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Segurança do alimento e segurança alimentar: uma análise a partir da agroindústria familiar de derivados de leite na microrregião de Itapetininga – SP
(Universidade Federal de São Carlos, 2022-04-11) Granato, Leticia Senteio Silles; Santos, Leandro de Lima; https://lattes.cnpq.br/2750978055015275; https://orcid.org/0000-0001-8413-5372
This research analyzes the production of dairy products by family farmers in the Microregion of Itapetininga - SP, and aims to provide a Food Safety Indicator (ISA) derived from dairy products and the safety grau to feed families by means of the Brazilian Food Safety Scale. Feed (EBIA). We applied semi-structured questionnaires in interviews with ten family farmers in two municipalities of Angatuba, Buri, Campina do Monte Alegre and Itapetininga. Both indicators are categorized according to the levels observed, and other productive and socioeconomic variables obtained during the field investigations are also presented. The results indicate insufficient levels of hygienic-sanitary safety and oil derivatives, demonstrated by ISA. Despite this, the levels of marketing of the products are available to the families of family farmers who are not affected. Likewise, through the analysis of the EBIA indicator, it was possible to observe that the families studied were in conditions of food security.
Custos no processo de refino do petróleo: um estudo de caso da refinaria Alberto Pasqualini (REFAP)
(Universidade Federal de São Carlos, 2022-04-11) Oliveira, Matheus Raposo Gonçalves de; Queiroz, João Paulo Silva; https://lattes.cnpq.br/7316247674511327; https://lattes.cnpq.br/0632465014958748
Even with the growing demand for sustainable energy sources in recent decades, oil products continue to be the main fuels used in the world, also having several applications in various areas of industry. The oil refining process is very extensive in costs, with several operations that have the purpose of adapting the product to the necessary specifications in the market and having its profits fluctuating in a very volatile way, according to several factors that influence oil prices and its derivatives. This work aims to perform a study of the main costs involved in the oil refining process, analyzing the production units of a refinery, its main energy demands and operational expenses, thus being able to evaluate the impact that each production unit has on the fixed and variable costs within a plant. The study was carried out from available data from refineries in operation and cost research associated with the unit operations involved. From these costs and the prices of the commodities involved, which vary constantly, being traded on the stock exchanges, it was defined the refining margin of a Brazilian refinery, chosen as a model, in certain historical periods and was verified which production units had the greatest impact on costs. With the methodology used, it was possible to observe that the atmospheric distillation and catalytic cracking were the most expensive units, also finding the high impact that raw material costs had in the historical period, being the main costs of the studied refinery.
Análise da influência de injeção de água sobre o escoamento de ar em um lavador Venturi utilizando Ansys Fluent
(Universidade Federal de São Carlos, 2022-04-11) Sobral, Beatriz Moraes; Béttega, Vádila Giovana Guerra; https://lattes.cnpq.br/0752059622240208; https://lattes.cnpq.br/9407939075077544
Computational Fluid Dynamics (CFD) is a tool that simulates internal and external flows by solving models through numerical methods until reaching a predetermined value for convergence, with the advantage of reducing costs and time in data collection. The equipment that was studied was a Venturi scrubber with circular section because it is traditionally used in industries due to its high efficiency in gas scrubbing. Due to the fact that the atomization of the water jet occurs due to the high velocity of the air in relation to that of the liquid and that the fluids flow perpendicularly, the scrubber performance is influenced by factors such as the liquidgas ratio, the pressure drop and the configuration of the water injection holes. The main goal of this work was to check the influence of the liquid inlet on the air flow in a vertical Venturi scrubber with circular section and, for that, simulations were performed using the Fluent software contained in the Ansys Student 2021 R1 package. In the simulations, the gas inlet velocity and the water inlet diameter were kept constant, while the number of holes were varied from 1 to 4 and the liquid inlet velocity values were 4.5; 6.5 and 8.5 m/s; in addition, results were obtained for cases in which there was no water injection, in order to compare the scenarios obtained. Considering the data collected for the same mesh, the greater the number of holes, the bigger the pressure drop obtained and, the higher the water inlet velocity, the greater the pressure drop and the longer the penetration of water. As for the quality of the meshes, their refinement resulted in more accurate results and smoother curves with lower computational cost; thus, better results were obtained in the same range of number of iterations. In view of the results obtained, the scenario indicated would be of 4 holes with water inlet at 6.5 m/s due to better distribution of liquid within the equipment, absence of vortices and higher velocity in the central region of the equipment.
