Repository logo
Communities & Collections
Entire repository
About
English
العربية
বাংলা
Català
Čeština
Deutsch
Ελληνικά
Español
فارسی
Suomi
Français
Gàidhlig
ગુજરાતી
हिंदी
Magyar
Italiano
Қазақ
Latviešu
മലയാളം
मराठी
Nederlands
ଓଡିଆ
Polski
Português
Português do Brasil
Русский
Srpski (lat)
Српски
Svenska
తెలుగు
தமிழ்
Türkçe
Yкраї́нська
Tiếng Việt
繁体中文
Have you forgotten your password?
  1. Home
  2. Browse by Date

Browsing by Issue Date, starting with "2023-07-15"

Filter results by year or month
Now showing 1 - 20 of 5462
  • Results Per Page
  • Sort Options
  • Loading...
    Thumbnail Image
    Item type:Item,
    Marcadores de estresse oxidativo em pacientes internados por COVID-19: estudo de coorte
    (Universidade Federal de São Carlos, 2023-07-15)
    Neves, Fabio Fernandes
    ;
    https://lattes.cnpq.br/2652568399519714
    ;
    https://orcid.org/0000-0001-6536-3249
  • Loading...
    Thumbnail Image
    Item type:Item,
    Do the oxidative stress biomarkers predict COVID-19 outcome? An in-hospital cohort study
    (Universidade Federal de São Carlos, 2023-07-15)
    Neves, Fabio Fernandes
    ;
    Pott-Junior, Henrique
    ;
    Yamashita, Kaori Maria Carolina
    ;
    Santos, Sigrid de Sousa
    ;
    Cominetti, Marcia Regina
    In SARSCoV-2 infections, excessive activation of the immune system dramatically elevates reactive oxygen species levels, harms cell structures, and directly increases disease severity and mortality. We aimed to evaluate whether plasma oxidative stress biomarker levels could predict mortality in adults admitted with Coronavirus Disease 2019 (COVID-19), considering potential confounders. We conducted a cohort study of 115 adults (62.1 ± 17.6 years, 65 males) admitted to a Brazilian public hospital for severely symptomatic COVID-19. Serum levels of α-tocopherol, glutathione, superoxide dismutase, 8-hydroxy-2′-deoxyguanosine, malondialdehyde, and advanced oxidation protein products were quantified at COVID-19 diagnosis using real-time polymerase chain reaction. Serum levels of α-tocopherol, glutathione, superoxide dismutase, and advanced oxidation protein products differed significantly between survivors and non-survivors. Serum glutathione levels below 327.2 μmol/mL were associated with a significant risk of death in COVID-19 patients, even after accounting for other factors (adjusted hazard ratio = 3.12 [95% CI: 1.83–5.33]).
  • Loading...
    Thumbnail Image
    Item type:Item,
    Estágios imaturos de Palyadini (Lepidoptera, Geometridae) e seus parasitoides associados a Myrsine umbellata Mart. (Primulaceae) em áreas de Cerrado em São Carlos, SP
    (Universidade Federal de São Carlos, 2023-07-17)
    Rodrigues, Elizabeth Moreira
    ;
    Penteado-Dias, Angélica Maria
    ;
    https://lattes.cnpq.br/8637344058859147
    ;
    https://orcid.org/0000-0002-8371-5591
    ;
    Dias Filho, Manoel Martins
    Tritrophic interactions are those that involve relationships between three trophic levels: producer, primary consumer and secondary consumer. They are considered complex, since they involve physical-chemical regulatory mechanisms, in addition to high dependence or susceptibility to each other. Thus, changes in the habitat or in other living conditions of any of these groups can cause an imbalance that will extend to the others. The Cerrado biome, the second largest biome in South America, is mainly made up of savannas. Due to human action, mainly through arson, the biome undergoes major changes, affecting many species. The species Myrsine umbellata Mart. (Primulaceae) (producer), in abundance in the Cerrado Biome, has ecological importance, being indicated for the recovery of degraded areas of grassland or secondary vegetation because it is a pioneer. The Primulaceae family, according to the literature, is closely associated with Palyadini larvae (Geometridae: Ennominae) (primary consumer), while the Hymenoptera parasitoids (secondary consumer) stand out for controlling populations of other insects that interfere with food chains. However, studies involving taxonomic and bionomic knowledge regarding the Neotropical fauna of Lepidoptera (Geometridae) and Hymenoptera parasitoids associated with the Primulaceae family are scarce. Thus, this work aimed to characterize the immature stages of Neotropical Geometridae species associated with Myrsine umbellata (Primulaceae) collected in Cerrado areas of the Federal University of São Carlos, São Carlos, SP - Brazil, aiming at the taxonomic and bionomic knowledge of the group; in order to contribute to the knowledge of the immature stages of Palyadini (Geometridae: Ennominae), including their morphology, bionomic aspects and associated parasitoids. As a result, the areas presented a richness of Geometridae larvae equal to 496 individuals, where the species Phrygionis polita Cramer, 1780 and Argyrotome paraguayaria Schaus, 1927 presented greater abundance and higher parasitism index, respectively. Glyptapanteles sp. (Hymenoptera, Braconidae, Microgastrinae) and Euplectrus sp. (Hymenoptera, Eulophidae), with a gregarious habit, were the genera with the highest abundance of emerged adult parasitoids. While Casinaria spp. (Hymenoptera, Ichneumonidae, Campopleginae) presented greater diversity of morphospecies. Also, the first record of Distatrix flavus Rodrigues, Dias & Penteado-Dias, 2023 was obtained. Finally, the communities of both Geometridae larvae and their parasitoids present in the Cerrado Y of UFSCar, a preserved Cerrado area, showed greater diversity, consequently lower levels of equitability when compared to the communities of Geometridae larvae and their parasitoids present in the Trilha da Natureza, São Carlos, SP, Cerrado area recovering after fire.
