite containing 30 wt% of HA and 30 wt% of HDPE-g-MAH (relative to the HA content in the composite) showed a good balance of mechanical properties, nearly negligible hemolysis percentage, and a mass increase of 8% during the hydrolytic degradation test. The hybrid joint of the composite with the optimized composition, injection molded onto Ti6Al4V, showed good interfacial anchoring, resulting in outstanding shear strength (3 MPa) and fatigue life (> 106 cycles). This multi-material approach has provided subsidies for the advanced manufacture of biomedical devices with optimized mechanical and biological properties, exploiting efficient processing techniques.
Previsões de preço de criptomoedas utilizando algoritmos de Aprendizado de Máquina
(Universidade Federal de São Carlos, 2023-10-10) Nordi, Victor Hugo Werneck; Cantão, Renato Fernandes; https://lattes.cnpq.br/3016268479248046; https://lattes.cnpq.br/1825035215515061
Cryptourrencies are decentralized digital currencies created with the intent of replacing traditional forms of payment. Their high volatility is one of the aspects that causes distrust among investors. Artificial Intelligence based on Machine Learning algorithms can be an invaluable tool to analyse this characteristic, helping to predict prices. In this sense, this project’s goal is to use algorithms implemented in Python — Support Vector Machine and Long Short-Term memory — alongside convenient performance metrics such as mean squared error, mean absolute error, maximum error and R^2 to assess their price prediction capabilities in face of such randomness.
Thermodynamics of the Ramsey Zone
(Universidade Federal de São Carlos, 2023-10-10) De Assis, Rogério Jorge; Diniz, Ciro Micheletti; Almeida, Norton Gomes de; Villas-Bôas, Celso Jorge; https://lattes.cnpq.br/7703787869253387; https://lattes.cnpq.br/3102671365275808; https://lattes.cnpq.br/3182841849332242; https://lattes.cnpq.br/5700887540085418; https://orcid.org/0000-0003-1133-6012; https://orcid.org/0000-0002-7602-0468; https://orcid.org/0000-0001-8517-6774; https://orcid.org/0000-0001-5622-786X
Obtenção de nanocelulose de palha de cana-de-açúcar com diferentes teores de lignina residual
(Universidade Federal de São Carlos, 2023-10-10) Almeida, Gabriela Fornaziero de; Farinas, Cristiane Sanchez; https://lattes.cnpq.br/9933650905615452; https://orcid.org/0000-0002-9985-190X; Mattoso, Luiz Henrique Capparelli; https://lattes.cnpq.br/5839043594908917; https://orcid.org/0000-0001-7586-1014; https://lattes.cnpq.br/5921412271390732; https://orcid.org/0000-0002-0210-5506
Brazil stands out for its high production of sugarcane. This production generates a significant amount of byproducts, such as sugarcane straw. Due to its high cellulose content, converting straw into nanocellulose can be a promising alternative to add value to such a side-stream. Recent studies have shown that producing nanocellulose with residual lignin is a sustainable alternative to modify its surface properties. Residual lignin reduces the hydrophilicity of the nanocellulose, improves its compatibility with hydrophobic polymers and increases its thermal stability. Given the growing interest in the study of lignin-containing nanocellulose (L-NC) and the possibility of using sugarcane byproducts for this purpose, this work aimed to obtain L-NC from sugarcane straw with different residual lignin contents to investigate the effect of lignin on the thermal, morphological, surface, and structural properties of nanocellulose. The lignin content in the straws was varied by bleaching with chlorine dioxide under two conditions of reaction time and amount of bleaching chemicals. Three types of L-NC were produced using sulfuric acid hydrolysis from three biomass samples, namely: unbleached straw (U), mildly bleached straw (MB), and severely bleached straw (SB). The resulting lignin contents were 17.3 ± 0.3% for US, 14.7 ± 0.3% for MB, and 4.6 ± 0.8% for SB. Higher yields were observed for the L-NC obtained from bleached straws, which are purer in terms of cellulose. Atomic force microscopy confirmed the isolation of cellulose nanocrystals and nanofibers, regardless of the bleaching severity. Finally, lignin was found to increase the thermal stability of nanocellulose while reducing its crystallinity index, and colloidal stability. Its width and hydrophilicity did not vary significantly.
Surdez em linhas de fuga: políticas de subjetividades outras na educação inclusiva
(Universidade Federal de São Carlos, 2023-10-10) Monti, Luísa Leôncio; Martins, Vanessa Regina de Oliveira; https://lattes.cnpq.br/4768682330164550; https://orcid.org/0000-0003-3170-293X; https://lattes.cnpq.br/3519999475085077; https://orcid.org/0000-0002-3342-4286
The various obstacles imposed on the implementation of the inclusive education have made its effective implementation impossible. As a thesis, I assume that the subjecting violence manifests itself in the inclusive context, through normative logic, activated in the classification and categorization of disabled bodies and their affections. This movement weakens plural forms of life and, therewith, to maintain singularities, some bodies rise up, establishing resistance through lines of flight. In this sense, I aimed to map the practices of (non) violence in inclusive education composed of molar, molecular and lines of flight that act in the production of subjective marks in the deaf ethos. This is a cartographic research, based on a paradigmatic case, carried out in a school unit located in the interior of the state of São Paulo, in the high school stage. In school cartography, I problematized the practices of deaf subjectivation arising from the relations of knowledge and power produced in school discursive practices. I turned to the internal and capillary productions of/in the school, through the eyes of the deaf person, as well as about their insertion in inclusive educational practices. The field research took place on two fronts: observations in the school territory, with entries in a field diary and an interview, as a cartographic procedure. We opted for a cartographic analysis, conceptually based on the philosophies of difference. The theoretical reference came from Michel Foucault, Gilles Deleuze, and Félix Guattari. Were identified, interspersed with the narrative of the life poem, four molar lines (linguistic, physical space, affective and symbolic-religious violence) and four molecular lines (non-violence of the encounter, of being queer, of being umbandista, and other deafness), which guided the discussions. It is believed that the research contributes to recognizing aspects that lead to violence and non-violence in the constitution of subjectivity during the school trajectory of deaf people. In view of the signs found, there is a way of existence, a pragmatic of singularity in the life-poem, and that their voices/experiences in common rooms and the inclusive school stand as local knowledge that resists and announces more ethical practices in favor of differences made along lines of flight.