https://repositorio.ufu.br/handle/123456789/5147 Thu, 27 Aug 2026 22:36:16 GMT 2026-08-27T22:36:16Z 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/123456789/49925 Title: Aplicações comerciais dos processos de separação por membranas Abstract: Membranes are semipermeable barriers that separate two phases and restrict the passage of one or more chemical species between them. Consequently, they have emerged as a highly attractive alternative in the field of separation processes, further supported by their low operating and maintenance costs. Research in the area of membrane separation processes has yielded advances that allow these technologies to be increasingly adopted across diverse commercial sectors. The present work aims to conduct a brief literature review on membrane separation processes and their applications, providing the foundation for a subsequent, more detailed study focused on their commercial applications. Wed, 05 Aug 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49925 2026-08-05T00:00:00Z https://repositorio.ufu.br/handle/123456789/49886 Title: Características do abacate e sua potencial aplicação do produto seco Thu, 27 Aug 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49886 2026-08-27T00:00:00Z https://repositorio.ufu.br/handle/123456789/49834 Title: Application of membrane separation processes to purify and concentrate bioactive extracts from annatto seeds (Bixa orellana L.) Abstract: The growing demand for natural colorants and functional compounds highlights the strategic potential of annatto (Bixa orellana L.), especially due to the presence of bixin, norbixin, and phenolic compounds. However, conventional extraction and purification methods still present limitations regarding efficiency, sustainability, and environmental impact. In this context, membrane separation processes emerge as an innovative and environmentally responsible alternative, capable of producing purer, more stable extracts with higher added value, in line with current industrial and regulatory requirements. This study aimed to investigate the application of polymeric and ceramic membranes for the purification and concentration of bioactive compounds from annatto seed extracts, with emphasis on the influence of membrane structure and material on the retention efficiency of bixin, phenolic compounds, and the associated antioxidant potential. The methodology encompassed the production of alumina-based hollow fiber ceramic membranes, subsequently characterized in terms of morphology, mechanical strength, chemical stability, and filtration performance. In parallel, experiments were conducted using polymeric membranes in a dead-end configuration, with the aim of evaluating their selectivity and retention capacity of bioactive compounds. Furthermore, the use of natural deep eutectic solvents, classified as a green alternative, was investigated for bixin extraction, with results compared to those obtained by conventional solvents, such as ethanol and water. The resulting samples were analyzed using chromatographic techniques, including high-performance liquid chromatography and mass spectrometry, enabling the precise quantification of bixin and phenolic compounds. The main results revealed that polymeric membranes with a molecular weight cut-off (MWCO) of 5 kDa were able to retain up to 90% of bixin and approximately 54.2% of phenolics compounds. The microfiltration ceramic hollow fiber membranes showed similar performance, reaching retentions close to 90% of bixin and 47,53% of phenolics compounds. The final permeate fluxes with polymeric and ceramic membranes were of 10.72 and 9,26 L h-1 m-2, respectively. Thus, both membranes were efficient for the concentration of bioactive compounds from annatto seed extracts, which reinforces the role of additional retention mechanisms in addition to the pore size exclusion. Results regarding the use of natural deep eutectic solvents confirmed not only higher extraction efficiency but also demonstrated their ability to stabilize bixin, preventing its degradation and ensuring greater preservation of bioactive properties. In these trials, the maximum yield reached 2.31% (w/w), while the ethanol:water mixture (1:1 v/v) yielded only 0.0075% (w/w) for bixin extraction. In addition to the superior performance, the extracts obtained were richer in bixin and showed greater stability compared to those produced by conventional solvents, reinforcing both the technical feasibility and the environmentally sustainable contribution of green solvents over the evaluated alternatives. It is concluded that membrane separation processes associated with natural deep eutectic solvents represent a promising route for the valorization of annatto seeds, by combining technical efficiency, sustainability, and feasibility of industrial-scale application. This study contributes to broadening the understanding of the use of clean technologies in obtaining natural colorants and bioactive compounds, providing foundations for the development of innovative processes aimed at the food, pharmaceutical, and cosmetic industries. Wed, 29 Jul 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49834 2026-07-29T00:00:00Z https://repositorio.ufu.br/handle/123456789/49778 Title: Análise da força gel de fluidos de perfuração contendo microesferas ocas de vidro Abstract: This study investigated the rheological behavior of gel strength in olefin-based synthetic drilling fluids modified with hollow glass microspheres (HGMs). The development of low- density fluids is essential for drilling fragile or depleted formations or those with narrow operational windows, reducing the risk of rock fracturing, undesired circulation losses, and formation damage. Gel strength is a critical rheological property that ensures the static suspension of drilling cuttings and weighting agents during circulation interruption, preventing solids settlement without generating excessive pressure spikes upon pump restart. Using a Central Composite Rotatable Design (CCRD) seventeen samples were formulated by varying the concentrations of lime, hollow glass microspheres (HGS19K46), and organophilic viscosifier. Tests were performed in triplicate at 30°C on a coaxial cylinder rheometer to measure gel strength after 10 seconds (G10s) and 10 minutes (G10min), adopting Petrobras' maximum reference limits of 10 and 15 lbf/100 ft², respectively. Results showed that nine formulations met the G10s criterion and six satisfied both parameters simultaneously (PE4, PE6, PE14, PE15, PE16, and PE17). Variable analysis revealed that approval was primarily conditioned on lower organophilic viscosifier concentrations (10.2 to 12 lb/bbl), whereas the simultaneous increase of additives in sample PE10 resulted in the highest gel value (33. lbf/100 ft² for G10min). It is concluded that the incorporation of hollow glass microspheres enables the formulation of viable low-density fluids, in which strict control of viscosifier dosage ensures fragile, flat gels, preserving wellbore integrity and maintaining hydrostatic pressure within safe operational limits. Wed, 05 Aug 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49778 2026-08-05T00:00:00Z