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Simulação da combustão em motores a jato utilizando CFD
(Universidade Federal de São Carlos, 2021-11-16)
Marini, Luca Martins
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Béttega, Rodrigo
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https://lattes.cnpq.br/1379682125857376
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https://lattes.cnpq.br/9189550285118444
Computational Fluid Dynamics (CFD), usually applied in the simulation of flows, combined with the simulation of chemical reactions is an interesting tool in the design and development of highly complex equipment, such as engines and combustors. In the present study, a computational simulation of combustion in a jet engine was performed using ANSYS Fluent software, initially using methane as the fuel, considering 5 chemical species along the combustion reactions involved, and then using Jet A, considering 32 chemical species involved in the combustion reactions. The simulated results were compared with simulated results from the literature, in addition to empirical data. The adopted model consisted of a Steady Diffusion Flamelet with chemical state relation, in addition to a non-adiabatic treatment, with a k-epsilon Realizable turbulence model. From the mathematical model and numerical procedure verified, a simulation of the combustion of commercial fuel Jet A (A2) was performed, in addition to the use of a geometry based on real models of jet engine combustors, demonstrating advantages mainly in relation to the computational cost involved. There was a substantial correlation between empirical and simulated data in the study with methane, in addition to a reduction in time per iteration in relation to the modeling reference found in the literature, allowing for deeper analysis, related to reaction kinetics, for example, such as profiles of concentration of intermediate reaction products, at lower computational costs. In the study with Jet A fuel, points of improvement in the geometry could be observed through the profiles of concentration, temperature, velocity, among others, making it possible to achieve greater efficiencies with the equipment in question and lower rates of generation of pollutants such as NOx that are generated in zones of high temperature and long residence times, in addition to enabling a better understanding of its operation.
Análise e simulação da reação de metanação do dióxido de carbono
(Universidade Federal de São Carlos, 2021-11-16)
Campeiro, Richard Rafael
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Santos, João Batista Oliveira dos
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https://lattes.cnpq.br/0285313473901330
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https://lattes.cnpq.br/2315779782016020
With the increasing environmental appeal nowadays, the question arises: how to use carbon dioxide in a way that reduces its impact on the environment? One possibility is the capture of CO2 and its transformation into chemicals. One of the possible reactions is CO2 methanation, which aims to produce CH4 through the reaction between CO2 and H2. There are two possible routes for this methanation, the first is the so-called "Sabatier reaction", in which CO2 reacts with H2 under the presence of a nickel catalyst and the second initially consists of the RWGS (reverse water-gas shift) reaction – which produces carbon monoxide through the hydrogenation of CO2 and then methanation the CO. Obtaining methane through these routes can be a means for the production of synthetic natural gas or it can be used in the production of other hydrocarbons. The methanation reaction was simulated with the software Aspen Plus, in which the reaction equilibrium was performed with the Gibbs reactor and the reaction kinetics was used together with the fixed bed reactor. The results indicated that the determination of the equilibrium constant by the Gibbs reactor with the RKSMHV2 model presented similarities to real conditions. The simulation in isothermal reactors showed a maximum CO2 conversion of 64.9% at 30 bar and 400°C. However, when comparing the simulation results with the experimental data, lags were observed in relation to methane yield, CO selectivity and CO2 conversion. Feeding excess hydrogen gas can be a viable alternative for increasing methane production.
Percepção dos estudantes de engenharia de produção de uma universidade pública quanto a prática do estágio em home office durante o contexto da pandemia de COVID-19
(Universidade Federal de São Carlos, 2021-11-16)
Camacho, Igor Mantuani
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Fontes, Andréa Regina Martins
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https://lattes.cnpq.br/4848646681792317
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https://lattes.cnpq.br/2860217974210689
In the COVID-19 pandemic scenario, with social distancing and the consequent need to adapt to this new global configuration, a lot of changes were observed in the fields of work and study. The distance services emerged, context where the supervised internship is inserted. With this premise, this research sought to assess the main points identified during the internship experience in the home office among students, through a case study with the application of interviews with 15 university students from the Production Engineering course of a public university from the state of São Paulo who went through this experience. The analysis consisted of comparing the benefits and disadvantages of this work regime, already discussed in the literature and in previous studies, with what was actually reported by students who performed their distance internships. The results allowed to identify the main limitations found in the process, so that they can be discussed and analyzed in the future, seeking a better application of the home office in conventional jobs and, mainly, in the supervised internship itself. It was concluded that the aspects reported are directly related to each experience, being directly influenced by the profile of each intern and by the way this work format was applied by the company. It was also noted that the entire context experienced influenced on the mental health of students, who exposed in their perspectives the anxieties, concerns, fears and doubts about academic and professional life.