  • Loading...
    Thumbnail Image
    Item type:Item,
    O papel das políticas públicas no desenvolvimento de sistemas agroflorestais no Brasil
    (Universidade Federal de São Carlos, 2023-07-17)
    Ballerini, Ariel Pollo
    ;
    Aguiar, Danilo Rolim Dias de
    ;
    https://lattes.cnpq.br/1889207481986151
    ;
    https://orcid.org/0000-0001-9791-9774
    ;
    https://lattes.cnpq.br/2634809737541030
    Climate change is a reality and its effects directly affect society, including the production of food and commodities. Given this scenario, the need to face the consequences of climate change leads to studies to verify alternatives for agricultural production that are sustainable and compatible with contemporary reality. Agroforestry systems (AFS) have socioeconomic and environmental benefits, and are the subject of international studies that evaluate the factors that determine their success. In order to be successful in the implementation of SAFs, and maximum use of their advantages, it is necessary that the State acts in the regulation of markets, in the incentives to the use of the technique through credit lines and payment for environmental services, among other aspects that are up to it. In this sense, the objective of this work is to identify the role that public policies play in the development of SAFs in Brazil, highlighting the programs and laws that contemplate national agriculture and that have an impact on the expansion of the use of agroforestry. Brazil has a legal framework that puts sustainability in agriculture on the agenda, as well as programs that propose investments in agroforestry, but there is no direct and specific direction of public effort for the development of SAFs in the country.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Fotodegradação de contaminantes emergentes por catalisadores à base de PHI (Poli Heptazina Imida)
    (Universidade Federal de São Carlos, 2023-07-17)
    Pastana, Vitor Gabriel da Silva
    ;
    Teixeira, Ivo Freitas
    ;
    https://lattes.cnpq.br/9782517948999001
    ;
    https://lattes.cnpq.br/3569736875764585
    ;
    https://orcid.org/0000-0001-7587-6603
    The remediation of pollutants promoted by systems that are cheap and viable remains an important challenge in the field of catalysis. Carbon nitrides applied in photocatalytic systems are a promising class of materials for promoting advanced oxidative processes, with several studies demonstrating their potential in removing contaminants. In the work that follows, rifampicin and tetracycline, two antibiotics with latent human and environmental toxicity, were photodegraded/removed by Fe-PHI, a crystalline carbon nitride with potential applications in oxidative reactions. The synthesis of the material followed the processes reported in the literature. Unlike other orders of the class, the PHI has cations inserted between the heptazine structures, which can be exchanged for other transition metals, being classified in certain cases as single-atoms, catalytic sites with good activity and stability. The obtained catalysts had their structure analyzed by DRX, FT-IR, HR-TEM and EXAFS. Contaminants were reserved in aqueous solution and their respective photodegradations/adsorptions were monitored by spectroscopy in the UV-Vis region (~80% removal), being almost 100% remedied in the subsequent irradiation. Tetracycline, once more durable in the medium, displayed around 65% of remediation in 8 hours of irradiation with Fe-PHI and neutral pH. The catalyst recycles showed continuous activity, for both sorption and photoremediation. With such a prolonged activity, in addition to its simple synthesis, carbon nitrides have shown promise in the application of contaminant removal.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Bioatividade da semente de abacate (Persea americana Mill) sobre Atta sexdens Forel, 1908 (Hymenoptera: Formicidae)
    (Universidade Federal de São Carlos, 2023-07-18)
    Zanini, Juliana Keppe
    ;
    Prado, Jeanne Scardini Marinho
    ;
    https://lattes.cnpq.br/8742593129238690
    ;
    https://orcid.org/0000-0002-1638-3224
    ;
    Fujihara, Ricardo Toshio
    Leaf-cutting ants are insects of great agricultural importance due to their harmful attack on different production systems, resulting in large economic and production losses. Currently, the use of chemicals to control these insects is the most used method, however, this has been associated with various environmental and human damages. Faced with the need for new alternatives with less environmental impact, the objective of this work was to evaluate the potential of avocado seed oil to control leaf-cutting ants. Oil extraction was carried out at the Contaminant Waste Laboratory – LRC (Embrapa Meio Ambiente), using soxhlet-type extractor devices, using hexane as a solvent. For the topical tests, 180 Atta sexdens workers were collected and used five different volumes of oil and a control treatment: control 0.5 μL (distilled water), V1 - 0.25; V2 - 0.5; V3 - 0.75; V4 - 1.0 and V5 - 2.0μL. The oil was applied topically on the workers' pronotum, which were then individualized and kept in BOD at 24 ± 2°C. The evaluations occurred every 24 hours, for eight days. In the evaluation of topical toxicity, for both tests, mortality rates were higher in the first days after application of the oil, but the results referring to the second topical test were more promising concerning the first test. This factor may be due to the higher proportion of linoleic acid present in the oil from the second extraction, which was used in the second topical test. The accumulated mortality of the control treatments was high in both tests and for this reason, further studies