A tension between two opposing forces, that is, the force of division and that of unity, is increasingly sharpened in the law of the sea today. An essential question that arises is how one can protect community interests in the divided ocean. The law of dédoublement fonctionnel advocated by Georges Scelle provides an insight into this question. According to Scelle’s theory of the law of dédoublement fonctionnel, State organs perform a dual function: the national function of protecting State interests and the public service function of safeguarding community interests. The law of dédoublement fonctionnel seeks to reconcile these functions. Scelle’s harmonistic vision of international law is well worth reconsidering in the law of the sea and beyond. This article examines the relevance of Scelle’s theory in the context of the law of the sea and explores two models for the protection of community interests at sea.
The protection of critical maritime infrastructures has become a top political priority, since the September 2022 attacks on the Nord Stream pipelines in the Baltic Sea. This contribution reveals why the protection of infrastructures at sea is a difficult task. Reviewing the spectrum of maritime infrastructures (transport, energy, data, fishing, ecosystems) and the potential threats to them (accidents, terrorism, blue crime, grey zone tactics) demonstrates that designating infrastructures as critical and worthy of special protection measures is a political choice. The analysis moreover shows the need of protective instruments that are tailored to the specificities of maritime space, and the need for integrating diverse policy fields, including defense, diplomacy, marine safety, maritime security and cyber security. Cooperation with the infrastructure industry, enhanced surveillance and investments in repair capacities are also required.
This work is part of the ongoing implementation of hydroelastic solution for ships inside the OceanWave3D-seakeeping code. This solver has been developed by the Maritime Group at DTU- Department of Civil and Mechanical Engineering based on linearized potential flow theory. The numerical implementation has been conducted on overlapping grids using a high-order finite difference method. A Fast Fourier Transform (FFT) has been employed to transform the time-domain hydrodynamic solutions to frequency-domain solutions. A pseudo-impulse tailored to the desired frequency range is used as the forcing for the time-domain solution. In previous work, a preliminary implementation of hydroelastic solutions was implemented in OceanWave3D-seakeeping with an Euler-Bernoulli beam model to represent the eigenmodes of the flexible ship hull. However, shear effects are ignored by this beam theory, even though the shear effect is very important to acurately predict the structural deformation especially for a thick beam model. In this work, ship hulls have been treated using the Timoshenko beam model includ- ing shear effects. The influence of shear effects are also discussed through a couple of numerical test cases. Good agreement with reference solutions illustrates the effectiveness of the numerical implementation. The current work focuses on zero speed, and work is also in progress to validate the implementation at forward speeds
Ice-breaking cones are commonly used in the design of marine structures in cold regions. This study investigates the effects of higher-harmonic wave loads and wave runup on a 5-MW offshore wind turbine with and without ice-breaking cones under extreme wave conditions on the Liaodong Peninsula in China. Two ice-breaking cones (upward-downward and inverted types) are considered. The numerical model adopts a two-phase flow by solving unsteady Reynolds-averaged Navier-Stokes (URANS) equations using the volume of fluid (VOF) method. A phase decomposition method through a ‘Stokes-like’ formulation was adopted to obtain the parameters for each harmonics. The presence of the conical part is seen to increase the second-harmonic wave loads by up to 40%, but it has only limited influence on the fourth and fifth harmonics. The upward-downward-type ice-breaking cone increases the third harmonic, while the inverted-type ice-breaking cone decreases the third harmonic. Due to the phase difference between the first-harmonic and higher harmonics, the largest wave runup occurs at 0°, and 135° is the location with the smallest wave runup. This is because at the 135-degree location, the linear component is positive but the other nonlinear components are negative. For the 0-degree location, all harmonics are positive. By contrast, the inverted type has little effect. The high harmonic wave runup of the minimum point is backwards compared with that of the monopile, and most nonlinear wave runups are different upstream of the monopile.
How value is created through service has recently undergone massive changes. Centralized service provision with clear distinctions between service offerers and beneficiaries is increasingly being substituted by value creation within decentralized networks of distributed actors integrating digital resources. One of the drivers of this transformation is blockchain technology. Applying the lens of service-dominant logic and discussing examples of blockchain-based decentralized finance, we shed light on how properties of decentralized technology stimulate value creation in service ecosystems. With this conceptual research, we postulate five propositions of decentralized value creation along the axiomatic foundations of the service-dominant logic. We provide first definitions for decentralized service as well as decentralized service ecosystems. Thereby, we contribute with an extension of the service-dominant logic to the context of decentralized ecosystems. To our knowledge, this research is among the first to add to the growing literature on blockchain value creation from a service science perspective.