Análise espacial de parâmetros ecológicos para a conservação de aves marinhas no litoral do estado de São Paulo
(Universidade Federal de São Carlos, 2021-11-16)
Coelho Netto, Bruna Zappia
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Toppa, Rogério Hartung
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https://lattes.cnpq.br/0673898572494729
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https://lattes.cnpq.br/6412704788639232
There are four taxonomy orders of marine birds commonly found in Brazil (Charadriiformes, Pelecaniformes, Procellariiformes and Sphenisciformes). Habitat modifications are the main cause for its populational decrease, in which nesting and foraging sites are the most decisive for species ecology and, simultaneously, the most afected by antropic interference. The present study aims to evaluate the spacial distribution of marine birds ecologic parameters at São Paulo’s sheashore for the discussion of conservational strategies propositons to the group. From the study area, set out by all of 15 paulista coastline counties, data collection was executed through Sistema de Informação de Monitoramento da Biota Aquática (SIMBA), accountable for archiving the marine tetrapods registers of Projeto de Monitoramento de Praias da Bacia de Santos (PMP-BS). Only the Birds occurrences were taken, between August 20, 2019 and April 26, 2021. Attribute analysis was proceeded in GIS environment (Geographical Information System) and through descriptive statistics based on two fundamental ecologic parameters (foraging habits and reproductive seasonality). Tables and tematic cartographic products were created (coastal region, foraging habits and reproductive seasonality), crossing individual geographical coordinates and aplying the rescue date of each one of them as criteria to validate its presence at paulista seashore. 36 species and 4.395 individuals of marine birds were registered, specially at Ilha Comprida. They were classified in five foraging habits (cleptoparasitism, diving, scavenging, pecking and surface fishing) and four southern breeding seasons (spring, summer, autumm and winter). For foraging habits, surface fishing was the most abundant on the amount of species (n=14), while diving was the most abundant on the number of individuals (n=3.366). For reproductive seasonality, the most abundant season was spring (n=26 species). Spatial analysis sugests that the distribution of marine birds at São Paulo state seashore it's reasonably in agreement with the biology of the species. The main conservation strategies proposed are the diversification of the target fauna in focus through environmental education actions, the elaboration of protocols for limits on visitation to the municipalities on the coast of São Paulo, especially in seasons, and the revision of the Management Plans of the corresponding marine APAs.
Pandemia, teletrabalho e o impacto na carga mental do trabalhador
(Universidade Federal de São Carlos, 2021-11-16)
Machado, Michelle Salas Corrêa
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Fontes, Andréa Regina Martins
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https://lattes.cnpq.br/4848646681792317
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https://lattes.cnpq.br/8490023864575007
Telework began to become natural and even emerge changing the reality of many companies and workers. The changes that the expansion of this modality imposed had impacts on the worker's mental health. The purpose of this article is to examine the impacts on the teleworker's mental health, especially during social isolation. This research is classified as exploratory, with a case study method and a qualitative and quantitative approach, with the application of a questionnaire and interviews based on the Inventory on Work and Risk of Illness (ITRA). The results indicated that feelings of anxiety and sadness are the highlights in the answers, as well as difficulty in concentrating, sadness and irritability. These impacts are triggered mainly by the lack of time for rest, excessive pace and lack of humanization. It was concluded that knowing and acting on issues that afflict teleworkers can make it viable to continue this modality or to combine hybrid regimes with in-person moments. Technologies allow and some functions favor the adoption of this regime, but alleviating issues of suffering and promoting issues of pleasure at work can increase the quality of life of workers and improve the performance of the company itself.
