Partial shading conditions can cause low output power, hotspots, and a reduced lifespan in photovoltaic arrays. Interconnection (IC) and differential power processing (DPP) can be used to mitigate these effects. When individually applied to an array, these techniques can significantly increase the generated power. A few authors studied the combined use of these schemes under specific conditions such as large-scale arrays or a complex combination of several techniques, making it difficult to identify the individual contribution of each technique. Here, we aimed to determine whether the combined use of a switching-inductor DPP circuit and a total-cross-tied interconnection scheme presents better performance than each standalone technique, using a small-scale photovoltaic array. An array was tested using IC, DPP, and a combination of both techniques, and the array was subjected to 13 shading patterns and two irradiance levels. The performance in each case was assessed using maximum output power, performance ratio, mismatch power loss, and power enhancement indicators. The results showed that a standalone differential power processing circuit presents better performance than when it is combined with an interconnection. The DPP showed performance ratio values of up to 97%, mismatch power losses lower than 36.9%, and a power enhancement of up to 95.9%. The standalone interconnection shows the worst performance among the three techniques.

The concern for sustainability, understood as the responsible use of natural resources to ensure the well-being of future generations, has grown across various sectors. One of the main drivers of environmental degradation is the use of fossil-fuel-based transportation, which produces pollutant emissions and contributes to climate change. In this context, electric cars have emerged as a smart and sustainable alternative, as they do not emit polluting gases and, when powered by renewable energy sources such as photovoltaics, can significantly reduce the carbon footprint. Based on this concept, it is noted that electric cars are an intelligent alternative to reduce the degradation caused by fossil fuels. The generation of electricity from renewable sources, such as photovoltaics, biogas and others, combined with the low maintenance costs and long service life of these technologies, represents an extremely sustainable solution. In this work, methodologies are applied for sizing and analysis of the cost of electricity generation through photovoltaic energy. The operational cost of the electric car being fueled by electricity provided by this source and by energy from the utility grid compared to the operational cost of an internal combustion engine car is also considered. The (CO₂)eq emitted by the use of the photovoltaic plant, energy from the grid and the gasoline used in the internal combustion engine car is also determined. It is concluded that the return on investment for the energy generated by photovoltaic energy is approximately 5 years. The annual cost for an electric car is 76.49% lower when using electricity provided by energy concessionaires in Brazil and 81.35% lower for energy from photovoltaic plants compared to an internal combustion engine vehicle, also considering that the harm to the environment is low for this technology. These data emphasize the importance of looking for technological and sustainable solutions that adapt energy production systems, reduce costs and, above all, help to mitigate the impact on the environment, reflecting a commitment to the future of our planet and the quality of life of future generations.

The current critical global climate situation, which is due to greenhouse gas emissions, has led society to look for ways to preserve the environment. One of these is the use of renewable energies, including wind power. This energy uses the wind to operate. Based on this, this work seeks to design and produce wind blades using polymeric materials in an additive manufacturing process, in this case, with a 3D printer. The materials used were ABS, PETG, PLA and Tritan. The shapes developed were straight, curved and curved tip for the Tritan polymeric material, while for the other materials, the shape designed was straight. Once manufactured, the blades were subjected to performance tests with a wind turbine coupled to an alternator consisting of a tripod turbine. During the experiments, the construction materials, the shapes and the angle of attack as a function of the linear wind speed generated by a wind tunnel were changed so that the analysis was consistent. The results obtained were compared to identify the best combinations of the parameters analyzed. In the end, it was concluded that the blades printed with the Tritan polymeric material could be applied to various wind speed conditions—low, medium and high—as well as having good mechanical properties and the best performance in their manufacturing process, making them the best of those studied.

The growing replacement of metallic alloys by polymer matrix composites in the transport and mobility industries has intensified the need for reliable methods to predict the strength of laminates weakened by fastener holes. As a preliminary step toward the design of composite bolted joints, this work investigates the open-hole (notched) tensile strength of carbon fiber/epoxy laminates using a uniaxial fracture framework based on both the Point Stress Criterion (PSC) and the Average Stress Criterion (ASC) of Whitney and Nuismer. Six balanced carbon/epoxy fabric stacking sequences ranging from [0]₅ to [45]₅ were analyzed for four different hole diameters (3.18, 6.35, 9.52, and 12.70 mm), together with the unnotched reference, totaling 30 evaluated conditions (six different stacking sequences × four different hole diameters and one unnotched laminate). The Konish–Whitney analytical stress distribution was applied to both criteria. The characteristic dimensions d₀ (PSC) and a₀ (ASC) were obtained by fitting reference experimental data. The ASC integral was evaluated numerically over the same stress distribution used for the PSC. A complementary two-dimensional finite-element model with 360-element azimuthal mesh refinement was developed and validated against the classical isotropic infinite-plate solution (K_t ≈ 3), with an accuracy better than 0.1%. Across all 24 (laminate × diameter) combinations, the ASC reduced the root-mean-square prediction error from 15.1% (PSC) to 11.0%, and the mean absolute error from 11.7% to 7.8%. For balanced [0/45] configurations both criteria remained within ±10% of the experimental notched strength, with the ASC narrowing the band to ±3.6%; unidirectional laminates, non-conservative by up to 16% under the PSC, were brought below 7% by the ASC, and ±45°, dominated stacks remained conservative (15–23%), reflecting matrix-driven failure mechanisms outside the scope of either point-wise criterion. Condensed error maps are used to delineate the envelope of applicability of each criterion on the fabric laminate dataset of Soriano and Almeida. The comparative assessment supports the ASC as the more accurate of the two criteria for fiber-controlled configurations within the dataset, while highlighting that any transfer of the calibrated characteristic dimensions to other material systems, geometries, or off-axis-dominated layups would require dedicated validation and, for off-axis stacks, progressive damage modeling.

Anais do Congresso Internacional e Workshop de Design e Materiais (978-65-272-1860-9) - Breve Revisão Sobre A Amônia Verde Como Vetor De Hidrogênio Verde E Sua Aplicação Em Motores De Combustão Interna

Este trabalho apresenta uma pesquisa bibliográfica sobre a produção e aplicação de modelos fabricados através da manufatura em uma fundição em areia. É descrito o conceito de manufatura aditiva, suas diferentes características e tecnologias e como este processo está relacionado com a indústria de fundição em areia. Através de trabalhos anteriores, os resultados são apresentados por meio de comparações de elementos como desempenho, tempo e custo de produção entre modelos feitos pela manufatura aditiva e modelos convencionais, geralmente de aço, madeira, isopor ou epóxi. Foi avaliado que os modelos 3D apresentam um menor custo e tempo de produção e uma maior produtividade que modelos de epóxi e madeira, além de ser observado que, quanto mais complexa é a peça final, mais vantajosa se torna a utilização da manufatura aditiva. Também são apresentadas comparações entre modelos feitos pelas tecnologias FDM e InkJet 3D Printing, com esta se mostrando mais vantajosa por não apresentar defeitos relevantes na peça final, como ocorreu com a peça de FDM, e possuir características como maior taxa de resfriamento, menor volume e massa total, menor tempo de produção e, consequentemente, uma maior produtividade. Ao final, são dadas sugestões para que se consiga transformar esta pesquisa teórica em um trabalho empírico.