The effect of vegetation harvest on the operation of a surface flow constructed wetland

Constructed wetlands represent a low-cost and highly efficient municipal wastewater treatment alternative, due to their low technological and energy demands. Wetland vegetation releases an amount of carbon to the system, when it is decomposed (winter period). Part of this organic matter could remain in the system, and will be decomposed at very low rates during winter and spring. In this research, a constructed superficial-flow wetland was divided into two equal parts and vegetation (Typha latifolia) was harvested in one of them. The organic load applied to the system was 11.2 gBOD/m2·d. The control of the organic matter was carried out during 141 d (111 d in winter and 30 d in spring). Differences in efficiencies (TSS, BOD and COD), were observed between both types of the wetland, with an important increase in these differences during spring. Vegetation released organic matter to the system, specially suspended and biodegradable matter. BOD and TSS released per dry gram of Typha were 4.24 mgBOD/gTypha and 4.36 mgTSS/gTypha, respectively. Harvest is a recommended practice in systems treating diluted wastewater, especially in productive areas like the Mediterranean. The recommendations can also be applied to a broader geographic area.Keywords: wastewater treatment wetlands, Typha, decomposition, biodegradable organic matter, suspended organic matter, harves

Probabilistic Load Forecasting Based on Adaptive Online Learning

Load forecasting is crucial for multiple energy management tasks such as scheduling generation capacity, planning supply and demand, and minimizing energy trade costs. Such relevance has increased even more in recent years due to the integration of renewable energies, electric cars, and microgrids. Conventional load forecasting techniques obtain singlevalue load forecasts by exploiting consumption patterns of past load demand. However, such techniques cannot assess intrinsic uncertainties in load demand, and cannot capture dynamic changes in consumption patterns. To address these problems, this paper presents a method for probabilistic load forecasting based on the adaptive online learning of hidden Markov models. We propose learning and forecasting techniques with theoretical guarantees, and experimentally assess their performance in multiple scenarios. In particular, we develop adaptive online learning techniques that update model parameters recursively, and sequential prediction techniques that obtain probabilistic forecasts using the most recent parameters. The performance of the method is evaluated using multiple datasets corresponding with regions that have different sizes and display assorted time-varying consumption patterns. The results show that the proposed method can significantly improve the performance of existing techniques for a wide range of scenarios.Ramon y Cajal Grant RYC-2016-19383 Basque Government under the grant "Artificial Intelligence in BCAM number EXP. 2019/00432" Iberdrola Foundation under the 2019 Research Grant

Minimax Forward and Backward Learning of Evolving Tasks with Performance Guarantees

For a sequence of classification tasks that arrive over time, it is common that tasks are evolving in the sense that consecutive tasks often have a higher similarity. The incremental learning of a growing sequence of tasks holds promise to enable accurate classification even with few samples per task by leveraging information from all the tasks in the sequence (forward and backward learning). However, existing techniques developed for continual learning and concept drift adaptation are either designed for tasks with time-independent similarities or only aim to learn the last task in the sequence. This paper presents incremental minimax risk classifiers (IMRCs) that effectively exploit forward and backward learning and account for evolving tasks. In addition, we analytically characterize the performance improvement provided by forward and backward learning in terms of the tasks’ expected quadratic change and the number of tasks. The experimental evaluation shows that IMRCs can result in a significant performance improvement, especially for reduced sample sizes.Funding in direct support of this work has been provided by projects PID2022-137063NBI00, PID2022-137442NB-I00, CNS2022-135203, and CEX2021-001142-S funded by MCIN/AEI/10.13039/501100011033 and the European Union “NextGenerationEU”/PRTR, BCAM Severo Ochoa accreditation CEX2021-001142-S / MICIN / AEI/ 10.13039/501100011033 funded by the Ministry of Science and Innovation, and programes ELKARTEK, IT1504-22, and BERC-2022-2025 funded by the Basque Government

Comparing walking accessibility variations between groceries and other retail activities for seniors

