https://repositorio.ufu.br/handle/123456789/5147 Thu, 17 Sep 2026 08:05:52 GMT 2026-09-17T08:05:52Z https://repositorio.ufu.br:443/retrieve/1d2d1217-ca9d-4a67-b0fc-a088fae067e3/FAEQ-removebg-preview.png https://repositorio.ufu.br/handle/123456789/5147 https://repositorio.ufu.br/handle/123456789/50288 Title: Anais da XXVI Jornada em Engenharia Química e VI Semana da Pós-graduação em Engenharia Química: catalisando ideias, construindo pontes entre desafios e soluções https://repositorio.ufu.br/handle/123456789/50288 https://repositorio.ufu.br/handle/123456789/50264 Title: Produção de biomassa de Saccharomyces cerevisiae em meios de cultivo à base de melaço de cana-de-açúcar: avaliação de regimes de alimentação e aeração Abstract: The growing demand for sustainable alternatives for the valorization of agro-industrial by- products has stimulated the development of biotechnological processes aimed at microbial biomass production. In this context, sugarcane molasses stands out as a low-cost and widely available carbon source that can be employed for yeast cultivation, generating biomass with potential applications in animal nutrition. The present study evaluated biomass production by industrial strains of Saccharomyces cerevisiae cultivated on commercial sucrose and sugarcane molasses, with emphasis on the effects of different operational strategies on metabolic regulation and substrate-to-biomass conversion efficiency. Initially, a physiological screening of five industrial strains (Y904, PE-2, PhibroADY, Ethanol Red, and FT858) was performed in batch cultures, leading to the selection of strain FT858 for subsequent experiments. Cultivations were then carried out in a bench-scale bioreactor under different feeding regimes, aeration conditions, and oxygen supply conditions. The results demonstrated that oxygen availability was the most influential factor affecting the physiological performance of the selected strain. Replacing compressed air with pure oxygen increased biomass yield by 301%, from 0.069 to 0.277 g·g−1. In cultures conducted with sugarcane molasses using pure oxygen, increasing the aeration from 0.5 to 1.67 vvm improved biomass yield from 0.157 to 0.255 g·g−1 while reducing ethanol formation. Conversely, fed-batch strategies that promoted residual sugar accumulation intensified the Crabtree effect, decreasing the efficiency of substrate conversion into biomass. Under the selected cultivation conditions, the biomass exhibited a crude protein content of 40.5 ± 1.9% on a dry-weight basis, highlighting its potential for application in animal feed formulations. Overall, the findings demonstrate that the simultaneous control of carbon availability and oxygen supply is essential to maximize biomass production by strain FT858 when cultivated on sugarcane-derived substrates. Thu, 16 Jul 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50264 2026-07-16T00:00:00Z https://repositorio.ufu.br/handle/123456789/50259 Title: Modelagem preditiva da estabilidade de formulações cosméticas multicomponentes: um estudo comparativo de modelos de aprendizado de máquina Abstract: Physicochemical stability is a critical attribute in the development of multicomponent cosmetic formulations, and its assessment traditionally relies on time-consuming empirical tests. In this context, the present study aimed to compare the performance of tree-based machine learning models, such as Decision Tree, Random Forest and XGBoost, in the classification of shampoo formulation stability, using ingredient mass fractions as predictor variables. As a database, the experimental dataset of 812 formulations available in the literature was employed, from which stability was selected as the binary target variable (stable or unstable). The methodology involved data preparation and exploratory data analysis, followed by stratified splitting into train and test sets, cross-validation and hyperparameter optimization through grid search (GridSearchCV). The exploratory analysis revealed high sparsity, strong asymmetry and the absence of linear separability between classes, which justified the use of non-linear models. Performance was evaluated using F1-score, accuracy, precision and recall metrics, as well as error analysis through confusion matrices. A consistent progression in performance was observed with increasing model complexity: the Decision Tree, used as a reference, achieved an F1-score of 0.66 and accuracy of 68%, while the ensemble models, Random Forest and XGBoost, improved these metrics to an equivalent extent, reaching a test F1-score of 0.71 and accuracy of approximately 77%. Given the statistical equivalence between the two ensemble models on the test set, the mean cross-validation performance was adopted as the selection criterion, in which Random Forest achieved the best result (F1-score of 0.70), being selected as the final model. Feature importance analysis indicated thickeners and conditioning polymers as the most influential ingredients on stability, consistent with the combinatorial nature of the system. The results illustrate the potential of tree-based predictive models as a tool to support more agile and data-driven cosmetic formulation development. Thu, 06 Aug 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50259 2026-08-06T00:00:00Z https://repositorio.ufu.br/handle/123456789/50243 Title: Estudo da redução do teor de óxidos de ferro na produção industrial de ácido fosfórico Abstract: Phosphoric acid is the second most produced and consumed inorganic acid in the world and the most important chemical intermediate in the production of phosphate fertilizers, serving as raw material for all high concentration phosphates. The agronomic potential of fertilizers produced with phosphoric acid is highly dependent on its contaminant levels, especially iron oxides. The presence of various iron oxides on phosphate rocks or concentrates can generate fertilizers containing iron phosphates, which are partially soluble on neutral ammonium citrate (NAC) and water-insoluble, therefore of lesser agronomic and commercial value. Approximately 95% of the phosphate rocks used in Brazil originates from igneous mines, on which iron oxides are the main contaminants and its total removal during the rocks` beneficiation is technical and economically unfeasible. Aiming at improving the phosphoric acid quality for fertilizer production, as well as enabling the use of phosphate concentrates with high contaminant levels as raw material for its production, the present work had as objective the development of routes enabling the removal of iron oxides from the acid. Preliminary bench tests of 43 different purification routes led to 4 potential processes, which were mapped through the Central Composite Design (CCD) technique. The experimental designs results showed that up to 75% of the Fe2O3 was removed from phosphoric acid by the usage of aminotris(methylenephosphonic acid) on the defined temperature and precipitation time. To validate the developed route, a pilot test followed by two industrial trials conducted on a 900 t P2O5/day industrial site, on which were consumed 50 metric tons of test reagent. The trials indicated technical and industrial viability for the iron oxides removal thus leading to consequent purification of phosphoric acid. Mon, 30 Jul 2018 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50243 2018-07-30T00:00:00Z