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Simulação numérica do processo de secagem de concretos refratários em aplicações tecnológicas
(Universidade Federal de São Carlos, 2022-03-21)
Cunha, Túlio Mumic
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Luz, Ana Paula da
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https://lattes.cnpq.br/3470395641242374
;
Pandolfelli, Victor Carlos
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https://lattes.cnpq.br/7369376873984839
Refractory ceramics are used in high temperatures due to their unique properties that enable a high thermal and chemical stability, mechanical strength, thermal properties and others. These materials are split into two main groups: shaped and monolithic. The latter acquires its shape during application and is commonly obtained as a powder, to which a liquid, commonly water, is added for mixing and for reacting with the binding agents to guarantee suitable green strength. Following, it is subjected to careful heating schedule to withdraw this water, because rapid generation of steam can lead to the failure of the lining. The drying process is often approached empirically in the industry, and this work aims to introduce a computational methodology for comparison and optimization of such heating profiles. Initially, a finite element method modeling was developed, with the help of a library, in Python, which was the basis for a number of simulations that were divided into three stages: profiles with constant heating rate, others with a plateau and also complex curves. The analyzes showed the need to use properties as a function of temperature, so it is as close as possible to a real material; high heating rates (≥ 50°C/h) are viable for linings with small thickness (< 20 cm); the withdrawal of free water at plateaus with temperatures below, but close to, the temperature of the beginning of the hydrate decomposition process enables the use of short plateaus at higher temperatures, speeding the drying process. Finally, using indicators such as drying status, resistance ratio and energy consumption, it was possible to compare the curves with each other to choose the one that best meets the needs of the end-user.
Valorização da propriedade rural: uma análise comparativa das diferentes formas de valorização aplicados a imóveis rurais no município de Angatuba-SP
(Universidade Federal de São Carlos, 2022-03-21)
Verardi, João Paulo
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Santos, Leandro de Lima
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https://lattes.cnpq.br/2750978055015275
This work addresses the existence of different forms of property valorization, as they are attributed at different times: one from the calculation of the Real Value, which is given at the time of contributing as the government through the collection of taxes and taxes, also through the calculation of the Market Value in the marketing and collection of resources such as financing, being obtained, for analysis purposes, from primary and secondary data. The data obtained primarily are based on the use of the proposed method for NBR 14.653 on a rural property selected by the author of this work, and contrasted with the value obtained through the Venal Value Calculator of the Institute of Agricultural Economics (IEA). For the secondary data, an analysis was carried out based on information obtained from the real estate agencies of the municipality of Angatuba in contrast to the values measured in the Municipal Decree of Angatuba No 519/2021. The results obtained point to a higher valuation of the property by defining the Market Value of the property, which is used for example as a guarantee in financing, and to undervaluation of the property measured from the Market Value, used, for example, for property payments. imposts and transfer or declaration of benefits. Finally, it was discussed the practical result of the possible contrast between the Sales Value and Market Value of the property.
Potencial antifúngico de nanoemulsões de óleo essencial de Cravo-da-Índia (Syzygium aromaticum)
(Universidade Federal de São Carlos, 2022-03-22)
Cipriano, Lavinia
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Ferreira, Marcos David
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https://lattes.cnpq.br/6652079760634274
;
Sousa, Cristina Paiva de
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https://lattes.cnpq.br/9002619114161319
Essential oils are extracts derived from plants, defined as secondary metabolites compounds, being an important defense mechanism of plants. The antimicrobial activity of the oils is mainly due to their hydrophobic nature, and it is believed that this activity against bacteria and fungi is directly related to the major compounds present in the essential oil. Clove (Syzygium aromaticum) is a plant native to Indonesia, with an extensive literature record of the activity of clove essential oil against bacteria and fungi. Phytopathogenic fungi that attack crops after harvest are responsible for the loss of tons of crops worldwide. In tropical regions, Penicillium spp. and Rhizopus stolonifer have a high incidence, and cause diseases known as “Green Rot” and “Black Rot”, respectively. The use and application of essential oils in their pure form has some limitations, such as their volatility, high reactivity and hydrophobicity, making their direct incorporation into foods difficult. In order to maintain their biological properties and reduce the impact of their application on food, the oils were incorporated into emulsions and nanoemulsions to later be encapsulated. Materials and methods: The production and characterization of nanoemulsions with Clove EO was carried out, after the determination of the Hydrophilic-Lipophilic Balance (HLB), from the mixture between aqueous and organic phase, consisting of the EO and a mix of surfactant composed by Tween 80 and Span 80. After characterization, a comparison was made between the antifungal activity of the pure essential oil, emulsion and nanoemulsion against postharvest fungi Penicillium spp. and Rhizopus stolonifer. Results: After the determination of the BHL, a nanoemulsion with a particle size of 50 d.nm was produced. From the antifungal activity tests, it is concluded that the nanoemulsion did not increase the essential oil activity against the tested fungi, being the oil in its pure form more efficient than the emulsion and nanoemulsion.