Design of a solid-state hydrogen storage tank for application in the European Spallation Source (ESS)
(Universidade Federal de São Carlos, 2021-11-16)
Dias, Gabriela Chimello Mayer
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Ferreira, Marcelo Juni
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https://lattes.cnpq.br/5471938976013160
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Zepon, Guilherme
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https://lattes.cnpq.br/7924187202036614
The European Spallation Source, located in Lund, Sweden, is one of the largest scientific and technological infrastructures currently under construction and will be the world’s most powerful neutron source. Its operation will be based on proton acceleration and scattering technology, giving rise to neutron beams up to 100 times brighter than those obtained by existing sources in Europe. In summary, a proton beam is produced by rapidly varying electromagnetic fields, heating hydrogen gas so that electrons evaporate from the hydrogen molecules. The beam will then be accelerated until it hits a target made of stainless steel and containing bricks of tungsten, generating scattering neutrons used in various scientific instruments. However, there is a problem related to the storage of the hydrogen gas used in producing the proton beam. Initially, a cylinder containing 5 liters of H2 at 150 bar pressure was designed, but local regulations state that the pressure cannot exceed 1.45 bar. In this scenario, hydrogen storage in the solid state through metal hydrides would be an excellent alternative for storing the required volume of hydrogen at a much lower pressure level and with a higher volumetric density. Therefore, the goal of this work was to design a tank for solid-state hydrogen storage, ensuring a pressure level below 1.45 bar. For this, a multicomponent alloy was selected through results reported in the literature and compositional adjustments based on a thermodynamic model that allows the prediction of PCT (Pressure-Composition-Temperature) diagrams. Furthermore, calculations were performed for the tank sizing, and its components were selected and analyzed, resulting in two project options. Next, a cost projection for the tank production was elaborated, involving the costs of raw materials to produce the selected alloy and the components chosen to compose the tank. Finally, a prototype and proof-of-concept tests were proposed to verify essential properties for this project, such as the H2 flow rate reached.
Estudo da viabilidade de aplicação do transporte pneumático para abastecimento de sulfato de sódio em indústria de fibra de vidro
(Universidade Federal de São Carlos, 2021-11-16)
Almeida, Thales Rosado de
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Béttega, Rodrigo
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https://lattes.cnpq.br/1379682125857376
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https://lattes.cnpq.br/6556795587311620
Technology advances changed the way we approach fine powder loading within the industry. Efficient and focused on problem-solving, these solutions drastically reduced losses in industry activities. The purpose of this project is to investigate new solutions for sodium sulfate loading in a fiberglass plant, assessing safety, utilities, installation, maintenance, and operational impacts. Studies regarding modern sodium sulfate loading led to two scopes, structured for further understanding. One of them is an airoperated diaphragm pump, modified for fine powder pumping, while the other is a reallocation of an inactive blow tank. Each scope was analyzed concerning safety risks, start-up costs, and monthly expenses. Costs related to the initial situation were estimated in 198,25 R$/month, while the blow tank proposition had an projected cost of 102,86 R$/month and the AODD pump, 90,16 R$/month. Safety was handled by risk based process safety guidelines, whose results for risk managing was 440 for current sodium sulfate loading, 275 for the blow tank operation, and 110 in an AODD pump activity, the only one that requires no further action to mitigate risks. In the end, the AODD pump was chosen as the most viable, mainly because of its safety benefits.
Perspectivas de implementação de conceitos da indústria 4.0 no bioprocesso de produção de Bacillus thuringiensis
(Universidade Federal de São Carlos, 2021-11-16)
Chagas, Pablo Almeida
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Casciatori, Fernanda Perpétua
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https://lattes.cnpq.br/1269950652196294
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https://lattes.cnpq.br/8220907672938755
Brazil is one of the largest agricultural producers and exporters in the world, and is consequently a major user of agricultural pesticides to guarantee the sale of crops. It is globally known that many types of pesticides used on plantations are harmful to human health and cause serious damage to the environment, which requires an urgent need for a route of pesticides that has high efficiency, is not harmful to the environment and health human, and is economically viable. In this sense, the biopesticide based on the bacterium Bacillus thuringiensis is an alternative that meets the aforementioned criteria to replace the use of pesticides. However, the production process is currently not conducted as industry 4.0 global trends, which may result in less pesticides being eliminated in the market. Given the above, the objective of this work was to evaluate the production process of the biopesticide based on Bacillus thuringiensis and to bring possible interfaces with Industry 4.0, suggesting possibilities of artificial intelligence and internet of things applications in different stages of the productive bioprocess, in order to to obtain a more integrated, optimized and economically viable bioprocess.
