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On the value of Fano resonance in wave energy converters
Get PDFThe article evaluates the potential of the Fano resonance operational principle in wave energy converters (WECs), using a 2-body loosely moored self-referenced WEC as an illustrative example. By leveraging Fano resonance, the point absorber buoy can remain relatively stationary with low loading on mooring lines, serving as an efficient wave energy transmitter while concurrently achieving resonance within the internal power take-off (PTO) system. This arrangement reduces the motion of the point absorber hull, thereby decreasing loads on the WEC structure, mooring lines, and anchors. As a result, operational and structural costs are minimised, further reducing the levelised costs of generated energy. Additionally, by ensuring minimal fluctuations in the WEC, confidence in using traditional linear mathematical models is increased, as commonly employed for WEC performance assessment and control design. The article presents a resonance study and introduces newly derived solutions in the frequency domain for the proposed operational concept. It analytically demonstrates the viability of employing the Fano resonance operational strategy for WECs, suggesting that this strategy has the potential to compete with traditional methods of wave energy transformation. Furthermore, the insights gained from the study contribute to identifying optimal parameters for a PTO system, as well as optimising the design of the heaving buoy
Concerns and barriers surrounding the farm succession process – perception versus reality for beef farmers in Ireland
Get PDFGenerational renewal is widely acknowledged as key to the survival and sustainability of the European agricultural industry. In Ireland and many other European countries an aging farming population, and the lack of succession planning by farmers, are significant concerns regarding the future of the industry. Farm succession is a complex and multifaceted process with the literature highlighting one of its main barriers as a reluctance of older farmers to retire and effectively step-a-side to pass their farm onto the next generation. Such resistance of older farmers is undoubtedly a huge issue in terms of generational renewal of the Irish agricultural industry, however, it is important to understand that there are many sources of concern for farmers that can act as barriers to developing a succession plan. In this context, the objective of this study is to develop a deeper understanding of the concerns and barriers surrounding the farm succession process. Discussions on the topic of farm succession, which took place during semi-structured interviews and consultation meetings with 30 beef farmers in Ireland as part of an intervention programme to support farmers in succession planning, reveal that the source of such concerns appear to stem from two broad areas: successor identification concerns and financial and legal concerns. While acknowledging that such issues cause genuine concern for farmers, we argue that overcoming them may not be as difficult as some farmers may imagine. Hence a distinction between what constitutes real concerns versus what constitutes perceived concerns in the farm succession process emerges. The evidence gathered suggests that where farmers engage the services of professional advisors to discuss farm succession, many of those concerns can be alleviated. Consequently, by reflecting on the findings emerging and by highlighting the case of Irelands Succession Planning Advice Grant as a policy framework solution, we recommend for similar policy development in other countries facing the generational renewal challenge in agriculture. The novel findings emerging from this study provide a valuable contribution to the literature, to practice, and to policy development
Real-time control of oscillating water column wave energy converters
Get PDFIn order to build a carbon-free society, the production of clean and affordable
electric energy is vital. Furthermore, to reduce variability and minimise the need
for potentially expensive energy storage systems, the diversification of renewable
energy resources is essential. To this end, wave energy is a significant and almost
untapped source of renewable energy, which can considerably contribute to the
renewable energy mix and, ultimately, to decarbonisation.
Wave energy converters (WECs) harness wave power by exploiting different
operating principles. However, due to the relatively high levelised cost of energy
(LCoE) associated with wave energy projects, WECs struggle to penetrate in the
electric power industry market. A key step to minimise the LCoE, and therefore
improve WEC commercialization, is to develop high-performance, real-time, control
strategies to maximise the electric energy produced over the WEC lifetime. In
particular, this thesis focuses on enhancing the economic viability of a specific
type of WEC, known as the oscillating water column (OWC) WEC, by improving
state-of-the-art OWC control techniques.