Compactly-supported and relative integration in differential cohomology
(Universidade Federal de São Carlos, 2022-04-11) Barbosa, Brenno Gustavo; Ruffino, Fabio Ferrari; https://lattes.cnpq.br/2512107188781159; https://lattes.cnpq.br/4460266811084097
In this work, we have constructed more general versions of differential integration maps in differential cohomology theories. Among the obtained versions we can mention the integration with compact supports, the integration with vertically compact supports and their relative versions. To obtain these maps, it was necessary to construct a special product between parallel and relative differential classes and to extend differential cohomology theories to a category of sequences of manifolds.
Avaliação molecular do fígado de girinos de rã-touro americana (Lithobates catesbeianus) por espectroscopia de infravermelho com transformada de Fourier (FTIR)
(Universidade Federal de São Carlos, 2022-04-11) Souza, Eduardo Garcia; Carvalho, Cleoni dos Santos; https://lattes.cnpq.br/7233550271936621; https://orcid.org/0000-0003-0755-5239; https://lattes.cnpq.br/6358077697283470
Fourier Transform Infrared Spectroscopy – FTIR – is an easy-to-perform technique that can be applied to different types of samples, such as: solids, liquids, gases, semi-solids, polymers, biological materials, among others. The present work used the FTIR technique to detect possible molecular alterations in the liver of American bullfrog tadpoles (Lithobates catesbeianus) exposed to water collected from the Itupararanga dam in Votorantim (BV) and its reservoir in Ibiúna (RI); both points belong to the Sorocaba river. In this study, molecular changes were observed in the range of 3200 – 2600 cm-1 of the infrared spectrum for the liver of tadpoles exposed to the collected water. The observed changes may be associated with the presence of metals (Al, Cd, Mn and Zn) in the water. Although alterations have been identified in the spectra of the samples that were exposed to the water collected in relation to the control, complementary analyses to this study need to be carried out so that the exposed is, in fact, confirmed. Therefore, in this work, it was endeavoured to understand the changes observed in the spectra and also to propose the use of this technique as an alternative tool for application in ecotoxicology.
Impacto das propostas de alteração do mapa de ventos no projeto de edifícios em concreto armado no Brasil
(Universidade Federal de São Carlos, 2022-04-11) Dias, Lucas Vitoretti; Almeida Filho, Fernando Menezes de; https://lattes.cnpq.br/0447825383222965; https://lattes.cnpq.br/2891424597188503
The wind action is one of the most relevant for the design of reinforced concrete buildings, especially in recent years with the growing demand for taller and slender buildings. Thus, it is essential that this action be determined accurately and in accordance with reality, to ensure both the safety of the building and its occupants as well as the economic feasibility of the project. In Brazil, the process of determining the wind action is established by ABNT NBR 6123 (1988), considering that it is already 34 years old and is based on a study of isoplet maps of Brazil of almost 50 years, it is currently under revision. Therefore, the objective of this work is to evaluate the impact that the proposed isoplet maps presented as suggestions for the revision of the wind standard will have on the design of reinforced concrete structures in several regions of the country for buildings of various heights. Structures of 4, 10 and 20 floors were evaluated using the commercial software TQS, in 8 cities with different basic wind speeds, and both the Ultimate Limit State and the Service Limit State of the structure were studied. The results indicate that for 4-story buildings there is no impact on the design with the change of the wind speed, whereas for 10 and 20-story buildings the results point to a more significant impact. Furthermore, the analysis of the results and the isoplet maps proposals make clear the need for revision in ABNT NBR 6123 (1988).
