Forecasting plausible scenarios using general morphological analysis and clustering techniques

Funding Information: This work has been developed in the frame of the activities promoted and supported by the Programa de Ciencia y Tecnología para el Desarrollo ( CYTED ) under the thematic network REMAR: OPORTUNIDADES DE INTEGRACIÓN EN REDES ELÉCTRICAS IBEROAMERICANAS DE LAS ENERGÍAS DEL MAR – https://www.cyted.org/es/remar . Funding Information: General Morphological Analysis (GMA) allows the framing of complex problems, dependent on technical and (primarily) non-technical influences, such as social interactions, learning effects, technological disruption, amongst many others. It was first proposed by Fritz Zwicky, a Swiss astrophysicist and aerospace scientist (Zwicky, 1948a, 1948b, 1960) Interestingly, it was first implemented to support the classification of astrophysical objects, but the potential of the method for supporting the analysis of wicked problems has been steadily revealed up to today. Morphological analysis has been implemented by several research groups in the USA and Europe working in policy and foresight. It was in 1995, with the implementation of advanced computer support for GMA, that the Swedish Defence Research Agency made it possible to create complex non-quantified inference models, that significantly widen the applicability of the method (Ritchey, 2011). Michel Godet has also strongly contributed to the development and adaptation of morphological analysis for future forecasting, notably through the Morphol tool (Godet, 2001).Although there have been advances in terms of generating conditions for testing these technologies, there have been some setbacks, as well. In Portugal, the feed-in tariff scheme defined for wave energy in the past is now terminated. Furthermore, the political support given to these technologies cooled down after the unsuccess of some projects and the appearance of more promising technologies – such as floating offshore wind.This work has been developed in the frame of the activities promoted and supported by the Programa de Ciencia y Tecnología para el Desarrollo (CYTED) under the thematic network REMAR: OPORTUNIDADES DE INTEGRACIÓN EN REDES ELÉCTRICAS IBEROAMERICANAS DE LAS ENERGÍAS DEL MAR – https://www.cyted.org/es/remar. Publisher Copyright: © 2023 The AuthorsMarine renewables – which include mainly wave, tidal and current energy – have been hailed, for the past decades, as a potential solution to support the decarbonization of the society. Portugal and Spain have been traditionally avid for the testing and demonstration of such technologies, but the implementation of marine capacity is yet marginal, and there are many uncertainties regarding the future of the sector in the region. The main objective of this article is to show a future projection of marine renewable energies in both Iberian and Macaronesian regions for 2030 to research and technological development communities. To obtain this future projection, General Morphological Analysis and advanced clustering techniques have been used. The results are divided into five groups of potential scenarios, which vary significantly due to different political, social and technological parameters. The influence of variables such as innovation speed, infrastructure implementation, and comprehensive metocean data availability emerges as pivotal determinants shaping the sector's course. The knowledge from this systematization is expected to be used by researchers, technicians, governments or by any other agency involved in marine renewable energies in Spain and Portugal, as a guidance for their new projects and research lines.publishersversionpublishe

Inspiratory Muscle Training in the Intensive Care Unit: A New Perspective

BACKGROUND: Prolonged use of mechanical ventilation (MV) leads to weakening of the respiratory muscles, especially in patients subjected to sedation, but this effect seems to be preventable or more quickly reversible using respiratory muscle training. The aims of the study were to assess variations in respiratory and hemodinamic parameters with electronic inspiratory muscle training (EIMT) in tracheostomized patients requiring MV and to compare these variations with those in a group of patients subjected to an intermittent nebulization program (INP). METHODS: This was a pilot, prospective, randomized study of tracheostomized patients requiring MV in one intensive care unit (ICU). Twenty-one patients were randomized: 11 into the INP group and 10 into the EIMT group. Two patients were excluded in experimental group because of hemodynamic instability. RESULTS: In the EIMT group, maximal inspiratory pressure (MIP) after training was significantly higher than that before (P = 0.017), there were no hemodynamic changes, and the total weaning time was shorter than in the INP group (P = 0.0192). CONCLUSION: The EIMT device is safe, promotes an increase in MIP, and leads to a shorter ventilator weaning time than that seen in patients treated using INP.info:eu-repo/semantics/publishedVersio

Advances in the development of dielectric elastomer generators for wave energy conversion

