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Simulação da combustão em motores a jato utilizando CFD
(Universidade Federal de São Carlos, 2021-11-16) Marini, Luca Martins; Béttega, Rodrigo; https://lattes.cnpq.br/1379682125857376; 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.
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; Fontes, Andréa Regina Martins; https://lattes.cnpq.br/4848646681792317; 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 e simulação da reação de metanação do dióxido de carbono
(Universidade Federal de São Carlos, 2021-11-16) Campeiro, Richard Rafael; Santos, João Batista Oliveira dos; https://lattes.cnpq.br/0285313473901330; 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.
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; Lima, Alice Medeiros de; https://lattes.cnpq.br/0038936541518854; 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
Estudo da aplicação do SURMOF em componentes eletrônicos utilizados em circuitos digitais
(Universidade Federal de São Carlos, 2021-11-16) Colletti, Julia Cantovitz; Scuracchio, Carlos Henrique; https://lattes.cnpq.br/0896060959622431; 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.
Interpretando hiperinflação como bolhas racionais: o caso da América Latina
(Universidade Federal de São Carlos, 2021-11-16) Revoredo, Jonatas Rodrigues; Silva Junior, Geraldo Edmundo; https://lattes.cnpq.br/5138808982229139; 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.
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; Gomes, Alexandre Lopes; https://lattes.cnpq.br/5002157193962189; 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.
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; Arruda, Eliane Pintor; https://lattes.cnpq.br/8843243211552880; 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.
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; Pádua, Thiago Faggion de; https://lattes.cnpq.br/8909812973749651; 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.
Desenvolvimento do protótipo: cervejaria artesanal móvel automatizada - CAMA
(Universidade Federal de São Carlos, 2021-11-16) Nascimento, Bryan Jonathan do; Casciatori, Fernanda Perpétua; https://lattes.cnpq.br/1269950652196294; https://lattes.cnpq.br/7874172612652628
Beer is a drink consumed worldwide, based on a combination of grains that generate a sugary must which, in turn, undergoes fermentation, prepared in the final drink. There are variations in the method of production, which gives rise to different types of beer. However, in general, the legislation in Brazil defines that: “Beer is the beverage resulting from fermentation, from brewer's yeast, malted barley must or malt extract...”. In recent years, there has been an increase in the number of micro breweries in Brazil, giving rise to the opportunity to associate the process process, characteristic of engineering courses, with cheaper solutions for the electronic control system of the industrial plant. Given the above, the objective of this work is to present a prototype that combines the production process of a mini brewery with low-cost and returned technologies, thus seeking automation and control of the brewery, being capable of replication in micro craft breweries. The hardware was developed using a small single board computer the Raspberry Pi, a commercially available mechanical relay module, a handcrafted solid state relay driver and other accessories such as valves and pumps. The programming was developed on a stream-based platform, Node-RED, created by IBM, based on JavaScript. Among the functionalities of the prototype called automated mobile craft brewery (AMCB), it includes automatic opening and closing of valves, automatic activation of electrical resistances and automatic activation of electric pumps. In this way, the processes of heating and pumping fluids between the different tanks through which the brewer's must passes can take place in a well-controlled and automated way, contributing to the quality of the drink and to the optimization of production, even in small breweries. The control center and the developed software met their goals, performing a temperature ramp in the heating part of the process together with a recirculation and maintaining a fermentation temperature in the refrigeration part.
Tecnologias de produção de biodiesel: uma revisão
(Universidade Federal de São Carlos, 2021-11-16) Orsi, Helena Medeiros; Assaf, José Mansur; https://lattes.cnpq.br/9563312407691130; 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.
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; Ribeiro, Marcelo Perencin de Arruda; https://lattes.cnpq.br/0381402687491195; 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.
Os impactos do teletrabalho na carga mental das trabalhadoras administrativas de empresas de bens de consumo durante a pandemia do COVID-19
(Universidade Federal de São Carlos, 2021-11-16) Poles, Marina de Souza; Fontes, Andréa Regina Martins; https://lattes.cnpq.br/4848646681792317; https://lattes.cnpq.br/9463050719896843
With the measures of distancing the COVID-19 pandemic, the telework model was adopted by companies, generating economic, sociological and psychological impacts in a different way for each population group, such as for women. The aim of the case study was to investigate the impacts generated by teleworking on the mental workload of consumer goods companies’ female administrative workers. To carry out this study, the ten women were interviewed with a pre-structured script, which covered economic, sociological and psychological impacts. An analysis of the union of the workspace with the home space enabled a holistic investigation of the impacts on the workers’ mental load, as well as on their routines, work environment, and family relationships. Positive impacts were noted, such as reduced commuting time, productivity and quality of life, and impacts such as lack of social contact, increased workload and reconciliation of personal and family tasks. It is concluded that women have great mental overload during the implementation of telework regret, mainly due to the increased workload and the reconciliation of work with home and/or family. For the future, most of the interviews proposed that a hybrid work model be established and that the companies' support be more coherent with the situation.
