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Avaliação da influência da carbodiimida na reciclagem de tecidos a base de PA6
(Universidade Federal de São Carlos, 2023-11-30) Baccarin, Graziela Solferini; Staffa, Lucas Henrique; https://lattes.cnpq.br/2896049826673626; Cruz, Sandra Andrea; https://lattes.cnpq.br/9632409046763256; https://lattes.cnpq.br/3937929188683347
The remaining fabric from the textile industry, especially that related to clothing, is a growing environmental and economic problem. On a global scale, in 2015, 92 million tons of fabric were discarded and it is expected that by 2030 this number will increase to 148 million tons. Concomitantly with consumption, there is disposal that occurs in landfills, through incineration for conversion into energy, and also inappropriately in landfills. An alternative to disposing of waste from the textile industry is its recycling. Therefore, in this project, post-industrial waste polyamide 6 (PA6) was recycled with the aim of developing a material that can return to its original application, promoting adequate circularity. Furthermore, the influence of the presence of carbodiimide, as a functional molecule, on the recycling of dry and wet PA6 was studied. The results of X-ray diffraction and differential scanning calorimetry indicated that there was a change in the crystalline phase of PA6 from α to γ with the incorporation of CDI. The rheology results indicated an increase in molar mass of 73% for dry samples and 147% for wet samples, indicating that carbodiimide is more effective in humid media. Intrinsic viscosity analyzes together with rheology analyzes indicated that the increase in CDI probably induces the formation of long branches. Finally, the mechanical tests indicated that for the dry samples there was an increase in tensile strength, while for the wet samples there was no change. These tests also indicated that carbodiimide increases the ductility of PA6, with dry samples showing an increase of around 70% in elongation at break, while wet samples showed an increase of around 55%.
Semiótica, saúde e regimes de interação: um estudo sobre relatos de profissionais da saúde e pacientes do SUS
(Universidade Federal de São Carlos, 2023-11-30) Sousa, Stephani Izidro de; Barros, Mariana Luz Pessoa de; https://lattes.cnpq.br/4830505244404566; https://orcid.org/0000-0002-1662-2125; https://lattes.cnpq.br/7408186965865643; https://orcid.org/0000-0002-1925-6458
It is necessary to take a non-naive look about the role of communication in society so that the relationship between health professionals and patients can be analyzed and even contribute, albeit indirectly, to its humanization. For that, this research examines reports about the interaction between health professionals and patients, found through open interviews, in an attempt to understand some aspects of communication within the scope of public health. The research focus is on a unit of the Unified Health System (SUS) in the city of Campinas (SP), and the creation of the corpus occurred in two distinct stages: data collection, selection and transcription of the material. This transcribed material was analyzed with theoretical support, above all, from French Discursive Semiotics, in dialogue with Discourse Analysis, as well as with other studies on social interaction, developed in Linguistics, but also in the field of Health, such as Anthropology of Health. In our analysis, the construction of the ethos, images of health professionals and patients and the actor of enunciation stood out, as well as the interaction regimes activated, valued and devalued by the participants in their narratives.