Hydrogen can be key in the energy system transition. We investigate the role of offshore hydrogen generation in a future integrated energy system. By performing energy system optimisation in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050, we find that offshore hydrogen generation may likely only play a limited role, and that offshore wind energy has higher value when sent to shore in the form of electricity. Forcing all hydrogen generation offshore would lead to increased energy system costs. Under the assumed scenario conditions, which result in deep decarbonisatiton of the energy system towards 2050, hydrogen generation – both onshore and offshore – follows solar PV generation patterns. Combined with hydrogen storage, this is the most cost-effective solution to satisfy future hydrogen demand. Overall, we find that the role of future offshore hydrogen generation should not simply be derived from minimising costs for the offshore sub-system, but by also considering the economic value that such generation would create for the whole integrated energy system. We find as a no-regret option to enable and promote the integration of offshore wind in onshore energy markets via electrical connections.
With the current revolution in Shipping 4.0, a tremendous amount of data is accumulated during vessel operations.
Data quality (DQ) is becoming more and more important for the further digitalization and effective decision-making
in shipping industry. In this study, a practical DQ assessment method for raw data in vessel operations is proposed.
In this method, specific data categories and data dimensions are developed based on engineering practice and existing
literature. Concrete validation rules are then formed, which can be used to properly divide raw datasets. Afterwards,
a scoring method is used for the assessment of the data quality. Three levels, namely good, warning and alarm,
are adopted to reflect the final data quality. The root causes of bad data quality could be revealed once the internal
dependency among rules has been built, which will facilitate the further improvement of DQ in practice. A case study
based on the datasets from a Danish shipping company is conducted, where the DQ variation is monitored, assessed
and compared. The results indicate that the proposed method is effective to help shipping industry improve the quality
of raw data in practice. This innovation research can facilitate shipping industry to set a solid foundation at the early
stage of their digitalization journeys.
Scrubbers have gained importance in the maritime sector following recent tightening of the emission legislation regarding sulphur. In this work, a model framework based on an Eulerian-Eulerian multiphase model for a packed bed marine scrubber has been developed. The framework account for both dispersed droplets and a packed bed, where sub-models for interfacial forces and heat- and mass transfer are applied for the respective regions. Additionally, a chemistry model and boundary conditions for the nozzles injecting seawater into the scrubber are also implemented. The model framework is calibrated using data from an ocean-going vessel, where the model predictions were within 3% of the measured pressure loss while the discrepancy in the gas and liquid temperatures were between 0.5% and 3.5%. The sulphur concentration predicted by the model varies between − 24% and 25%. However, the concentrations were within 5 ppm of the measured values for all but a single data set.
Formålet med denne anden version af dette notat er stadig at få de vigtigste fakta om atomkraft i Danmark på bordet. I første version af notatet lagde vi op til en åben debat og inviterede til kommentarer og input. Dem har vi modtaget mange af. Det vil vi gerne takke for. Vi har brugt de mange kommentarer til at rette, forbedre, tilføje og uddybe, hvorfor vi nu kan fremlægge anden forbedrede og udbyggede udgave af notatet. Vi er selvfølgelig stadig åbne for at modtage kommentarer og inputs frem mod en version 3.
Nogle af de væsentligste ændringer i forhold til version 1 er:
Der er blevet spurgt til detaljerne i vores analyser og modelberegninger, da det for mange kan være svært at forstå, hvordan en fremtidig elforsyning baseret på vedvarende energi kan være stabil. Derfor har vi uddybet modelberegninger fra version 1 af notatet i to appendikser og tilføjet nye modelberegninger, som uddyber analyserne i forhold til det danske energisystems rolle i Europa. Desuden har vi tilføjet et helt afsnit om stabilitet, som forklarer, hvordan stabilitet og forsyningssikkerhed sikres i et vedvarende energisystem såvel som i et atomkraftsystem.
Der har været kritik af vores valg af eksempler på atomkraftværker, når vi har identificeret anlægsomkostninger og byggetider. Derfor har vi tilføjet flere til listen og uddybet diskussionen af hvilke omkostninger og byggetider, der er
relevante og aktuelle i en dansk sammenhæng. Et særskilt kritikpunkt har været valg af ’kapacitetsfaktor’. Kapacitetsfaktoren udtrykker, hvor meget et værk producerer igennem en periode sammenlignet med, hvor meget det maksimalt vil kunne producere, hvis det kørte ved fuld belastning (fuldlast) i hele perioden. Ved en kapacitetsfaktor på 100% vil værket køre fuldlast i hele perioden og ikke have ’udetider’, hvor værket ikke kan benyttes f.eks. ved direkte nedbrud, vedligehold eller regulering af driften for at følge behovsprofiler. Vi er her blevet kritiseret for at vælge 75% for atomkraftværker, og i stedet er der blevet peget på 85% som mere retvisende. Vi er også blevet kritiseret for ikke at indregne en eventuel udnyttelse af overskudsvarmen fra et atomkraftværk til fjernvarme, og der er blevet spurgt til, om vi har alle omkostninger til elnettet med. Som svar på disse kritikpunkter har vi foretaget flere beregninger med forskellige kapacitetsfaktorer for atomkraftværker samt analyser med og uden fjernvarmeudnyttelse. Hermed kan man klart se betydningen af disse valg af forudsætninger.