Avaliação do ciclo de vida de discos de vinil
(Universidade Federal de São Carlos, 2021-11-16) Dela Corte, Guilherme Castro; Marini, Juliano; https://lattes.cnpq.br/4533610255047654; Moreira, Francys Kley Vieira; https://lattes.cnpq.br/7156680316782417; https://lattes.cnpq.br/6542955144830927
PVC is the second most consumed thermoplastic worldwide, but the life cycle assessment (LCA) of PVC-based products is still a rare topic of scientific publications. There are only a few environmental studies on long-term lasting PVC products. In this work, the potential environmental impacts of the vinyl record (LP) life cycle were evaluated. Two distinct simulations comprising LP disposal by landfilling and incineration were carried out to describe the eco-indicators for postconsumer treatments considered to be critical upon a circular economy basis. Thus, the LCA of LPs was carried out using the ReCiPe 2016 Midpoint (E) method to assess potential environmental impacts involving PVC resin production, electroplating and thermo-pressing, packaging, and disposal. Three impact categories were studied using the openLCA software: global warming potential, human toxicity, and fossil resources scarcity, with the functional unit considered as 1000 LPs containing 150 kg of PVC compound, 125 kg of paperboard, and 10 kg of PE. In the PVC resin formulation, the main environmental bottlenecks were the tin and soybean oil used as primary and secondary stabilizers, respectively. The electroplating and thermomoulding step had the higher impacts on the evaluated categories than the PVC resin formulation step, except in terms of fossil resource scarcity, for which the two steps performed equally. Cardboard packaging was the process with the largest impacts on all categories, followed by vinyl chloride production, extrusion and thermoforming processes and PE film packaging production. The landfill end-of-life of LPs exhibited lower eco-indicators than incineration, except when evaluated for human toxicity. It was concluded that landfilling is subtly preferable to incineration. Overall, LCA studies of PVC resin synthesis, the manufacture of LPs and their final disposal still need to cover several other considerations, with no definitive solution existing for the environmental impacts caused by disposal of vinyl records.
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; Castello-Simões, Viviane; Trimer, Renata; Garcia-Araújo, Adriana Sanches; Silva, Andréa Lúcia Gonçalves da; Dixit, Snehil; Di Lorenzo, Valéria Amorim Pires; Archiza, Bruno; Silva, Audrey Borghi; https://lattes.cnpq.br/9634590922242052; https://lattes.cnpq.br/8573168804662842; https://lattes.cnpq.br/3102516235444475; https://lattes.cnpq.br/0104886088821769; https://lattes.cnpq.br/5625129949363675; https://lattes.cnpq.br/4556834059114607; https://lattes.cnpq.br/9071791546812165; https://lattes.cnpq.br/1129428210391656; https://lattes.cnpq.br/4855616925791895
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; Costa, Lidiane Cristina; 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; Rosa, Paula Rúbia Ferreira; https://lattes.cnpq.br/4284223404098079; 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.
O papel das pesquisas científicas na indústria química para a inovação no país
(Universidade Federal de São Carlos, 2021-11-16) Vicentin, Marina; Bernardo, André; https://lattes.cnpq.br/5705402824877708
The wide recognition of the association between innovation and economic and social development motivated Brazil to adopt a series of mechanisms to encourage innovation explicitly directed at the productive sector in the country, such as the Innovation Law. Although in the accumulated period from 2015 to 2020, Brazilian scientific production grew 32.2%, it was not possible to feel significant changes in the country's innovative power, much less in its economic and social development. To understand the possible reasons that compromise the country's progress in this regard, this work sought to look at the political, industrial, social and economic characteristics of Brazil, as well as at the aspects of the research itself, such as its quality and its applicability within the companies, an applicability that has proved to be very adherent within the chemical industries since its emergence in Europe, mainly from a close relationship with universities. Both universities and the chemical industry will also be highlighted in this work along with scientific research. Universities for being the main research centers in Brazil and participating in various ways as a vector of innovation, and the chemical industry for having a great impact on the Brazilian economy and for participating in the production of products of all technological intensities. In all these aspects, Brazil will be compared with other countries so that it is possible to identify structural bottlenecks that may be preventing the advance of innovation in the country, especially in the national chemical industry. In general, in the ST&I (Science, Technology and Innovation) indicators, Brazil is positioned at an intermediate level – behind developed countries and next to developing countries. Regarding the conditions necessary to innovate, the country has a weakness in relation to the quality of basic education, especially in the exact areas, which is reflected in higher education. Due to the lack of planning and prioritization, the infrastructure of the research centers are small and short-term projects, which prevents the construction of large state-of-the-art technology centers. Furthermore, when compared to other countries, Brazil still has an economy closed to foreign trade and faces many difficulties in doing business internally.