Proteínas moonlighting e sua relação com a patogenicidade da bactéria Xanthomonas citri subsp. citri, causadora do cancro cítrico
(Universidade Federal de São Carlos, 2022-04-11) Ferreira, Jéssica Camila; Souza, Dulce Helena Ferreira de; https://lattes.cnpq.br/3428955299526003
Citriculture has been present in Brazil since its colonization when orange seedlings were imported and commercialized. Due to the fertile soil and favorable climate, over the decades, Brazil has become the largest producer of oranges and exporter of orange juice worldwide, generating a lot of profit for the country. Nevertheless, over time, several diseases that bring significant losses to the citrus industry have also developed, and many of them still have no cure. Citrus canker is one of them and is caused by the bacterium Xanthomonas citri subsp. citri (Xac). Many investigations have been carried out to elucidate the infection mechanism of the bacteria in the host, how they defend themselves and why they are so virulent. After a proteomic analysis of the cell surface performed on Xac under two different conditions, host infection and non-infection, different amounts of some proteins on the surface were found, being many of them already reported and related to virulence in other bacteria and classified as moonlighting proteins, which are proteins that have a well-defined function usually in the cytosol, but were also found performing completely different functions in other cellular regions, mostly on the surface. Such proteins may be related to biofilm production, defense response against the host, adhesion of bacteria to surfaces, and various other functions. Studies in recent years have tried to unravel their possible recognition mechanisms inside the cell and how they are secreted out, as well as trying to understand what functions they have when they are on the surface. In this work, the topics mentioned above were addressed in detail and the possible relationship of surface moonlighting proteins with the virulence of the citrus canker-causing bacteria was discussed.
Análise da modelagem matemática sobre a secagem de alumina em leito fixo espesso
(Universidade Federal de São Carlos, 2022-04-11) Mello, Mateus Araújo de; Barbosa, Luan da Silva; https://lattes.cnpq.br/7228332759151003; Freire, Fábio Bentes; https://lattes.cnpq.br/8937961078558996
The fixed bed is widely applied, studied and reported in the literature. From the stuffing towers found in the chemical industry to the modern fixed beds with membranes used in the production of hydrogen, many were the contributions to reach the state of the art of this type of reactor. Fixed bed drying, in which the bed of particles remains stationary while the air percolates through the porous medium, yielding heat and absorbing moisture, is more used when dealing with impact-sensitive grains, even so, on a small scale. However, knowledge about fixed bed drying processes can be extended to conveyor belt dryers, in addition to storage silos, with regard to dynamic behavior. Unlike drying with bed movement, fixed bed drying accentuates the temperature and humidity gradients of the particles, and this non-uniformity is a generally undesired effect. The Final Paper proposal summarized here aims to simulate a dynamic model of alumina drying in a fixed bed, varying both typical operating conditions and bed dimensions. Numerical tests will then be carried out using a MatLab program developed in the Particulate Systems area of DEQ/UFSCar. With the results of the simulations it is intended to identify trends of change in the magnitude of the internal gradients in face of the variations made in the program.