Avaliação da viabilidade técnico-econômica da etapa reacional da hidrogenação seletiva de CO2 a metanol
(Universidade Federal de São Carlos, 2021-11-16)
Valadares, Arthur Coutinho
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Lima, Alice Medeiros de
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https://lattes.cnpq.br/0038936541518854
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https://lattes.cnpq.br/8379652553257979
Methanol is a very important raw material used in the chemical industry, being applied in the production of other chemicals, such as formaldehyde, acetic acid and plastics. In the last decade, the annual methanol production doubled, reaching 98 million metric tons (Mton), and is estimated to be 500 Mton in 2050. However, due to being produced from fossil sources, like coal and natural gas, there is a big release of carbon dioxide. Nowadays, about 10% (0,3 Gton) of all CO2 produced by the chemical industry comes from the methanol cycle, which encompasses from production to consumption. If new sources of methanol, renewables, are not delevoped, it is estimated that in 2050, 1,5Gton of CO2 will be released annually in the cycle of this alcohol. The major obstacle to produce methanol with less impact on the environment, currently, is the cost to produce hydrogen gas. There are different lines of studies that seek the feasibility of producing methanol from new sources, including: the generation of synthesis gas from biomass (Bio-methanol or Green methanol); hydrogen production from electrolysis, with the use of renewable energies (E-methanol or green methanol); and carbon capture (blue methanol), which is the case studied in this work. The objective of this work was to simulate, using the software Aspen Plus® and a kinetics developed on a laboratory scale available in the literature, and verify the economic feasibility of the reaction step on an industrial scale. The simulations were divided into three stages: the initial stage was a simulation of the thermodynamics of the system, to verify the response of the simulation with values presented in scientific publications; then, the kinetics reported in the literature were implemented, and a validation of the simulated results was carried out based on the empirical data; finally, it carried out an analysis study varying the operating conditions (reactor temperature and pressure, feed flow, catalyst mass) to assess the economic viability of the process, using the Net Present Value (NPV) as a metric. It is expected as a result of this work to find the conditions that can make the process viable or even indicate possible paths to economic viability. With the function obtained, it was possible to optimize the NPV within the limits of the kinetics under study, however, no case was found in which such value is positive, therefore, with limitations imposed by the kinetics used, profit with sales and cost of inputs, it is not feasible to perform the implementation of such a project
Propriedades mecânicas e bioativas de PLA, PCL e suas blendas com HA impressas por FFF
(Universidade Federal de São Carlos, 2021-11-16)
Shimomura, Kawany Munique Boriolo
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Costa, Lidiane Cristina
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https://lattes.cnpq.br/8246109223926480
Bone repair measures involving surgeries and tissue replacements are increasingly present today, in addition to the progressive advancement of the market for prostheses, implants and technologies that invest in the health area. From 2009 to 2011, approximately 225 million patients had a medical diagnosis related to orthopedics, costing about 215 billion dollars if hip and knee replacement are included (CHEN, 2019). In this context, numerous researches are currently carried out with the aim of developing a more advantageous option for cases of surgeries involving bone tissue. Based on Materials Engineering, it is possible to go deeper into bioactive and biocompatible materials, including polymers and composites, which are highly qualified candidates for a possible replacement of the referred tissue. Through a literature review, it was possible to find numerous materials and the most promising techniques and to delve into them. In this work, we will study the feasibility of scaffolds, obtained by the FFF process (Fused Filament Fabrication), of a PLA/PCL (polylactic acid/polycaprolactone) blend with HA (hydroxyapatite) load to be used in order to replace bone tissue.