are needed to explain such results. The different volumes evaluated did not present significant differences among themselves, only for the control treatment. From the chemical analysis of the oil, performed by the GC-MS and GC-FID method, several non-saponifiable and saponifiable compounds were identified, among them linoleic, palmitic, oleic, alpha-linoleic and myristic fatty acids. Linoleic acid showed a higher proportion in both oil samples, being the compound most commonly associated with the observed insecticidal activities. Regarding the subcolonies, 30 pellets were offered per treatment: control pellets (without oil) and pellets containing 0.5 μL of avocado seed oil, totaling eight repetitions and 120 pellets each. The evaluation of the number of dead workers and the loading of baits occurred every 24 hours, for six days. The number of pellets containing the oil carried by the workers was low, however, it was possible to observe a higher mortality in the control treatment.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Onde "Falha a fala. Fala a bala": discursos da violência no romance Cidade de Deus
    (Universidade Federal de São Carlos, 2023-07-18)
    Vieira, Ricardo Loiola
    ;
    Carvalho, Pedro Henrique Varoni de
    ;
    https://lattes.cnpq.br/0019513394358070
    ;
    https://orcid.org/0000-0002-1492-4891
    ;
    https://lattes.cnpq.br/0457446348246092
    Supported by the theoretical framework of Discourse Analysis, starting from the Foucaultian discursive studies, this dissertation aims to investigate the effects of meaning provoked by the discourses of violence in Cidade de Deus (2002), a novel by Paulo Lins. For that, we take as a starting point its second version – adaptation to the work, first, from 1997. We analyzed, in this way, 30 utterances extracted from passages of the book, with a view to recognizing, in this version, the installation and maintenance of discursive events of violence in the lives of subjects from the periphery. As a hypothesis, it is guided by the fact that Cidade de Deus, as a historical/documentary/literary record − since the author comes from the periphery − proposes an analysis of the way in which criminality is placed in the space of the favela and, in addition, discusses questions about cultural life there. Against the order of violence and criminality of the poor space, where the absence of the State prevails, a poetry that resists is present, a record of the beats between poetic and literary discourses from a perspective, and raw discourses − of violent reality – for another. To prove this intent, we resorted to Foucault's theoretical contribution, therefore, it is possible to place the research from three assumptions: discursive formation, utterance and subject. Therefore, possible dialogues are created, seeking, therefore, a theoretical-methodological delimitation that could contribute to the field of discourse studies. Thus, having discursiveness as an analysis tool, it would be possible to verify the mechanisms operated in the construction of narrative making, which encompasses cultural, ideological and social issues, as well as linguistic and literary ones. It also invests in its repercussions on other levels, whether cultural and/or historical-social. Through the discursive functioning of violence in the favela, we work the emergence of a peripheral voice that constitutes itself as a discursive event. That said, we think the author's constitution, the writer Paulo Lins, in the subject of discourse.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Estudo teórico da influência da adição de adesivante nas propriedades físico-quimicas do polipropileno reforçado com fibras de vidro
    (Universidade Federal de São Carlos, 2023-07-20)
    Sena, Sthefany dos Santos
    ;
    Souza, Ernesto Chaves Pereira de
    ;
    https://lattes.cnpq.br/1505400360366643
    ;
    https://orcid.org/0000-0003-1058-302X
    ;
    https://lattes.cnpq.br/0058914943112867
    Fiber-reinforced polymeric composites are widely used today, being applied in several areas such as aeronautics, automotive, military, medical, among others. However, some polymers present low adhesion in the interfacial region with the glass fiber due to the polarity of the chains. In order to improve this property, adhesive molecules can be added to the system, which can increase the surface polarity of the silica, the polymer or both. In this work the adhesive molecules were bonded to the polymer molecule. The polymer studied was polypropylene with and without addition of maleic anhydride, in addition to modification of the silica surface, with and without hydroxyls. The molecular dynamics method was used to study the effects of these modifications, as well as the change in behavior when the system is subjected to a mechanical test. It was found that the systems containing the modified polymer did not suffer detachment from the silica because the adhesion was more efficient, showing that increasing the polarity of the chains through the addition of adhesive agents is effective. In addition, the umbrella sampling method was used to calculate the adhesion free energy. It was possible to observe that there is a significant difference between the system with and without coupling agent, with better interfacial adhesion for the first case. In addition, the silica that had hydroxyls on the surface together with pure polypropylene showed a free energy of adhesion very similar to the system that contained the coupling agent but the silica did not contain terminal hydroxyls. On the other hand, the system that had the two possible modifications, coupling agent and hydroxyls in the silica, presented the best adhesion performance, justified by the intermolecular interactions that could occur in the interfacial region. This result corroborates the tensile test, where this system showed an improved behavior in the formation of voids in the polymeric matrix compared to the system MAPP-SiO2.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Biopolímeros ferti-liberadores: uma proposta de recipiente no cultivo de mudas de antúrio
