Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
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Gas and water sampling from the FEBEX in situ test
No full textFern??ndez, A.M., 2019. Gas and water sampling from the FEBEX in situ test Nagra Technical Report NAB 16-13, 211 pp.The FEBEX (Full-scale Engineered Barrier EXperiment in Crystalline Host Rock) full-scale heating in situ test was performed at the Grimsel Underground Laboratory in Switzerland with the general aim of studying the behaviour of near-field components in a repository for high-level radioactive waste.
One of the objectives of the FEBEX in situ experiment was to analyse the gases generated and transported through the bentonite barrier because the accumulation, consumption and release of gases from a HLW repository system may affect a number of processes that influence the long-term safety (e.g., gas pressure build-up, changes in bentonite properties, influence of groundwater transport, radiological hazard, ???.).
In different phases of the FEBEX in situ test (First Operational Phase: 1996-2002, and Second Operational Phase: 2002-2015), various pipes were introduced inside the bentonite buffer for analysing the evolution of the gases and the chemical composition of the porewater. For this purpose, different gas/water sampling campaigns were performed since 1996 until 2011, before and after dismantling of Heater #1. Two additional campaigns were carried out in 2014 and 2015 during the FEBEX-DP Project for understanding the gas generation/consumption processes in the buffer and to establish the chemical conditions and redox state inside the bentonite barrier.
The main gases detected in the FEBEX in situ during the 18 years of experiment were O2, N2, CO2, CO, H2, CH4 and other saturated and unsaturated aliphatic hydrocarbons (alkanes up to C5 and alkenes). Fluid pressures remained close to atmospheric pressure because the FEBEX in situ test cannot be considered as a gas-tight system, and any excess of gas pressure generated could be dissipated. The highest fluid pressures measured (between 2 and 4.5 bar) at the beginning of the experiment were related to water pressures because of the water inflow during the saturation process of the bentonite. Furthermore, part of the gases identified were consumed in different (bio)-geochemical processes. Although the concentration of oxygen decreased over time, oxygen was never depleted completely, showing minimum values between 3 and 0.2 vol.%. However, the presence of hydrogen, methane and other hydrocarbons indicate the presence of spatial microenvironments where anoxic/anaerobic conditions were established, as confirmed by the reducing redox potentials calculated from hydrogen contents and measured in some pore waters collected from the different pipes
A Novel Methodological Approach to Simulating the Growth of Photosynthetic Organisms Using Long-Term Meteorological Sequences: A Case Study of Microalgae (Chlorella vulgaris)
Full text linkThe growth of photosynthetic organisms requires specific ranges of temperature and photosynthetically active radiation. Monitoring and maintaining these conditions is technically difficult, especially in outdoor cultures. In such cases, a typical meteorological sequence can be a useful tool for estimating the growth of photosynthetic organisms. This study proposes a new methodology based on long-term meteorological sequences to simulate the growth of photosynthetic organisms. This case study addresses microalgae growth simulation (Chlorella vulgaris) in Riosequillo in the north of the Madrid region (Spain) for the four seasons of the year. Then, these estimates are
compared with the observed results of an experimental culture of microalgae in domestic wastewater.