Produção de hidrogênio como fonte de energia e estratégia de gestão de resíduos e mudanças climáticas
(Universidade Federal de São Carlos, 2021-11-16)
Prado, Vitória Batista Candido do
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Rosa, Paula Rúbia Ferreira
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https://lattes.cnpq.br/4284223404098079
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https://lattes.cnpq.br/3807387025305454
With the increasing population growth and industrial development, the level of waste generated by human beings and industries has reached an alarming point. Allied to this fact, the air pollution brings to light the need to develop sustainable techniques and cleaner energy production which could give added value to these wastes. Hydrogen gas can be a clean energy source, having the highest heat content per unit of mass among all the fuels we use, and having a very high potential as an energy carrier. The biological hydrogen production involves using microorganisms which degrade the organic matter present in organic waste in an anaerobic way, in order to provide hydrogen at the end of the process. In this context, the present study aims to carry out an analysis of scientific publications on the subject, presenting the most relevant works, detailing the most important parameters for the hydrogen production from organic waste, and comprising global references on the matter. For this, a detailed analysis of scientific data was performed using the database on the Web of Science. China is the country with the largest number of publications on this topic, and the year 2020 stood out as the most prolific in terms of number of studies. The articles constitute 83.72% of the studies found in the research, and the two scientific journals that published the most were Bioresource Technology and the International Journal of Hydrogen Energy. The results found in the Web of Science were refined based on the relevance given by the platform, selecting 42 articles for analysis. Among them, 45.23% had the objective of optimizing the hydrogen production, and the two most varied parameters to verify the influence on the H2 production were the organic loading rate and the hydraulic retention time, in 21.42% of the studies. The batch reactor was the most used, in 35.71 of the studies. In 72% of the studies, the temperature was used in the mesophilic range, between 35 and 38 oC. The most used pH was in the range between 5 and 6, and in relation to the organic loading rate (OLR) the vast majority used 4 to 100 g COD / L.day. The hydraulic retention times used were in the range between 6 h and 36 h.
Interdependência produtiva e emissões em São Paulo: uma aplicação do método de extração hipotética
(Universidade Federal de São Carlos, 2021-11-16)
Vilas Bôas, Larrisa Alves
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Gomes, Alexandre Lopes
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https://lattes.cnpq.br/5002157193962189
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https://lattes.cnpq.br/1074068916366452
Due to the generation of greenhouse gases (GHG) in production processes, several methodologies have been applied in order to measure and monitor emissions from countries and regions. In this context, the discussion about the responsibility of emissions is important, by investigating the pollution, not only from the production principle, but also from the consumption, through the demand of other sectors by those characterized as pollution-intensive. Thus, the analysis of the sectorial linkages of the economy allows verifying the direct and indirect flows of pollution. This paper aims to bring an investigation of the dependency structure of São Paulo sectors through an interregional input-output matrix, São Paulo and the rest of Brazil, for the year of 2011. The hypothetical extraction method was used to investigate sectorial relations and the degree of sectorial and regional interdependence. In addition, the responsibility of emissions for São Paulo sectors is analyzed through trade flows. In the results, the sectors which was identified as pollution intensive were Land Transport, Other Transport, Metallurgy, Non- Metallic Mining, and for São Paulo, Agriculture. The sectors that presented the highlight backward linkages were Trade and Services, Other Industries, Chemicals and Food and Beverages. Through the forward effects, the sectors indicated as interdependent were Trade and Services, Other Industries, Energy and Chemicals. It was possible to verify that sectors not characterized as intensive in emissions have significant dependence on sectors determined as intensive, mainly Land Transport.