This paper presents a summary of recent progress towards the development and upscaling of an emerging class of electrostatic power take-off (PTO) systems for wave energy converters (WECs), called dielectric elastomer generators (DEGs). DEGs are electromechanical devices able to convert mechanical energy into electrical energy by exploiting the deformation of rubber-like dielectric materials. The high power density (in the order of hundreds of Watts per kilogram), good efficiency and ease of assembling, combined with the low-cost of the employed materials (a few euros per kilogram) and their intrinsic resilient/reliable response to mechanical shocks make DEGs a very promising option for the deployment of a future generation of WECs. In the last decade, some specific concepts of WECs based on DEGs have been devised and a considerable interest in the topic has been aroused in the wave energy community. Among the candidate DEG topologies for wave energy harvesting, recent studies have suggested that a specific layout, namely the axial-symmetric inflating DEG diaphragm, could be a very promising candidate for future upscaling. This paper first describes the operating principle of DEG PTOs and the effect of electro-mechanical material parameters on their energetic performance. With reference to the above-mentioned inflating DEG diaphragm topology, an overview of concepts for integration on WECs is then provided, with a special focus on advanced concepts enabling the achievement of dynamical tuning with the incoming waves. A general lumped-parameter modelling approach for the design of DEG-based WECs is proposed. Experimental activity carried out to date, i.e. dry-run laboratory tests, wave-tank tests and preliminary sea trials is reviewed, with the aim of showing the progression in the device's scale and performance. Finally, economical and technological considerations are outlined, in order to point out challenges, future research opportunities and to draft a roadmap for future research and technological transfer

The status of the Quijote multi-frequency instrument

The QUIJOTE-CMB project has been described in previous publications. Here we present the current status of the QUIJOTE multi-frequency instrument (MFI) with five separate polarimeters (providing 5 independent sky pixels): two which operate at 10-14 GHz, two which operate at 16-20 GHz, and a central polarimeter at 30 GHz. The optical arrangement includes 5 conical corrugated feedhorns staring into a dual reflector crossed-draconian system, which provides optimal cross-polarization properties (designed to be < -35 dB) and symmetric beams. Each horn feeds a novel cryogenic on-axis rotating polar modulator which can rotate at a speed of up to 1 Hz. The science driver for this first instrument is the characterization of the galactic emission. The polarimeters use the polar modulator to derive linear polar parameters Q, U and I and switch out various systematics. The detection system provides optimum sensitivity through 2 correlated and 2 total power channels. The system is calibrated using bright polarized celestial sources and through a secondary calibration source and antenna. The acquisition system, telescope control and housekeeping are all linked through a real-time gigabit Ethernet network. All communication, power and helium gas are passed through a central rotary joint. The time stamp is synchronized to a GPS time signal. The acquisition software is based on PLCs written in Beckhoffs TwinCat and ethercat. The user interface is written in LABVIEW. The status of the QUIJOTE MFI will be presented including pre-commissioning results and laboratory testing

Power Supply Solution for Ultrahigh Speed Hyperloop Trains

The paper analyses the alternatives for the power supply of a Hyperloop type railway transport. The particular case of the technology of the Spanish company ZELEROS was studied. Based on previous technical specifications related to both the first prototype and a commercial system, different options were analyzed. We selected the use of a linear motor driven by a single power electronic converter, a distribution scheme comprising different sections along the acceleration area of the track, and an energy storage system based on supercapacitors for the energy supply. The power/energy ratio and the cycle capability are the reasons to become a feasible and competitive solution. A preliminary design methodology for the energy storage requirements is presented in the paper. Once the type of linear motor was selected, the power supply scheme was presented, based on a motor-side power electronic converter and a DC/DC converter which connects to the energy storage devices. An additional low power grid-tie converter for the recharge of the energy storage system was also used. Different track sections were defined, connected to the power electronic converter through corresponding switches, being supplied sequentially when the capsule presence is detected along the track. The particular characteristics of this application, with relatively short traction track area, as well as the high energy recuperation ratio due to the low losses, make more suitable the use of energy storage systems as the source of power supply than the direct connection to the grid

Advances in the development of dielectric elastomer generators for wave energy conversion