Subsídios ao planejamento da infraestrutura verde na bacia hidrográfica do Córrego do Gregório (SãoCarlos-SP)
(Universidade Federal de São Carlos, 2023-11-30) Vicente, Ana Paula Zimiani; Peres, Renata Bovo; https://lattes.cnpq.br/6045407453925020; https://orcid.org/0000-0002-5455-6667; https://lattes.cnpq.br/8948738087214733; https://orcid.org/0000-0002-1802-2502
The process of urbanization in Brazil, whose foundations are based on pronounced and disordered growth and intense exploitation of natural resources, generates urban flooding as one of its major consequences. In recent decades, there has been a growing recognition of the need to integrate planning with environmental issues in order to reverse outdated urban drainage models. In this context, the concept of Green Infrastructure (GI) has gained prominence as an integrated approach to promoting more sustainable urban development and mitigating problems related to urban water. The objective of this research is to analyze how the concept of Green Infrastructure has been addressed in the Hydrographic Basin of stream do Gregório (São Carlos, SP), focusing on academic production, journalistic media, and landscape understanding to provide inputs for planning. To this end, academic production on the stream Gregório Hydrographic Basin was analyzed over the past 20 years, with a focus on drainage and urban water issues. 91 works, including articles, theses, and dissertations, were identified, with analysis focusing on 34 published articles. A documentary survey of journalistic media over the last 10 years was also conducted, identifying 101 news items. Of these, 31 news items relate to flood events, 28 news items cover the works carried out in the basin, and 42 news items encompass general themes such as the damages and losses caused by floods and the resources and studies developed. The understanding of the current landscape dynamics in the basin focused on GI planning and the potential Free Space System (FSS). The methodology included macro landscape analysis based on a proposed GI and FSS-based cartography, as well as visual landscape analysis through photographs focusing on the pedestrian scale. The basin was divided into 5 sections considering the specificities of the landscape. Additionally, plans and projects developed for the basin were identified, considering proposals against floods from the current administration and unrealized projects. Based on the proposed analytical axes, the research highlights a growing trend in scientific studies and projects for the basin that emphasize Green Infrastructure as a suitable approach to mitigate issues related to urban production and planning. However, this trend is not reflected in flood-related news in the local media. The analysis of the current landscape emphasizes the increasing soil impermeability, particularly through new developments, while also recognizing potential spaces for the implementation of a Free Space System and Green Infrastructure in the basin. It is hoped that this will contribute to planning inputs and broaden the perspective on the landscape, encouraging actions that bring nature and the urban environment closer together in the face of territorial complexity.
Comportamento mecânico do concreto de alta resistência reforçado com fibras
(Universidade Federal de São Carlos, 2023-11-30) Almeida, Ricardo Laguardia Justen de; Carnio, Marco Antônio; https://lattes.cnpq.br/9718956606062025; https://orcid.org/0000-0002-2005-8555; Parsekian, Guilherme Aris; https://lattes.cnpq.br/7798651726059215; https://orcid.org/0000-0002-5939-2032; https://lattes.cnpq.br/7352278288074474; https://orcid.org/0000-0002-4251-1146
The addition of fibers to concrete provides ductility and their contribution to high-strength concrete may be even more relevant due to the high brittleness of the material. Nevertheless, research in the literature investigating the mechanical behavior of high- strength fiber-reinforced concrete (HSFRC) is limited and mostly involves concrete reinforced with steel fibers. This research investigated the mechanical behavior of high-strength fiber-reinforced concrete (HSFRC) through an extensive experimental program with six different types of fiber divided into three categories according to the material of the fiber: hooked-end steel fiber, crimped steel fiber, chopped glass fiber, pultruded glass fiber, monofilament polymeric fiber and twisted polymeric fiber. Each one of these fibers was studied at three different volume fractions (Vf) (0.50%, 0.75% and 1.00%), making a total of 29 different mixes in the experimental program. The parameters analyzed were the type and fiber content and the compressive strength of the concrete (60 and 90 MPa). The mechanical behavior was investigated through compressive displacement-controlled tests to obtain the complete stress-strain curve and three-point bending tests in notched beams to determine the residual strengths. The test results showed that the addition of fibers can affect the mechanical properties of concrete, such as compressive strength, elastic modulus and peak strain, depending on the type and fiber content. Toughness, on the other hand, is clearly influenced by the fiber addition and content. In general, the greater the fiber content, the greater the toughness and residual strength in bending regardless of the fiber type. Steel fibers provided the highest toughness and residual strengths in compression, followed by glass fibers and polymeric fibers. Constitutive models in compression were proposed for each type of fiber and showed good agreement with the experimental results and can be used to estimate the ductility and toughness of the HSFRC. In bending, the limit of proportionality is slightly influenced by the fiber content and hooked-end steel fibers also provided the highest residual strengths, followed by pultruded glass fibers and crimped steel fibers, polymeric fibers and chopped glass fibers. Furthermore, the requirements of technical standards for using fibers in structural applications were discussed and must be reviewed for high-strength fiber-reinforced concrete. The experimental results of the bending tests were used in finite element modelling (FEM) to obtain the constitutive model in tension by inverse analysis. The results obtained with the numerical model showed good agreement with the experimental results in terms of toughness and proved to be a useful tool for numerical simulations of fiber- reinforced concrete. From the validation of the numerical model, multilinear constitutive models were proposed and can be used for design purposes. The analyzes carried out also demonstrated that the simplified models of the technical standard can overestimate (in the case of the linear model) or underestimate (in the case of the rigid-plastic model) the toughness of HSFRC and do not represent the post-cracking behavior of high-strength concrete reinforced with glass and polymeric fibers.
