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Modelos de branas em (5+1) dimensões e o espectro dos leptóns carregados
(Universidade Federal de São Carlos, 2023-10-27) Gauy, Henrique Matheus; Bernardini, Alex Eduardo de; https://lattes.cnpq.br/5215976260958847; https://orcid.org/0000-0001-7357-5479; https://lattes.cnpq.br/1412367289023716; https://orcid.org/0000-0003-0067-9570
This manuscript is concerned with a mechanism for explaining the mass spectrum of the charged leptons within (5 + 1)-dimensional braneworlds. As a preliminary objective, new two co-dimensional thick braneworlds ought to be proposed and investigated. By considering a twofold-warp factor constructed from two intersecting warp factors and scalar fields that generates the extra dimension defect, an alternative bulk configuration is examined. With the brane localization thus driven by two crossing scalar fields, the possible solvable models obtained from such a two co-dimensional setup are systematically discussed. The obtained solutions are classified into two subsets, string and intersecting-like. The intersecting-like models are sorted in six different models organized into two subsets for which some of their physical properties are evaluated. For models I and II , in the first subset, Einstein equation solutions are rigidly defined, up to some arbitrary constant. For models III , IV , V and V I , in the second subset, an additional degree of freedom not constrained by Einstein equations is admitted. For all intersecting-like models, gravity and standard matter fields are shown to be localized in the vicinity of the brane. Finally, by studying the zero modes of leptons, which are localized by the inclusion of a non-trivial gauge field, over asymmetric versions of the classified braneworlds, one is able to model the masses of the electron, muon and tauon based on two parameters: the gauge field strength and the ratio between the sizes of the co-dimensions.
Língua exótica: a libras como um dispositivo de condução
(Universidade Federal de São Carlos, 2023-10-27) Nascimento, Gabriel Silva Xavier; Martins, Vanessa Regina de Oliveira; https://lattes.cnpq.br/4768682330164550; https://orcid.org/0000-0003-3170-293X; https://lattes.cnpq.br/4507944299087617; https://orcid.org/0000-0001-9308-7296
Based on the concept of exoticization as a technique of existence-driving, this thesis analyzes the historical trajectory and discursive practices that shaped linguistic governance in the history of deaf education in Brazil. It is a documentary bibliographical research that relies on compiling a historical archive encompassing the proceedings and supplementary records from international congresses about deaf education between 1878 and 1980. The main objective is to construct the exotic and linguistic exoticization concept to examine how the historical trajectory and discursive practices in the history of deaf education enabled forms of governmentality. The specific objectives are: i) Conceptually structure exoticization as a lens for analyzing discursive practices; ii) Delimit the idea of a historical archive as a multifaceted set of organized sources for weaving history; iii) Engage in reflections on how perspectives on sign languages allow for the emergence of alternative ways of being deaf. The archive's bibliographical materials allow for an exploration of the Brazilian colonial period to the machinery of linguistic governance of the Modern State, with its reverberations on the sociopolitical aspects of deaf people and Brazilian Sign Language - Libras. The reflections are woven within the scope of authors in Foucauldian Studies, Deaf Studies, and Historical Sociolinguistics, employing the concepts of governmentality and counterconduct as analytical tools. The notion of the exotic is conceived as an invention strengthened by colonial invasions to characterize groups diverging from the white-European sociocultural standard. Thus, the practice of a understanding marked by exoticization takes on three historical facets: colonial exotic – focusing on the domination and exploitation of labor; docile exotic – focusing on the capture and docility of bodies subjected to State machinery and; counter-conduct exotic – focusing on the protagonism and subversion of governance techniques for historical reclamation and self-management for a deaf way of being in and through sign language. The thesis contributes to a modern understanding of Libras as an exotic language, i.e., a philosophical perception denoting an existence marked by governmental strategies that not only subject but also produce resistance and counterconduct among Brazilian deaf individuals, enabling the maintenance of deaf life within difference, operating within inclusive rationality. Keywords: Special Education; Deaf Education; History; Exoticization.