The results also show strong agreement with the probability distribution function of the daily biomass concentration, giving the best results for typical summer and spring meteorological sequences. The methodology seems to confirm the representativeness of typical meteorological sequences, allows for the identification of the most likely production scenarios for project feasibility analyses, and may be
applied to decision-making processes
Architectural Optimization of Dynamic Inception Modules in Convolutional Neural Networks using the Coral Reef Optimization Algorithm
Full text linkThe rapid advancement of Deep Learning (DL) has led to increasingly complex neu-
ral network architectures in Artificial Intelligence (AI), often increasing computational requirements and environmental impact. This master???s thesis presents a novel methodology for optimizing the architecture of Inception modules within Convolutional Neural Networks (CNNs) that process data at multiple scales using the Coral Reef Optimization (CRO) algorithm, a bio-inspired evolutionary approach. Aligning with Green AI
principles that emphasize efficiency and sustainability, we integrate a dynamic Inception module capable of adjusting branches, depths, and filter sizes with the CRO algorithm to effectively explore and exploit the architectural search space. To promote smaller, resource-efficient architectures, we introduce a custom evaluation metric that balances accuracy and model complexity by penalizing excessive parameters. Experimental results on the MNIST dataset demonstrate that the optimized models achieve competitive performance, reducing the number of parameters by up to 40% while maintaining accuracy comparable to standard models. This work contributes to the development of sustainable AI models and provides a foundation for future research in efficient neural architecture optimization
PICA-CI: un modelo sobre la imagen de la ciencia
No full textEste informe recoge los resultados del proyecto PICA-CI: un modelo sobre la imagen de la ciencia, financiado por la Fundaci??n Espa??ola para la Ciencia y la Tecnolog??a (FECYT) con referencia FCT-23-18915. En ??l se aborda c??mo influyen el contexto social y las caracter??sticas individuales en el segmento de la ciencia definido por la Percepci??n, el Inter??s, el Conocimiento y el desarrollo de acciones relacionadas con la ciencia. Metodol??gicamente se ha apoyado en el Cuestionario PICA-CI, una herramienta de medida desarrollada desde una aproximaci??n psicom??trica fundamentada en la Teor??a de Respuesta al ??tem que se compone de 104 ??tems m??s un conjunto de preguntas para identificar socio demogr??ficamente a las personas que han participado en el estudio. Se han incluido tambi??n algunas preguntas para medir la imagen de la ciencia para la pol??tica. Hemos encontrado que la imagen de la ciencia est?? formada por un complejo entramado de relaciones entre diversos elementos en los que el contexto desempe??a un papel muy importante. Hemos identificado tambi??n que no hay una actitud ??nica hacia la ciencia, de la que forma parte la actitud conspirativa, que contribuye a explicar el conspiracionismo y no al rev??s. Por ??ltimo, en un an??lisis muy preliminar, hemos encontrado que el contexto no parece influir, al menos de momento, en la imagen de la ciencia para la pol??tica, que est?? determinada fundamentalmente por el inter??s por la ciencia general, probablemente porque la poblaci??n tiene escaso conocimiento de esta forma de ciencia
Integrating a Wave Farm into an Isolated Power System with Energy Storage Systems: Analysis of Frequency Stability and Renewable Energy Penetration
Full text linkEst?? accesible s??lo la "author versi??n".Integrating non-dispatchable renewable energy sources (RES), such as wind, solar or wave farms (WF), into isolated power systems poses significant challenges due to their variability and limited predictability. This issue is particularly critical for islands like El Hierro (Canary Islands, Spain), where there is no interconnection with larger grids. Although wave energy offers substantial potential, assessing the maximum feasible RES penetration while maintaining system stability remains complex.
This study analyses frequency deviations in an islanded power system integrating a wave farm supported by an energy storage system (ESS). Frequency restoration is managed using droop control, where ESS power output responds proportionally to frequency deviations. The impact of varying wave energy penetration levels and droop control parameters on the system is analysed.
The simulation environment is built in MATLAB Simulink, incorporating a dynamic model of the electrical system, which includes wind power, a pumped-storage hydroelectric plant, and diesel generators. WF model is developed based on local wave resource data, simulating power output and variability. The Spanish Grid Code is used to assess regulatory compliance.