This paper presents a summary of recent progress towards the development and upscaling of an emerging class of electrostatic power take-off (PTO) systems for wave energy converters (WECs), called dielectric elastomer generators (DEGs). DEGs are electromechanical devices able to convert mechanical energy into electrical energy by exploiting the deformation of rubber-like dielectric materials. The high power density (in the order of hundreds of Watts per kilogram), good efficiency and ease of assembling, combined with the low-cost of the employed materials (a few euros per kilogram) and their intrinsic resilient/reliable response to mechanical shocks make DEGs a very promising option for the deployment of a future generation of WECs. In the last decade, some specific concepts of WECs based on DEGs have been devised and a considerable interest in the topic has been aroused in the wave energy community. Among the candidate DEG topologies for wave energy harvesting, recent studies have suggested that a specific layout, namely the axial-symmetric inflating DEG diaphragm, could be a very promising candidate for future upscaling. This paper first describes the operating principle of DEG PTOs and the effect of electro-mechanical material parameters on their energetic performance. With reference to the above-mentioned inflating DEG diaphragm topology, an overview of concepts for integration on WECs is then provided, with a special focus on advanced concepts enabling the achievement of dynamical tuning with the incoming waves. A general lumped-parameter modelling approach for the design of DEG-based WECs is proposed. Experimental activity carried out to date, i.e. dry-run laboratory tests, wave-tank tests and preliminary sea trials is reviewed, with the aim of showing the progression in the device's scale and performance. Finally, economical and technological considerations are outlined, in order to point out challenges, future research opportunities and to draft a roadmap for future research and technological transfer

Dimensioning Methodology of an Energy Storage System Based on Supercapacitors for Grid Code Compliance of a Wave Power Plant

The aim of this paper is to present a methodology for dimensioning an energy storage system (ESS) to the generation data measured in an operating wave energy generation plant connected to the electric grid in the north of Spain. The selection criterion for the ESS is the compliance of the power injected into the grid with a specific active-power ramp-rate limit. Due to its electrical characteristics, supercapacitor (SC) technology is especially suitable for this application. The ESS dimensioning methodology is based on a mathematical model, which takes into account the power generation system, the chosen ramp-rate limit, the ESS efficiency maps and electrical characteristics. It allows one to evaluate the number of storage cabinets required to satisfy the needs described, considering a compromise between the number of units, which means cost, and the reliability of the storage system to ensure the grid codes compliance. Power and energy parameters for the ESS are obtained from the calculations and some tips regarding the most efficient operation of the SC cabinets, based on a stepped switching strategy, are also given. Finally, some conclusions about the technology selection will be updated after the detailed analysis accomplished

Asymmetrical Rotor Skewing Optimization in Switched Reluctance Machines Using Differential Evolutionary Algorithm

Minimizing torque ripple in electrical machines for a given application is not a straightforward task, especially when the application imposes certain constraints. There are many techniques to improve torque ripple, either design-based or control-based. In this paper, a new geometry for switched reluctance machines based on rotor poles skewing is proposed to minimize torque ripple. This paper describes a methodology to design an asymmetrical skew rotor—switched reluctance machine using a multi-objective differential evolutionary algorithm. The main parameters of the optimization process are defined, as is the optimization methodology to obtain an improved design with less torque ripple than a conventional one. Moreover, the analytical formulas used in the optimization method, as well as the optimization technique, are deduced and explained in detail. The mathematical model used to simulate the electrical machine and the power converter are also described. Two-dimensional and three-dimensional finite element analyses were also conducted to assess whether 3D effects (end-effect and axial fringing field) affected the results. Finally, a particular case of a high-voltage direct current-controlled generator in the base of the More Electric Aircraft (MEA) concept or an energy storage system as an electrical machine was analyzed, and the results for the improved configuration were compared with those for the conventional one

Power Consumption Profile of a Service Robot: Characterization and Analysis

International audienceThis paper presents a comprehensive analysis of the power consumption characteristics of an autonomous service robot across different operational scenarios. The study investigates the discharging profile of a 14.8V 4-cell 10,000mAh LiPo battery, providing insightful observations on the relationship between the State of Charge (SOC) and internal resistance, alongside voltage dynamics during discharge. The results indicate an inverse relationship between the SOC and the system's internal resistance, and a consistent voltage decrement corresponding to SOC. Furthermore, the energetic impacts of various robot components during the Powering On Procedure and Teleoperation and Navigating Procedure are detailed, identifying critical components contributing to high energy consumption. The paper suggests an autonomy duration of approximately 3.5 hours for the electrical system and 2 hours of continuous movement. The study provides a basis for optimizing energy efficiency in autonomous service robots