    (Universidade Federal de São Carlos, 2023-07-21)
    Petruz, Alessandra
    ;
    Faez, Roselena
    ;
    Souza, Claudinei Fonseca
    ;
    https://lattes.cnpq.br/4858219292242433
    ;
    https://orcid.org/0000-0001-9501-0794
    The inadequate handling of plastic waste used in agriculture, associated with the high need for soil fertilization, has caused several negative impacts on the environment. Developing improved efficiency fertilizers (EEF) based on biodegradable materials has become a promising alternative for fertilizer intensification since EEFs ration the amount of available fertilizer, reducing losses. Such sustainable agricultural practices have contributed to achieving the Sustainable Development Goals (SDGs). The objective of this work was, in the first stage, to produce films based on carrageenan (KC) and alginate (ALG) and to evaluate the influence of nanofibrillated cellulose (CNF) in concentrations of 0, 2, 3, 4, and 5 % (m/m ) and monoammonium phosphate (MAP) at a concentration of 20 % (m/m) on the thermal, structural, morphological and mechanical properties of films cast on aluminum substrates coated with Teflon, polypropylene (PP) and acrylonitrile-butadiene-styrene (ABS). We also evaluated the biodegradation, swelling, and release of PO43- ions in the water. In the second stage, to produce a material with 4 % (m/m) of CNF and a multi-nutrient formulation (calcium nitrate, potassium nitrate, MAP (monoammonium phosphate), MKP (monopotassium phosphate), potassium sulfate, magnesium sulfate, and ConMicros) to achieve 0.4 dS m-1; 0.8 dS m-1; 1.2 dS m-1 and 1.6 dS m-1 according to the nutritional recommendation for the anthurium culture and to evaluate its thermal, structural, morphological, biodegradation and field performance properties. Higher concentrations of CNF altered the morphology of the composites and aided in fertilizer dispersion, delaying the release rate. The addition of fertilizer influenced the biodegradation process by increasing the microbiota and tensile strength. According to the biometric analyses, the highest concentration of fertilizers corresponding to 1.6 dS m-1 contributed to the better development of anthuriums. In conclusion, CNF and fertilizer contribute to more resistant films, with a lower PO43- ion release rate and biodegradable potential, making them a potential for cultivation containers used in anthurium (Anthurium andraeanum) culture.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Design de aços inoxidáveis austeníticos de alto teor de nitrogênio via triagem de alto desempenho por método CALPHAD
    (Universidade Federal de São Carlos, 2023-07-21)
    Ferreira, Victor Hugo Mafra Monfredo
    ;
    Coury, Francisco Gil
    ;
    https://lattes.cnpq.br/8609825406277730
    ;
    https://orcid.org/0000-0002-0457-2087
    ;
    Koga, Guilherme Yuuki
    Nickel is essential for austenitic stainless steels of the 3xx class (8-10 wt%) due to its austenitizing character. However, its notorious price volatility directly affects the stainless steel industry. In light of this, there is a need to develop stainless steels that partially replace nickel with other austenitizing elements. The aim of this work was to develop compositions of austenitic stainless steels with a high N content using computational methods. Computational tools based on the CALPHAD method were employed to select a composition based on predefined criteria (composition, phases present, % N, cost, and PREN). The alloy's microstructure was analyzed through optical and scanning electron microscopy, while the phases present were identified through X-ray diffraction. The chemical composition was determined using spark emission spectroscopy; elements C, S, N, and O were analyzed by combustion and quantified by infrared absorption. Mechanical properties were evaluated according to ASTM E8/E8M-11 standards. Pitting corrosion resistance was assessed through cyclic potentiodynamic polarization in 3.5 wt% NaCl, and sensitization was evaluated following ISO 12732; susceptibility to intergranular corrosion was determined according to ASTM A262-15 Practice A. Electrochemical impedance spectroscopy tests were also conducted as a complement. After high-performance screening, manual modifications were made to the compositions to improve nitrogen solubility. The results demonstrated that the developed alloys exhibited an austenitic microstructure with the presence of AlN, reducing the nitrogen content in solid solution. The mechanical properties of the alloy surpassed those of AISI 201 steel. However, due to the presence of AlN, the corrosion resistance behavior of the alloy was affected. These findings are significant for the development of austenitic stainless steels with a high nitrogen content, aiming to enhance their mechanical properties and corrosion resistance.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Identificação de atividades cotidianas com membros superiores através de sensores inerciais
    (Universidade Federal de São Carlos, 2023-07-21)
    Girardi, Paulo Matheus
    ;
    Nogueira, Samuel Lourenço
    ;
    https://lattes.cnpq.br/2287847504423307
    ;
    https://orcid.org/0000-0002-3342-7436
    ;
    https://lattes.cnpq.br/8258774819324497
