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Interfacial engineering of van der Waals heterostructures: impacts on the excitonic and valley properties
(Universidade Federal de São Carlos, 2024-08-27) Brito, Caique Serati de; Barcelos, Ingrid David; https://lattes.cnpq.br/8297155290206349; https://orcid.org/0000-0002-5778-7161; Gobato, Yara Galvão; https://lattes.cnpq.br/7558531056409406; https://orcid.org/0000-0003-2251-0426; https://lattes.cnpq.br/7229755502198114; https://orcid.org/0000-0003-3992-1731
The study of two-dimensional (2D) materials has attracted significant attention due to their unique physical properties and potential applications in optoelectronics, spintronics, and quantum technologies. Transition metal dichalcogenides (TMDs) are a crucial class of these materials, offering exceptional electronic and optical properties, such as strong excitonic effects and valley selectivity. Additionally, the emergence of layered magnetic materials, such as CrSBr, has opened up new opportunities for exploring magnetic effects in 2D heterostructures. Combining various 2D materials through interfacial engineering enables the realization of unique properties, including superconductivity, Mott insulators, moiré effects, exciton hybridization, and single-photon emitters (SPE), providing unprecedented control over physical properties. This thesis investigates the optical properties of semiconductor TMD monolayers in van der Waals heterostructures (vdW-HS), focusing on their excitonic and valley properties. Through systematic studies of photoluminescence (PL) and magneto-PL, the research explores the impact of local and smooth strain, charge transfer, moiré patterns, and magnetic proximity effects on these properties. Our findings demonstrate the generation of SPEs in WSe2 monolayers transferred to polished borogermanate glass doped with Tb3+. The nanoroughness of the glass surface, resulting from polishing, imposes a local strain on the TMD, directly influencing SPE formation. Moreover, the substrate morphology, modified by Tb3+ doping, plays a crucial role in the hybridization between defect-localized and dark excitonic states, as evidenced by magneto-PL measurements in Voigt geometry. The impact of moiré patterns in MoSe2/WS2 heterostructures with stacking angles of 0º and 60º was studied using circularly polarized magneto-PL measurements. The obtained g-factors were very similar for both high-symmetry angles, indicating weak hybridization of the conduction bands. Additionally, PL peaks at lower energies exhibited reduced g-factors, suggesting exciton confinement due to the moiré potential. These results are consistent with the developed theoretical model, which predicts weak hybridization due to type I band alignment. The combination of MoSe2 monolayers with CrSBr, an antiferromagnetic material with in-plane magnetic ordering, revealed that the PL peaks of MoSe2 acquire linear polarization orthogonal to the anisotropic emission of CrSBr, with an enhanced effect in the ferromagnetic phase. Circularly polarized PL measurements were conducted with magnetic fields ranging from -9 to 9 T along the three principal crystal axes of CrSBr. The study revealed that the intensity variations of the MoSe2 exciton and trion peaks closely follow the behavior of CrSBr, reflecting the transition from antiferromagnetic to ferromagnetic ordering. These variations were attributed to charge transfer effects and type III band alignment. The valley Zeeman effect was also observed, with distinct g-factors for positive and negative magnetic fields, indicating asymmetric coupling for the K and K’ valleys of MoSe2 to the magnetic ordering of CrSBr. These findings highlight the complex interaction between TMD monolayers, layered magnetic materials, and their interfaces, demonstrating how interfacial engineering can be employed to modulate physical properties in 2D systems. This research contributes to the understanding of condensed matter physics and suggests pathways for integrating 2D materials into advanced quantum information and spintronic technologies.
O aporte da neurociência na concepção de desenvolvimento humano da fundação Maria Cecília Souto Vidigal: uma análise crítica
(Universidade Federal de São Carlos, 2024-08-27) Oliveira, Vinícius Bertazini de; Magalhães, Giselle Modé; https://lattes.cnpq.br/2726281356078379; https://orcid.org/0000-0003-4045-7040
Given the prominent presence of the Maria Cecilia Souto Vidigal Foundation (FMCSV) in the political and educational field of São Paulo, it is essential to understand its origins, movements, proposals for education and the theoretical bias that underpins its projects. Thus, after a scientific initiation research in which we understood that the conception of human development of this foundation is based on the assumptions of neuroscience, the objective of this final course work was to understand what the so-called neurosciences are and what they are within the area of education. Based on a documentary analysis and under the assumptions of Historical-Cultural Psychology, based on Historical-Dialectical Materialism, it was found that this is a very broad area of knowledge that has been increasingly branching out within the human sciences. We understand the need for neuroscientific studies, but we emphasize the importance of not understanding them dislocated from the social reality that produces them so as not to run the risk of falling into organicist explanations for human development and learning. We also understand that the FMCSV aims to train human beings useful to the capitalist process, which requires the observation that the neuroscientific arguments present in the analyzed documents corroborate the international neoliberal and market-oriented agenda. The research proves that there is a movement in the educational field, promoted by the private sector, to maintain the neoliberal nature of Brazilian society.
