RESUMO Este trabalho objetivou avaliar os custos envolvidos na construção de modelos de biodigestores (indiano, chinês e canadense) no município de Cascavel – PR. Determinaram-se os custos de produção de energia a partir do biogás produzido por dejetos de caprinos, bovinos e suínos, para sistemas de semiconfinamento. Foram utilizadas propriedades rurais com 20; 40; 60; 80 e 100 animais de cada um dos três grupos avaliados. A partir do volume de dejetos produzidos por animal, foram dimensionados os biodigestores e calculados os custos para a construção e a implantação de cada modelo, e o custo total da produção anual de energia em função do número de animais. O biodigestor modelo canadense apresentou o menor custo de construção e de implantação, variando de R$ 2.104,00 a R$ 7.266,00. A geração de energia com dejetos de suínos apresentou o menor custo, variando de 0,015 a 0,050 R$/KWh em biodigestor modelo canadense. A maior produção anual de energia foi verificada para bovinos, variando de 24.090 kWh/ano a 120.450 kWh/ano, para os três modelos de biodigestor em estudo.

Sustainable mobility in university environments presents both a challenge and an opportunity to reduce environmental impact and promote energy efficiency. This study assesses the feasibility of implementing electric buses in the internal transportation system of the Federal University of Paraíba (UFPB), considering environmental, economic, and operational aspects. The analysis demonstrates that transitioning to this model can lead to a significant reduction in greenhouse gas (GHG) emissions, noise pollution mitigation, and optimization of operational costs throughout the vehicle’s life cycle. The study examines technical, structural, and financial factors, emphasizing the necessary infrastructure, academic community acceptance, and the economic viability of the project, as well as the strategic advantage of integrating the electric fleet with photovoltaic energy generation. The key highlights of this research include: (i) Sustainability and energy efficiency, emphasizing a reduction of up to 52.52% in CO₂ emissions when vehicles are powered by photovoltaic energy in an LCA context, alongside improvements in air quality and noise pollution mitigation. (ii) Economic feasibility analysis, comparing operational and maintenance costs between electric and conventional diesel buses, evaluating the financial viability and potential return on investment. (iii) Infrastructure and implementation challenges, addressing the need for charging stations, adaptation of UFPB’s infrastructure, and financing models, including government subsidies and strategic partnerships. (iv) Impact on the academic community, analyzing student and staff perceptions and acceptance of fleet electrification and the promotion of sustainable practices. (v) Future projections and replicability, exploring trends in the sustainable transportation sector, as well as the potential expansion of the electric fleet and its integration with energy storage systems. The results indicate that adopting electric buses at UFPB can position the institution as a benchmark in sustainable mobility, serving as a replicable model for other universities and contributing to carbon emission reduction and modernization of university transportation.

Herbicide Spot Spraying (PLH, Pulverização Localizada de Herbicidas) using remote imaging, performed by low-cost drone, represents an innovative method in Agriculture 4.0. It enables the identification of areas with the highest weed infestation, allowing for targeted herbicide application in strategic locations. This approach reduces both the quantity of herbicides applied and their associated ecological and economic impacts. Therefore, this study aimed to assess the impact of PLH through remote sensing with low-cost drones on weed control. It was based [...] Abstract Herbicide Spot Spraying (PLH, Pulverização Localizada de Herbicidas) using remote imaging, performed by low-cost drone, represents an innovative method in Agriculture 4.0. It enables the identification of areas with the highest weed infestation, allowing for targeted herbicide application in strategic locations. This approach reduces both the quantity of herbicides applied and their associated ecological and economic impacts. Therefore, this study aimed to assess the impact of PLH through remote sensing with low-cost drones on weed control. It was based

In this study, we investigate the dual-fuel operation of compression ignition engines using biodiesel at varying concentrations in combination with biogas, with and without hydrogen enrichment. A response surface methodology, based on a central composite experimental design was employed to optimize energy efficiency and minimize pollutant emissions. The partial substitution of diesel with gaseous fuel substantially reduces the specific fuel consumption, achieving a maximum decrease of 21% compared with conventional diesel operation. Enriching biogas with hydrogen, accounting for 13.3% of the total flow rate, increases the thermal efficiency by 0.8%, compensating for the low calorific value and reduced volumetric efficiency of biogas. Variations in biodiesel concentration exhibits a nonlinear effect, yielding an additional average efficiency gain of 0.4%. Regarding emissions, the addition of hydrogen to biogas contributes to an average reduction of 5% in carbon monoxide emissions compared to the standard dual-fuel operation. However, dual-fuel operation leads to higher unburned hydrocarbon emissions relative to neat diesel; hydrogen enrichment mitigates this drawback by reducing hydrocarbon emissions by 4.1%. Although NO_x emissions increase by an average of 26.6% with hydrogen addition, dual-fuel strategies achieve NO_x reductions of 11.5% (hydrogen-enriched mode) and 33.3% (pure biogas mode) relative to diesel-only operation. Furthermore, the application of response surface methodology is robust and reliable, with experimental validation showing errors of 0.55–8.66% and an overall uncertainty of 4.84%.

Este experimento teve como objetivo analisar o comportamento da diferença de geração entre uma usina fotovoltaica utilizando o sistema de rastreamento solar (Tracker) em comparação com um sistema Fixo voltado ao norte. Ambas as usinas instaladas na região de Cascavel - Paraná. O sistema consiste em duas usinas on-grid de 300kW com 810 módulos de 500wP. No primeiro período de coleta de dados no mês novembro e dezembro 2021, verificou-se que a usina que utiliza o rastreador solar, durante a coleta de dados, alcançou maior eficiência de geração em comparação com a usina fixa. Atingindo uma média de eficiência de 30%, a mais que a usina fixa. Para o segundo período com os dados coletados em janeiro e fevereiro de 2022, a eficiência de geração da usina utilizando o rastreador solar ficou superior aos 30% em comparação com a usina fixa. O teste utilizou-se não paramétrico de Wilcoxon com correção de continuidade. O teste foi significativo (p=2,578 x 10-6) indicando diferença significativa entre os métodos comparados (Tracker x Fixo).

Este estudio verificó la influencia alelopática del extracto de hojas del frijol canavalia (Canavalia ensiformis), sobre el cultivo de cártamo (Carthamus tinctorius) aplicado en diferentes concentraciones. Diez genotipos de cártamo fueron sembrados en 20 contenedores y la preparación del extracto acuoso fue a partir de la maceración de hojas de frijol canavalia con agua. Se aplicaron cinco tratamientos (0%, 25%, 50%, 75% e 100%) del extracto de hoja con cuatro repeticiones. Se evaluaron los parámetros velocidad de germinación, porcentaje de germinación, masa seca y fresca, tamaño de hojas y raíces. Se encontró que el extracto acuoso de frijol canavalia influye de diferentes formas en los parámetros evaluados, presentando en algunos momentos características neutras, inhibitorias y estimulantes, variando de acuerdo al porcentaje del extracto aplicado.