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- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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- Hoché, T., et al.
(författare)
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Charging management of shared taxis : Neighbourhood search for the E-ADARP
- 2020
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Ingår i: 2020 IEEE 23rd International Conference on Intelligent Transportation Systems, ITSC 2020. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- The electric vehicle market is booming. However, these vehicles need to be refilled more often and do so much more slowly than internal combustion engine (ICE) vehicles. The arrival of autonomous vehicles will enable both fully centralised systems for taxi fleet management and a 24/7 use of each taxi. Finally, the ride-sharing market is also booming. Thus, efficient future taxi fleets will have to provide efficient, integrated solutions for ride-sharing, charging and automation. In this paper, the problem focused on is a variation of the Dial-A-Ride-Problem (DARP) where charging as well as the availability of charging stations are taken into account: Given a fleet of autonomous and electric taxis, a charging infrastructure, and a set of trip requests, the objective is to assign trips and charges to taxis such that the total profit of the fleet is maximised. Our contribution consists in the development of a greedy method, and of a simulated annealing. Our methods are evaluated on large instances (10000 requests) based on taxi trip datasets in Porto. Our conclusions show that while high-capacity batteries are largely unneeded in normal circumstances, they are capital in case of disruption, and useful when the charging infrastructure is shared, with queueing time to access to a charger. Parking searches also represent a significant energy expense for autonomous taxis.
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- Olsson, MIT, et al.
(författare)
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Gender Gap in Parental Leave Intentions : Evidence from 37 Countries
- 2023
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Ingår i: Political Psychology. - : Wiley-Blackwell Publishing Ltd. - 0162-895X .- 1467-9221. ; 44:6, s. 1163-1192
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Tidskriftsartikel (refereegranskat)abstract
- Despite global commitments and efforts, a gender-based division of paid and unpaid work persists. To identify how psychological factors, national policies, and the broader sociocultural context contribute to this inequality, we assessed parental-leave intentions in young adults (18–30 years old) planning to have children (N = 13,942; 8,880 identified as women; 5,062 identified as men) across 37 countries that varied in parental-leave policies and societal gender equality. In all countries, women intended to take longer leave than men. National parental-leave policies and women's political representation partially explained cross-national variations in the gender gap. Gender gaps in leave intentions were paradoxically larger in countries with more gender-egalitarian parental-leave policies (i.e., longer leave available to both fathers and mothers). Interestingly, this cross-national variation in the gender gap was driven by cross-national variations in women's (rather than men's) leave intentions. Financially generous leave and gender-egalitarian policies (linked to men's higher uptake in prior research) were not associated with leave intentions in men. Rather, men's leave intentions were related to their individual gender attitudes. Leave intentions were inversely related to career ambitions. The potential for existing policies to foster gender equality in paid and unpaid work is discussed.
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| 9. |
- Opedal, Mihaela Tanase, et al.
(författare)
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Steam explosion of lignocellulosic residues for co-production of value-added chemicals and high-quality pellets
- 2024
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Ingår i: Biomass and Bioenergy. - : Elsevier Ltd. - 0961-9534 .- 1873-2909. ; 181
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Tidskriftsartikel (refereegranskat)abstract
- The demand of pellets as energy carrier and the competitiveness of wood biomass are the drivers for finding alternative raw materials for production of pellets. The aim of this study was to investigate the steam explosion of lignocellulosic residues such as, straw, sawdust birch, sawdust spruce, GROT (mixture of 30 % bark and 70 % industrial chips), and their mix to co-production of value-added chemicals and high-quality pellets. The raw materials were first impregnated with water/acetic acid prior to steam explosion process, while leaching and washing of steam exploded biomass was used to reduce the ash content. The value-added chemicals were extracted with MIBK, and a gas chromatography was used to determine which value-added chemicals are present in the MIBK filtrates after extraction of the steam exploded biomass. Thermogravimetric analysis and Fourier transform infrared spectroscopy, elemental analysis, calorific values, compression strength and density were used to assess and compare the quality of steam exploded biomass and pellets quality. The results from the extraction experiments shows that furfural, HMF, vanillin, syringaldehyde and coniferaldehyde are the most value-added chemicals extracted from lignocellulosic residues where higher yield of the valuable chemicals was obtained when the biomass was presoaked in acetic acid. The ash content was reduced by 83 % for straw material by washing and leaching of steam exploded straw material when the biomass was presoaked in acetic acid. High quality pellets with high calorific value (20 MJ/kg), high compression strength (228 kN/m), high density (1300 kg/m3) and low ash content (0,06 %) were produced from sawdust spruce and GROT:Spruce mix used in our study. Based on our results, we can therefore suggest that steam explosion process of lignocellulosic residues improves the quality of the biomass to pellets production and at the same time open for the possibility to produce value-added chemicals.
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