Influência da adição de Nb-B na microestrutura de solidificação da liga Al-0,8%Mg-0,7%Si (6201)
(Universidade Federal de São Carlos, 2022-04-11) Sousa, Sarah Maria de Albuquerque; Spinelli, José Eduardo; https://lattes.cnpq.br/8882038118634925; https://lattes.cnpq.br/9197496818628556
The AA6201 alloy, widely used in the manufacturing of power cables, was modified by the addition of a Al-Nb-B master alloy in order to investigate the possible effects on the microstructure. Therefore, the Al-0.8%Mg-0.7%Si (AA6201) and Al-0.8%Mg-0.7%Si-0.5%Nb-0.1%B alloys were directionally solidified. in a transient heat extraction regime and solidified rapidly by means of centrifugal solidification, to ensure a broad spectrum of cooling rates and microstructures, which can be correlated with each other. Analyses were performed on determining both dendritic spacings (λ) and grain size (GS). While the directionally solidified Al-0.8%Mg-0.7%Si (6201) alloy presented exclusively columnar grains, the addition of Nb-B favored the occurrence of a columnar to equiaxial transition CET in the modified casting and, in addition, a reduction in grain size, either for columnar or equiaxial grain morphologies, promoting a reduction of up to 13 times the average value of grain size. Within the range of directional solidification cooling rates (0.5 to 33 °C/s), it was observed that for the ingot with the addition of 0.5%Nb-0.1%B there was high cooling rate-cells arrangement for cooling rates greater than 5.5 °C/s and minimal variation in secondary dendritic spacing. However, the fast solidification conditions revealed that increasing the cooling rate (~240 °C/s) reduced both TG and λ2. It was proposed that the TG/λ2 ratio could characterize the micromorphology of the α-Al cells that grew in the modified 6201 alloy, occurring when the ratio was less than 6. Finally, tensile properties were determined for several samples and related to different λ2 and GS values through the proposition of Hall-Petch types equations, where it was observed that the ultimate tensile strength of the alloy containing Nb-B (~190 MPa) was higher than that observed for the alloy without Nb-B.
Efeito da luz de LED branca, vermelha, azul e verde em parâmetros da fisiologia da cianobactéria Aphanocapsa holsatica: taxa de crescimento, produção de biomoléculas e biofixação do CO₂
(Universidade Federal de São Carlos, 2022-04-11) Lima, Amanda Ellen Viana; Lombardi, Ana Teresa; https://lattes.cnpq.br/6737850858443813; https://lattes.cnpq.br/6850287915173077
Cyanobacteria is unicellular prokaryotic group of microrganisms that is receiving attention as a commercial producer of biomolecules through the ability to biofix CO₂. This match in ecology and industry is being encouraged by companies and governments to reduce the impacts of global warming. Highlighting even more these photosynthetic organisms with industrial application and their commercialized biomolecules, such as proteins, biomass and pigments. Thus, the identification of new strains with biotechnological potential and their physiological elucidation are very important . To identify cultivation conditions that are favorable to produce biomolecule concomitantly with high rates of CO₂ biofixation is important for the implementation of such ecological initiatives. The use of different colors of light modifies photosynthesis and, consequently, the metabolism. Therefore, it can be applied as a strategy to increase microorganisms growth rate and the accumulation of biomolecules. This work aimed to analyze the effects of red, green, blue and white lights on photosynthesis, biomolecule production and population growth of the cyanobacterium Aphanocapsa holsatica (CCIBt 3053). In a physiological perspective, we analyzed the total concentration of proteins, carbohydrates, lipids and pigments (chlorophyll a, total carotenoids and phycocyanin). In addition, we monitored photosynthesis parameters using the Phyto-PAM II equipment. The results showed that white light is the best for biomass accumulation, with 287.11 ± 17.13 mg/L at the end of the experiment (96 h). Green light induced a 3-fold increase in protein concentration per dry biomass (63.78%), in addition to increasing the concentration of chlorophyll a without reducing the carotenoids concentration. Blue light cells culture was identified with the highest electron transfer rates as well as the highest effective photosynthetic yield. Furthermore, we conclude lower energy lights improved health parameters of A. holsatica (CCIBt 3053) by increasing the photosynthetic yield and protein concentration. The strain did not show chromatic acclimatization. This research is a contribution to the physiology of a cyanobacteria that can be applied to biotechnology related to photosynthesizing prokaryotic organisms.