Interpretando hiperinflação como bolhas racionais: o caso da América Latina
(Universidade Federal de São Carlos, 2021-11-16)
Revoredo, Jonatas Rodrigues
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Silva Junior, Geraldo Edmundo
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https://lattes.cnpq.br/5138808982229139
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https://lattes.cnpq.br/8512469196896594
Inflation is one of the most fruitful areas of the economy, being the target of several studies and hypotheses, whose control is essential for the maintenance of economic stability and social well-being. Appropriate policy management to deal with hyperinflationary environments is dependent on the inflation-generating factor, an incorrect diagnosis will lead to unresolved measures. Thus, the early identification of price movements and the root of their causes become decisive factors in the implementation of efficient actions for hyperinflationary control.One of the factors that affect the price trajectory is the demand for currency, which in times of inflationary surges tends to be determined by agents' speculative factors. Thus, the present work advances in the identification of bubbles of a speculative nature, the so-called rational bubbles. These are bubbles that are influenced by the behavior of agents, detaching themselves from the endogenous factors that should explain their variations. Thus, the crucial hypothesis of the work is that discrepant changes between the price level and the market fundamentals in hyperinflationary periods configure the existence of a rational bubble. A money demand model that relates real money stocks to a single variable, inflation expectations, is used as a structural model. Such a model presents great adequacy in hyperinflationary periods, duet o the behavior of agents on future price speculation. For the identification of bubbles in the series, the RADF, SADF and GSADF tests were used, which apply ADF tests on the sample, alternating the taking of the windows within the sample. To verify the relationship between the price level and market fundamentals, cointegration tests were used. The results for the money demand model were robust both in terms of what the theory predicts and adequacy and adjustment statistics. Bubble tests identified 11 total bubbles in the series for Bolivia, Brazil, ChileColombia, Peru, and Suriname. Of these, Brazil, Peru, and Suriname presented zero cointegration vectors in the trace and Lambda Maxtests, between the logarithm variables of prices, exchange rate, and monetary base, identifying the presence of rational bubbles in the hyperinflationary processes of these countries.
Estudo da aplicação do SURMOF em componentes eletrônicos utilizados em circuitos digitais
(Universidade Federal de São Carlos, 2021-11-16)
Colletti, Julia Cantovitz
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Scuracchio, Carlos Henrique
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https://lattes.cnpq.br/0896060959622431
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https://lattes.cnpq.br/5578561399386294
Faced with technological advances and the requirement for increasingly stable, more compact and more versatile materials, nanotechnology enables the study and manipulation of materials for the construction of new components and devices in order to meet the demands of the technological industry. Among the countless results of nanotechnology, we can mention the creation of increasingly compact and integrated microprocessors, used to produce computers and cell phones that are more powerful, faster and with less energy consumption. One of the branches of nanotechnology is the study of materials with unique properties for integration into nanoscale devices. An example of a material whose scientific and technological interest is currently growing are surface-mounted metalorganic frameworks (SURMOFs). SURMOFs are porous crystalline materials obtained from the deposition of thin films of metal-organic frameworks (MOFs) grown on solid substrates functionalized with self-assembled monolayers (SAMs). The presence of immobilized SAMs on the substrate allows the growth of a MOF film with high crystalline orientation, high porosity, homogeneous and uniform, which allows its use in a wide range of applications. In this context, the work will show how SURMOF can be applied in electronic components used in digital circuits, evaluating, through recent studies, their physical, optical and electrical properties.
Estudo de caso: seleção de revestimento antiaderente para redução de setup do tratamento de sementes de milho
(Universidade Federal de São Carlos, 2021-11-16)
Marçal, João Vitor Menezes
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Pádua, Thiago Faggion de
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https://lattes.cnpq.br/8909812973749651
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https://lattes.cnpq.br/4376725863272804
Corn is the most produced cereal in the world, being used on a large scale for various purposes. Corn seeds go through processing units, and in one of the stages of the process a treatment is applied to protect them from insects, microorganisms, among others. In this sense, the industrial polymer-based treatment has been increasingly used to increase the durability and make easier to cultivate seeds. However, due to the characteristics of this treatment, the solution used builds up on the lid of the treater over time, making it necessary to interrupt production to remove it. This setup is a bottleneck in the production process and is considered a waste in the lean manufacturing philosophy. Thus, the present work aimed to select a non-stick coating to reduce the sector's setup time. In this context, comparative tests of incrustation and cleaning of 7 specimens coated with non-stick and control were carried out. The results were analyzed statistically, and indicated that the Gentoo coating was one-third less encrusted than steel and cleaned ten times faster. Furthermore, in the technical-economic evaluation, it was the only one that showed profitability above the minimum attractiveness rate, with an internal rate of return of 20.03% p.y. Therefore, although there are uncertainties about its durability, the coating has shown promise to be applied on the treater's lid and thus reduce setup time. As side benefits, this investment should also reduce waste generation and improve the ergonomics of operator activities.