An analysis of the relationship between additive manufacturing and circular economy
(Universidade Federal de São Carlos, 2022-03-22)
Tavares, Thais Moreira
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Godinho Filho, Moacir
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Ganga, Gilberto Miller Devós
;
https://lattes.cnpq.br/9062191157466610
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https://lattes.cnpq.br/4310619949372745
Additive Manufacturing (AM) is an important technology of Industry 4.0. It allows the fabrication of objects layer by layer in a continuous or incremental way. Circular Economy (CE) aims to improve resource efficiency in order to lead to a shift from the current linear model of receiving, transforming and disposing to a model where resources flow in a circular manner. Some early studies refer to Additive Manufacturing as a promise of sustainability and development of more circular material flows. However, there is still uncertainty about the impacts and benefits of Additive Manufacturing for circularity. From this context, this work aims firstly to understand the relationship between additive manufacturing and circular economy. To achieve this goal, a multi-method study was carried out to understand how AM is beneficial or challenging in a Circular Economy context. Second, it aims to collaborate in the implementation of AM strategies in an EC context. To coordinate the elaboration of the strategies, a second multi-method study was carried out, using a fuzzy DEMATEL method. This method was used to understand the interdependence relationships between the barriers raised in the first study. The study of these relationships is essential in the elaboration of strategies for implementing a more circular AM. The research contributes to practice and theory. In theory, it elaborates the state of the art of the intersection between the themes, evolving into a framework addressing benefits and barriers (validated by experts) that AM brings to CE. The study also contributes to practice by showing to organizations what developments and strategies need to take place to smooth the way for a circular AM.
Alterações genéticas associadas ao gene apoe em pessoas com declínio cognitivo subjetivo (DCS): uma revisão sistemática
(Universidade Federal de São Carlos, 2022-03-22)
Fernandes, Carla Nunes Fonseca
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Cunha, Anderson Ferreira da
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https://lattes.cnpq.br/0329741640375661
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Vale, Francisco de Assis Carvalho do
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https://lattes.cnpq.br/7135183635933470
Subjective cognitive decline (SCD) consists of a self-perception of cognitive decline, with no objective impairment on cognitive tests and no functional impairment in activities of daily living. It represents a transitional stage between the asymptomatic state and the impairment of cognitive functions. Studies indicate that neurobiological bases participate in the process of the loss of cognitive function in the early stages of SCD. There is evidence that the neurobiological processes are related to polymorphisms in different nucleotide positions of the gene that codes for apolipoprotein E (APOE), changing the sequence of the original amino acids and modifying its structural properties. It is therefore believed that these alterations may influence the functional properties of APOE and promote the accumulation of β-amyloid plaques and the formation of neurofibrillary tangles. The molecular and physiological mechanisms leading to these clinical conditions are not yet known in detail, and therefore correlating the studies already developed aimed at further exploring these questions are critical. We performed a data collection that relates the APOE gene with DCS, through the libraries: PubMed, Mendeley and Web of Science, in the period from June to August 2021. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) model was used to construct this systematic review. Ninety studies were identified, of which only 34 met the inclusion criteria. Fifty-six studies were excluded by the following criteria: no characteristics related to DCS and APOE genotype, animal research, systematic review or meta-analysis, other genetic biomarker, protein receptor or hormonal factor, book chapter, DCS or APOE related to another disease or early onset AD, which is not associated with APOE as a risk factor, or articles that do not deal with the pre-clinical phase or year less than the stipulated date of the study. The related data pointed out in this literature review corroborate the literature in the possible existence of a clear relationship between DCS and the APOE genotype specifically in the ε4 allele in memory impairment in its early stages
Agricultura familiar e crédito via PRONAF: fatores determinantes da utilização nas regiões Serrana, Norte e Noroeste do Rio de Janeiro
(Universidade Federal de São Carlos, 2022-03-23)
Almeida, Claudio Cezar
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Batalha, Mario Otávio
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https://lattes.cnpq.br/1015001063418091
;
https://lattes.cnpq.br/6717374300414740
Family farming is of great importance to the Brazilian economy, due to its participation in food production and its ability to employ labor. Also, in Rio de Janeiro, family farming is highlighted, especially in the Mountain, Northern and Northwest regions. However, throughout Brazil, family farming faces important challenges to fully exploit its potential. The credit is among these challenges. For family farmers, credit is a vitally important element. With this perspective and aiming to strengthen the granting of credit under conditions consistent with the reality of family farming, the federal government created in 1996 the National Program for Family Agriculture (PRONAF). This program has played an important role in providing credit for family farmers throughout Brazil. In eight months of the 2021/2022 harvest, 1,274 thousand rural credit contracts were financed, corresponding to an amount of R$ 188.4 billion (BRASIL, 2022). However, in some regions it is less used than in others. In the northeast, for example, only 7.3% of family farmers accessed PRONAF in 2016, while in the southern region this percentage reaches 48.8% (IBGE, 2017). This is the case, for example, of the regions studied in this thesis. Without having the objective of making a comparative study between regions of Brazil, it is important to know which factors can best explain the raising of credit, via PRONAF, by farmers in the Mountain, Northern and Northwest regions of the State of Rio de Janeiro. Thus, this work has as main objective to identify determining factors of access to rural credit by family farmers located in the Mountain, North and Northwest regions of the State of Rio de Janeiro. To achieve this objective, were used primary data collected through face-to-face interviews in 499 households, distributed in the three regions. These data were analyzed in a logistic linear regression model, built from a set of hypotheses that are based on a conceptual model built with theoretical elements of the Resource-Based View and the Transaction Cost Theory. The results obtained through the econometric model made it possible to confirm the identification of four factors (marital status of the family farmer, the share of the value of rural production in the total income of the property, the availability of guarantees and access to technical assistance) as determining factors of access to PRONAF credit by family farmers in the state of Rio de Janeiro, in addition to providing subsidies to suggest measures related to rural credit and improvements in the management of properties and production processes of family farmers.