Análise comparativa entre a operação convencional e a com reversão de escoamento durante a secagem de alumina em leito fixo
(Universidade Federal de São Carlos, 2022-04-11) Böing, Hugo Mendes; Barbosa, Luan da Silva; https://lattes.cnpq.br/7228332759151003; Freire, Fábio Bentes; https://lattes.cnpq.br/8937961078558996
When sugar is added to a hot cup of coffee, the first action, almost intuitively before drinking, is to mix the drink so that it gets evenly sweetened. When preparing a cocktail, the most important stage is shaking the drink’s different ingredients. This action of mechanically mixing is very common. In larger scale, chemical reactors also adopt mechanical mixing systems to homogenize the processed material, ensuring uniformity to both the properties and the quality of the final product. In applications involving fixed bed, however, it is impossible to use mechanical mixers, due to the equipment’s nature. Instead, an alternative is to change the direction of the air flow from time to time. The bed’s homogenization during the drying process may be essential in some applications. The existence of significant internal gradients of moisture and temperature alike may make it unfeasible to use this kind of dryer depending on the application. In other words, this unwanted nonuniformity may result not only in a final product below the quality standards but also significant losses in subsequent operations. This happens, for example, in coffee processing during the roasting stage, in which beans with high moisture content may not pyrolyze and those with low humidity may roast. In this context, the objective of this work was to analyze the reduction of internal gradients during thick fixed bed alumina drying with the reversal technic, when compared to results that would be attained in the conventional operation. Numerical assays were carried out in MatLab® with a script developed by Particulate Systems Research Group of DEQ/UFSCar. The simulation results showed the effectiveness of the airflow reversal technique that allowed the reduction of moisture and temperature gradients of alumina.
Efeitos isolados e combinados dos metais zinco e alumínio sobre representantes de três níveis tróficos de organismos aquáticos dulcícolas
(Universidade Federal de São Carlos, 2022-04-11) Gebara, Renan Castelhano; Rocha, Giseli Swerts; https://lattes.cnpq.br/9522932409165588; Melão, Maria da Graça Gama; https://lattes.cnpq.br/8342306603661310; https://lattes.cnpq.br/7552826388478784
Metals are widely distributed throughout the Biosphere, and the increase in their concentration in aquatic ecosystems may cause concern. Although environmental legislation utilizes the isolated metal toxicity in normative about maximum allowed concentrations in the environment, it is known that the metals cooccur; therefore, studies dealing with the toxicity of metals’ mixtures are of great importance. The aim of our study is to analyze the individual and combined effects of mixtures of zinc (Zn) and aluminum (Al) on the green microalga Raphidocelis subcapitata and on the Neotropical cladoceran Ceriodaphnia silvestrii and, besides that, we also evaluated the isolated effects of Zn on initial stages of zebrafish (Danio rerio). Results indicate that both metals inhibited the growth of R. subcapitata, with IC50-96h: 0.026 mg Zn L-1 and 0.74 mg Al L-1. Regarding the photosynthetic parameters, we observed decay in the efficiency of O2 evolving-complex (F0/Fv) and efficiency of photosystem II (PSII) and the increase of non-photochemical quenchings. Analyzing the growth of R. subcapitata after 96 h, Zn and Al mixtures exerted synergic effects at low concentrations and antagonistic effects at high concentrations. Observing F0/Fv e ΦM, we found antagonistic effects at high Al concentrations. By plotting species sensitivity distributions (SSD), the hazard concentrations to 5% of the species were calculated, HC5: 0.062 mg Zn L-1 and 0.15 mg Al L-1; according to SSD, R. subcapitata was the most sensitive organism to Zn, and it was one of the most sensitive to Al. Regarding the cladoceran C. silvestrii, we observed immobility on acute toxicity tests, 48 h-EC50: 0.22 mg Zn L-1 and 0.52 mg Al L-1; and reduction on the reproduction during chronic toxicity tests,7d-EC50: 0.11 mg Zn L-1 and 0.37 mg Al L-1. Mixtures of Zn and Al on C. silvestrii exert synergism to mobility. Preliminary risk assessments (RA) of C. silvestrii show a higher ecological risk of metal mixtures than the isolated metals’ effects. To zebrafish, we obtained 96h-LC50: 24.18 mg Zn L-1; we also observed that Zn altered the uptake of some essential elements, and altered behavior of zebrafish. Analyzing the RA of Zn on organisms from 3 trophic levels, Zn exerts high ecological risk to R. subcapitata and C. silvestrii, and moderate risk to zebrafish. Therefore, observing mixture data, we can infer that the toxicity of mixtures is often unpredictable since the responses are not always additive. Thus, based on results from this study we reinforce the importance of including ecotoxicological tests of mixtures in risk assessments.