The OWC system is one of the most promising WECs, especially due to its
simplicity of operation, the possibility to easily dissipate excessive power, and the
fact that all the moving parts are above the water level, meaning that maintenance
operations are potentially less complex and expensive. To date, due to the critical
importance of turbine performance, OWC control strategies mainly focus on an
oversimplified control objective, namely turbine efficiency maximisation, ignoring
hydrodynamic and electric generator performance. In this thesis, possible staticefficiency-
based and dynamic control strategies to optimise the (overall) wave-towire
(W2W) energy conversion process of OWC WECs are designed. Furthermore,
as an alternative to relatively laborious model determination from first principles,
the potential of data-based modelling techniques to provide parsimonious, controloriented,
OWC hydrodynamic models, is investigated. Finally, to maximise OWC
WEC profitability, it is important to consider peak-shaving (or rated power) control,
to extend the OWC operational range and, consequently, improve the capacity
factor. Since peak-shaving control affects the optimal sizing problem for an OWC
PTO, a control co-design approach is devised in this thesis to assess the benefit
of rated power control. Ultimately, peak-shaving control, used in combination
with control co-design techniques, can significantly reduce the LCoE by improving
the capacity factor
Trending extinctions: online interest in recently extinct animals
Get PDFHalf of all species are predicted to face extinction by the end of the century. Despite this, awareness of certain species' extinctions remains surprisingly muted, highlighting the need to improve and quantify public awareness. We explore the connection between biodiversity loss and public awareness by quantifying the changes in online interest on Twitter (now known as X) and Wikipedia both before and after the extinctions of eight species and following their reclassification in the IUCN Red List. Our findings reveal that extinction announcements generally spike online interest for most species, albeit briefly on Twitter (i.e. tweets and retweets about species), while Wikipedia (i.e. article pageviews of species) exhibits a more prolonged interest. IUCN reports were generally not associated with increased interest. Coordinated media coverage, especially when aligned with broader environmental narratives and key events, enhanced the impact of extinction announcements. On Twitter, spatially we observed a shift from local to global interest of users following extinction. We also found a small subset of influential users on Twitter, including content creators and media organisations, who disproportionately shaped conservation discussions. Environmentally oriented individuals and organisations also play a significant role, collectively comprising a third of the top retweeted users. Overall, these results highlight the need for conservation bodies, such as the IUCN, to engage more directly both with media organisations and content creators in order to drive public interest for conservation efforts, especially for less charismatic species. The tragedy of species extinction necessitates such efforts to ensure sustained and meaningful public awareness. Our findings also show that while social media outlets can generate global interest quickly, which may drive public discussions regarding ongoing extinctions and potential future de-extinctions, this is likely to be short-lived, underscoring the importance of alternative platforms such as Wikipedia, which can foster longer-term engagement
A Validation of OLCI Sentinel-3 Water Products in the Baltic Sea and an Evaluation of the Effect of System Vicarious Calibration (SVC) on the Level-2 Water Products
Get PDFThe monitoring of coastal waters using satellite data, from sensors such as Sentinel-3 OLCI,
has become a vital tool in the management of these water environments, especially when it comes to
improving our understanding of the effects of climate change on these regions. In this study, the latest Level-2 water products derived from different OLCI Sentinel-3 processors were validated against a comprehensive in situ dataset from the NW Baltic Sea proper region through a matchup analysis.