    In this work, the development of data processing strategies and methodologies for identifying 7 everyday activities performed with the upper limbs was proposed, with the support of inertial sensors and machine learning techniques. Computational methods were used for data processing, including data synthesis to homogenize the number of samples, digital filter bank, Hamming windowing, feature extraction, and classification using a neural network with the Matlab Neural Net Pattern Recognition toolbox. In this study, two units of inertial measurement were used, one on each wrist. This choice was made because a significant portion of the performed activities requires cooperation between the two limbs. Thus, through supervised training of the neural networks, an average accuracy of over 90% was achieved for activity identification, demonstrating the feasibility of the proposed strategies for identifying daily activities involving the upper limbs.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Estudos sobre a construção e uso de materiais manipuláveis no ensino de ciências naturais para estudantes com surdocegueira
    (Universidade Federal de São Carlos, 2023-07-21)
    Perassolo, Valquiria
    ;
    Costa, Maria da Piedade Resende da
    ;
    https://lattes.cnpq.br/2791098416503955
    ;
    https://orcid.org/0000-0002-7420-5602
    ;
    https://lattes.cnpq.br/7152098940158098
    The school inclusion of people who are the target audience of Special Education is still one of the great challenges of Brazilian education. The large number of people excluded from the right of access to schooling is real and the issue is even more complex when it comes to people with disabilities, such as those with deafblindness. This research focuses on the education of children, adolescents and young people with deafblindness, who are socially invisible and who often have their right of access and permanence in education denied due to failures of the educational system to receive and include them. The main objective is to highlight and analyze the potentialities and challenges found on the use of manipulable materials in teaching of Natural Sciences for students with deafblindness. As methodology, the qualitative approach was the option of the kind of case research. Two deafblind students from the Center for Care and Support to the Deafblind (CEAADA) participated in the research, their guardians who participated in the interview to characterize them, two teachers who attended them in the year 2021, and two teachers who attended them in the year 2022. Propositions of manipulable materials used by teachers in teaching natural sciences to students with deafblindness were observed and materials were also made and supplied according to the students' needs. All these materials were handcrafted, that is, not industrialized. The analyzes were guided by the effort to understand the demands of schooling deafblind students and the potentialities and challenges as to the use of manipulable materials adopted for teaching such students. As a result, the data indicate that families consider the schooling process important, but show many difficulties in passing on the activities proposed by the teachers during remote teaching. The teachers participating in the research, although they have little experience in teaching students with deafblindness, they tried to research and adapted the activities that would be proposed. The participating teachers and the researcher established a partner relationship, in which they discussed and developed together the preparation of materials and activities proposed during the research period. The teachers proved that they have knowledge of what manipulable materials are and these materials show great potential in the teaching of these students, as they allow them to explore different textures, formats and sensations. It is also evident that the teachers notice the need for a differentiated pedagogy for teaching people with this disability.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Biestabilidade óptica em átomos de três níveis em uma cavidade óptica
    (Universidade Federal de São Carlos, 2023-07-21)
    Proença, Lucas Araujo
    ;
    Souza, James Alves
    ;
    https://lattes.cnpq.br/2212240621620011
    ;
    https://lattes.cnpq.br/2808532350048558
    The phenomenon of optical bistability in atomic systems confined in an optical cavity has been extensively explored due to its potential for applications such as optical switches, memories and optical transistors. The bistability observed in multi-level atomic systems has some advantages over the usual two-level system with respect to non-linear optical properties, absorption and scattering. The configuration of atoms with more than two levels allows the use of other electromagnetic fields by coupling different atomic transitions resonantly, or quasi-resonantly, making it more feasible to manipulate and control non-linear optical processes, which may be related to the phenomena of electromagnetically induced transparency (EIT - \textit{Electromagnetically Induced Transparency}) and coherent population trapping (CPT - \textit{Coherent Population Trapping}). In this work we theoretically study the CPT phenomenon in cavities to explore the control and properties of optical bistability in systems composed of $N$ three-level atoms in $\Lambda$ configuration, independently coupled to the same field mode of an optical cavity. To obtain the interaction hamiltonian of the system we used the semiclassical approximation, which consists of considering atoms quantumly and the cavity field classically. Through the formalism of the master equation, we derive the Maxwell-Bloch equations and the dynamics of the system was obtained through computational simulations performed in MATLAB. The obtained results show that it is possible to obtain a sensitive control of the optical bistability from the adjustment of parameters external to the system, such as the frequency and intensity of the test field and the intensity of the control field. The possibility of controlling light with observed light in the studied system, through the phenomenon of optical bistability, can be promising for the development of optical devices with different functionalities.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Avaliação de aditivos poliméricos e cerâmicos para a otimização microestrutural de refratários semi-isolantes