Diferenciação morfométrica da concha de Anodontites trapesialis (Lamarck, 1819) (Mollusca-Bivalvia) em diferentes bacias hidrográficas brasileiras
(Universidade Federal de São Carlos, 2021-11-16)
Marques, Rafael Cavalheiro
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Arruda, Eliane Pintor
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https://lattes.cnpq.br/8843243211552880
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https://lattes.cnpq.br/2308471722619499
Considering the relevance of Anodontites trapesialis, a freshwater bivalve of the Mycetopodidae family that has differences in shell shape throughout its wide distribution, this study analyzed and morphometrically compared individuals of A. trapesialis from different watersheds, seeking to select shell characteristics that could help in the identification of the species, and looking for relevant morphological and biogeographic information. The collections used were: MZUSP, UFMT, MCN - FZB and CIB (UFSCar). From a total of 118 analyzed individuals, 35 belonged to Paraguay river basin, 32 to Paraná, 18 to Uruguay, 18 to South Atlantic and 15 to Amazon river basin. Photographic records were taken from the internal face of each specimen shell, where the landmarks were localized (10 in total). With the TPSDIG software, landmarks were digitized, and x and y coordinates of each landmark were obtained. With the MorphoJ software, these coordinates were overlaid using GPA (General Procrustes Analysis) separating size and shape components and generating a matrix of the procrustes coordinates, that were used later in statistical analysis. The statistical analysis made were Procrustes Anova, Principal Components Analysis (PCA), Canonical Variate Analysis (CVA, maximum shell shape differentiation), Discriminant Analysis with cross validation and Mahalanobis Distance. The Procrustes Anova indicated significant differences between populations according to latitude (F=4,87 p<0,0001), while the PCA pointed that the axis that best explain the difference between shell shapes were 1 (40,918% of variation) e 2 (16,588%). The CVA resulted in 2 main axes: the 1st axis (shape) explained 51,356% of the variation - the analysis showed significant difference among Uruguay river and Paraguay river basins, and slight difference showing an overlay between other river basin groups. The Discriminant Analysis showed high percentages of identification, confirming the CVA (higher percentages show groups with higher distance, resulting in 100% when comparing Uruguay and Paraguay river basins), and showing that the shells from Paraguay and Amazon River basins are taller, while the ones from Paraná, Uruguay and South Atlantic are usually rhomboid. When analysing Mahalanobis Distance, the biggest difference is found between the populations from Amazon River basins and South Atlantic watershed, matching the higher geographic distance. The regression analysis allying the centroid size and the Regression Score pointed that a fraction of the shape variation is influenced by the size of the shell. Finally, this study led to the conclusion that there are differences between populations from varied basins, such as greater (like those from Paraguay river basin) or shorter heights (such as the ones from Paraná river basin), with similar shapes (such as South Atlantic and Uruguayan shells) or contrasting shapes (alike those from Uruguay and Paraguay), all that taking into account that a fraction of all variation is related to size and other fractions are related to environmental variables.
Tecnologias de produção de biodiesel: uma revisão
(Universidade Federal de São Carlos, 2021-11-16)
Orsi, Helena Medeiros
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Assaf, José Mansur
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https://lattes.cnpq.br/9563312407691130
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https://lattes.cnpq.br/7201519322056184
Biodiesel is a synthetic biofuel considered as a natural and renewable substitute for petroleum diesel, which can be produced from vegetable oils, oils of microbial origin and / or animal fats in reaction with an alcohol, in the presence of a catalyst. This reaction is called transesterification. Biodiesel represents an essential component in the establishment of a sustainable energy matrix, taking into account the increase of consumption in today's society, the increase of the price of petroleum, the possibility of depletion of fossil fuels and the environmental impacts caused by them. The purpose of this project is to carry out an extensive and commented review of the available literature on the different technologies for the production of biodiesel. For the development of this project, the following topics will be addressed with emphasis: reagents; catalysts; type of process (chemical or enzymatic, batch or continuous); reaction route; separation and purification of biodiesel; physicochemical characteristics of the product; economic outlook and market demand; storage and distribution; by-products; diesel oil / biodiesel blends. Finally, a proposition to use ethanol on the transesterification process to produce biodiesel was presented, considering concepts learnt during the Chemical Engineering graduation and the current context.
