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Desenvolvimento de nanocompósito de poliamida 6 e óxido de grafeno e união com alumínio 6061 por sobremoldagem por injeção
(Universidade Federal de São Carlos, 2023-04-28) Luiz, Giuliana De Mitri; Canto, Leonardo Bresciani; https://lattes.cnpq.br/7287108960864123; https://orcid.org/0000-0002-4138-005X; https://lattes.cnpq.br/6260013149420556; https://orcid.org/0000-0002-9689-2044
Polymer-metal hybrid structures are presented as an alternative to the transportation industry, since they are able to combine high mechanical strength and lightness. The present study focuses on obtaining hybrid joints of polyamide 6 (PA6) and graphene oxide (GO) nanocomposite with aluminum alloy AA6061 through injection overmolding. GO was synthesized from pristine graphene using modified Hummers method and characterized by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The PA6-GO nanocomposite (99.5/0.5 %) was prepared by melt mixing from a concentrate produced in a thermokinetic mixer (DRAIS), followed by dilution in a twin-screw extruder. The obtained material was injection molded into standard specimens for testing and analysis. SEM analysis showed the absence of GO clusters in PA6. Thermogravimetric analysis (TGA) demonstrated that the thermal stability of PA6 is not affected by the incorporation of GO. Differential scanning calorimetry (DSC) revealed that GO acts as a nucleating agent and reduces the crystallization rate of PA6. Mechanical tests showed that the addition of 0.5% GO provided a 21% increase in the elastic modulus and a 16% increase in the tensile strain, with an 81% reduction in strain at break and a 44% reduction in the IZOD impact strength. The metallic substrate AA6061 was laser-textured with grooves spaced by 100 μm, with a width of 56 ± 6 μm and a depth of 50 ± 5 μm, analyzed by confocal laser microscopy. Optical microscopy analysis of the cross-section of PA6/AA6061 and PA6-GO/AA6061 hybrid joints revealed complete polymer penetration into the metal cavities, resulting in good mechanical anchoring and shear strength of 8,3 ± 0,8 and 7,1 ± 1,7 MPa, respectively, with failure by delamination and polymer fracture. Fractured surfaces were analyzed by SEMEDS, where the presence of aluminum adhered to the polymer was observed, indicating cohesive joint failure.
Avaliação numérico-experimental da hidrodinâmica e da transferência de oxigênio em biorreator coluna de bolhas utilizando fluidodinâmica computacional
(Universidade Federal de São Carlos, 2023-04-28) Silva, Ana Carolina Borges; Badino Júnior, Alberto Colli; https://lattes.cnpq.br/6244428434217018; https://orcid.org/0000-0001-8350-9846; Béttega, Rodrigo; https://lattes.cnpq.br/1379682125857376; https://orcid.org/0000-0002-5647-5385; https://lattes.cnpq.br/1905711299836661; https://orcid.org/0000-0003-4599-5956
Pneumatic bioreactors are increasingly employed in bioprocesses due to their effective heat and mass transfer, rapid mixing, and efficient suspension of solids. Computational Fluid Dynamics (CFD) has emerged as a key tool for studying transport phenomena in engineering equipment, utilizing conservation equations for momentum, energy, and mass to describe fluid dynamics. This study evaluates the hydrodynamics of a square-section bubble column bioreactor both experimentally and numerically through CFD simulations. Key parameters such as global gas holdup (αG), volumetric oxygen transfer coefficient (kLa), and mean (γAV) and maximum (γmax) shear rates are analyzed. Numerical simulations employ the Euler-Euler approach and vary bubble diameters (4, 5, and 6 mm) alongside specific air feed rates (1.0, 3.0, and 5.0 vvm), incorporating drag and lift interfacial forces. Following the selection of the optimal mathematical model, population balance equations (PBE) are integrated into the fluid dynamic model to predict bubble size distribution and assess the impact of breakage (Luo model) and coalescence (turbulent model) phenomena on air distribution and hydrodynamic parameters. These are compared with initial simulation results to refine the model. Simulated values of αG, kLa, γAV, and γmax is compared with experimental and literature data to validate the mathematical model and numerical approach. Results indicate that simulations incorporating lift forces closely match experimental outcomes, with the smallest bubble diameter (4 mm) yielding the highest parameter values. Notably, maximum shear rate (γmax) predictions show good agreement with semi-empirical correlations when considering interactions of breakage and coalescence. Adjusting the fluid dynamic model with PBE confirms accurate prediction of bubble size distribution and Sauter mean diameters within experimental ranges. The coupled CFD-PBM model, considering breakage and coalescence effects, provides superior predictions for gas retention and volumetric oxygen transfer coefficient compared to experimental values. For mean shear rate, the model aligns well with semi-empirical correlations, while maximum shear rate predictions maintain consistent order of magnitude when considering interaction effects.