Revisão bibliográfica: erros causados por raios cósmicos em dispositivos eletrônicos
(Universidade Federal de São Carlos, 2023-10-27) Paulo, Isabella Moreira de Sousa; Galeti, Helder Vinicius Avanço; https://lattes.cnpq.br/3876752605313288; https://orcid.org/0000-0002-5217-8367; https://lattes.cnpq.br/4096799016142464; https://orcid.org/0009-0007-7335-0510
Cosmic rays, coming from outer space, can penetrate eletronic devices in order to change several characteristics such as functioning, performance and useful life. These particles are composed of an atomic nuclei, made up of ultra energetic protons and neutrons, that travel at high speeds towards the earth's surface, due to their high energy they can easily penetrate electrical and electronic components. These effects are easily found at higher altitudes, but can be observed at sea level on a smaller scale. With the advancement of microelectronics, the collision of these particles with electronic components generates a parasitic electrical charge that harms the operation of several devices, from memories, power electronics to relays and supercomputers. Thus, the purpose of this work is to report and provide an in-depth understanding of the influence of cosmic rays on the operation of electrical and electronic components, through a review of data available in the literature. The aim is to assess the impact on the operation of electronic components, electrical devices, and the advancement of new technologies.
Funcionalidades elétricas mediadas por defeitos em óxidos semicondutores do tipo-p
(Universidade Federal de São Carlos, 2023-10-27) Silva, Ana Luiza Costa; Godoy, Marcio Peron Franco de; https://lattes.cnpq.br/2609654784637427; https://orcid.org/0000-0002-8376-8642; https://lattes.cnpq.br/6209435717853686; https://orcid.org/0000-0002-3692-5828
Structural defects, such as point defects, play an important role in the electrical transport in semiconductor oxide films. This work presents a systematic study of photoconductivity at room temperature in thin films of Co3O4 as well as ZnO doped with different sodium contents. Polycrystalline samples grown by spray pyrolysis exhibit positive photoconductivity. Both Co3O4 and ZnO films underwent thermal treatment under different controlled atmospheres. The aim was to explore the modifications that annealing can induce in defects, subsequently affecting structural, morphological, optical, and electrical attributes. The thermal treatment of the Co3O4 films was carried out under controlled atmospheres such as Ar, N2, O2, and synthetic air. After tuning the excitation energies, we performed photoconductivity measurements that provided insights into the optical absorption edges of the oxide (Co2+ and Co3+). We also evaluated the effect of different atmospheres on photoconduction measurements. Inherent defects within ZnO result in charge compensation effects and play a role as transport traps when exposed to light excitation. Sodium doping triggers a conductivity switch from n-type to p-type within specific temperature ranges. Photoconductivity measurements of ZnO:Na films were conducted using excitation above the material's absorption edge. In this scenario, the sample containing 10% Na displayed the most remarkable photoresponse. Annealing in different atmospheres shows significantly faster responses of the highly transparent films in visible light. Additionally, we analyzed the resistive memory effects of the ZnO doped with 10% sodium as well as the influence of the atmosphere on the film's memristive responses.
