Repositório Científico do Instituto Politécnico de Castelo Branco
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Recent Submissions
Topography and hydrology modeling and influence on soil erosion simulation, at small basin scale
Publication . Duarte, A.C.; Ferreira, Carla; Vitali, Giuliano
Diffuse pollution from agricultural activities is a major environmental problem. The extent of the impacts is driven, e.g., by local topography due to the influence on hydrological processes. This study aims to investigate the use of dif-ferent scale topographic data in assessing runoff-erosion processes. The TopAG-NPS module, a component of the AnnAGNPS model (Annualized Agriculture Nonpoint Source), was used to assess the impact of the vertical resolution of the Digital Elevation Model (DEM) on the topographic and hydrological configura-tion of a basin, and on the simulation of soil erosion. The study focuses on a small agro-forestry basin (190 ha) located in the municipality of Idanha-a-Nova, Portu-gal. A georeferenced survey of the basin’s surface drainage network was carried out and then compared with the results of the simulated drainage networks gener-ated by the TopAGNPS module using two DEMs with vertical resolutions of 1 m and 5 m. The DEM with a 5 m vertical resolution produced unsatisfactory results, as evidenced by significant discrepancies between the simulated and observed nat-ural drainage networks. On the other hand, the drainage network generated with the DEM of 1 m resolution was very similar to the observed drainage network. The use of distinct topographic configurations modeled based on different vertical resolution DEMs on the estimation of soil erosion by water using the RUSLE model (Revised Universal Soil Loss Equation), resulted in significant differences considering the values of 5.85 and 4.17 ton/ha.year for the DEM with 1 m and 5 m vertical resolution, respectively. Considering that soil erosion by water and other processes, such as the transport of pollutants, are distributed processes, it is of great relevance to consider good topographic and hydrologic configurations to achieve more reliable simulations and better support decision-making.
Reproductive toxicity assessment of four portuguese plant hydrolates: Effects on oocyte maturation and sperm viability
Publication . Dias, Sandra D.F.; Andrade, L.P.; Rolo, Joana; Gaspar, Carlos; Ruivo, Patrícia Gomes; Oliveira, Ana Sofia; Ferreira, Sandra Saraiva; Oliveira, Rita Palmeira; Oliveira, José Martinez de; Gonçalves, José Carlos; Delgado, F.M.G.; Oliveira, Ana Palmeira de
Extracts of aromatic medicinal plants have been extensively studied regarding their numerous bioactivities. However, despite being highly used by humans, studies on the safety of these extracts for animal use are scarce. In this study, we aim to contribute to the determination of the safety profile of plant extracts by focusing on the reproductive toxicity of hydrolates (a by-product of essential oils production) of four endogenous Portuguese plants—Cistus ladanifer, Cupressus lusitanica, Helychrisium italicum, and Thymbra capitata—by studying their effects on bovine oocytes and spermatozoa. To achieve our aims,we determined the oocyte maturation and viability rate in the bovine in vitro maturation test (bIVM) and the bovine sperm viability using the eosin–nigrosin test, in the presence of five concentrations of each hydrolate at half-log intervals (% v/v of culture media). We found that hydrolates did not affect oocyte maturation or viability (maximum concentration tested: 0.2%, v/v). Regarding the sperm viability test, we found that T. capitata and C. ladanifer hydrolates impaired sperm viability (p < 0.05) (maximum concentration tested: 0.2%, v/v), in comparison with the negative control. In summary, we found that H. italicum and C. lusitanica hydrolates were safe regarding oocyte maturation, oocyte viability, and
sperm viability, being candidates to be included in bovine husbandry as feeding additives.
Connecting present and future soil erosion risk in the upper Tagus river region of Portugal
Publication . Duarte, A.C.; Quinta-Nova, L. C.; Monteiro, M.C.H.