Atomização a gás do aço ferramenta A2: efeito dos parâmetros de processo nas características do pó
(Universidade Federal de São Carlos, 2022-03-23)
Mathias, Laura Emi Tavoni
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Gargarella, Piter
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https://lattes.cnpq.br/4641435644243916
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https://lattes.cnpq.br/6497697599064366
Gas atomization is the main method in powder metallurgy to produce powders for additive manufacturing (AM). The gas atomization process allows generally spherical and very fine metallic powders with great yield on the particle size range for AM applications. Moreover, this is a rapid solidification process that ensures chemical homogeneity and a high degree of microstructural refinement. Iron-based alloys have wide properties range and low cost, in which tool steels are especially important for industrial applications. This project produced A2 tool steel powders by gas atomization and evaluated the influence of the process parameters on the characteristics of the powders. No systematic study has been carried out on atomization and AM of this tool steel. Thus, analyzing the gas atomization process of this material is important to ensure the production of powders with proper characteristics. The statistical tool of design of experimental (DOE) was applied, and the atomization pressure and melt superheat process parameters were analyzed. The response variables analyzed were morphology, median particle size, particle size distribution, density and flowability. The powder characterization was done by laser diffraction, sieving, scanning electron microscopy, chemical analyses by EDS, flowability by Hall and Carney Flowmeter Funnel, density by helium pycnometry and apparent density. This study showed that the gas atomization process of the A2 tool steel was suitable for the production of powders for applications in AM. The model proposed by Lubanska, which formulate the mass median particle diameter, was also validated. Furthermore, the process with the lowest pressure level (20Bar) and the highest melt superheat (300K) has the lowest gas/metal ratio and mean particle size (D50) and particle size distribution similar to the other powders produced.
Modelos para estimativas de propriedades físico- mecânicas de espécies de madeiras tropicais em função da densidade aparente e da frequência de vibração transversal
(Universidade Federal de São Carlos, 2022-03-23)
Silva, Larissa Soriani Zanini Ribeiro Soares
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Lahr, Francisco Antonio Rocco
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https://lattes.cnpq.br/2333091200416653
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Christoforo, André Luis
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https://lattes.cnpq.br/7623383075429186
The wood is an excellent material of constructive application, little inserted to the market of the national construction, but with great potential of exploration. This fact is justified not only by restrictions of a social-historical nature, but also by the ignorance of the species and their properties. The difficulties in characterization the wood, given the amount of test required and the need for specific machinery and specialized labor, contribute even more to the current situation. As an alternative to simplify the knowledge of the properties of wood, this study aims to adopt a new technological solution to estimate the physical-mechanical properties, non- desctrutive characterization, of tropical wood through the combination of apparent density and the natural frequency (first mode) of the transverse vibration test, based on regression models, given the lack of studies, at national and global levels, that use these two tests combined as estimators of all the physical-mechanical properties of wood. For this, 05 species of tropical wood were distributed in the resistance classes (C20 to C60) of the hardwood group. Sixty transverse vibration tests were be carried out on pieces of structural dimensions of square section (12 cm x12 cm) and variable length (2 m to 2.7 m) and another 720 of wood characterization, in specimens standardized according to ABNT NBR 7190:1997, totaling 780 experiments. For each species, and for the grouping, linear regression models were generated as a function of bulk density and transverse vibration frequency, as well as multivariable quadratic regression models using bulk density and vibration frequency as independent variables in order to estimate the physical-mechanical properties of the woods. From the regression models for the species in isolation, with the exception of the class C40 species, little correlation was noted between density and natural frequency with the other properties, resulting in estimates of poor precision. For the set of species, the best adjusted coefficients of determination (R²aj) were obtained when analyzing the quadratic multivariable regression models, obtaining values greater than 70% for 13 models out of the 16 evaluated. It is noteworthy that, for the main mechanical properties of the woods, and of greater importance for the structural calculation (fc0, fv0, fM, Ec0 and EM), the adjusted coefficients of determination were above 80%, indicating models with excellent fits for the prediction of properties.