Estudo metabolômico de espécies de Picramnia e reavaliação da classificação morfológica do gênero
(Universidade Federal de São Carlos, 2023-04-28) Souza, Alicia Ludymilla Cardoso de; Silva, Maria Fátima das Graças Fernandes da; https://lattes.cnpq.br/0457632122660653; https://orcid.org/0000-0002-7081-817X; https://lattes.cnpq.br/8337215013085181; https://orcid.org/0000-0002-1949-5520
The species Picramnia sellowii Planch. is a species of the order Picramniales, in the family Picramniaceae, with the vernacular name “Gogoia”. In reviews of the genus Picramnia and according to the APG IV reclassification, the chemotaxonomic marker of this family are the anthraquinones. Due to the complexity of these metabolites, metabolomics is the technique that investigates and assists in the identification or quantification in order to contribute not only to taxonomy, but to advances in the pharmaceutical industry from the search for active compounds in plants. Through tandem mass spectrometry, it is possible to accelerate the dereplication of molecules using molecular networks, before the subsequent isolation of compounds and then identify the potentially bioactive molecules. By means of tandem mass spectrometry, it is possible to accelerate the dereplication of molecules using molecular networks, before the subsequent isolation of the compounds and, subsequently, to identify potentially bioactive molecules. Still, citric canker is an important disease for citrus cultivation in several countries, such as Brazil and the United States, the two largest orange producers in the world. Caused by the bacterium Xanthomonas citri subsp. citri, the disease affects all commercially important citrus varieties and species. Chemical control of citrus canker in endemic areas is based exclusively on cupric bactericides. Cupric bactericides have no curative or systemic activity and are therefore applied in preventive management of citrus canker. Thus, metabolomics based on untargeted UHPLC-QTOF-MS/MS along with molecular networks was used to identify the classes of secondary metabolites present in P. sellowii. The library obtained from the analyses allowed the visualization of glycosylated flavonoids, catechins, chlorogenic acids, vitanolídeos, dimeric anthrones and quassinoids in Picramnia species. Thus, in order to search for new bactericides with low environmental toxicity, we first performed microbiological tests on P. sellowii extracts and fractions, evaluating their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The Xanthomonas strains used throughout this study were resistant, tolerant and susceptible to copper. The results were promising with the fractions F3 and F2, the former at concentration of 125 µg mL-1 (MIC and MBC) against resistant, tolerant and susceptible strains, the latter at concentration of 250 µg mL-1 (MIC and MBC), 125 µg mL-1 and 250 µg mL-1 against resistant, tolerant and susceptible strains, respectively. Furthermore, this was the first report of the presence, isolation and structural identification of 5-O-caffeoylquinic acid (5-CQA) in the genus Picramnia and first profile performed by LC-MS/MS of the ethanolic extract of P. sellowii leaves, thus contributing to the chemotaxonomic knowledge of the species.
