https://ri.ufs.br/jspui/handle/riufs/2494 2026-04-26T08:34:30Z 2026-04-26T08:34:30Z Siqueira, José Ítalo Porto https://ri.ufs.br/jspui/handle/riufs/23599 2025-10-22T17:38:26Z 2025-07-25T00:00:00Z

Título: Operação de reservatórios por otimização estocástica explícita baseada nos momentos estatísticos: redução da dependência da distribuição de probabilidade Autor(es): Siqueira, José Ítalo Porto

2025-07-25T00:00:00Z Leite, Leonardo Fellipe Prado https://ri.ufs.br/jspui/handle/riufs/21803 2025-04-16T15:56:49Z 2025-02-20T00:00:00Z

Título: Aplicações do método de homogeinização assintótica e a técnicas de camadas fictícias em formulações variacionais zig-zag de alta ordem para vigas compósitas laminadas Autor(es): Leite, Leonardo Fellipe Prado Abstract: In the field of materials mechanics, many structural problems exhibit periodic characteristics or can be approximated as such, related to the variation of elastic modules due to the heterogeneity of the internal structure, external forces on the body and/or geometry, and which may also occur over time in a manner that is not necessarily periodic (combined effects of seasonality, temporal variation of external forces and/or, for example, fatigue or stiffening/softening due to the evolution of the internal structure). The more repetitive and complex the structure, the more challenging it becomes to solve the problem, as classical numerical techniques require modeling in two or three dimensions and very fine discretization of the domain, resulting in high computational costs. Additionally, it is observed in nature that most materials are heterogeneous at some scale, and their properties may vary randomly or in a standardized manner. Examples include concrete, whose behavior varies with its components and proportions; wood, with its anisotropic characteristics; and composite materials reinforced with fibers or particles, which are essential for ensuring the mechanical efficiency of structures. To avoid direct modeling of problems with rapidly oscillatory coefficients, mathematical homogenization methods are essential, as they aim to transform these coefficients into homogeneous equivalents. This work proposes a twodimensional modeling of heterogeneous materials beams by concurrently utilizing high-order zig-zag multilayer theories and the one-dimensional asymptotic homogenization method, allowing the description of periodic or random materials through fictitious layer techniques. Based on problems resolved using experimental results from the literature, the results demonstrate that the methodology is highly efficient, as it maintains good accuracy in twodimensional models even when using one-dimensional functions for composite, laminated and periodic materials problems.

2025-02-20T00:00:00Z Silva, Diewelly Maria https://ri.ufs.br/jspui/handle/riufs/21583 2025-04-07T17:58:42Z 2024-08-29T00:00:00Z

Título: Modelo de otimização mecanicista e funcional aplicado ao dimensionamento de pavimentos semirrígidos Autor(es): Silva, Diewelly Maria Abstract: Road networks are critical for the global transportation of goods and passengers, accounting for the largest share of infrastructure investments. Since pavement design directly impacts the Life Cycle Cost (LCC) of pavement, achieving optimal solutions within specific technical and economic contexts is highly desirable. The primary objective of this research was to optimize the structural design of flexible and semi-rigid pavement layers, considering variables such as structural type, layer thicknesses, and material costs. Consequently, the application of optimization techniques has proven to be highly effective in achieving suitable pavement designs. Intelligent search algorithms emerge as valuable tools in the quest for the "ideal project," maximizing benefits while minimizing pavement construction costs. This technique was implemented by means of the free software and numerical computation platform Octave, integrating mechanistic-empirical, functional, and economic approaches to optimize pavement layer thicknesses. The ELSYM5 software served as a specialized subroutine for calculating critical stresses and strains in the pavement. These analysis results were evaluated using performance prediction models to estimate damage and service life. The mechanically suitable pavement structure was also subjected to a performance analysis of Roughness (International Roughness Index – IRI). Given that feasible solutions are those with economic viability, i.e., with LCC within the available budget, various optimization techniques were tested and compared to the engineering solution applied in a Monitored Section of BR-101/SE. Among the four optimization techniques tested in this research, evolutionary algorithms stood out as a robust and promising approach, primarily due to their ease of implementation and for providing the most economically viable technically feasible solution, with an estimated 18% LCC savings compared to the solution applied on BR-101/SE.

2024-08-29T00:00:00Z Santos, Ana Lara Araújo https://ri.ufs.br/jspui/handle/riufs/21418 2025-03-31T13:06:06Z 2025-02-06T00:00:00Z

Título: Aplicação de técnicas alternativas no tratamento de água subterrânea para comunidades rurais Autor(es): Santos, Ana Lara Araújo Abstract: In Brazil, although thousands of people still do not have access to a quality water supply, they resort to individual solutions, such as the use of underground water, which is sometimes of lower quality than recommended by legislation. There are several alternatives that can mitigate the situation, such as the use of slow filters with casual and non-occasional filtering media or the use of natural coagulants/flocculants, making it possible to reduce social problems adverse to water supply, especially for the rural population, which they live in more isolated places without a quality water supply. Therefore, this study's main objective was to verify the efficiency of water filter treatments using conventional and non-conventional slow, and using natural coagulant/flocculant from cactus, in the treatment of groundwater. Thereby, in slow filtration, three downward flow filters were used, these being a filter with sand (FA), a filter with sand and activated carbon (FACA) and a filter with sand and biochar from cactus (FABC). For the treatment of water with coagulation/flocculation, the best result was evaluated with the use of coagulant/flocculant from cactus in the treatment of groundwater, for subsequent analysis of the efficiency of the aforementioned treatment in comparison with FABC. Thus, according to statistical tests, the results indicated similar performance between conventional and non-conventional filters for the parameters apparent color, turbidity, electrical conductivity and total iron, with significant differences between raw and filtered water. Besides, the hardness and electrical conductivity parameters had similar behavior with the use of filters, having moderately higher values with FABC only until the end of the first filtration career. In coagulation/flocculation, 100% of the true color, turbidity and chemical oxygen demand were removed, in addition to 97% of the total iron. Furthermore, both treatments did not show significant changes in relation to temperature and pH. When comparing the treatments (coagulation/flocculation and slow filtration), they showed statistically significant differences (except for the total iron parameter), demonstrating that, although both methodologies present significant removals in the evaluated water quality parameters, they have behavior of different treatments. Therefore, the results indicated that both alternative solutions significantly improved water quality, making them viable for reducing inequalities regarding the availability of quality water between rural and urban areas.

2025-02-06T00:00:00Z