Engajamento de crianças com Transtorno do Espectro Autista nas rotinas da educação infantil
(Universidade Federal de São Carlos, 2022-03-23)
Morais, Giovana Cássia de
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Elias, Carina Sousa
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https://lattes.cnpq.br/0070734946202776
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Della Barba, Patrícia Carla de Souza
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https://lattes.cnpq.br/6448489426438006
Child development monitoring is increasingly essential for identifying potential and difficulties in learning. Engagement in routines is one of the factors that can contribute to the achievement of children's goals in a variety of areas, whether they have typical or atypical development. The beginning of the school life of children with Autism Spectrum Disorder (ASD) can be a challenge for quality participation in Early Childhood Education routines. In this way, understanding the functioning and profile of engagement in school routines can make an important contribution, both to the educators and family members, and also to the gain of academic knowledge. Therefore, the present study aimed to identify how the engagement of children aged 3 to 5 years old with a diagnosis of ASD in the routines of Early Childhood Education occurred, from the point of view of educators. The research was carried out in the national territory and the method was quantitative and descriptive, without manipulation of variables. Data collection and analysis took place under the following structure: response to an online form via “Google Forms” by each child's educator, with questions of the ClaMEISR’s instrument - Classroom Measure of Engagement, Independence, and Social Relationships. The objective of the protocol is to help the school team and the family in the evaluation of the routines of children aged between 3 and 5 years old. The score was obtained through questions about activities carried out by the children during a day at school, making it possible to assess how engaged the child was in each of their routines, so this could be monitored and worked on. As a result, it was found that the children with ASD did not show sophisticated engagement in the analyzed routines, demonstrating the need for curricular adaptations as something fundamental for expanding engagement in the educational context for students who are part of school inclusion programs. In the conclusion there is the suggestion of future studies to cover different age groups, in order to understand the impacts of engagement in the scholar context, and also how the environmental factors may favor or limit it.
Influência da morfologia no comportamento magnético em aglomerado de CoTPP
(Universidade Federal de São Carlos, 2022-03-23)
Rocha, Alberto José Moreira
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Souza, Ernesto Chaves Pereira de
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https://lattes.cnpq.br/1505400360366643
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Oliveira, Adilson Jesus Aparecido de
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https://lattes.cnpq.br/4640148190073166
The study of magnetic properties in organic molecules with transition metals has been intense in recent decades, mainly due to the ease of changing their magnetic behavior, either through the introduction of different types of atoms or through changes due to proximity effects with other materials. This thesis we presents the investigation of the magnetic behavior of samples of Cobalt 5-10-15-20-meso-tetraphenylporphyrin (CoTPP) deposited on SiO2 surface. The results showed high values of magnetic moment which as a consequence, led to the appearance of superparamagnetism in samples with a morphological aspect a few deposit, which suggest an interdependence between the morphology and the magnetic response. With aid of morphological techniques, it was possible to suggest the causes magnetic response. These results indicate the possibility of altering the magnetic behavior from changes in the morphology of the samples.
Sistema mecatrônico para identificação automática de filamento polimérico utilizado em processo de Manufatura Aditiva (Impressão 3D)
(Universidade Federal de São Carlos, 2022-03-23)
Cardinal, Gabriel Cioffi
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Endo, Marcos Tan
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https://lattes.cnpq.br/7506367468260024
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Aroca, Rafael Vidal
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https://lattes.cnpq.br/9262228584082064
Technological development and the improvement of manufacturing processes allowed the emergence of new manufacturing techniques over time. 3D printing has become a practical and affordable way to manufacture parts, products and components, whether mechanical or structural. This technology is increasingly common, both in industrial and private environments, due to its versatility and easy interaction with the method. However, in additive manufacturing, it is necessary to know the material that is being used, since the configuration of FDM (Fused Deposition Modeling) 3D printers for a given polymer directly impacts the proper functioning and quality of the manufactured part. In the present work, the construction of a low-cost prototype capable of differentiating Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) filaments was carried out through the indirect measurement of an intrinsic mechanical property of the materials, the hardness. This procedure was possible by building a system, driven by a servo motor linked to a four-bar mechanism, capable of measuring the difference in the penetration depth of a metallic tip in the filaments, through the interaction of a magnet with a Hall effect sensor. It was possible to identify both filaments from the differentiation of hardness, and the results were in line with the references provided by the manufacturer of PLA and ABS filaments.