Kilden for vores valg af 75% er Det Internationale Energiagenturs World Energy Outlook, hvor de forudser, at atomkraft i 2050 i det Europæiske energisystem vil have en kapacitetsfaktor mellem 70% og 80%. 85% er teknisk muligt, men vælges typisk når atomkraft ikke indgår i sammenhæng med et energisystem med vedvarende energi.
For at styrke gyldigheden af vores beregninger har vi desuden tilføjet nye analyser af Danmark i en Europæisk sammenhæng, hvor vores beregningsmodeller både optimerer på investeringer i produktionskapacitet og på transmissionsledninger.
Disse ekstraanalyser ændrer dog ikke på den centrale hovedkonklusion: At et dansk energisystem med atomkraft er dyrere end et med vind og sol, og at atomkraft tager længere tid at opføre end vind- og solanlæg.
Endelig har der blandt nogle været en forvirring om, hvem vi er, og hvad vores faglighed er i forhold til atomkraftdebatten sammenlignet med forskere, som har en mere specialiseret baggrund i kernefysik eller lignende. Vi er en bred sammensætning af ingeniører, fysikere og økonomer. Vores fælles faglighed er koncentreret om energisystemanalyse, og vores forskningsområde er at analysere, hvordan vi på energiområdet bedst og billigst kan gennemføre den grønne omstilling og hurtigst muligt opnå et CO2-neutralt samfund. Vi er således ikke kun specialister i en enkelt teknologi. Vi er først og fremmest specialister i, hvordan teknologierne spiller sammen, så vi kan finde de bedste løsninger og
optimere det samlede energisystem.
Det er vores vurdering, at det netop er den faglighed og de forskningskompetencer, der er brug for, når konsekvenserne af at investere i atomkraft i Danmark skal sammenlignes med ikke at gøre det. Når trafikforhold skal udvikles og optimeres, er det også trafikforskerens kompetence, der efterspørges, og ikke ekspertise i f.eks. forbrændingsmotorteknologien.
Samlet set er rapporten inddelt i fire kapitler, der fokuserer på forskellige pointer. I kapitel 1 sammenlignes omkostningerne ved at producere en enhed (MWh) el fra henholdsvis atomkraft, sol og vind uafhængigt af resten af energisystemet;
Kapitel 2 har et fokus på de samme teknologier, men hvor de er i drift i energisystemet, og dermed kan betydningen af forskelle i produktionsmønstre fra vedvarende energi og atomkraft kvantificeres. Kapitel 3 fokuserer på den del af energisystemanalyserne, der omhandler forsyningssikkerhed og stabilitet. I kapitel 4 diskuterer vi bygge- og planlægningstider på atomkraft.
Despite the relatively rich literature on the omnipresence of microplastics in marine environments, the current status and ecological impacts of microplastics on global Marine Protected Areas (MPAs) are still unknown. Their ubiquitous occurrence, increasing volume, and ecotoxicological effects have made microplastic an emerging marine pollutant. Given the critical conservation roles of MPAs that aim to protect vulnerable marine species, biodiversity, and resources, it is essential to have a comprehensive overview of the occurrence, abundance, distribution, and characteristics of microplastics in MPAs including their buffer zones. Here, extensive data were collected and screened based on 1565 peer-reviewed literature from 2017 to 2020, and a GIS-based approach was applied to improve the outcomes by considering boundary limits. Microplastics in seawater samples were verified within the boundaries of 52 MPAs; after including the buffer zones, 1/3 more (68 MPAs) were identified as contaminated by microplastics. A large range of microplastic levels in MPAs was summarized based on water volume (0–809,000 items/m 3) or surface water area (21.3–1,650,000,000 items/km 2), which was likely due to discrepancy in sampling and analytical methods. Fragment was the most frequently observed shape and fiber was the most abundant shape. PE and PP were the most common and also most abundant polymer types. Overall, 2/3 of available data reported that seawater microplastic levels in MPAs were higher than 12,429 items/km 2, indicating that global MPAs alone cannot protect against microplastic pollution. The current limitations and future directions were also discussed toward the post-2020 Global Biodiversity Framework goals.