Bioplásticos e plásticos biodegradáveis: revisão bibliográfica dos principais materiais e seus impactos ambientais
(Universidade Federal de São Carlos, 2021-11-16) Loureiro, Amanda Oriani; Béttega, Vádila Giovana Guerra; https://lattes.cnpq.br/0752059622240208; https://lattes.cnpq.br/1415713441102435
Plastic is an extremely versatile, low-cost material that can be used for a wide variety of purposes, from food packaging to hospital supplies. It was a revolutionary discovery made in 1907, began to be produced on a large scale in 1950, and today, due to unbridled consumption and production, is a major environmental problem. Plastic is a polymer derived from petroleum, a fossil source that is extremely harmful to the environment, and its degradation time ranges from 20 to 600 years. Even with this long period, due to the actions of time, they do not degrade completely, giving rise to small particles that are called microplastics. These particles are impossible to remove from the environment and have been accumulating for years, especially in the seas. Studies have found microplastics even in the depths of the ocean, where other types of waste are not normally found. In this scenario, the search for materials that are less harmful to the environment has been growing. The awareness of part of the population makes it necessary for industries to seek more sustainable solutions for their products. Thus, plastics produced from renewable sources and biodegradable plastics have been gaining space in the market. In this paper will be conduct a literature review seeking relevant information on three types of bioplastics: a non-biodegradable plastic produced from renewable sources (Green Polyethylene), a biodegradable plastic produced from renewable sources (Polyactic Acid), and a biodegradable plastic produced from a fossil source (Ecoflex). The intent is to differentiate these three types of plastics, elucidating their classifications as environmentally friendly and addressing their main characteristics. The production processes and the advantages and disadvantages of each material will be analyzed. In addition, innovative biopolymers that are being studied as alternatives to some conventional polymers will be addressed. Finally, it will be possible to evaluate the conditions under which these materials are actually more sustainable and which are the best ways to be taken towards sustainability.
Projeto de controle de um reator cerâmico para produção de cloreto de alumínio anidro utilizando microcontroladores de hardware livre
(Universidade Federal de São Carlos, 2021-11-16) Martins, Christian de Oliveira; Tavares Júnior, Adalberto Teógenes; https://lattes.cnpq.br/3645533092024985; Furlan, Felipe Fernando; https://lattes.cnpq.br/4136352953168873; https://lattes.cnpq.br/3013890150468691
Aluminium chloride (AlCl3) is a salt commonly applied in industry since it is a Lewis acid. Such feature makes aluminiun chloride a good catalyst in the production of several organic compounds. Between its main applications, there is the production of ethyl benzene and dyes in general. Many raw materials can be used in AlCl3 synthesis by the chlorination of a aluminum source. In one of these paths, vapour hydrogen chloride reacts with metallic aluminum in high temperatures, producing aluminum chloride and hydrogen gas. Alumina based ceramic reactors are used in this case, since the raw materials have a corrosive behavior and to avoid possible contamination of the product with other metals, such as iron from metallic alloy reactors. Ceramic reactors are sensible to fast temperature variations, which could cause fractures by cycle or thermal shock. For this reason the temperature control must be smooth, without fast variations of the supplied power. Therefore, the objective of this work is tuning a temperature feedback control system for a tubular ceramic reactor to produce anhydrous aluminum chloride. The model used is a PID (proportional-integral-derivative) control, which is traditionally used in process control. PID control action on the manipulated variable is proportional to the deviation in the controlled variable (difference between its current value and the desired value), to the integral and to the derivative of this deviation. Two programmable microcontrollers were chosen for the reactor control. The first one was the nodeMCU ESP-8266 with a ESP12F module. This microcontroller can communicate by Wi-Fi signal with other devices, which allows its use for IoT, the “Internet of Things”. Furthermore, it uses a 32-bit processor with a maximum clock of 80 MHz, a good advantage in relation to Arduino Uno, which have a clock of 16 MHz. The second controller used was the Arduino Uno itself. Despite its lower processing capacity, it is more consolidated in market, so it has an advantage in terms of support. The temperature control was realized by the manipulation of the reactor heat supply through the control of the power provided to resistance heating alloy. The relay method was applied for the initial tuning of PID parameters in the reactors without reaction. With this control, we reduced the time of heating until the operating temperature of the reactor about 2 times and the temperature variation caused by external perturbations.