Estudos do tratamento de águas residuárias do café usando coagulação e processos de oxidação avançada
(Universidade Federal de São Carlos, 2023-10-27) Colpa, Poliana Coste e; Bocchi, Nerilso; https://lattes.cnpq.br/5930614700886481; https://lattes.cnpq.br/8098870460818023
"STUDIES ON COFFEE WASTEWATER TREATMENT USING COAGULATION AND ADVANCED OXIDATION PROCESSES" Brazil leads global coffee production, accounting for more than one-third of the global production and playing a crucial role in the national economy. Post-harvest coffee bean management includes the wet processing method. The residues generated in this process are known as coffee wastewater (CWW). Therefore, it is necessary to study an alternative treatment for the CWW generated in the wet processing of coffee produced at IFSULDEMINAS, Campus Muzambinho. This work proposes the treatment of CWW using coagulation and Advanced Oxidation Processes (AOPs) as treatment methods. Initially, it was necessary to analyze some parameters of the CWW samples, such as: total solids mass concentrations, total suspended solids, total volatile solids, turbidity, pH, conductivity, Chemical Oxygen Demand (COD), and Total Organic Carbon (TOC). Due to high turbidity values (279.0 NTU) and COD (9067.0 mg L-1), it was adopted to always perform a coagulation pre-treatment using aluminum sulfate. This process removed about 97% of turbidity and 20% of COD from the CWW samples. For the electro-Fered-Fenton process, an electrochemical system was used (with a titanium anode coated with ruthenium dioxide and titanium dioxide (DSA – Dimensionally stable anode), and two AISI 304 stainless steel cathodes). In this treatment, it was possible to achieve a COD removal of approximately 78% and 95% turbidity removal. For the photo-electro-Fered-Fenton process, there was an efficiency of COD removal of around 86% and 95% turbidity removal. For comparison of treatment efficiency, the Fered-Fenton processes were used, obtaining a COD removal of about 83% and 95% turbidity removal, and photo-Fered-Fenton, where the COD and turbidity removal were 87% and 97%, respectively. These results indicate a better removal efficiency using the photo-Fered-Fenton treatment, which also shows a 70% TOC removal. Despite the slightly lower efficiency of the photo-electro-Fered-Fenton treatment, the photo-Fered-Fenton has a lower cost since it does not use electrical current and does not require an electrochemical system and electrodes, making the process simpler. With this treatment, the removal percentage recommended by current legislation is achieved, considering a minimum COD removal of 80%.
O enriquecimento ambiental previne comportamentos do tipo ansioso em camundongos submetidos ao modelo de empatia pela dor
(Universidade Federal de São Carlos, 2023-10-27) Carmona, Isabela Miranda; Oliveira, Paulo Eduardo Carneiro; https://lattes.cnpq.br/9776309560034777; Souza, Azair Liane Matos do Canto de; https://lattes.cnpq.br/2352004564367849; https://lattes.cnpq.br/2950733595921138
Empathy is the ability to share emotions, enabling the prediction and understanding of the feelings, actions, and motivations of others. In animal models, empathy can be studied through experimental protocols that investigate the behavioral reactions of conspecifics subjected to experiencing the suffering of their partners. In this context, data from our research group have shown an increase in anxiety-related behaviors in mice housed with conspecifics subjected to chronic sciatic nerve injury. These findings encouraged us to seek a non-pharmacological alternative to alleviate the impact of living with a partner experiencing chronic pain. Thus, the main objective of the present research was to analyze the effects of environmental enrichment (EE) on anxious behavior in mice exposed to the empathy for pain paradigm and tested in the elevated plus-maze (EPM). Additionally, we investigated the neuronal activation pattern of the basolateral and central nuclei of the amygdala, as well as the CA1 (cornu ammonis 1) subarea and dentate gyrus of the dorsal hippocampus. To achieve this, male Swiss mice were exposed to a 28-day cohabitation protocol. On the 21st day after birth (postnatal day; PND 21), mice were housed in pairs (observer and demonstrator) for 14 days to establish familiarity. On the 14th day (PND 35), all demonstrators underwent (constriction nerve injury demonstrator) or did not undergo (sham demonstrator) sciatic nerve constriction surgery. After this procedure, pairs were housed in either a standard environment (SE) or an environmentally enriched environment (EE). On the 28th day (PND 42), observer and demonstrator animals were exposed to the EPM. Our findings demonstrated that EE prevented the anxiogenic effect induced by the empathy for pain protocol. Furthermore, we observed that constriction nerve injury demonstrators showed increased anxiety-related responses, which were alleviated after exposure to EE. Interestingly, we noted that in constriction nerve injury demonstrators, EE significantly reduced thermal sensitivity, but did not eliminate it completely. Moreover, the constriction nerve injury condition was able to decrease activation in the dorsal hippocampus but not in the amygdala, both in the demonstrator and the observer. The data indicate that anxiety-related behaviors shared between partners were prevented in animals housed in enriched environments. This body of evidence sheds light on non-pharmacological interventions, such as adopting an environmental enrichment protocol, for managing behavioral changes, providing an effective strategy to mitigate consequences resulting from stressful contexts such as living with chronic pain.