O ensino remoto durante a pandemia nas escolas da Educação Básica de São Carlos na visão dos professores
(Universidade Federal de São Carlos, 2022-04-11) Oliveira, Karina Domingos de; Carnio, Michel Pisa; https://lattes.cnpq.br/0198207700485715; https://lattes.cnpq.br/5463430776928206
The outbreak of the Covid-19 virus reached billions of students around the world and ended up bringing traditional school classes to a halt in Brazil, as in many other places. This work proposes to understand the perception of teachers about the adoption of remote teaching during the pandemic. A qualitative research approach was used through semistructured interviews with three elementary school teachers in the city of São Carlos. The data generated from the interviews were analyzed according to the Discursive Textual Analysis of Moraes (2003), which resulted in four major categories of analysis: Technological Resources and Teacher Training, Proletarianization of Teaching Work, Teaching Autonomy and School Hierarchy and Communication and Support between Educational Agents. In this way, it was possible to identify that the adoption of remote teaching brought the perception of an increase in working hours, related to the adaptation and construction of the skills to operate new tools needed in this different environment. We also identified in the participant teachers who felt that they were not part of the remote teaching implementation decision taking, mostly because the relations of authority and hierarchy of the school environment significantly reduced the autonomy of the teachers during the pandemic, in addition to not taking into account the experiences lived by them. Finally, it was possible to conclude that collective work through the sharing of experiences among fellow teachers proved to be a factor of professional enrichment in this period. Through this research, we identified the need to investigate the relationship between teachers and students, an aspect that was not presented as the main focus of this work but which is extremely relevant for the teaching-learning process in the current times, as well as elements related to the possibilities expansion of dialogues between teachers and educational authorities, which were included in the analyzes but which must be deepened, given their complexity and importance for the development of education in Brazil.
Implementação de treinamento para padronização de normas de biossegurança no LaFaC, LaTecC e LaDABio
(Universidade Federal de São Carlos, 2022-04-11) Piassi Filho, Marco Aurélio; Horta, Antonio Carlos Luperni; https://lattes.cnpq.br/5923938048634505
This work shows the current worldwide relationship with Biosafety protocols in Laboratories, presenting the main practices to guarantee a safer environment for handling living beings. The Department of Chemical Engineering at UFSCar currently has biotechnology laboratories that present microorganisms that require safe handling and, therefore, adequate training of users. Previous work by the group identified the main improvements that could be applied in the training offered to users of LaTecC, LaFaC and LaDABio, such as organization of access and standardization of training materials. In this context, Google applications were used to centralize training and control their execution for teachers and students who make use of these laboratories. For this, a policy was developed in which the recurrence of training, responsibilities, where to find the training and a menu to consolidate good practices for the use of laboratory space, which may even be used by other interested groups, are presented. The training consists of six modules and six assessments to assess user learning. The implementation in PoCA (Portal de Cursos Abertos - UFSCar) is a suggestion for future works related to the topic.