This paper aims to compare walking accessibility levels between groceries and other types of retail for seniors, examining whether patterns are uniform (or not). The city of Granada, Spain served as case study. First, a questionnaire was administered with persons older than 55 years, assessing their willingness to reach different types of retail opportunities on foot. A total of 202 valid responses were obtained (171 face-to-face and 31 online): 56% women, average age 69 years old, 20% living alone, and average monthly family income between €1000-€2000. Second, the K-modes clustering algorithm was used to identify four seniors sub-groups: “non-motorized seniors between 65 and 75”, “motorized seniors between 65 and 75”, “non-motorized seniors older than 75”, and “motorized seniors younger than 65”. The variables used were: age, car availability, household income, and household composition. Third, by using the Kruskal-Wallis and Mann-Whitney tests (p-level <0.05), a comparison of time-willingness functions to walk to retail was made between seniors sub-groups. The results revealed that walking accessibility to groceries are not significantly different among those sub-groups, while the accessibility levels to weekly retail are significantly lower for the “motorized seniors younger than 65” for time-willingness slots of 20–30 min. R software was used for statistical analysis

Estudio morfológico, mediante luz reflejada, de piritas procedentes de la mina "Solitaria" (arres, Vall D'Aran, Lérida)

Se lleva a cabo el estudio y la interpretación de los diferentes tipos de cristales de pirita que se encuentran en el yacimiento Mina "Solitaria" (Arrés, Vall d'Aran) Lérida

Estudio, mediante luz reflejada, de las maclas de calcopiritas metamórficas procedentes de mina "Saubader" (Vall D'Aran, Lérida)

Se describe la morfologia de las maclas observadas en calcopiritasmetamórficas procedentes de la Vall d'Arán (Lérida, España). Las maclas son de dos tipos: 1. Maclas lineales engendradas por un mecanismo de deformación; 2. Maclas irregulares debidas a la aparición de una fase polimórfica de la calcopirita. Se lleva a cabo su interpretación en relacióncon los procesos metamórficos

Identificación de diversas fases de metamorfismo regional en las mineralizaciones de Bossost (Vall d'Aran, Lérida)

Metamorfisrno desarrollado en el Pirineo central afecta conjuntamente a los estratos y a las mineralizaciones en ellos englobadas. Se lleva a cabo el estudio comparativo entre las estructuras metamórficas desarrolladas en la roca y la sucesión de fases metamórificas en las masas mineralizadas

Sobre la presencia de gahnita ferrífera en Bossost (Vall D'Aran, Lérida)

Identificación de la gahnita ferrífera (creitonita) (AlFe)2 O4 (Zn, Fe, Mg), en mina "Victoria" Val d'Aran ( Lérida)

Analysis of the behavior of daily maximum rainfall within the department of Atlántico, Colombia

In the Colombian Caribbean region, there are few studies that evaluated the behavior of one of the most commonly used variables in hydrological analyses: the maximum daily rainfall (Pmax-24h). In this study, multiannual Pmax-24h time series from 19 rain gauges, located within the department of Atlántico, were analyzed to (a) determine possible increasing/decreasing trends over time, (b) identify regions with homogeneous behavior of Pmax-24h, (c) assess whether the time series are better suited under either a stationary or non-stationary frequency analysis, (d) generate isohyetal maps under stationary, non-stationary, and mixed conditions, and (e) evaluate the isohyetal maps by means of the calculation of areal rainfall (Pareal) in nine watersheds. In spite of the presence of both increasing and decreasing trends, only the Puerto Giraldo rain gauge showed a significant decreasing trend. Also, three regions (east, central, and west) with similar Pmax-24h behavior were identified. According to the Akaike information criterion test, 79% of the rain gauges showed better fit under stationary conditions. Finally, statistical analysis revealed that, under stationary conditions, the errors in the calculation of Pareal were more frequent, while the magnitude of the errors was larger under non-stationary conditions, especially in the central-south region. © 2019 by the authors

Mineralogénesis de los yacimientos del área de Bossost (Vall d'Aran, Lérida)

Basándose en todo el conjunto de datos que se poseen en la actualidad, se establecen las sucesivas fases y los diferentes mecanismos que han tenido lugar durante la mineralogénesis de los yacimientos de sulfuros metálicos de Bossost (Vall d'Aran, Lérida)