Soil water erosion causes soil degradation, affecting its fertility and, consequently, leading to the loss of its productive capacity and may contribute to a process of desertification. Countries in the Mediterranean basin are under the influence of a climate pattern that is unfavorable to maintaining effective soil cover, with peak precipitation events occurring, and an increase in soil erosion rates is expected in changing scenarios. Climate, where the occurrence of extreme meteorological phenomena will be more frequent. The aim of this study is to evaluate the present situation and estimate the future soil erosion risk of in the upper region of the Portuguese part of the Tagus River basin, where agricultural use and livestock activities are dominant in soils that are highly susceptible to erosion. The soil loss estimation was carried out for the current situation and for the climatic conditions projected for 2050, considering two Representative Concentration Pathways (RCP 4.5 and RCP 8.5). We use the RUSLE methodology to determine the risk of soil water erosion. Although annual precipitation decreases for both RCPs, the erosivity index will increase in both scenarios. Our findings provide insights into the consequences of socioeconomic development options on physical land degradation and loss. To understand the process of soil water erosion, using modeling and other tools, is very important for the design of policy instruments that minimize the effects of climate change on soil.
Unsupervised anomaly detection in industrial machines supported by vibration analysis under data scarcity constraints
Publication . Torres, Pedro; Spencer, Geoffrey; Esteves, Arthur; Sousa, Fernando; Pereira, Fernando J.G.; Guerreiro, Rui M.L.
The integration of the use of Artificial Intelligence (AI) in industrial environments often faces the lack of labeled data, as well as historical records. This lack of information becomes a problem when implementing predictive maintenance solutions, particularly in monitoring the condition of industrial machines and automatic fault detection. This work addresses this issue in an industrial scenario, through the analysis of vibrations in a spindle motor of an ornamental stone cutting machine. Unsupervised learning techniques are explored for anomaly detection through vibration data, using the training and implementation of an LSTM (Long Short-Term Memory) Autoencoder model. Datasets consist only of unlabeled accelerometer signals acquired during normal machine operation. An analysis based on the extraction of statistical features from the signal is adopted to use them as inputs of the Machine Learning algorithm, to learn
the normal behavior of the machine and detect deviations that may correspond to potential anomalies. The experimental results show that even in the absence of labeled data, it is possible to extract meaningful insights from the machine state and establish a practical pipeline for anomaly detection in industrial machines through vibration analysis.
Índice VL e Índice VL-Erva : vivem-se bons momentos para a rentabilidade das explorações leiteiras
Publication . Rodrigues, A.M.; Vouzela, Carlos; Marques, Nuno; Pitacas, F.I.
Analisa-se neste número da Ruminantes os Índices VL e VL - ERVA para o período de maio a julho de 2025. Durante o trimestre em análise, o preço médio do leite pago aos produtores individuais do continente foi de 0,471 €/kg, para leite com 3,75% de gordura e 3,29% de proteína. O preço variou entre 0,473 €/kg em maio e 0,468 €/kg em julho. Na Região Autónoma dos Açores o preço médio do leite pago aos produtores individuais que possuem tanque de refrigeração na exploração foi de 0,432 €/kg, para leite com 3,74% de gordura e 3,22% de proteína, tendo variado entre 0,434 €/kg em maio e 0,429 €/kg em junho. Relativamente ao leite Bio produzido em Portugal, durante o trimestre em análise preço médio do leite obtido, segundo o modo biológico de produção, foi de 0,530 €/kg, leite com 3,78% de gordura e 3,25% de proteína. A evolução do preço do leite pago aos produtores e a evolução dos custos da alimentação refletiu-se nos Índices VL e VL - ERVA que, em julho de 2025, foram, respetivamente, 2,005 e 2,871. Parece que se estão a viver bons momentos para a rentabilidade das explorações de bovinos de leite em Portugal. Desde dezembro de 2023 que os índices VL e VL-ERVA apresentam uma linha de tendência crescente, mesmo continuando o leite a ser pago em Portugal a um valor muito mais baixo do que a média trimestral da UE27 (-7,18 cêntimos / kg de leite).