    (Universidade Federal de São Carlos, 2023-07-21)
    Farias, Thiago Wisley Barbosa de
    ;
    Luz, Ana Paula da
    ;
    https://lattes.cnpq.br/3470395641242374
    ;
    https://orcid.org/0000-0002-5941-5388
    ;
    https://lattes.cnpq.br/3160573002957297
    Macroporous insulating refractories have been extensively investigated due to their low thermal conductivity, low density, and non-toxicity compared to fibrous ceramic insulators. However, there are still challenges in adjusting the processing parameters of these materials to obtain microstructures with optimized characteristics. In this context, the present project aimed to evaluate the feasibility of using expanded polymeric microspheres or hollow ceramic microspheres in semi-insulating refractory compositions, with the goal of identifying the most suitable conditions for achieving materials with apparent density of up to 1.7 g/cm3 and thermal conductivity lower than 1 W/m·K in the temperature range between 30 and 800°C. Additionally, to optimize the mechanical strength of the prepared semi-insulating materials, compositions containing calcium aluminate cements or geopolymers as binders were prepared and compared. Formulations based on fused silica were processed and characterized for their rheological, physical, mechanical, and thermal properties. The results indicated that the selected microspheres acted effectively as pore-forming agents, with the polymeric additives promoting the formation of closed pores in the resulting microstructure. In particular, the ceramic containing 0.6 wt.% of polymeric microspheres and a calcium aluminate cement richer in alumina (Secar 71) exhibited the best performance among the studied systems. This castable achieved a flexural strength of 9.21 MPa (after drying at 110°C) and 4.29 MPa (after firing at 815°C), an apparent density of 1.62 g/cm3, and a thermal conductivity of 0.668 W/m·K at 800°C. The semi-insulating materials prepared with geopolymers also demonstrated promising properties, as even in the absence of pore-forming agents, it was obtained refractories with superior flexural strength (surpassing the compositions with cement), an apparent density of 1.68 g/cm3, and a thermal conductivity of 0.735 W/m·K at 800°C.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Aplicação web back-end de um fantasy game
    (Universidade Federal de São Carlos, 2023-07-21)
    Rodrigues, Kaio de Melo
    ;
    França, Celso Aparecido de
    ;
    https://lattes.cnpq.br/4547836128892982
    ;
    https://orcid.org/0000-0003-2235-9551
    ;
    https://lattes.cnpq.br/5730881171653658
    In Brazil, the most popular sport is football and, therefore, it is recognized in scenarios that go beyond the lawns, such as the Fantasy Games. Users of this game style create and manage their own teams online, using real players from football teams around the world. Each player is assigned a point value based on their skill and performance history. Today there are different fantasy football games, but the most relevant in the country is Cartola FC. In this work, a Back-End web application of a Fantasy Football Game similar to Cartola from Rede Globo, called InterRep Manager, was developed. In it, users manage the scores of real players who participated in InterReps, a football tournament between the republics of São Carlos that took place in the year 2022. The tournament scores were used in the application. To evaluate the functionality of the application, the performance of three users and 15 players in three matches was simulated. So far, the software has proved to be functional, from the login stage to the calculation of the score.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Atividades de pronúncia no ensino de inglês como língua estrangeira: reflexões com professores em contexto de aulas individuais
    (Universidade Federal de São Carlos, 2023-07-21)
    Sarturato, Gabriel Maldonado Fabbro
    ;
    Paula, Sandra Regina Buttros Gattolin de
    ;
    https://lattes.cnpq.br/9228036521343293
    ;
    https://lattes.cnpq.br/0797881241667691
    In Applied Linguistics there is increasing attention to foreign language pronunciation, and many pedagogic ideas explore beyond the classic practice of ‘listen and repeat’, which is still very common in many language teaching contexts. Many aspects of pronunciation need to be treated in class, and repetition only is not sufficient to address them all. Research has shown that description of the phonological structures, listening discrimination activities, and other forms of oral production that do not focus only on repetition show efficacy in pronunciation development, speaking, and listening. Repetition activities also can be reshaped to reach better contextualization and student engagement. The advancements in research, however, find little insertion in many language learning courses and teacher education. This research aimed to analyze how some teachers of English as a foreign language understand pronunciation instruction and its function in class. The context studied was one-to-one