Data of "Hydride Destabilization in the Ti–Nb–Cr System Through Nb/Ti Ratio Adjustment"
(Universidade Federal de São Carlos, 2024-08-27) Dias, Gabriela Chimello Mayer; Silva, Bruno Hessel; Martins, Alice de Sousa; Felderhoff, Michael; Botta, Walter José; Zepon, Guilherme; https://lattes.cnpq.br/7085380229734116; https://lattes.cnpq.br/6735270859581901; https://lattes.cnpq.br/3488830080839093; https://lattes.cnpq.br/8956458007749112; https://lattes.cnpq.br/7924187202036614; https://orcid.org/0000-0001-9526-3943
Desenvolvimento e construção de plataformas analíticas portáteis para detecção de RNA viral visando o diagnóstico de doenças infecciosas
(Universidade Federal de São Carlos, 2024-08-27) Santos, Daniel Júnior Almeida dos; Faria, Ronaldo Censi; https://lattes.cnpq.br/8659496864305621; https://orcid.org/0000-0003-1094-9597; https://lattes.cnpq.br/8161817151331695; https://orcid.org/0000-0002-8537-5797
Viral respiratory infections represent a major threat to the health of the population around the world. In many cases, COVID-19 presents symptoms that can be confused with Influenza, a disease caused by the Influenza A virus. A simple, rapid, and selective assay, capable of identifying the etiological agent and differentiating the diseases, is essential to provide the correct management clinician to the patient. Here, we describe the development of a genomic assay for the selective capture of SARS-CoV-2 and Influenza A virus RNA in saliva samples using two portable analysis systems, consisting of a platform for electrochemical detection (PDE) and a platform with digital image detection (PID). The proposed methods showed excellent performance in the detection and quantification of viral RNA, with PDE presenting a limit of detection (LoD) and limit of quantification (LoQ) of 5.0 fmol L-1 and 8.6 fmol L-1 for SARS-CoV-2 and 1.0 fmol L-1 and 108.9 fmol L-1 for Influenza, respectively. PID was applied to detect the Influenza A virus and presented LoD and LoQ for 0.093 pmol L-1 and 0.310 pmol L-1, respectively. Genomagnetic assays were used to evaluate the presence of viruses in 36 saliva samples from volunteers and the results were in agreement with those obtained by reverse transcription polymerase chain reaction (RT-PCR), demonstrating the viability of the proposed methods for diagnosis. of COVID-19 and Influenza with point-of-care capability.
Saúde mental de jovens adultos: presença da arte e do lazer no cotidiano e na Terapia Ocupacional
(Universidade Federal de São Carlos, 2024-08-27) Carvalho, Luana Mara Nunes de; Fornereto, Alana de Paiva Nogueira; https://lattes.cnpq.br/0361502737203825
The use of art as a therapeutic tool in Psychosocial Care Centers (CAPS) is widely applied, but how do the users themselves perceive this practice in their daily lives? This raises the need to investigate the presence of art in the daily lives of young people who utilize mental health services and to understand how this artistic interaction influences their treatment processes. Although the scientific literature recognizes the relevance of art in this context, it still lacks deeper analyses from the users' perspectives. The motivation to explore this topic lies in the search for a broader understanding of how art integrates into these young people's lives, their access to cultural and leisure activities, and the role they play in society. Objective: To analyze the impact of art on the mental health of young people served by CAPS, aiming to understand how it contributes to their well-being, its presence in their daily lives, and the participants' perceptions of access to and the significance of art in their lives. Methodology: The present study employed the Photovoice methodology, a participatory and qualitative method that allows participants to reflect on their challenges, visually document these aspects, and share the meanings attributed to the images. This approach promotes a deeper understanding of the issues addressed and facilitates the development of intervention strategies and engagement with policymakers.