Análise de diferentes configurações do leito de jorro com agitador mecânico e do equipamento convencional
(Universidade Federal de São Carlos, 2022-03-24)
Barros, João Pedro Alves de Azevedo
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Freire, José Teixeira
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https://lattes.cnpq.br/2270677706718167
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https://lattes.cnpq.br/9478039068045142
The mechanical spouted bed emerged as a modification of the conventional spouted bed to minimize problems in the movement of solids and the need for high air flows just for the existence of the spouting regimen. Therefore, this study aimed to analyze the modified spouted bed configurations incorporating three different types of the mechanical stirrer, and to observe the differences relative to the conventional equipment. Straight-blade, inclined-blade, and helical screw agitators were used with different types of inert particles (glass, alumina and polyethylene). For the analysis, variables such as the fluid dynamic behavior, velocity profile, air flow reduction, cycle time, drying and granulometry. The fluid dynamics of the mechanical spouted bed depends on the geometry of the stirrer and its speed of rotational. In the agitators with the form of straight or inclined-blades, the fluid dynamics was qualitatively similar to the conventional spouted bed, however, the differences between the conventional and the agitated bed become significant as the rotation speed of the agitator increases. For example, as a result of the increase in the rotation of the stirrer, there is a reduction in the fluid dynamic parameters, mainly in relation to the air flow required to agitate the bed. Similarly, the air velocity profile will also depend on the type of stirrer, the air flow used and the rotation speed, with higher values in the center of the bed, except for the screw-type stirrer. The effects of rotation speed and blade inclination on fluid dynamics were minimized from 240 rpm, depending on the mass of the particles inside the bed. The inclined-blade stirrer showed the best reduction in airflow and pressure drop, considering the effect of rotation speed and the different groups of particles, mainly in the tests with a greater height of the static bed. The increasing in the number of stirrer blades resulted in reduced air flow and better bed stability, but these results were only more evident at low rotational speeds. The proposed model for the straight-blade stirrer provided good predictions in terms of maximum pressure drop and air flow. In the drying process, it was evident that the time to reach equilibrium was different for each of the configurations, that is, the changes caused a change in the transient regime of the drying process. Rotation speed is also a parameter that can control the drying process, which also affects the characteristics of the final product, such as moisture and granulometric distribution. In general, the use of stirrers in the spouted bed provided significant improvements, reducing the air flow needed to stirrer the bed and pressure drop, in addition to providing greater stability to the bed. The XVII insertion of the stirrer in the bed can favor new applications and also expand the operating ranges of the conventional spouting, since in this equipment there are no problems of spout collapse and geometric limits.
Genealogia dos corpos e a crítica da razão eucórpica
(Universidade Federal de São Carlos, 2022-03-24)
Severino, Fulvio Cesar Garcia
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Riscal, Sandra Aparecida
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https://lattes.cnpq.br/0328618752218708
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https://lattes.cnpq.br/0701677359537574
Esta investigación es el resultado de un emprendimiento arqueogenealógico sobre el cuerpo desde el discurso biomédico. Más que producir una genealogía del cuerpo, se produjo una genealogía de los cuerpos. Con la intención inicial de comprender qué cuerpo se enseñaba en las escuelas, la investigación se ha dirigido a los siglos XVIII y XIX para construir una línea genealógica entre el cuerpo biomédico construido en esos siglos y el cuerpo biológico enseñado en el siglo XXI. Entre estos dos cuerpos (llamados con el mismo nombre, eucuerpo) se ha encontrado una variedad de otros cuerpos subsumidos y desaparecidos en el discurso del cuerpo biomédico. El eucuerpo se convirtió en el patrón de eficiencia económica y sexual para la inteligibilidad de esos otros cuerpos a través del hostigamiento y aniquilamiento de elementos que tendrían el potencial de componer la subjetividad: la voluntad, el espíritu, la conciencia, el deseo, la sensibilidad. Sin embargo, todos estos fueron incorporados en un engranaje mecánico-cibernético que atribuye menos un sobrefuncionamiento a la “máquina corporal” que controla y regula los cuerpos a través de este sobrefuncionamiento. Esta forma de concebir el cuerpo (como institución) condiciona una racionalidad, compuesta de discursos (enunciados y prácticas), que impone una semiología para la inteligibilidad de los diversos cuerpos: a este conjunto de procedimientos lo he llamado Razón Eucuérpica. En efecto, los cuerpos se convierten en recursos utilizables, los oicuerpos: todos somos oicuerpos, estamos inseridos en un engranaje social cuya eficiencia económica y sexual se exige como sobrefuncionamiento. Se trata de una especie de pacto social subrepticio (pacto oicuérpico), en el que no caben algunos cuerpos y, por tanto, necesitan ser despojados de su propio cuerpo (los aneucuerpos) – evaluados, vigilados y sancionados, predominantemente, por el sistema-dispositivo jurídico – y aquellos cuyos cuerpos fueron tan utilizados y/o tan reprimidos en sus subjetividades que se enferman (los superoicuerpos) – evaluados, monitoreados y “tratados” por el sistema-dispositivo médico. Eucuerpo (como cuerpo anatomo-metafísico producido por la racionalidad eucuérpica) y oicuerpos (como cuerpos anatomo-políticos) se unifican a través de una sutura empírico-metafísica en la que los oicuerpos se vuelven imagen y semejanza del eucuerpo (y no más de Dios). La ruptura de esta sutura como inteligibilidad exige la iansanidad, que sería el resultado de la capacidad de sustraer la propia subjetividad (la voluntad, el espíritu, la conciencia, el deseo, la sensibilidad) del fondo del engranaje mecánico-cibernético. Por lo tanto, todo el sistema eucuérpico produce iansanoabyección (evitación de las iansanidades); de hecho, las iansanidades necesitan ser constantemente reprimidas y resentidas para que el engranaje eucuérpico funcione, siendo su principal estrategia el fetiche eucuérpico como la ilusión de tener un eucuerpo. Esta tesis presenta el recorrido genealógico que ha permitido concebir toda la construcción teórica que propongo, denominada Razón Eucuérpica.