Cadastro territorial multifinalitário na elaboração da planta genérica de valores do município de Cubatão/SP
(Universidade Federal de São Carlos, 2023-04-28) Medeiros, Raphael Duarte; Stanganini, Fábio Noel; https://lattes.cnpq.br/6774358264004600; https://orcid.org/0000-0002-2497-2395; https://lattes.cnpq.br/4450361407255547
The aggravation of the financial crisis in recent decades has highlighted the dependence of municipalities on the Union. The decrease in revenue makes Mayors and Secretaries seek new methods to balance income and expenses. In this scenario, the use of the Multipurpose Technical Cadastres (MTC) emerges as a powerful tool for territorial organization, assisting municipal managers in decision-making. Despite its effectiveness, the high cost of such tools and the low level of specialization of the operational layer of the municipalities sometimes impedes the use of technological tools such as CTM. With the creation of the Program for Modernization of Municipal Tax Administrations (PMAT) and the popularization of Geoprocessing techniques, small and medium-sized municipalities have an unprecedented opportunity to use resources to build and/or optimize the CTM, balance their revenue, and reduce dependence on Union transfers. This study aims to propose a methodology and use CTM to create Generic Value Plants.
Sistemas de estabilização em polipropileno submetidos à radiação UV-C
(Universidade Federal de São Carlos, 2023-04-28) Basaglia, Marcos Vinícius; Staffa, Lucas Henrique; https://lattes.cnpq.br/2896049826673626; Bettini, Sílvia Helena Prado; https://lattes.cnpq.br/3687551763124327; https://lattes.cnpq.br/1834682544092039
UV-C radiation (200 - 280 nm) is a range of the electromagnetic spectrum with increasing and satisfactory studies as a method of disinfection against microorganisms, however, it is little studied in terms of degradation of polymeric materials. This range of radiation is more energetic compared to UV-A and UV-B radiation, presenting potential to break chemical bonds that would be stable in these two ranges. In this sense, the degradative effects caused to polypropylene subjected to UV-C radiation for 24, 48, and 96 hours in the presence of different stabilization systems containing phenolic stabilizers (Irganox 1010), hydroxylamine (Irgastab FS 042), phosphite (Irgafos 168), and UV absorber (Tinuvin 1577) were analyzed. The formulations were processed in an internal mixer and shaped into films with 180 μm thickness. As the processing step can influence the degradative effects of subsequent steps, these were also analyzed for the same additive sets. Degradation levels were analyzed in terms of rheology, molecular weight, Fourier-transform infrared spectroscopy (FTIR), mechanical properties, contact angle, and scanning electron microscopy (SEM). For processing, Irganox 1010 proved to be more efficient in all process conditions used, while Irgastab FS 042 was unable to provide stability at high temperatures (240 ºC) and oxidative atmosphere, which was improved using lower temperatures and inert atmosphere. After UV-C irradiation, FTIR and rheology analyses showed that the use of hydroxylamine is more efficient in initial exposure times, while the phenolic class is more effective for longer times. After 96 hours, polypropylene begins to exhibit brittle behavior, which can be avoided with the joint use of UV absorber and phenol or hydroxylamine-based stabilizers, suggesting a synergistic effect between additives.
Replicação síncrona para sistemas de armazenamento chave-valor em memória primária
(Universidade Federal de São Carlos, 2023-04-28) Ferreira, Danilo José Pereira; González, Sahudy Montenegro; https://lattes.cnpq.br/9826346918182685; Viera, Gustavo Maciel Dias; https://lattes.cnpq.br/9020007815886406; https://lattes.cnpq.br/4654486821945363
In response to consistency and replication challenges found in Redis, this paper addresses the use of synchronous replication as a strategy to provide fully data consistency to a database, with the option of on disk data persistence and recovery support. In addition, this work sheds some light on the trade off between consistency and performance in replicated in-memory databases. In this work, a proxy was developed using the Treplica synchronous replication framework, which implements the Paxos consensus algorithm and gives Redis the properties of data replication in a P2P model, data consistency, and supports the fail-recovery failure model. A benchmark was carried out comparing the proposed system with an application that uses Redis's native replication and failure recovery model, with the aim of understanding the trade-off between consistency and system performance. We have observed that the trade-off between eventual data consistency and fully data consistency in this application reduces performance by 8.4 to 12.4 times, as expected, but still delivers a high write rate, between 32.82 to 213.92 transactions per second in the tests performed.