Sinterização por métodos não convencionais e propriedades magnetoelétricas de compósitos nanoestruturados (1-x)BaZr₀‚₀₈Ti₀,₉₂O₃/(x)CoFe₂O₄ (0,10 ≤ x ≤ 0,50) livres de chumbo
(Universidade Federal de São Carlos, 2023-10-27) Caminata, Laís Pacheco; Kiminami, Ruth Herta Goldschmidt Aliaga; https://lattes.cnpq.br/7643216999108223; Eiras, José Antônio; https://lattes.cnpq.br/6653223814715498; https://lattes.cnpq.br/6407002611399130; https://orcid.org/0000-0002-5720-7438
Lead-free magnetoelectric composites have been widely investigated due to the current need for new potential applications in miniaturized devices. To this end, developing nanostructured materials and exploring their properties have attracted interest in the scientific field. In this context, the objectives of this thesis are obtaining nanostructured magnetoelectric particulate composites based on the system (1-x)BaZr0.08Ti0.92O3/(x)CoFe2O4 (BZT/CFO) (0.10≤x≤0.50), and analyzing their properties. For this purpose, nanopowders of the biphasic composites synthesized by the one-pot Pechini method assisted by microwave were used in the conventional sintering (CS), microwave-assisted sintering (MWS), and Spark Plasma Sintering (SPS). In an unprecedented way for this system, in addition to the concomitant study of the three sintering methods (CS, MWS, and SPS), the sintering kinetics for densification in the initial stage were evaluated. It was established that the activation energy for densification of the biphasic composite with a higher content of BZT (80BZT/20CFO) is higher than the composite with a higher content of CFO (50BZT/50CFO). The density values for all biphasic composites were higher than 91%, mainly influenced by the CFO content. The XRD structural analysis confirmed the presence of both BZT and CFO phases for 0.20≤x≤0.50, and small traces of spurious phases are predominant in composites sintered by CS and for lower proportions of CFO. Micrograph analysis confirmed the success in obtaining nanostructured composites, with significantly smaller values of average grain sizes provided by MWS and SPS sintering. The multiferroic properties were analyzed by ferroelectric and magnetic hysteresis loops. The coupling between the ferroic orderings was successfully verified for the nanostructured composites (1-x)BZT/(x)CFO (0.20≤x≤0.50). The highest values of magnetoelectric coefficients were observed for 80BZT/ 20CFO-CS and 50BZT/50CFO for MWS and SPS.
Análise da capacidade ao cisalhamento de paredes de contraventamento em alvenaria estrutural
(Universidade Federal de São Carlos, 2023-10-27) Tinoco, Vinícius Navarro Varela; Parsekian, Guilherme Aris; https://lattes.cnpq.br/7798651726059215; https://orcid.org/0000-0002-5939-2032; https://lattes.cnpq.br/7222549742841551; https://orcid.org/0000-0002-6033-3320
Structural masonry systems are widely used in civil engineering due to the popularization of this construction method and potential savings. Several shear resistance equations are presented in the national and international normalization, and are used by structural engineers for analysis and design of this structures in the matter of lateral load structure resistance. It is necessary too to analyze and compare the different standards so that they can advance at the same pace as scientific knowledge, adding greater fidelity to the expected behavior, combining safety with economy. Therefore, it becomes essential to carry out a comparative study between the regulations and the most faithful predictions available of the behavior of the masonry structure responding to lateral loading that can, based on analysis, add to knowledge and design. Aiming at this issue, the present work seeks to present the main differences between the regulations for the resistant design of masonry structures, seeking to add, from the finite element study, to the prediction of the behavior of structural partially grouted masonry, under the design of different vertical regions between openings. For this, a parametric study was carried out based on what is most current in the literature regarding structural masonry modeling to form the database that will be used in the validation of this work. Among the five norms used, it was possible to perceive the following increasing order of resistant lateral load: Eurocode by diagonal compression (EN 1996-1-1, 2005); Canadian (CSA S304, 2014); Eurocode for slippage (new proposition of EN 1996-1-1); American (TMS 402/602, 2016); Australian (AS 3700, 2018) and Brazilian (NBR 16868-1, 2020), with the American being the closest to the modeling results and the reliable equation used. The flexo-compression was evaluated, with no significant difference in values between the standards. Based on the evaluation of other standards, a correction was also proposed to the Brazilian standard for the following factors to make it more conservative: net area of the masonry section; initial shear strength value; and decrease of the friction angle to be considered in the precompression portion. The proposal makes the standard more conservative and uses calculation factors that are already used in other standards.