Influência da adição de elementos de liga na microestrutura de superligas Ni-15%Nb-xAl-yTi
(Universidade Federal de São Carlos, 2023-11-30) Arruda, Matheus Stolf Toledo; Kuroda, Pedro Akira Bazaglia; Afonso, Conrado Ramos Moreira; https://lattes.cnpq.br/2176215981291453; https://lattes.cnpq.br/9774306943389051
Controlling the fraction of precipitates and their morphology are important parameters in precipitation-hardenable superalloys, since precipitates provide increased mechanical properties in these alloys that are exposed to severe conditions of temperature and mechanical strength. Ni Nb superalloys with additions of Ti and Al were produced in concentrations of Ni15Nb2Al2Ti, Ni15Nb2Al4Ti and Ni15Nb4Al1Ti and obtained polycrystalline alloys composed of a matrix of Ni (γ), an irregular phase of Ni3Nb (γ’’) and precipitates of the Gamma Prime phase (γ ') composed by γ' Ni3(Al,Ti). Solubilization and aging thermal treatments were carried out to obtain greater volume and control of the morphology of the precipitated phases. Optical microscopy (OM), scanning electron microscopy (SEM), electron emission spectroscopy (EDS) and X-ray diffraction (XRD) analyzes were performed on the samples to evaluate the microstructures, the chemical composition of the phases and crystalline structures . Vickers microhardness tests were carried out to observe the effects of heat treatments on the material's hardness properties. Thus, it was possible to observe the influence of Nb together with the effects of adding Al and Ti on the microstructures and hardness of Ni superalloys. Due to additions of Ti and Al other phases may form precipitates. By varying the concentrations of Ti and Al in the samples, different Ti/Al ratios were obtained and thus it was possible to analyze their effects on the microstructure and hardness property. The increase in the Ti/Al ratio led to a greater formation of the Ni3Ti phase. Increasing the amount of Ti + Al increased the microhardness values of the Ni15Nb2Al4Ti alloy (469 HV in the aged condition), followed by the Ni15Nb4Al1Ti alloy (422 HV in the aged condition) and finally the Ni15Nb2Al2Ti alloy (395 HV in aged condition).