Catalisadores baseados em nitretos de carbono grafíticos e metais de transição: síntese e aplicações
(Universidade Federal de São Carlos, 2022-03-24)
Silva, Marcos Augusto Ribeiro da
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Oliveira, Cauê Ribeiro de
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https://lattes.cnpq.br/5321313558714462
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Teixeira, Ivo Freitas
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https://lattes.cnpq.br/9782517948999001
Carbon nitrides are polymeric compounds with a C3N4 stoichiometric ratio and formed by sp2 nitrogen bonds. Most of the works in the literature uses polymeric carbon nitride as a catalyst for application in organic reactions, however, this substance has poor crystallinity, high structural disorder and low reproducibility. In this study, we synthesized crystalline carbon nitrides through a thermalcondensation process with NaCl, controlling the structural organization during the polymerization and with high reproducibility. These compounds, organized as poly(heptazine imide), or PHI, possess cations stabilized between its layers of carbon nitride, which can be exchanged for transition metals such as Fe, Ni, Co and Cu. These metals coordinate with the PHI structure covalently, bonding to N atoms and stabilizing as highly dispersed metal sites, which can be called single atoms. Single atoms catalysis allows a higher efficiency per mole of metal and an environment that resembles metallic complexes, all in stable and recyclable supports. Catalysts with single atoms stabilized in crystalline carbon nitride have been applied in different organic reactions with major industrial appealing. The Fe-PHI tested in this work showed a high activity for benzene photo-oxidation reactions, generating relatively high conversions and high selectivity for phenol (61% of conversion and 99% of selectivity). Detailed analyzes verified that the active sites are formed by iron-oxo species, the formation of these species is promoted by light. The Ni-PHI was efficient in the conversion of nitrobenzene into azo and azoxybenzene compounds in a coupling mechanism, where Ni sites are responsible for the abstraction of an oxygen atom, such reactions are facilitated in ethanol and in the presence of NaBH4. The Cu-PHI was the most effective catalyst in the photoconversion of methane to methanol (and other oxygenated products) in the presence of H2O2, the results indicated that Cu atoms react photocatalytically with peroxide, forming Cu-OH species on the surface of the catalyst, which react with methyl radicals present in the solution. The results obtained with Cu-PHI showed the highest values (2900 μmol.g-1) reported, so far, for methane oxidation reactions under ambient conditions.
Análise bibliométrica do controle de pragas de produtos armazenados por óleos essenciais
(Universidade Federal de São Carlos, 2022-03-24)
Santos, Ramon Ferreira dos
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Araújo, Tamíris Alves de
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https://lattes.cnpq.br/4224270419293652
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Matos, Andreia Pereira
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https://lattes.cnpq.br/6155202940087696
Brazil is one of the biggest producers of grains in the world, but its maximum production potential has been threatened by the presence of stored grain pests that reduce the quality and quantity of grains. Given the inappropriate use of synthetic insecticides, selection pressure makes many of these pests increasingly resistant to control. On the other hand, the growing concern about the health of the population and the environment demands the development of less toxic and persistent products. Thus, essential oils, in their phytocomplexity, have potential for the management of unwanted organisms because they consist of several bioactive compounds, such as terpenes. The aim of this study was a bibliometric analysis of the evolution of the use of essential oils against the main pests of stored products in the world, through a systematic analysis of the bibliography indexed in the Web of Science and Scopus databases, seeking to understand the evolution of production scientific research in the scope of the use of essential oils in the control of pests of stored products, the identification of the main pests according to the analyzed bibliography and also the identification of plant species with potential for use in the control of these insects. Based on this analysis, it was found that the two most frequent species were the beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the corn weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). The data obtained also allowed us to observe the progress of research in the use of these oils in the control of these two pests in the last 20 years, as well as to verify the performance of the main molecules present in oils of species belonging to 39 botanical families in these insects.