O direito de ingresso das pessoas com deficiências na Educação Superior: atos e agentes administrativos em tela
(Universidade Federal de São Carlos, 2022-04-11) Machado, Jairo Maurano; Cabral, Leonardo Santos Amâncio; https://lattes.cnpq.br/5306031040506357; https://lattes.cnpq.br/6839756025507159
The admission's right of people with disabilities to Higher Education was recently evidenced by the system of reservation of places, mandatory at the level of education. However, when two candidates with disabilities occur from the registration and will not be accepted, the question arises: what are the institutional ways to guarantee the income right to the population, when it is for? In this scenario, this research aimed to identify and analyze the institutional instruments available to guide the effectiveness of the income of people with disabilities in Higher Education outside a Public Institution in the State of São Paulo. Specifically, it is intended to: a) identify and portray the acts performed by the institution to legitimize the rights of people with disabilities; b) know and discredit the acts performed by the candidate with a disability to fulfill his right to income; c) analyze, based on the data identified, the process of legitimizing the right to income for people with disabilities in Higher Education from a biopsychosocial perspective. The study was determined in two dimensions of analysis: a) candidate students; b) institutional staffs. It is a case study and documental, analytical-critical-descriptive, which uses public and institutional archives, whose contents are treated with the use of specific registration protocols and analyzed from the perspective of Disability Studies. The research reveals materialities inherent to the right to income of people with disabilities in Higher Education and the institutional contributions to legitimize it. The results obtained indicate the need to review two documents guiding two selection processes. In public practice, they do not always reach all candidates and distortions sometimes occur when there is a fear of a conception of disability in the social model.
Definição de estratégias de vendas na indústria química
(Universidade Federal de São Carlos, 2022-04-11) Oliveira, Leonardo Silveira; Bernardo, André; https://lattes.cnpq.br/5705402824877708
n the chemical industry scenario, there is a high complexity in identifying competitive advantages for each company and, from that, defining the best sales strategy. This is due to the diversification of the sector, since there are subdivisions into smaller areas with specific characteristics. In view of this, it is important to analyze a set of definitions of these subdivisions and the practices used in the scenario that most collaborate with the development of an industry, thus understanding the entire sales strategy for each type of business, considering its particularities. and market trends. The objective of this work was to define the main sales strategies of the industry through a bibliographic review of materials related to the theme, with a critical, analytical and exploratory reading, under a qualitative approach of the selected materials. The starting point was the identification of different sectors within the chemical industry and their characteristics, making a survey of the main competitors of each one. From this, industry practices related to the implementation of improvements in the points highlighted as competitive advantages were raised and, finally, the main sales channels used by the chemical industry were raised.
Influência dos parâmetros de reversão na homogeneidade de um leito durante a secagem de alumina
(Universidade Federal de São Carlos, 2022-04-11) Souza, Lucas Guellis de; Barbosa, Luan da Silva; https://lattes.cnpq.br/7228332759151003; Freire, Fábio Bentes; https://lattes.cnpq.br/8937961078558996
An undesirable aspect of fixed bed dryers is that they generate a product with uneven distribution of moisture and temperature of the particles along it, in the direction of drying air flow. This can result in a non-quality product, which can lead to significant losses in subsequent operations. This disadvantage can be overcome by periodically reversing the direction of flow of the heated air, whose burden is the longer drying time and the higher cost. In the conventional process without inversion, the temperature in the layer closest to the inlet of the heated air reaches dynamic equilibrium faster than the later layers, while the layer farthest from the inlet takes longer to do so. In the drying process with periodic inversion, the dynamic temperature equilibrium is disturbed with each inversion. Thus, the reversal of the air flow direction confers a mixing character to the fixed bed drying, which must be proven in numerical experiments by the reduction of the humidity gradient. The reversal technique has as operational parameters the initial moment of application of the first change in flow direction and the time between subsequent inversions. The final paper proposal summarized here, aimed to evaluate the influence of these parameters on the degree of uniformity of a fixed bed during the drying of alumina particles. Numerical tests were performed using a MatLab® program developed in the Particulate Systems area of DEQ/UFSCar. With the results of the simulations, it was possible to identify trends of change in the homogeneity of the fixed bed, and that the parameters evaluated significantly alter the operation of the bed and must be analyzed in order to obtain the best uniformity of the process.