The products validated were those of the regionally adapted Case-2 Regional Coast Colour (C2RCC)
OLCI processor (v1.0 and v2.1), as well as the latest standard Level-2 OLCI Case-2 (neural network)
products from Sentinel-3’s processing baseline, listed as follows: Baseline Collection 003 (BC003),
including “CHL_NN”, “TSM_NN”, and “ADG443_NN”. These products have not yet been validated
to such an extent in the region. Furthermore, the effect of the current EUMETSAT system vicarious
calibration (SVC) on the Level-2 water products was also validated. The results showed that the
system vicarious calibration (SVC) reduces the reliability of the Level-2 OLCI products. For example,the application of these SVC gains to the OLCI data for the regionally adapted v2.1 C2RCC products resulted in RMSD increases of 36% for “conc_tsm”; 118% for “conc_chl”; 33% for “iop_agelb”; 50% for “iop_adg”; and 10% for “kd_z90max” using a ±3 h validation window. This is the first time the effects of these SVC gains on the Level-2 OLCI water products has been isolated and quantified in the study region. The findings indicate that the current EUMETSAT SVC gains should be applied and interpreted with caution in the region of study at present. A key outcome of the paper recommends the development of a regionally specific SVC against AERONET-OC data in order to improve the Level-2 water product retrieval in the region. The results of this study are important for end users and the water authorities making use of the satellite water products in the Baltic Sea region
Introductory Remarks in East Asian Religiosities in the European Union
Get PDFThis volume aims to provide an overview of East Asian religiosities in the European
Union, with the aim of shedding light on their increasingly significant presence,
revolving around the informal or structured practices of several million Europeans and
East Asians (Chinese, Korean, Japanese, and Vietnamese people) living in Europe. In
this introductory chapter we address some of the main scholarly issues concerning the
study of these religiosities, paying attention to the reasons why this topic is relevant to
Religious Studies and other related disciplines, to the methodological challenges
inherent to this field, and to some conceptual questions emerging from the countryrelated and thematic chapters
Assemblage theory, data systems and data ecosystems: The data assemblages of the Irish planning system
Get PDFThe work of the state has been transformed by digitalisation and datafication, with paper systems increasingly complemented and replaced by digital data systems. While much research has been undertaken on the effects of these data systems on e-government and e-governance, relatively little critical attention has been paid to the ontological nature of the data systems themselves, how they come into being, operate, iterate, and work in conjunction with other systems. In this paper, we build on work that understands the nature of data systems as data assemblages; that is, as being thoroughly socio-technical in nature, emerging and unfolding contingently, contextual and relationally through material and discursive practices and processes. We extend Kitchin (2014) and Kitchin and Lauriault’s (2018) notion of a data assemblage through an engagement with assemblage theory, and detail how data systems are articulated and scaffolded into being, and scaled into a functioning data ecosystem, which is conceptualised as an assemblage of data assemblages. We illustrate the utility of this reconceptualization through an analysis of the development and control function of the Irish planning system, which is composed of a number of interlinked data systems used for managing the entire planning process from seeking planning permission, monitoring construction, to completed property
Exploiting Fano resonance in wave energy systems
Get PDFEnergy maximising control of wave energy converters (WECs) typically results in exaggerated motion of the device, with consequent increases in mooring and other forces which can adversely affect WEC lifetime. In addition, the exaggerated motion typically increases the incidence of nonlinear hydrodynamic effects, confounding linear analysis upon which many WEC control design paradigms are based. This paper explores the potential to exploit Fano resonance in a wave energy context, where the WEC body remains relatively stationary, while the active power take-off elements are well exercised. Preliminary results suggest that significant WEC body motion reduction is possible, with a modest reduction in energy capture
Qualitative Data Collection and Archiving in the DANCING Project
Get PDFThis report is part of the project entitled ‘Protecting the Right to Culture of Persons with
Disabilities and Enhancing Cultural Diversity through European Union Law: Exploring New
Paths – DANCING’. This project has received funding from the European Research Council
(ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant
Agreement No. 864182). This report reflects only the authors’ views and does not necessarily
reflect those of the European Union or the ERC
Minoritized mother politicians in Ireland: Subjectivities and subjectivation in the political workplace
Get PDFMinoritized mother politicians that include ethnic racialized minority Traveller (an Irish indigenous community), racialized ethnic minority women, and migrant women face considerable disadvantages as workers arising from the intersection of their maternal status, gender, racialized or migrant and class position. The experiences of minoritized mother candidates and politicians in Ireland are viewed through the lens of subjectivities providing insight into how these mother-workers mediate identities and status positions that place them outside of, or in tension with, a predominantly white masculinist workplace. Empirical data analysis reveals how minoritized mother candidates and politicians respond in strategic ways to forces of subjectivation that may risk affirming idealized motherhood, while obscuring gendered and racialized inequalities in the political workplace. Paradoxically, motherhood seeds political ambition while acting as a material, temporal, and affective constraint, a source of invisible labor and violence in gendered and racialized ways. However, minoritized mothers' presence and representations also offer an important challenge to this white masculinist workplace