Combinar o corte de trepadeiras com o plantio de mudas de árvores é a melhor estratégia para restaurar as bordas de florestas estacionais semideciduais
(Universidade Federal de São Carlos, 2024-08-27) Santos, Guilherme Aparecido Melo; Viani, Ricardo Augusto Gorne; https://lattes.cnpq.br/3250752369062840; Martini, Valéria Forni; https://lattes.cnpq.br/0686674300788674; https://lattes.cnpq.br/8489466565648580
Due to the negative impacts of overabundant climbers on the structure of tropical forests, it is necessary to restore and manage degraded fragments. Climbers become extremely abundant in degraded tropical forest fragments, creating a significant demand for ecological restoration. In these cases, the main restoration strategy has been climbing plants cutting, but it is still necessary to understand the outcomes of cutting in combination with the planting of native tree seedlings (cutting + planting), especially at the edges of fragments, which are subject to greater disturbances than the forest interior. We tested whether cutting + planting is the best strategy to restore a degraded edge of a Semideciduous Seasonal Forest fragment in southeastern Brazil. To do this, we used mixed linear models to evaluate the effect of cutting + planting, cutting, and no management (control) on the density and basal area of climbers, the density and basal area of trees, the percentage of dead trees, and the density, species richness, and diversity of seedlings 8 years after the start of the experiment. Cutting + planting resulted in the greatest decrease in climbing plants density and basal area, and the greatest increase in tree density and seedling diversity. Although cutting + planting reduced the percentage of dead trees and increased seedling richness, these variables were more affected by cutting alone. Management had no effect on the basal area of trees and the density of seedlings. This study provides evidence that cutting climbers combined with planting native tree seedlings is the best strategy to restore degraded edges of tropical seasonal forests, as it reverses the trajectory of increasing dead trees and decreasing tree density and diversity resulting from the excessive abundance of climbers.
Formação docente e o ensino de ciências: uma reflexão sobre os anos iniciais
(Universidade Federal de São Carlos, 2024-08-27) Costa, Jessica Yule da; Silva, Fernanda Keila Marinho da; https://lattes.cnpq.br/6390725197649567; https://lattes.cnpq.br/2001871263919209
The teaching of Science in the early years of basic education is fundamental for the construction of scientific knowledge and for the formation of citizens capable of making informed choices, recognizing the broad connections between science, technology, society, and the environment. The introduction of this knowledge helps build a solid foundation for future studies. However, for this to happen, it is essential that teachers, especially those with a degree in pedagogy, receive adequate training that enables them to teach scientific topics confidently. The presented research aims to analyze and discuss teacher training for Science education at this stage of schooling, based on educators' perceptions. This is a qualitative study whose target audience consisted of teachers from primary schools in the public education system of the metropolitan region of Sorocaba. The study involved 14 teachers from state and municipal schools, who answered a questionnaire about their perspectives on Science teaching, their training, and their classroom practice. The data collected were analyzed using content analysis, contributing to a reflection on the initial and ongoing training of pedagogy graduates for teaching Science. The results indicate that although teachers consider Science education essential, they emphasize the need for more robust training, both initial and continuous, that enables the construction of solid knowledge for effective educational practice, addressing the various areas of scientific knowledge.
Bases para uma Educação Menstrual Popular e LGBTQIAPN+
(Universidade Federal de São Carlos, 2024-08-27) Chacon, Za Saggioro; Teixeira, Iraí Maria de Campos; https://lattes.cnpq.br/8274452304759860; https://lattes.cnpq.br/7840481666604266; https://orcid.org/0009-0005-1237-1807
This research arises in response to the lack of pedagogical references about a menstrual approach that includes the diversity of bodies that bleed, beyond the existing social boundaries of the term “people that menstruate”. It can be described also as a manifest from a nonbinary author searching for non cis-heterocentric answers for his menstrual experience. There is a scientific theoretical apparatus that describes the body that bleeds, anchored on discourses by the church, medicine, psychiatry and psychoanalysis, together with conceptions of gender that are based on the dictatorship of sexual difference. Both cis women, the universal subject, and trans people, have a history of definitions, narrated by these same institutions, from a pathological bias. The difference is that only the first is related, in an essentialistic and stigmatized way, to the experience of bleeding. The goal, given this scenario, is to propose menstrual practices and the search of educational processes that could contribute to a more popular and inclusive menstrual approach from the perspective of the diversity of bodies that bleed. As it is a study intrinsically linked to the principles of Educação Popular em Saúde (EPS), data collection was adapted to the conext demands and included a moment of participatory investigation and an autoethnographic narrative about my gender transition to better represent the exchanges that constructed the research. As a result of this process, foundations were determined for any space that wishes to discuss menstruation in a popular and LGBTQIAPN+ centric approach, paving the way for the construction of practices committed to a trans-referenced and post-heterocolonialist epistemology, as well as the design of a game that encourages menstrual debates.