Efeitos toxicológicos da nanopartícula de dióxido de titânio (TiO2) utilizando modelos experimentais in vitro e in vivo
(Universidade Federal de São Carlos, 2023-11-30) Fattori, Ana Carolina Maragno; Rossi, Karina Nogueira Zambone Pinto; https://lattes.cnpq.br/4705154788194140; https://orcid.org/0000-0002-7142-9889; Anibal, Fernanda de Freitas; https://lattes.cnpq.br/4918261968772806; https://orcid.org/0000-0003-0571-8516; https://lattes.cnpq.br/9855158621715652; https://orcid.org/0000-0002-4868-9148
The advent of nanotechnology and its applications in diverse areas is due to the increase in the physical and chemical properties of nanoparticles because of their nanometric scale. However, these new characteristics can trigger biological effects that harm health and the environment, highlighting the need to assess the safety of using these nanomaterials. Therefore, this study analyzed the toxicological effects of titanium dioxide nanoparticles (TiO2 NP) functionalized with sodium carboxylate (-COO-Na+), of interest to the oil industry, using in vitro and in vivo models. The physicochemical characterization of the TiO2 NP was carried out using Dynamic Light Scattering (DLS), determining its hydrodynamic size, zeta potential and polydispersity index (PdI), Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and High-Resolution Scanning Electron Microscopy (SEM-FEG). For the in vitro model, the LA-9 fibroblast lineage was used and cytotoxicity was evaluated for the concentrations of 250, 150 and 50 μg/mL using the cell viability assay (MTT) and cell morphology analysis after exposure to TiO2 NP for 24, 48 and 72 hours. After exposure to TiO2 NP for 24 hours, intracellular production of Reactive Oxygen Species (ROS), production of cytokines IL-6 and TNF in the cell supernatant by ELISA and cell death by flow cytometry were also evaluated, as well as clonogenic survival 7 days after exposure. In the in vivo model, Balb/c mice were exposed intranasally to TiO2 NP (500, 250, 100 and 50 μg/animal) in 4 doses over 14 days. Throughout the exposure period, the animals' feed and water intake and weight variation were assessed. Subsequently, leukocyte levels were analyzed in the blood, bronchoalveolar lavage (BAL) and peritoneal cavity lavage (PCL), quantification of cytokines (INF-ɤ, TNF, IL-6 and IL-10) in plasma and BAL and IgE antibody in BAL by ELISA, evaluation of liver function (TGO/TGP), weighing of the lungs and histological analysis of the organs (brain, lungs, heart, liver, spleen and kidneys). Our results showed that NP TiO2 is functionalized with sodium carboxylate ligands and suggests that it has an anatase crystalline form, as well as heterogeneous dispersion and a hydrodynamic size of around 3.5 nm in water and 2.96 nm in PBS, increasing to 7.62 nm in DMEM medium due to the agglomeration process. For the LA-9 fibroblast cell line, there was a reduction in cell viability (250 and 150 μg/mL) dose and time-dependent as well as oxidative stress and cell death by apoptosis (150 μg/mL). For the 150 μg/mL concentration there was a possible cell recovery after the NP was removed. In the in vivo model, NP generated histopathological changes in the brain, lungs, liver and kidneys of Balb/c mice after intranasal exposure with 4 doses over a period of 14 days. No changes were observed in the other parameters evaluated, with the exception of an increase in TGO at a concentration of 250 μg. The results of this study showed that NP TiO2 functionalized with sodium carboxylate has cytotoxicity for the LA-9 fibroblast line and toxicity with histopathological alterations for the brain, lung, liver and kidneys in Balb/c mice, contributing to knowledge about the effects of this NP TiO2 in in vitro and in vivo models. It is also interesting to analyze long-term exposure in order to determine the safety of using this nanomaterial.
Práticas pedagógicas nas escolas multisseriadas do campo: para além da seriação
(Universidade Federal de São Carlos, 2023-11-30) Tardivo, Pamela; Santos, Maria Cristina dos; https://lattes.cnpq.br/1095065753077001; https://orcid.org/0000-0003-3130-9433; https://lattes.cnpq.br/4509668710004516
Multigrade classrooms are a historical reality in rural education, whether in multigrade schools or not. As a rule, it often ends up being the only way the State is present in communities, as well as the sole means of access to school education. The main characteristic is catering to students of different ages and educational levels, instructed by a single teacher. Despite being a reality across the country, it is still viewed with much prejudice and often relegated to the background by public authorities. This neglect is responsible for the scarcity of public policies aimed at improving these schools. This study aims to identify and analyze the pedagogical practices carried out in multigrade classrooms in rural schools based on the academic production available, examining to what extent they adapt to the specific nature of this form of teaching or conform to the graded paradigm. The theoretical framework relies on the contributions of Salomão Hage and Dermeval Saviani. The methodology of this study was developed based on a bibliographic research collected from data obtained through consultations in the INEP (National Institute of Educational Studies and Research) database and Google Scholar (books and articles), as well as the selection of 17 dissertations and 03 theses from the CAPES (Coordination for the Improvement of Higher Education Personnel) theses and dissertations database. The research findings show that school education offered in multigrade rural schools presents recurring pedagogical and infrastructural problems. Additionally, there is a lack of adequate teacher training and minimal attention from educational public policies, often leaving these schools aside and even viewing them as marginalized education. In most cases, the complexity of pedagogical work in these classrooms is not considered in the Pedagogical Political Projects (PPPs) and generally conforms to the urban graded model. Therefore, it is necessary to take a closer look at these multigrade classrooms/schools to develop pedagogical practices specifically geared towards multigrade rural education, practices that take into account the reality, specificities, and particular issues of these students. It's also imperative to have public policies focused on multigrade education to address all the difficulties encountered in this teaching organization, including teacher training.