Proposta de modelo para avaliação de espaços para pedestres quanto à percepção de seguridade
(Universidade Federal de São Carlos, 2022-03-24)
Silva, Otavio Henrique da
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Sanches, Suely da Penha
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https://lattes.cnpq.br/3857424839674606
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https://lattes.cnpq.br/4318259807867888
Different variables may or may not encourage the option of walking as a mode of transport. In particular, several studies have demonstrated the relevance of aspects related to personal safety, especially from a subjective point of view. But, unlike other dimensions related to walkability, perceived safety has not received, so far, a broad and detailed approach to its evaluation. From the perspective of urban planning, the availability of a tool with these characteristics could help formulate more efficient strategies to make cities safer. In this context, this research aimed to build a model for evaluating pedestrian spaces regarding the perception of personal safety, using a multi-criteria approach. For this, three main methodological steps related to (1) construction, (2) development of the technical evaluation system, and (3) the application of the model, named Perceived Personal Safety Index (PPSI), were performed. Regarding the construction of the tool, 17 characteristics of perceived safety that influence the option for walking transport were defined, based on literature, considering the urban dynamics of Brazilian cities. These characteristics were divided into two dimensions (Physical Space and Social Environment). After this, 405 questionnaires were applied to identify the users' understanding of the relevance of the selected characteristics. From the answers obtained, using Exploratory Factor Analysis, a hierarchical structure for the Index in indicators (relating to selected characteristics), factors, and domains (Physical Space and Social Environment), was developed and the relative weights of these three components were determined, using a bottom-up approach. Then, using a weighted linear combination, these indicators, factors, and domains were aggregated. The result of this mathematical expression, variable from 0.0 to 1.0, is equivalent to the final value of the model and indicates the perceived safety condition in a pedestrian space, which can vary from very poor to very good, respectively. The construction of the evaluation system included the definition of technical criteria and procedures, applicable even from images, for each indicator. Fuzzy functions were built to normalize the values of eight indicators within a range of 0.0 to 1.0. For the construction of the curves, information gathered from a panel composed of 36 specialists working in the transport area was used. Once the model was built and the evaluation system defined, the tool received an application. Using the Index, 24 images of the photography and Street View types, representative of different levels of perceived security, were evaluated. Also, six other urban scenarios were evaluated, represented in photographs during the day and night, which allowed exploring the variation of perceived security in these spaces in different situations. In general, the application of PPSI proved to be practical, indicating relevant information about the evaluated spaces from the point of view of personal safety. There is an understanding that the developed Index can be a tool to support decision-making aiming to promote safer spaces for pedestrians. Urban planners and managers and researchers can explore the potentiality of the model and investigate possibilities for adaptations, allowing for its continuous improvement.
Classes características de variedades topológicas e generalizadas
(Universidade Federal de São Carlos, 2022-03-24)
Barbosa, Alex Melges
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Santos, Edivaldo Lopes dos
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https://lattes.cnpq.br/2167472456497730
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https://lattes.cnpq.br/5225566478035439
In this work, we will initially present generalized bundles, a concept developed by Fadell with the objective of generalizing vector bundles, Stiefel-Whitney classes andWu’s formula from the context of smooth manifolds to topological manifolds. After that, we will use the generalized bundles to obtain original results of Thom, Stiefel-Whitney,Wu and Euler classes of topological manifolds, as well as present a second proof of Wu’s formula for topological manifolds and the topological version of the Poincaré-Hopf theorem. Finally, we will use the Poincaré and Poincaré-Lefschetz dualities to more comprehensively construct the Stiefel-Whitney classes of generalized manifolds in order to present, for the first time in the literature, a proof of the Wu’s formula for such manifolds.