Estudo ultrassonográfico do tendão de Aquiles de bailarinos assintomáticos: explorando as relações entre estrutura e medidas clínicas
(Universidade Federal de São Carlos, 2024-08-27) Tessarin, Bruna Mariana; Nunes, Guilherme Silva; https://lattes.cnpq.br/0722121177593722; https://orcid.org/0000-0001-9412-3236; Serrão, Fábio Viadanna; https://lattes.cnpq.br/8137335642635433; https://orcid.org/0000-0003-3655-9933; https://lattes.cnpq.br/2650518570167977; https://orcid.org/0000-0003-4967-1959
The central theme of this thesis is the study of structural changes in the Achilles tendon in classical ballet dancers. When a tendon is subjected to mechanical loads, it can respond positively (adaptation) or negatively, leading to tendon pathologies. These pathologies are structural changes observed via ultrasonography, characterized by tendon thickening and the presence of focal areas of low echogenicity, indicating collagen fibre disorganization. Tendon pathologies are found in individuals with tendinopathy and asymptomatic individuals. In the latter case, these individuals have a sevenfold increased risk of developing tendon pain. Classical ballet dancers belong to this group, exhibiting high frequencies of tendon pathologies. Modifiable clinical factors, such as plantar flexor strength, dorsiflexion range of motion, and subtalar pronation, are related to the occurrence of Achilles tendinopathy. However, the relationship between these measures and the presence of tendon pathologies in asymptomatic individuals is unclear. Thus, early identification of these pathologies, before symptom development, may offer an additional prevention opportunity. It is also known that the practice of dance places high loads on the Achilles tendon, but the long-term effect of this overload on the development of tendon symptoms is not well understood. Besides Achilles tendon impairments, the ankle joint is the region with the highest incidence of injury in dancers. Therefore, other structures in this region may be overloaded, resulting in posterior ankle pain, a common clinical presentation among various ankle conditions. Correct identification of the pain source is essential for effective therapeutic approaches and good prognoses. Based on the above, this thesis aimed to address some of the gaps presented. Study 1 was a cross-sectional study aimed at investigating the predictive value of clinical measures commonly associated with Achilles tendinopathy in identifying tendon pathologies in asymptomatic dancers. Study 2, using a longitudinal design, explored the structural response of the Achilles tendon, using Ultrasound Tissue Characterization (UTC), during the rehearsal and performance season of the repertoire ballet "Swan Lake." We also investigated clinical outcomes after 4 months as symptoms in the posterior ankle region through a comprehensive and differential clinical evaluation. The results from study 1 highlighted the importance of hip strength in Achilles tendon structure and indicated that interactions between hip torque and ankle dorsiflexion were associated with the presence of tendon pathology. In study 2, findings showed that the rehearsal and performance period did not adversely affect the Achilles tendon structure, and in the long term, few dancers developed clinical signs of tendinopathy when using the assessment tool presented in the study. This thesis provides new insights that can be implemented in clinical practice and incorporated into research methodologies.
Modelos para análise de textos: um comparativo do número de tópicos
(Universidade Federal de São Carlos, 2024-08-27) Coelho Filho, Edvaldo Capobiango; Zuanetti, Daiane Aparecida; https://lattes.cnpq.br/8352484284929824; https://lattes.cnpq.br/8395942173646672
Text modeling has gained significant visibility and popularity in recent years due to the large and ever-increasing amount of information present in daily life, consumed in various ways. For the efficiency and applicability of these models, the prior step of data preprocessing is of utmost importance, as it helps in the organization and treatment of texts. One branch within text analysis is topic modeling, whose methodologies aim to understand the topic structure that forms a document, segmenting multiple documents by their dominant topics (subjects) and thus simplifying the exploration of large volumes of textual data with the resulting dimensionality reduction. One of the pioneering methods in this context is the Mixture Model (MM), which assumes that each document will be composed of words from a single topic. Given this limitation, the technique of Latent Dirichlet Allocation (LDA) has gained considerable visibility due to its greater flexibility, as it allows each document to exhibit multiple topics. In both methodologies, model inference is generally given via a Bayesian approach. However, one of the characteristics of MM and LDA is the requirement that the user define the number of topics in the model from the outset. Therefore, the use of performance metrics becomes necessary after the application of the method, aiming to help in the definition and estimation of the best number of topics to be chosen. In this work, therefore, in addition to contrasting text analysis methodologies, we compare the metrics that measure the quality of the models and are used for choosing the number of topics. To do this, we apply the models and selection metrics to two sets of real data.