teaching. Three teachers and their respective students participated. They were exposed to pronunciation activity proposals, and selected the ones they found could be most helpful for their students, edited them, and implemented them in classes. Firstly, the teachers were interviewed about their perspectives on pronunciation and pronunciation teaching. Then, ideas for activities were sent by the researcher. The teachers then recorded the activities chosen. The researcher made an effort not to impose his views on the teachers, but to help them according to their own approaches. The students briefly presented their impressions of the activities. Later, recall sessions were recorded with each teacher for them to observe and reflect on the class. A last contact (via text message) was made with the teachers to ask questions that were raised during the analysis of the recall sessions. The results revealed that the teachers were keen to complement their common pronunciation instruction practices with the activities chosen. It was possible to recognize a clear influence of their teacher education backgrounds in their approaches. The three teachers demonstrated different views on the function of pronunciation and how to teach it. The students showed openness to the activities presented to them and pointed out that they would like to practice more with these activities.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Aspectos que conferem complexidade a interpretação na perspectiva do intérprete educacional do ensino médio
    (Universidade Federal de São Carlos, 2023-07-21)
    Oliveira, Patricia Cardoso de
    ;
    Lacerda, Cristina Broglia Feitosa de
    ;
    https://lattes.cnpq.br/9468232016416725
    ;
    https://orcid.org/0000-0002-3250-1374
    ;
    https://lattes.cnpq.br/8560935678654879
    At the expense of a greater insertion of the deaf in the academic environment, the educational intérpreter of Brazilian Sign Language - Libras, has been gaining recognition in relation to the importance of its performance and its influence in the teaching and learning process of students with deafness. That said, the present study explored the aspects that add complexity to the interpretation of Portuguese into Libras in the educational environment, aiming to identify, understand and offer reflections on the elements that foster this phenomenon, with the aim of building new perspectives in the field of action of the educational intérpreter Libras, with emphasis on collaborative work between the teacher and the educational intérpreter. For this, a single case study was carried out, using the simple self-confrontation instrument, proposed by Yves Clot (2010), in work psychology (Clinic da Atividade) and based on the principles of Bakhtin's dialectic (2006), together with the conception of “Saying the 'same' to others: essays on translation” by Adail Sobral (2008), as well as the theorization about the work in partnership between the teacher and the educational intérpreter. For the analyses, two categories were highlighted: i) constructions of new concepts or complex concepts in the source discourse; and ii) interpretive lapses. Such categories provided the survey of elements that confer complexity to the interpretative act in the educational sphere, which were organized in the following axes: I) Construction of concepts: from simple to complex; II) the collaborative work between the teacher and the educational intérpreter; III) emotional aspects in the performance of the educational intérpreter. The highlighted elements, which according to the perspective of the high school educational intérpreter, exert great influence in making the task of interpreting from Portuguese into Libras usually complex, if better known they can be tackled in the perspective of making the work of the educational intérpreter of Libras less arduous.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Vínculos transitórios: psicoterapia on line na sociedade pandêmica
    (Universidade Federal de São Carlos, 2023-07-24)
    Vasques, Juliana Pereira Damasceno
    ;
    Mendonça, Viviane Melo de
    ;
    https://lattes.cnpq.br/4827331651090223
    ;
    https://orcid.org/0000-0002-1368-1883
    ;
    Leite, Kelen Christina
    The new coronavirus pandemic has transformed habits across society around the world. As a result, technologies played a fundamental role in the most sensitive changes, re-signifying customs and professional routines, in social and consumer relations - and even in apparently immutable conventions. This exploratory project deals with the increase in online psychological and psychotherapeutic follow-up services and their immense demand in this unprecedented condition. A year and a few months after the declaration of the pandemic by the World Health Organization (WHO), however, the practice not only seems far from being ended, but can still be improved, with the emergence of a series of electronic service platforms, each more and more possible resources for the establishment of the so-called home-office and a delicate search - and increasingly critical - of subjects in the process of psychic illness, in addition to solutions as fast as the bytes and megs exchanged in minutes of consultation. How, therefore, is the question of the concept of work aligned with the production of meanings and subjectivities of the subjects, in this new format? Through the "snowball" method, which uses reference chains, we propose a qualitative, exploratory study with psychology workers, and a more in-depth analysis of this historical period, in a cut and a look more aimed at professionals, their needs and anxieties, faced with unprecedented personal and professional dilemmas.
  • Loading...