Caminhos e possibilidades para a alfabetização de pessoas com surdocegueira congênita: a importância da formação docente
(Universidade Federal de São Carlos, 2023-04-28) Falkoski, Fernanda Cristina; Costa, Maria da Piedade Resende da; https://lattes.cnpq.br/2791098416503955; https://orcid.org/0000-0002-7420-5602; https://lattes.cnpq.br/4322444777256456; https://orcid.org/0000-0001-9061-5954
The literacy of congenital Deafblind person is a little addressed topic that is little addressed nationally and internationally. This research intends to present paths and possibilities for the literacy of congenital Deafblind person, as well as the importance of teacher education. Therefore, the questions are: a) How does the literacy congenital Deafblind person happen in Brazil? and b) Does teacher education in Brazil support the choice of methodologies and strategies to be used in the literacy of congenital Deafblind students? To answer those questions the general objective is to identify and knowledge the possible ways for the literacy of congenital Deafblind students of different ages, from the report of experienced teachers who worked or have been working in the field in the last 10 years in Brazil. The research count on the participation of 9 teachers who had or has been literate congenital Deafblind students in Brazil. The methodology applied on this research is a descriptive exploratory approach, case study type. The participants were recruited through an exploratory questionnaire. In order to collect data, interviews were conducted, with the script that the questions were distributed in blocks to extract results on the follow situations: The teachers training; what they have done or are doing to literate the congenital Deafblind students; what resources they have or are using actually; which method is preferred or used; description of the methodology applied; others basic information about the procedure you have used or are using. Bardin content analysis was used for the data collected, and 10 categories of analysis were identified. In the results, we highlight the importance of initial and continuing education in relation to the literacy and Deafblindness for a successful intervention with students, and this pedagogical training being on job training. The research data mainly indicate that literacy is possible for the congenital deafblind person as long the teacher is prepared for it.
A gênese do equívoco: a partir de um ponto de vista epistemológico
(Universidade Federal de São Carlos, 2023-04-28) Whitaker Tosato, Caio; Stival, Monica Loyola; https://lattes.cnpq.br/0624149613819754; https://lattes.cnpq.br/1855634172466907
Le présent travail consiste en une enquête épistémologique sur le concept d'équivoque formulé par l'anthropologue brésilien Eduardo Viveiros de Castro. L'enquête a cherché à retracer la genèse et la structure du concept et, à partir de là, à explorer certaines de ses racines dans la pensée anthropologique et philosophique française. L'examen des problèmes qui entourent ce concept a révélé l'importance de l'opposition classique entre science et philosophie. Afin d' établir le sol sur lequel reposent les racines du concept, par rapport à cette opposition, il a fallu enquêter sur les présupposées épistémologiques du philosophe Gilles Deleuze et de l'anthropologue Claude Lévi-Strauss, représentant respectivement la philosophie et la science. Cela a permis d'évaluer la manière dont l'anthropologue brésilien est affilié à la science et à la philosophie. Le terrain conceptuel capable d'évaluer le statut du concept de Viveiros de Castro d'un point de vue historiographique a été forgé à partir d'une jonction discordante entre les deux français. Cela a fourni les fondements antagonistes capables d'éclairer la position de la pensée du brésilien. A partir de là, il a été possible d' essayer les premières étapes vers une interprétation du statut de la connaissance impliqué dans le concept d' équivoque de l'anthropologue brésilien.