Flumioxazina isolada e em associações no controle de plantas daninhas e sua dinâmica em palha, textura de solo e simulação de lâminas d’água
(Universidade Federal de São Carlos, 2024-08-27) Carvalho, Diego Vinícius de; Monquero, Patricia Andrea; https://lattes.cnpq.br/2766526793830455; https://orcid.org/0000-0002-9123-1861; https://lattes.cnpq.br/9531268232643008; https://orcid.org/0009-0008-6004-1732
Mechanized sugarcane harvesting can influence the weed population and modify the chemical and biological characteristics of the soil. The residual straw on the surface may hinder the penetration of pre-emergent herbicides, affecting control efficacy. In this scenario, the use of pre-emergent herbicides, combined with different molecules, becomes essential to optimize weed management. The dynamics of herbicide action are influenced by the amount of straw, soil texture, and water sheets (intervals before the first rain), factors that affect the transposition and persistence of the product in the soil. The objectives of the study were: i) To identify the interactions and effects of herbicides applied in combination with flumioxazin for controlling the main weeds present in sugarcane crops; ii) To analyze the persistence of flumioxazin in different soil textures; iii) To evaluate the influence of the amount of sugarcane straw and the intervals before the first rain on the efficacy and persistence of the product. The study was divided into two stages, with both experiments conducted in a greenhouse in a completely randomized design with four replications. In the first stage, six experiments were conducted (one for each weed species), using the following weeds: Rottboellia cochinchinensis (Loureiro) W.D. Clayton, Urochloa decumbens (Stapf) R.D. Webster, Digitaria horizontalis (Willdenow), Merremia aegyptia (Linnaeus) Urban, Merremia cissoides (Lamarck) A.R. Simões & Staples, and Ipomoea triloba (Linnaeus) var. genuina (Meisner). The experiments were organized in a factorial scheme of 8 x 5, with factor A consisting of 8 herbicide treatments (flumioxazin alone and in combination with ametryn, diclosulam, imazapic, isoxaflutole, metribuzin, metsulfuron-methyl, and S-metolachlor) and factor B consisting of 5 intervals between herbicide application and weed seeding (0, 10, 30, 40, and 60 days). In the second stage, two experiments were set up, one in medium-textured soil and another in clayey soil, using I. triloba as the weed species. The experiments were organized in a 9 x 2 factorial scheme, with factor A consisting of 9 treatments simulating the intervals between herbicide application and weed seeding, with and without simulated rainfall (0, 15, 30, 40, and 60 days, 15 days without rain, rain simulation followed by 15 more days without rain, repeating the same intervals for 30, 40, and 60 days). Factor B consisted of two treatments, representing the amount of sugarcane straw on the soil surface (0 and 10 t ha-1). Additionally, untreated controls were included, with and without straw. In both stages, the variables evaluated were weed control (%) and reduction of dry shoot biomass of the species. The combination of flumioxazin with other herbicides provided efficient control (>90%) of the evaluated species up to 10 days after application (DAA). The combination of flumioxazin + metribuzin maintained satisfactory control up to 60 DAA for I. triloba, M. aegyptia, M. cissoides, D. horizontalis, and R. cochinchinensis, and up to 40 DAA for U. decumbens. All treatments reduced the dry shoot biomass of R. cochinchinensis by more than 90%. In medium-textured soils, flumioxazin had residual activity of up to 60 days for controlling I. triloba without straw, regardless of precipitation. With 10 t ha-1 of straw, the residual activity varied between 55 and 60 days, with or without rain. In clayey soils without straw, residual activity was less than 40 days without rain and 55 days with precipitation. In the presence of 10 t ha-1 of straw, control was maintained for up to 60 days without rain and 75 days with precipitation. The combination of flumioxazin with other herbicides increases the residual period and improves weed control efficacy. In clayey soils, flumioxazin shows greater variation in response depending on the presence or absence of straw and precipitation.