1,720,962 research outputs found
Optimal Site Selection for Wave Energy Converter Installation on Pantelleria
No full textThe research aims to identify the best location for a Wave Energy Converter (WEC) on Pantelleria Island, evaluating criteria like energy resource, accessibility and feasibility. Bathymetric trend and coastal distance are key in locating suitable marine areas. An in-depth analysis was conducted to analyze the wave energy potential, considering both the mean wave power and the Wave Energy Development Index (WEDI). Sea states information are obtained from SWAN (Simulating Waves Nearshore) model, generating reliable time series data and providing waves characteristics. This study offers valuable insights for strategically deploying WECs, aligning with sustainable energy initiatives on the island
FEM-Aided Structural Design of a Natural Fiber Composite Made Skiff
Full text linkIn racing boat design, the research is moved to find always the best compromise between performance and safety. The present work focuses on the description of the structural design cycle used by Polito Sailing Team during the realization of its new skiff, a high-performance sailing dinghy, built mainly with natural composite material such as balsa wood and flax fiber. The whole boat was completely designed by students, according to eco-sustainable principles, to participate in a universities competition called 1001VelaCup. To determinate the sandwich composite stratification, a benchmarking of materials was made by mechanical tests run according to ASTM 3039 and 3518 regulations. A finite element (FE) model was built to evaluate the static response of the structure, aiming to obtain a safe and light hull. The fluid (sea) interaction is modeled with a linear springs system. The crew, rig and rigging loads are obtained from a one-dimensional model and hydrodynamics pressure from ISO 12215-5:2014. The outputs obtained are consistent with the physics of the problem and the stresses distribution shows that the maximum stress is in the proximity of the mast base. This work constitutes the first step to obtain a correct, reliable and innovative design tool
Comparison of the European Regulatory Framework for the deployment of Offshore Renewable Energy Project
Full text linkThe REPower EU Plan has set a minimum of total renewable energy generation capacity of 1,236 GW by
2030. Achieving this target, and emission reductions by 2050, will require the extensive deployment of offshore
energy facilities, especially offshore wind (OW) and wave energy converters (WECs). However, an incomplete and sometimes unfavourable regulatory framework still jeopardises the feasibility of both prototypes and largescale installations. There are, for example, significant differences between the permitting procedures in different Member States and regions. Moreover, following the transposition of the Directive 2014/89/EU “establishing a framework for maritime spatial planning”, important differences pertain to the way environmental and heritage protection is dealt with. An overview of the offshore permitting schemes for offshore wind in ten European counties (Germany, Denmark, Scotland, Sweden, France, Spain, Portugal, Italy, Belgium, and Ireland) is provided, demonstrating a mismatch between the current members’ complex regulations and the future offshore wind targets. Using customised key performance indicators, we describe and assess the extent to which the regulatory frameworks are conducive to installing industrial devices in achieving the country’s 2030 target. Finally, we propose actions to facilitate the installation of OW while ensuring both environmental protection and industry development in the countries under investigation
Comparative study of electric and hydrogen mobility infrastructures for sustainable public transport: A PyPSA optimization for a remote island context
Full text linkDecarbonizing road transportation is vital for addressing climate change, given that the sector currently contributes to 16% of global GHG emissions. This paper presents a comparative analysis of electric and hydrogen mobility infrastructures in a remote context, i.e., an off-grid island. The assessment includes resource assessment and sizing of renewable energy power plants to facilitate on-site self-production. We introduce a comprehensive methodology for sizing the overall infrastructure and carry out a set of techno-economic simulations to optimize both energy performance and cost-effectiveness. The levelized cost of driving at the hydrogen refueling station is 0.40 €/km, i.e., 20% lower than the electric charging station. However, when considering the total annualized cost, the battery-electric scenario (110 k€/year) is more favorable compared to the hydrogen scenario (170 k€/year). To facilitate informed decision-making, we employ a multi-criteria decision-making analysis to navigate through the techno-economic findings. When considering a combination of economic and environmental criteria, the hydrogen mobility infrastructure emerges as the preferred solution. However, when energy efficiency is taken into account, electric mobility proves to be more advantageous
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Estimating the Cost of Wave Energy Converters at an Early Design Stage: A Bottom-Up Approach
Full text linkThe role of ocean energy is expected to grow rapidly in the coming years, and techno-economic analysis will play a crucial role. Nowadays, despite strong assumptions, the vast majority of studies model costs using a top-down approach (the TdA) that leads to an unrepresentative economic model. WEC developers usually go through the the TdA approach because more detailed cost data are not available at an earlier design stage. At a very advanced design stage, some studies have also proposed techno-economic optimisation based on the bottom-up approach (BuA). This entails that the detailed cost metrics presented in the literature are very specific to the WEC type (hence not applicable to other cases) or unrepresentative. This lack of easily accessible detailed cost functions in the current state of the art leads to ineffective optimisations at an earlier stage of WEC development. In this paper, a BuA for WECs is proposed that can be used for techno-economic optimisation at the early design stage. To achieve this goal, cost functions of most common components in the WEC field are retrieved from the literature, exposed, and critically compared. The large number of components considered allows the results of this work to be applied to a vast pool of WECs. The novelty of the presented cost functions is their parameterization with respect to the technological specifications, which already enables their adoption in the design optimisation phase. With the goal of quantifying the results and critically discuss the differences between the TdA and the BuA, the developed methodology and cost functions are applied to a case study and specifically adopted for the calculation of the capital cost of PeWEC (pendulum wave energy converter). In addition, a hybrid approach (HyA) is presented and discussed as an intermediate approach between the TdA and the BdA. Results are compared in terms of capital expenditure (CapEx) and pie cost distribution: the impact of adopting different cost metrics is discussed, highlighting the role that reliable cost functions can have on early stage technology development. This paper proposes more than 50 cost functions for WEC components. Referring to the case study, it is shown that while the total cost differs only slightly (11%), the pie distribution changes by up to 22%. Mooring system and power take-off are the cost items where the TdA and the HyA differ more from the BuA cost estimate
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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