Aprendizado não supervisionado de métricas via redução de dimensionalidade para reconhecimento de dígitos numéricos
(Universidade Federal de São Carlos, 2021-11-16)
Chinen, Felipe Churuyuki
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Levada, Alexandre Luis Magalhães
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https://lattes.cnpq.br/3341441596395463
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https://lattes.cnpq.br/1275954908894553
Character recognition is a task that has occurred since the last century and is still a problem to be solved nowadays. One of the challenges is that the characters to be classified are images, therefore, they have many dimensions (each pixel is a dimension in a gray image). In this paper were used two different databases that contain handmade characters. Working with a database with many dimensions is a challenge, due to issues like the curse of dimensionality, and to try to solve this complication, dimensionality reduction is usually an attempt to mitigate the problem. In this work were used several supervised classification algorithms and were used non-linear dimensionality reduction algorithms: ISOMAP, LLE and Laplacian Eigenmaps with the purpose of learning a metric (a distance function) better suited than the Euclidean distance among the input images. Finally, the Wilcoxon test was used to compare statistically the dimensionality reduction algorithms.
Exercise-based pulmonary rehabilitation for interstitial lung diseases: a review of components, prescription, efficacy, and safety
(Universidade Federal de São Carlos, 2021-11-16)
Mendes, Renata Gonçalves
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Castello-Simões, Viviane
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Trimer, Renata
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Garcia-Araújo, Adriana Sanches
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Silva, Andréa Lúcia Gonçalves da
Análise e simulação dos efeitos da variação de pressão e temperatura no teor de monômero residual em polímeros vinílicos em emulsão
(Universidade Federal de São Carlos, 2021-11-16)
Pereira, Paulo Eduardo Sales
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Ribeiro, Marcelo Perencin de Arruda
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https://lattes.cnpq.br/0381402687491195
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https://lattes.cnpq.br/1131576032348114
The residual monomer content is a concern in any chemical polymeric synthesis process as it is both a commercial specification and a storage safety parameter; since most reagents release large amounts of flammable vapors at room temperature. This care is even more restricted when working with polymers based on Vinyl Acetate, the so-called PVAs, widely used as additives in the paint, paper and high-performance adhesive industries. Vinyl Acetate has a low flash point (-8°C) and, therefore, requires actions that guarantee the presence of molecules in the aqueous phase to the detriment of the vapor phase, thus favoring the polymerization reaction. In general, in PVA syntheses, a longer reaction time is dedicated in order to guarantee that the monomer content reaches the specification, therefore increasing the cycle time of the process. In this work, NRTL, Wilson and UNIFAC thermodynamic models are used for the activity coefficient of the simplified Gamma – Phi equation in order to simulate an emulsion polymerization process in the Aspen Plus software and, subsequently, compare the results with real content data monomeric in the liquid phase obtained by gas chromatography (GC) during the reaction inside an isothermal semi-continuous reactor. After choosing the best model to represent the liquid-vapour balance in the reaction tank, sensitivity analyzes were performed in the simulation software itself to evaluate different thermodynamic operating conditions (temperature and pressure) in order to find specification pairs that reduce the reagent loss by evaporation and increase its conversion in the process. After the sensitivity analyses, it was found that an increase in the pressure and temperature set-points, within industrial safety limits, after the end of the feeding of the reagents to the vessel contributes to accelerating the consumption of monomer to the desired value and, therefore, they reduce the time required for the process. Furthermore, after analyzing the simulation results and comparing them with the gas chromatograph responses, it was noticed that the three models accurately report the process phenomena, with emphasis on the Wilson correlation, which showed the smallest deviation.