Síntese e avaliação de ligante geopolimérico “one-part” para aplicação em cerâmicas refratárias
(Universidade Federal de São Carlos, 2023-10-27) Reitmann, Bruno; Bezerra, Breno Parente; Luz, Ana Paula da; https://lattes.cnpq.br/3470395641242374
Refractory ceramics play a pivotal role in the development and operation of strategic industrial processes worldwide. Due to their high versatility and excellent performance in extreme service conditions, refractory concretes containing calcium aluminate cement (CAC) as a binder are widely used. However, the search for alternative materials with a reduced environmental impact has been actively promoted in recent years, with geopolymers or inorganic polymers being potential substitutes for CAC in such ceramics. This study aimed to assess the feasibility of partially or completely replacing this cement with a "one-part" geopolymeric binder in the production of refractory ceramics. This binder was produced by mixing colloidal silica and NaOH solution, followed by drying at 200°C. The solid activator and precursor were chemically and physically characterized to understand their effect on the final ceramic properties. In a subsequent stage, a composition of the reference concrete matrix (containing only CAC as the binder) was prepared and analyzed, along with others containing different CAC contents and/or geopolymeric binders. The evolution of the physical and mechanical properties of the samples was studied after curing at 40°C and after firing at 800, 1000, and 1250°C to comprehend the impact of composition and thermal treatment on the final properties of the refractories. To achieve this, tests were conducted to determine porosity, apparent density, elastic modulus, dimensional variation, mineralogical composition, and mechanical strength of the test specimens produced. The results indicated limited geopolymerization during curing, resulting in low mechanical performance (<1 MPa) in the geopolymeric matrices, compared to matrices containing only CAC (7.2 MPa). Unlike the cement-containing system, the presence of hydrated phases was not identified in the geopolymer-bound compositions, with unreacted raw materials remaining in the microstructure. After firing, the geopolymeric compositions achieved a significant increase in the modulus of rupture, reaching values of around 41 MPa, surpassing the performance of the reference concrete. The effective sintering via a liquid phase in the microstructure, coupled with the formation of nepheline in the geopolymeric matrix, justifies this improved behavior of the produced ceramics. Therefore, the addition of the "one-part" geopolymer as an alternative binder to CAC in refractory formulations has proven to be an advantageous option in terms of the thermo-mechanical properties of the matrices produced. However, additional investigations are required to optimize its performance at low temperatures to ensure its broad applicability.