    Thumbnail Image
    Item type:Item,
    A relação do professor com o saber no ensino remoto mediado pelas novas tecnologias digitais: a formabilidade do sujeito biográfico
    (Universidade Federal de São Carlos, 2023-07-25)
    Rodrigues, Fabiana da Silva Santos
    ;
    Silva, Flávio Caetano da
    ;
    https://lattes.cnpq.br/7889803676083470
    ;
    https://lattes.cnpq.br/5391841502170976
    Due to the suspension of classes in 2020 by virtue of the Covid-19 pandemic, many teachers, including those working in Basic Education, were compelled to carry on with classes while deprived of school premises. Emergency remote teaching were the alternative chosen to continue the school year, demanding, to a certain extent, the use of new digital technologies to aid pedagogical practices and communication with students and parents. In this context, this study had the general objective of analyzing and comprehending the teacher’s relationship to knowledge with new digital technologies used due to the suspension of in-person classes and the adoption of distance learning. Our research was underpinned by two theoretical perspectives: Bernard Charlot’s theory of relationship to knowledge and Delory-Momberger’s theory of biographization, both being used as research tools and for data analysis. With regards to the methodology employed in the development of this study, we opted for qualitative biographical research interviews, based on the works of Delory-Momberger, which stand out for addressing the relationship between life, school, the formative process and self-education. Being developed from a perspective that looks at life stories, five early childhood educators working for the public sector in the city of Hortolândia - SP, Brazil, were interviewed. Educational research, on the other hand, brings us relevant contributions about the teacher’s knowledge, who reaches the core of the relationship to knowledge, while also pointing to other aspects of human life. From this point of view, the results point to a relationship between the teacher’s knowledge and the domain of various education actors during this period of emergency remote teaching. The biographical narratives of the teachers interviewed in this dissertation, inscribed in the dynamic of a personal project, reveal reflection and action through experience, shedding light on the concepts of reflective narratives and the formation of the biographical subject. Lastly, the theoretical perspectives about relationship to knowledge and biographization that guided this study raise elements that can contribute to new ways of thinking about education, paving the way for the advent of the Other School.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Ligas beta Ti-Nb-Zr(-Ta-Mo) multiprincipais com baixo módulo de elasticidade
    (Universidade Federal de São Carlos, 2023-07-25)
    Santos, Rafael Formenton Macedo dos
    ;
    Contieri, Rodrigo José
    ;
    https://lattes.cnpq.br/5491429306264177
    ;
    https://orcid.org/0000-0003-3883-2059
    ;
    Afonso, Conrado Ramos Moreira
    The use of Ti-6Al-4V alloy as a biomaterial is more convenient among Ti alloys, as it is produced on a larger scale due to aeronautical applications. However, it is known that Ti-6Al-4V alloy can be harmful to the patient’s health (due to the toxicity of Al and V) and it does not have the most adequate properties. Biomaterials’ scientific and technological development becomes necessary, especially those with application in orthopedics, once there is an increase in life expectancy. The metallic alloys currently used in Brazil have a modulus of elasticity (E) much higher than that of human bone (E = 10 to 30 GPa), such as steel (200 GPa), Co-Cr Alloys (220 GPa), Ti -6Al-4V (110 GPa) and, therefore, the search for alloys with better mechanical and chemical biocompatibility is necessary. The β-Ti (CCC) alloys show good mechanical (elasticity modulus, E = 44 to 80 GPa) and chemical (good corrosion resistance) biocompatibility. At present, the development of multicomponent, equimass, stable β-Ti alloys with medium and high entropy of the systems Ti-33Nb-33Zr, Ti-25Nb-25Zr-25Ta, Ti- 20Nb-20Zr-20Ta-20Mo (% weight ), in addition to alloys from the Ti-40Nb-xZr system with high Zr fractions and based on electronic parameters Bo and Md seeking an optimal value of modulus of elasticity (between 40 and 60 GPa). For the Ti-Nb-Zr ternary system, the new βTAP ratio (ternary alloy parameter) was determined and the higher its value, the lower the alloy’s modulus of elasticity. The Ti-40Nb-40Zr alloy showed the lowest modulus of elasticity (E = 42 GPa) in the rolled condition. The Ti-25Nb-25Zr-25Ta alloy showed better results in biological tests (adhesion and cell viability assay), and better combination of low modulus (E = 70 GPa) and high mechanical strength, making it possible to reconcile these properties in β multicomponent.
  • «
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • ...
  • 274
  • »
Siga as redes sociais do SIBi
Contato

Repositório Institucional da UFSCar (RI UFSCar)

Av. Biblioteca Comunitária, Campus São Carlos

Rod. Washington Luís, km 235 - SP-310

São Carlos, SP, 13565-905 (16) 3351-8477

Email: repositorio@ufscar.br

Acessos ao repositorio.ufscar.br
Consultar estatísticas de acesso

DSpace software copyright © 2002-2026 LYRASIS

  • Accessibility settings
  • Privacy policy
  • End User Agreement