Results identify optimal droop control parameters for each wave farm size, ensuring frequency deviations remain within acceptable limits. Additionally, the minimum required ESS capacity is estimated for stable operation under different scenarios. These insights support this methodology for effective dimensioning of wave farms and storage systems in isolated grids, enabling higher RES integration while preserving system reliability
Regulatory Strategies for Accelerating the Translation of Gene Therapies to Clinical Practice: Focus on GMO Considerations
No full textGene therapy has revolutionized modern medicine by offering innovative treatments for genetic disorders, cancers, and immune-related conditions through technologies such as viral vector delivery, genome editing, and genetically modified cell therapies. Despite significant advancements, the classification of gene therapy medicinal products (GTMPs) as genetically modified organisms (GMOs) under EU legislation imposes significant regulatory burdens, hindering early and timely patient access to such therapies. Current GMO regulations, originally designed for agricultural biotechnology, require environmental risk assessments (ERAs) and additional approvals, creating delays and increasing costs-with a particularly negative impact on early academic research. This article examines the scientific and regulatory discrepancies in classifying GTMPs as GMOs, arguing that replication-deficient vectors and non-persistent modified cells may not meet the criteria for GMOs. We highlight the negative impact of GMO requirements on clinical trial feasibility in Europe compared to the U.S., where a categorical exclusion from ERA applies to investigational medicinal products. Proposed solutions include adopting a risk-based regulatory model, harmonizing ERA processes under the revised EU Clinical Trials Regulation, and establishing exemptions for low-risk therapies. By aligning regulatory frameworks with scientific evidence, policymakers can accelerate the translation of gene therapies while maintaining safety standards, ultimately improving patient access to these transformative treatment
Exploring the operational limits of poloidal and helical arrays of Mirnov coils in stellarators by means of a synthetic diagnostic
No full textA synthetic Mirnov coil array diagnostic for non-axisymmetric magnetic configurations is presented and used to study the capabilities of the poloidal array of single-axis coils and the two helical arrays of tri-axial coils installed in the TJ-II stellarator. This tool integrates the plasma currents induced by Alfv??n-like perturbations of the electric potential inside the plasma and provides the induced magnetic field oscillations anywhere outside of it. The simulated signals can then be analyzed in the same manner as the experimental ones, and a scan on the radial position and width of the potential perturbation is conducted to find the limiting values that produce identifiable signals. We find that core-localized (?? ??? 0.5) modes are indistinguishable from one another and that the identification of low-n, low-m modes is often subject to off-by-one errors. We also determine the optimal polarization basis in which to analyze the tri-axial coil signals and address the diagnostic performance when resolving components of gap modes. In addition, selected cases have been analyzed with a simplified plasma response model, showing that plasma shielding of the mode currents may further deteriorate the accuracy of the mode identification method. We conclude with the analysis of an experimental case taken from the TJ-II database to illustrate the usefulness of this synthetic diagnostic
Masa de residuos de m??dulos fotovoltaicos
No full textEstimacion de masa de m??dulos fotovoltaicos instalados en Europa, los residuos generados anualmente y la masa de residuos acumulada, en 2030 y 2050 para dos escenarios concretos.Estimacion de masa de m??dulos fotovoltaicos instalados en Europa, los residuos generados anualmente y la masa de residuos acumulada, en 2030 y 2050 para dos escenarios concretos
Registro de interrupciones de cinta en m??dulos fotovltaicos y sus tipos
No full textRegistro de los tipos y n??meros de interrupciones de cinta conductora de cada uno de los m??dulos reparados en el proyecto FOTOVOL3RRegistro de los tipos y n??meros de interrupciones de cinta conductora de cada uno de los m??dulos reparados en el proyecto FOTOVOL3
What does it matter? Analysing the role of attitudes to the adoption of solar photovoltaic technology in Spain
No full textSolar photovoltaic (PV) systems are believed to have great potential in combating climate change and contributing to decarbonisation, especially in the residential sector. It is essential to determine the factors that shape individual decisions to adopt this technology, in order to facilitate its deployment. This paper analyses predictors of the intention to adopt solar PV in the residential sector, using a representative sample of 945 non-adopters in Spain who responded to an online anonymous survey. We aim to determine the direct and mediated effects of the Theory of Planned behaviour constructs, other attitudinal variables (perceived benefits, perceived barriers and
environmental values), peer effects, socio-demographics and house characteristics, on the intention to adopt solar PV. Two complementary statistical modelling approaches were used.
First, a logistic regression analysis predicting intention to adopt suggested that TPB variables such as attitude (OR = 2.39) and subjective norms (OR = 2.12) were the most relevant, while perceived behavioural control (OR = 1.28) was shown to be less relevant. Moreover, logistic modelling indicated that perceived economic barriers (OR = 0.66), having university studies (OR
= 2.96), and living in a house (OR = 3.85) also play an important role in the intention to install solar PV. The second analytic approach was path analysis through Structural Equation Modelling aimed at quantifying the determinants that both directly and indirectly influence the intention to
adopt. Its results revealed attitude (?? = 0.19) and subjective norms (?? = 0.18) as the factors having most influence on the intention to adopt. Consequently, different attitudinal variables should be taken into account when considering public willingness to install solar PV. We recommend that both policymakers and the market strengthen their recognition of economic and environmental benefits and enact measures to overcome economic barriers for potential solar PV
adopters