Investigações sobre uma língua profissional: uma leitura discursiva de publicações na rede social LinkedIn
(Universidade Federal de São Carlos, 2023-11-30) Quenzer, Viviane; Araújo, Lígia Mara Boin Menossi de; https://lattes.cnpq.br/7893136450669304; https://lattes.cnpq.br/7745877430495073
This master's thesis focuses on understanding the discursive construction of a Top Voice's prescriptive publications on the normative use of the Portuguese language, produced and broadcast in a digital environment, more specifically on the professional social network LinkedIn. For our investigation, based on the regularities observed, we divided the posts into three scenographies: coach, trainer and self-help. All these posts are about writing and communication for the corporate environment. Our aim, based on the analysis of authorial productions on the web, is to reflect on (i) the influence of web 2.0 on the production of discourses, (ii) what language is being spoken about and (iii) the scenography used to disseminate this language. To do this, we draw on the theoretical and methodological writings of Dominique Maingueneau (2015), especially the notion of Scenes of Enunciation, with a focus on topical and non-topical units for the analytical path, and the concepts covered in the book Digital Discourse Analysis: a dictionary of forms and practices by Marie-Anne Paveau (2021) to describe the LinkedIn social network and how publications on this network work. We will also give a brief theoretical outline of the structuring concepts of Discourse Analysis from the book Discourse and Discourse Analysis by Dominique Maingueneau and Popular Linguistics by Marie-Anne Paveau in France and Roberto Leiser Baronas in Brazil, in order to begin to outline this interface between Discourse Analysis and Popular Linguistics in relation to our analysis material. For the analysis itself, we selected the business profile and 13 authorial publications of Dalva, elected in 2020 as LinkedIn's Top Voice. In conclusion, the work showed that the discourse on the cultured norm of the language, the one supported by grammars, takes on a new guise in the digital environment, on a social network that connects people with professional themes, and that, through a unique discursive production, that is, specific scenographies, allows this transposition to be advocated, building a different relationship from that of books, closer to the subjects, and that it is a different language, aimed at the corporate environment.
Dinâmica de spin no comportamento do exciton
(Universidade Federal de São Carlos, 2023-11-30) Contreras, Jhon; Richard, Victor Lopez; https://lattes.cnpq.br/4492188799583104; https://lattes.cnpq.br/9549906259461838
This thesis presents a study on the spin dynamics of confined excitons under the influence of a magnetic field. Experimental observations reveal unique correlations between Zeeman splitting and spin thermalization, which can be tuned to both temperature and incident light power. The theoretical model, which considers the eventual spin thermalization of bright excitons, qualitatively agrees with the experimental observations and highlights the importance of the exchange interaction. Furthermore, this study goes beyond previous approaches, offering additional insights into spin relaxation and the effects of correlations between bright and dark excitons. Two fundamental conclusions are derived from this work: first, it is shown that the spin dynamics of excitons confined under a magnetic field can be tuned by both temperature and incident power. Second, it is noted that the polarization of the electrons is not appropriate to adjust the experimental curve of the degree of optical polarization, since under the same approximations it is obtained that the optical polarization is zero. These conclusions provide valuable insights for interpreting experimental measurements and guiding future investigations into the spin dynamics of excitons in confinement.