Estudo da remoção de contaminantes emergentes em estação de tratamento de esgoto equipada com biorreator acoplado a filtração por membrana: uma alternativa para a produção de água de reuso
(Universidade Federal de São Carlos, 2022-03-24)
Machado, Rafaela Gonçalves
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Fadini, Pedro Sérgio
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https://lattes.cnpq.br/3255060531838427
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https://lattes.cnpq.br/3047073509236470
The degradation of water bodies and the indiscriminate use associated with frequent and intense drought episodes have compromised the availability of water. Thus, the production of reused water from sewage treatment has been a highly encouraged practice. However, the concern with water resources is not restricted to availability, but also to water quality. In this sense, emerging contaminants in aquatic matrices have attracted the attention of researchers, since the effect of long-term exposure on aquatic ecosystems and human health is not yet fully known, and considering the fact that sewage treatment plants (ETE) represent the main source of emission of these pollutants in receiving bodies, it is important to understand the occurrence and dynamics of these pollutants in ETE, in order to reveal compounds that can be used as chemical markers of treatment efficiency. Thus, the present study was carried out and evaluated the occurrence, spatio-temporal distribution, and removal of emerging contaminants in a Reuse Water Production Station - EPAR Capivari II (Campinas-SP) equipped with a bioreactor coupled to a water filtration membrane (MBR). In a second moment, surface water was collected from rivers in the interior of the State of Sao Paulo, for later comparison (in terms of emerging contaminants concentration) with the reuse water produced by EPAR. The investigated compounds were determined by liquid chromatography coupled to mass spectrometry (UPLC-MS/MS) and by gas chromatography coupled to mass spectrometry (GC-MS). The compounds studied were detected in all samples of raw sewage from the sampling campaigns, with caffeine being the compound found in the highest concentrations, whose range varied from 14379 to 131358 ng/L, with a median equal to 56709 ng/L. Regarding removal, the contaminants with the highest mean values were paracetamol (≅100.0%), caffeine (99.8%), ibuprofen (99.2%) and its metabolites, 1-hydroxy-ibuprofen (≅100.0%) and 2-hydroxy-ibuprofen (96.7%), naproxen (97.8%) and atenolol (97.5%). Among the compounds that showed moderate removal are diclofenac and propranolol with removals of 70.5% and 61.5%, respectively. The estrogenic compounds showed removals of 88.0% for 17-β-estradiol, 33.6% for estrone and 33.0% for 17-α-ethinylestradiol. On the other hand, carbamazepine and its metabolites (10,11-dihydro-10,11-dihydroxy-carbamazepine and 2-hydroxy-carbamazepine) showed a persistent behavior during sewage treatment. Carbamazepine obtained the removal of -7.36% and due to several factors that justify its persistence during sewage treatment, it was possible to point it out as a chemical marker of treatment efficiency. In view of the comparison of reuse water produced by EPAR and water from springs, it was concluded that it is necessary to use complementary treatments for the removal of emerging contaminants when the use of this water requires a more restrictive quality standard in relation to this parameter. However, the reuse water produced by the MBR system has good quality in terms of caffeine removal, total organic load, total suspended solids, turbidity, coliforms, among other parameters.
Monitoramento da integridade estrutural a partir de sensoriamento de baixo-custo: investigação de índices de dano e de efeitos de variáveis ambientais
(Universidade Federal de São Carlos, 2022-03-24)
Melo, Rafael Faria
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Shiki, Sidney Bruce
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https://lattes.cnpq.br/0573973677787523
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https://lattes.cnpq.br/9127729962605908
Structures are constantly subjected to external inputs, such as the application of forces, wind actions, temperature variations, among others, which can generate wear, noise and failures. Hence, techniques for monitoring the structural integrity are being increasingly applied nowadays. In this methodology, sensors are implemented to measure vibrations and identify changes in vibration parameters generated by these inputs in real time, making it possible to predict and anticipate necessary maintenance, which increases the longevity and safety of systems in general. However, the sensors and data acquisition systems commonly used today demands intensive financial investment. Thus, an instrumentation was performed using a low-cost sensor, of microelectromechanical origin, in a simple structure with 2 degrees of freedom, under the action of vibrations generated by an impact-type input, in order to investigate damage indexes based on natural frequency variations, as well as identifying the influence of environmental variables present. It was simulated damage to the structure through cuts in one of the supporting beams and natural frequency data were extracted for different environmental conditions and different levels of damage. Regarding the effects of environmental variables, a directly proportional relationship between temperature and natural frequencies was found, although almost negligible. Regarding the damage levels, more significant frequency variations were observed as the damage increased. It was found that the implemented acquisition system is suitable to be used for damage detection in structures and that environmental variables can influence the determined natural frequencies. In this sense, the need of measuring environmental variables during the structural monitoring was verified in order to obtain a correct identification of the true state of the system.
Leis de conservação: teoria geral
(Universidade Federal de São Carlos, 2022-03-24)
Viana, Matheus Magaiver Barbosa
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Kondo, Cezar Issao
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https://lattes.cnpq.br/0900348462714778
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https://lattes.cnpq.br/2549634777165532
In this thesis we study some aspects of the theory of Partial Differential Equations (PDE's), the theory of the existence and the uniqueness of classical solutions to the Cauchy problem u_t+f'(u)u_x=0, u(0,x)=u_0(x) in the range Π_T=[0,T)xR, where f∈C²(R) and u_0∈C¹(R). Furthermore, we will show some results on generalized solutions and build a generalized solution for functions f(u)=u³ and f(u)=sen u, both with five discontinuities lines. Next, some notions of Kruzhkov's generalized entropy solution are presented. Finally, we will discuss the solutions of the Riemann problem for a concave or convex function f and how concave or convex envelopes allow us to solve the Riemann problem for a function f∈C¹(R).