Obtenção de nanopartículas de própolis encapsulado em quitosana com ação biocida para modificação de filtros de ar
(Universidade Federal de São Carlos, 2023-04-28) Pereira, Jéssica Claro; Aguiar, Mônica Lopes; https://lattes.cnpq.br/0431688649128529; Lucas, Alessandra de Almeida; https://lattes.cnpq.br/9754332336954137; https://lattes.cnpq.br/8612281786742802; https://orcid.org/0009-0008-1507-3006
Atmospheric air pollution represents increasingly harmful risks to public health and the environment. Attached to this problem, the coronavirus pandemic has brought several new challenges to our health system. Air conditioner filters are the first physical barrier between the external and indoor rooms, and, in addition to retaining pollutants and bioaerosols, it is important that the proliferation of retained microorganisms is inhibited, in order to prevent these filters from becoming a secondary source of contamination. Therefore, the present work had as objectives the synthesis of chitosan-propolis nanoparticles, and their impregnation in a commercial filter, attributing it a biocidal effect. Chitosan and propolis formulations were studied based on ideal physicalchemical parameters, and the nanoparticles were synthesized by ionic gelation method. Physical properties such as particle size, zeta potential, encapsulation efficiency, FTIR spectroscopy were investigated, as well as particle morphology. Two nanoparticle formulations were pre-selected, showing the best ratios between sizes (392nm e 457nm) and encapsulation efficiencies (78% e 75%), and the chemical analysis confirmed the propolis incorporation into the chitosan matrix. The nanoparticles showed antimicrobial action against S. aureus, with 97% inhibition, and, at least in the concentrations of nanoparticles evaluated, they didn’t show activity against the E. coli strain. Filtration efficiency, permeability, and filter quality factor were analyzed before and after nanoparticle’s impregnation, and their presence didn’t affect its final quality. Thereby, it was verified that these work results were promising for the manufacture of chitosan-propolis nanoparticles for later incorporation into functional matrices, in a sustainable way, in order to reduce the contamination of pathogens in the most diverse environments.
Desempenho ocupacional de crianças com comprometimento na expressão escrita
(Universidade Federal de São Carlos, 2023-04-28) Campos, Sara Domiciano Franco de; Figueiredo, Mirela de Oliveira; https://lattes.cnpq.br/3660487766535040; https://lattes.cnpq.br/4212087875207148
The work of occupational therapists focuses on the performance and engagement of people in their occupations. In this sense, school constitutes a typical occupation in childhood. Studies report that about 30% to 40% of children who have learning difficulties also have difficulties in writing and deficits that appear within the school. The general objective of this study was to identify children with impairment in writing expression, possible problems for occupational performance at school and correlations with motor skills, memory and attention. This is a correlational descriptive study with quantitative analysis, and each of the instruments used has the respective arithmetic procedures for analyzing the responses obtained. The research was approved by the Ethics and Research Committee of the Federal University of São Carlos, and acceptance and signature of the Term of Free and Informed Consent and the Term of Free and Clarified Assent. The research sample consisted of 19 children aged between 8 and 10 years, regularly enrolled in a public school in the interior of the State of São Paulo, indicated by the teachers for presenting impairment in written expression, with the exclusion criterion being the child have a diagnosis of a disability and/or developmental disorder. For data collection, the School Performance Test (TDE-II), Movement Assessment Battery for Children (M-ABC II), Cancellation Attention Test (TAC), Block Span Task - CORSI (TSB-C), Digit Span Task (TSD) and a questionnaire on occupational performance, created by the researcher. The results showed that children have very severe difficulty (n=78.95%) in writing and severe difficulty (n=21.05%) measured by TDE-II. It is observed that of these children with impaired written expression, 68.42% had a low score for age in relation to alternating attention (measured by TAC) and 31.58% had a low score for age in relation to complex selective attention ( measured by TAC). Of this sample, 42.11% had low scores for age in relation to short-term memory and visuospatial working memory (measured by TSB-C OI) and 26.32% had low scores for age in auditory memory short-term (measured by the TSD-OI). With regard to the general motor performance measured by the M-ABC 2, 26.32% of the children classified themselves as having motor difficulties, and specifically 15.79% classified themselves as having difficulty with manual dexterity, difficulty aiming and picking up, and difficulty of balance. Regarding occupational performance, there was impairment in occupational performance at school, with 29.55% of the children considered unable to perform, 19.70% only performing with parental assistance and 34.09% performing alone, however, with great difficulty. The research identified that the children in this study with impairment in writing expression, presented difficulties in their occupational performance at school and impairment in memory and attention components, corroborated with the literature, but did not present impairment in the motor component, being this hypothesis of study refuted despite the literature indicating a relationship between them.