Efeitos de defensivo agrícola em levedura para ração animal
(Universidade Federal de São Carlos, 2022-04-11) Alvim, Maurício Vidal; Batista Júnior, Ronydes; https://lattes.cnpq.br/5724682552766276; Horta, Antonio Carlos Luperni; https://lattes.cnpq.br/5923938048634505
Brazil is one of the largest ethanol producers in the world, within the production there is a facultative unicellular organism, the yeast, responsible for the bioreaction that transforms glucose and fructose, present in the sugar cane juice, into ethanol and more cells. As it is produced in large quantities, the yeast is used for the production of supplement for animal ration, Inactive Dry Yeast and Cell Wall. In Brazilian sugar cane fields the pesticide use, like herbicide, fungicide, insecticide etc, mostly is performed in an indiscriminate way and without supervision. The regulatory bodies does not do the right control and inspection on the use of these products. The leaflet of these products do not contains information of a potential danger after the decomposition of these products in soil or in the plants and how can these resulting products affects the food security and human or animal health. In these work the focus was on agricultural pesticides that contain the active ingredient MSMA (Monosodium Methyl Arsonate or Monosodium Acid Methanoarsenate), and how their by-products can affect animal health, and indirectly human health through animal feed. From the sugar-cane farming to the packed dry yeast, there are a large number of operations, but they do not include the removal of possible contaminants before reaching the final product. Finally, there are the recommendations for abolishing the use of this pesticide in Brazilian crops.
Sensores baseados em nanofios semicondutores de SnO2: fotodetector de luz UV e sensor de gás
(Universidade Federal de São Carlos, 2022-04-11) Araujo, Estacio Paiva; Chiquito, Adenilson José; https://lattes.cnpq.br/7087360072774314; https://lattes.cnpq.br/5669604578234007
In this work, sensors employing SnO2 semiconductor nanowires as active layer for gas and light detection were built. SnO2 nanowire samples were grown by VLS (VapourLiquid-Solid) method and morphological and structural properties were analyzed. XRD results exhibited SnO2 tetragonal rutile phase, within space group P42/mnm and lattice parameteres of a = b = 4.73 Å and c = 3.18 Å (JCPDS 41-1445). SEM images confirmed the desired morphology and TEM images revealed monocristaline character. Two different sensors’ architecture were chosen: a Metal-Semiconductor-Metal (MSM) with a nanowire network and a Field Effect Transistor with a single nanowire (NWFET). Current-voltage measurements of the SnO2 nanowire network devices with and without ultraviolet (UV) and visible (VIS) irradiation ranges were studied. Results indicated that a barrier is formed between the nanowire network and metallic contact when in absence of light, whereas under UV illumination there was an appreciable photoconductive gain and a small one under VIS illumination. NWFET’s values of charge density and mobility were estimate, of 1.6x1019 cm-3 and 3.7x10-4 cm2/Vs, respectively. Under UV illumination, the NWFET presented an ambipolar behavior, while under VIS illumination a unipolar response. SnO2 nanowire network’s photoresponse had a ION/IOFF ratio of 170 and 8.2 for UV and VIS light, respectively. In addition, response time was 2.8 s for UV light and 98s for VIS light, althought UV light measurements presented multiple decay times of 0.55 s and 145.84 s and for VIS light only one decay time of 153 s. NWFET photodetector response curves displayed a ION/IOFF ratio of 309 and 57 for VDS = + 1 V and VDS = - 1 V, respectively. For a positive voltage, VDS = + 1 V, the rise time was about 0.59 s and decay time was 0.63 s. Under a negative applied voltage, VDS = - 1 V, rise and decay times were 0.68 s and 0.75 s, respectively, were obtained. For the VIS light condition, no photocurrent variation in the NWFET was observed. The SnO2 nanowire network device was also used to study gas sensoring at room temperature. Sensor response, (), was found to be about 32 % and 9 % for acetone concentrations of 970 ppm and 50 ppm, respectively. In order to optimize and enhance the reponse, differentvii values of applied voltage were tested, resulting in a response of 32 % for V = + 9 V and 49 % for V = + 0.1 V. Given that, smaller values of applied voltage improved our sensor’s response.