Using renewable energies is one of the alternatives to mitigate climate change. Among them, photovoltaic energy has shown a relevant growth of participation in the electric sector. In the backdrop of such growth, in countries such as Brazil, photovoltaic energy has surpassed the generation of electricity by petroleum derivatives since 2019. The significant growth in photovoltaic generation around the world can be attributed to several key factors, including abundant sunlight, supportive government policies, falling solar panel costs, environmental concerns, energy diversification goals, investor interest, job creation, and local manufacturing. However, photovoltaic system performance is heavily tied to weather variability. Different models are used to account for this meteorological dependence; however, there is a gap regarding the differences in the outputs of these models. The study presented here investigates the variability and sensitivity of the models used to estimate photovoltaic production ($P_{pv}$). Six models were compared by percentage difference analysis. Statistical analyses from the perspective of variability revealed that the difference between the $P_{pv}$ estimated by these models reaches a 12.89% absolute power difference. Considering that temperature and solar irradiance are the meteorological variables that most influence $P_{pv}$, the sensitivity analysis focused on these. Regarding sensitivity, in the context of temperature changes, the average relative difference in $P_{pv}$ between models can reach up to 5.32% for a 10 °C change, while in the context of changes in solar irradiance, the average relative difference can reach up to 19.05% for a change of 41.67 W/m². The consideration of the variability and sensitivity of the main sets of equations used to estimate the potential of photovoltaic energy production can help refine methodologies and assumptions in future research in this area. There are variations and sensitivities, as observed, of such magnitude that, depending on the set of equations adopted in the study, they can alter the conclusion about photovoltaic energy production in a given region. Accurate estimations are pivotal not only for feasibility analyses but also for gauging economic and socio-environmental impacts. These divergences can, in turn, reformulate feasibility analyses and compromise the reliability of photovoltaic energy systems, thus leading to different economic and socio-environmental consequences.

During the production of petroleum and gas, the equipments employed for this activity are subjected to synergetic wear mechanisms, such as corrosion, corrosion-cavitation and corrosion-cavitation-erosion. Laboratory experiments has been performed to reproduce some of these mechanisms, however, sometimes the tests is not capable to recreate the complexities caused by hydrodynamic flows, physico-chemical and mechanical non-linearities. The main objective of this work is to evaluate specimens of low carbon steel under laboratory conditions, such as corrosive, cavitative-corrosive (CO₂) and corrosive-erosive (CO₂ + SiO₂) environments. During the tests, the specimens were subjected to a stirring aqueous saline solution (0 and 5.0 m/s) at two levels of temperature, with gas injection (5.0 L/min) and contaminated with by solids particles of SiO₂ (2.5% mass). The surface of the specimens subjected to upstream flow (0° in a cylindrical generatrix of the specimen), and downstream flows (180º) were analyzed by profilometry. The measurements of roughness and waviness of all specimens were statistically analyzed at a confidence level of 95% and significant differences observed in some matrices were discussed. The results suggest that the wear mechanisms that act in the upstream generatrix differ from that of specimen downstream.

Objective: The study investigated the intersection between Industry 4.0 and biotechnology, with the aim of analyzing how these areas converge to promote innovation and sustainability in contemporary industry. Methodology: An integrative review approach was adopted, using several SciELO and Google Academic databases As an inclusion criterion, Brazilian articles were selected in Portuguese and published between 2020 and 2023. Results and data analysis: The results highlighted significant advances, such as advanced automation, artificial intelligence and 3D printing in Industry 4.0, that not only optimize industrial production, but also strengthen sustainable practices by reducing waste and improving the use of natural resources. Biotechnology has emerged as an essential pillar, offering solutions such as bioprinting and cellular therapies, expanding the possibilities for sustainable product development. Despite the benefits, ethical and regulatory challenges have been identified that require appropriate government policies and innovation strategies to ensure the ethical use of these technologies. Conclusion: In conclusion, the convergence between Industry 4.0 and biotechnology not only redefines modern industry standards, but also establishes a new sustainable innovation paradigm, contributing to a more responsible and competitive future globally.

Objective: The objective of this research was to analyze the role of biomass as a renewable energy alternative. Methodology: To do so, an integrative literature review was carried out by surveying articles in the SciELO, Web Of Science and Google Academic databases. During the search, specific keywords and AND and OR search descriptors were used. As an inclusion criterion, only Brazilian scientific articles were selected, in Portuguese, available in full, free of charge and published between the years 2020 and 2023. Results and analysis of the data: As a result, it was found that the energy use of solid urban waste (MSW) in Brazil offers environmental, health and social benefits, in spite of not having sufficient potential to sustain the expansion of the country's electricity supply in the long term. Relevant public policies, such as the National Policy on Solid Waste (PNRS) and the Alternative Energy Incentive Program (PROINFA), are crucial, but the lack of clarity in the joint implementation makes it difficult to replicate initiatives. The management of MSW is the responsibility of municipalities, while energy planning is the responsibility of the Union, and the absence of clear guidelines and specific funding contributes to limited results. Projects such as those of ASJA and FURNAS show progress, but the greater dissemination of these projects requires integrated public policies and a normative framework that aligns the efforts of various actors to maximize the efficiency and benefits of using MSW in power generation. Conclusion: In conclusion, the energy use of solid urban waste (MSW) in Brazil offers environmental and social benefits, but is not sufficient to expand the supply of electricity in the long term. Existing public policies are important, but their effectiveness is limited by the lack of clarity in implementation and by the division of responsibilities between municipalities and the Union. Projects such as those of ASJA and FURNAS show progress, but greater dissemination and effectiveness require integrated public policies and a normative framework that aligns the efforts of the various players to optimize the use of MSW in power generation.

Objective: The research aimed to investigate the potential of using biomass as a green energy source in Brazil, seeking to understand both the opportunities and challenges associated with its implementation. Methodology: The research approach was qualitative, classifying itself as exploratory, descriptive and practical. The sample was composed of 32 environmentalists, and the data were collected by means of in-depth interviews. For the analysis, the technique of discourse analysis was used. Results and Analysis: The results showed that biomass has great potential to diversify Brazil's energy mix, create jobs in rural areas and contribute to sustainability. However, participants also highlighted several challenges, such as the lack of adequate infrastructure, the need for more efficient technologies for the conversion of biomass into energy, and issues related to sustainable land use. The research indicated that public policies and government incentives are crucial for fostering the development of the sector, as well as social awareness and the acceptance of biomass by the population. Conclusion: The research concluded that, in spite of the challenges faced, biomass has a promising role in the construction of a more sustainable energy future in Brazil. Progress in this sector depends on a joint effort between government, private sector and civil society, focusing on innovation, research and implementation of sustainable practices. If well managed, biomass could contribute significantly to Brazil's energy transition, promoting a more sustainable and inclusive future.

A BRIEF REVIEW ON THE ADVANTAGES, HINDRANCES AND ECONOMIC FEASIBILITY OF STIRLING ENGINES AS A DISTRIBUTED GENERATION SOURCE AND COGENERATION TECHNOLOGY