Propriedades magnéticas e magnetoelétricas de compósitos multiferroicos de Pb[Zr0,53Ti0,47]O3/NixCo1-xFe2O4
(Universidade Federal de São Carlos, 2023-10-27) Dalla Costa, Leonardo José; Gualdi, Alexandre José; https://lattes.cnpq.br/5751113105751035; Oliveira, Adilson Jesus Aparecido de; https://lattes.cnpq.br/4640148190073166; https://lattes.cnpq.br/6408030533333566
New technologies are arising from the research and development of magnetism, especially those related to processing, information storage and sensors, are becoming increasingly important. in this regard, magnetoelectric multiferroic materials have been extensively tested for technological applications. Composite multiferroic materials are a combination of two materials with different ferroic orders, such as ferroelectricity and ferrimagnetism. In magnetoelectric compounds, magnetoelectricity is observed due to the mechanics between a piezoelectric material (ferroelectric phase), with a magnetostrictive material, such as ferrites. Ferrites can be made of different elements, like cobalt (CFO) and nickel (NFO), these two examples present opposite behavior in their coercive fields and decreasing values of remanent magnetization and saturation magnetization. Which results in different magnetostrictive responses. In this Ph.D. thesis we propose to study compounds of Pb[ZrₓTi₁₋ₓ]O₃ (PZT) with NixCo1-xFe2O4 ferrites (N/CFO) with 0≤x≤1, in the molar proportion of 80% PZT and 20% N /CFO with the aim of varying the magnetoelectric behavior of these compounds by varying the influence of modified Nickel or cobalt. The results obtained demonstrated that when synthesizing N/CFO ferrites it was possible to vary the effective anisotropy and, as a consequence, the magnetostrictive behavior of these ferrites. It should also be noted that the saturation magnetization of the compounds depends on the electrical polarization, being reduced by up to 15%, but without changing the coercivity, a drop that occurs due to the presence of a high electric field inside the composite can lead to a change in the valence of the ions of Faith. Magnetoelectric measurements as a function of the magnetic field frequency showed a change in the resonance frequency as a function of the Ni concentration of the ferrite. The results obtained indicate that the replacement of Co2+ by Ni2+ in ferrites structure have significantly alters the magnetoelectric properties of the investigated compounds.
Produção recombinante de proteínas de fusão de SARS-CoV-2 para fins de diagnóstico e imunização
(Universidade Federal de São Carlos, 2023-10-27) Astolfi, Bianca Soares; Silva, Flávio Henrique da; https://lattes.cnpq.br/1757309852446263; https://orcid.org/0000-0003-3329-4597; https://lattes.cnpq.br/4257095476683493
In the current COVID-19 scenario, there is still a demand for more effective diagnostic methods and improved immunization strategies. So far, the Receptor Binding Domain (RBD) of the Spike protein (S) has been the focus of diagnostic and immunization approaches. However, the Spike protein is susceptible to mutations, which can compromise current control strategies. In this context, this study aimed to produce recombinant fusion proteins of SARS-CoV-2, containing gene fragments and epitopes from the Envelope (E) and Membrane (M) proteins, fused to the RBD. These proteins were designed to be immunogenic and potentially useful in diagnostic and immunization platforms. The production process involved cloning the coding sequences and expression in Escherichia coli Rosetta (DE3). Although the expression was insoluble, successful solubilization steps were implemented subsequently. Reactivity tests with sera from rabbits immunized with a DNA-RBD vaccine, sera from COVID-19 patients, and pre-pandemic sera showed that all fusion proteins were recognized, although with varying efficiencies. The fusion protein that includes fragments of the E protein at the N-terminal and epitopes of the M protein at the C-terminal fused to the RBD (E-RBD-M) stood out as the most promising. This fusion, along with the RBD, was used in mouse immunization schemes, triggering a robust humoral immune response, with the production of high-avidity antibodies assessed by ELISA. Furthermore, sera generated by both proteins demonstrated the ability to generate neutralizing antibodies, as evidenced by assays inhibiting RBD binding with ACE2. The RBD and the fusion were tested with sera from COVID-19 patients and vaccinated individuals, as well as sera negative for the infection. The E-RBD-M fusion, while sensitive, proved to be less specific compared to the RBD. Cellular immune response was also evaluated by qPCR and ELISA, revealing the induction of high levels of cytokines after immunization and restimulation of splenocytes, suggesting a robust cellular response. These results highlight the potential of RBD fusions as promising candidates for COVID-19 diagnosis and immunization, representing a simple and cost-effective production approach with immunogenicity comparable to the RBD expressed in this study.