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| 2. |
- Trilla, Lluis, 1981, et al.
(författare)
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Wave farm collection grid analysis and design
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this report, the collection grid of a wave farm is designed and analysed, the system under consideration goes from the connection point at each power converter (included in each wave energy unit) up to the point of common connection with the main grid. Time series that have been provided by Ocean Harvesting Technologies (OHT), being obtained from their simulation models for a scaled prototype and include data for mild, medium and strong sea states. The simulation models have been validated against small scale tank testing of a prime mover, a wave rider buoy, and scaled testing of the power take-off in a land based test-rig. Wave data is taken from EMEC, Scotland [7]. The design of the collection grid aims to optimize its size by minimizing its cost while maximizing the power output. For the economical assessment three layouts are taken into account and several scenarios for different energy prices and interest rates are presented. A life-cycle analysis is also done where the entire life span of the collection grid is considered showing that around 30Euro/MWh will be the share of the electricity price required to install and operate the collection grid. The power quality of the resultant layout and its compliance with the grid code of the UK are analysed as well. This analysis includes power factor and voltage fluctuation estimation, line-fault ride-through assessment and flicker contribution analysis. Given the pulsating nature of the wave power systems special emphasis in the study of flicker emissions is done concluding that the proposed wave park is within the grid code limitations and even a reduction of a 66% in the flicker coefficients is reported when considering the aggregation of several units in one model.
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| 3. |
- Aagergaard, Sine, et al.
(författare)
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Scandinavian women’s football in world : migration, management and mixed identity
- 2013
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Ingår i: Soccer & Society. - : Taylor & Francis. - 1466-0970 .- 1743-9590. ; 14:6, s. 769-780
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Tidskriftsartikel (refereegranskat)abstract
- This special issue has grown out of an ongoing Nordic collaborative research project (Nordcorp) using Scandinavian women’s football as a strategically selected extreme case (of organizational development) to study a Nordic sport model in transition. The common point of interest for the project group, which overlaps with the editors and authors in this issue of Soccer and Society, is a fascination with the current development of Scandinavian women’s football that stands out as an intriguing subject for bothsports research and the social sciences.
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| 4. |
- Abel, I, et al.
(författare)
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Overview of the JET results with the ITER-like wall
- 2013
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10, s. 104002-
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Tidskriftsartikel (refereegranskat)abstract
- Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z(eff) (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H-98,H-y2 close to 1 and beta(N) similar to 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.
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| 5. |
- Almgren, Maria, et al.
(författare)
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Länge leve skolan! En text om utbildning, estetik och skolutveckling
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna skrift har arbetats fram av en grupp studenter på Lärande och samhälle som fortsättning och utveckling av examinationsuppgift på en terminslång kurs, där de hade att iscensätta ett dokumentärfilmsprojekt på högstadiet. Projektet ägde rum inom ramen för huvudämnet Kultur, medier, estetik (KME) - skapat genom en sammanslagning av estetiska ämnen med medie- och kulturstudier 2001 – som ända från starten har tillskrivit det estetiska en särskild förmåga att vända upp och ner på invanda synsätt och kritiserat skolan för att inte lämna tillräckligt utrymme åt denna radikala potential. Den som är det minsta intresserad av skol- och kulturarbete kan inte undgå att dras in i det nät av glödande engagemang, intrikata spörsmål och brottstycken av teoretiska diskussioner som dessa sju studenter väver. Man kommer mycket nära de problem de brottas med utan att någonsin hitta några definitiva svar. Viljan att göra nytt tillsammans med eleverna och med utgångspunkt i deras horisont är obändig. Men så är det ramarna för arbetet... De sju befinner sig i ett interregnum, i en korseld av krav från lärarutbildarna, lärarna på skolan och eleverna, som påminner dem: "Ni är inte våra lärare. Ni kommer hit några timmar i veckan från någon annanstans". Ingenting visar sig vara enkelt. Varför gläds inte eleverna åt att få göra något som kan få betydelse för dem "på riktigt"? Vad är egentligen skillnaden mellan dokumentär- och fiktionsfilm? Hur bedömer man elevernas prestationer i ett så pass öppet projekt? Finns det över huvud taget rum i dagens skola för en pedagogik som vill vara på en gång passionerad, polyfon, prövande och provokativ? Alla dessa är ord som väl kännetecknar skriftens första del, ett grafiskt kaos av utlagda spår som läsaren kan välja bland att följa. Här får man en "cut-up-bild" av de tankevärldar som studenterna försöker orientera sig mot och inom. Den läsare som finner estetiken för provocerande kan alltid börja med andra delen i stället, som analytiskt redogör för de olika filmprojekten. Del tre, slutligen, diskuterar förutsättningarna för de förhållningssätt som utvecklats inom KME att göra sig gällande inom ramen för den nya läroplanen Lgr 11.
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| 6. |
- Andersson, A., et al.
(författare)
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An analysis of inverter switching loss minimization based on discontinuous PWM for a salient-pole PMSM
- 2014
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Ingår i: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
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Konferensbidrag (refereegranskat)abstract
- This article presents the result of an inverter switching loss minimization technique based on discontinuous PWM patterns for a salient-pole PMSM with a two-level voltage source inverter for an automotive application. The suggested PWM patterns are evaluated using the resulting electromagnetic torque considering peak-to-peak ripple as well as the DC-current harmonic spectra. The study focuses on high rotational speeds, from 0.6-2.5 ωbase considering both current and voltage limitations. The analysis focuses on electromagnetic torque characteristics evaluated at steady state operation. The results show that the electromagnetic torque ripple is increased by up to 73 % and 78 % whereas the inverter switching losses is decreased by up to -17%and -41%for the EUDC driving cycle using DPWM30 and DPWM60, respectively.
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| 7. |
- Andersson, A., et al.
(författare)
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Inverter losses minimization using variable switching frequency based on multi-objective optimization
- 2014
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Ingår i: Proceedings - 2014 International Conference on Electrical Machines, ICEM 2014. - 9781479943890 ; :Art. no. 6960271, s. 789-795
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Konferensbidrag (refereegranskat)abstract
- This article presents the result of an VSI-losses minimization technique based on multi-objective convex optimization for a salient-pole PMSM with a two-level VSI for an automotive application. The optimization, using the switching frequency as control variable, is based on a multi-objective cost function defined by the combination of VSI-losses and electromagnetic torque peak-peak ripple, analytically expressed using time-domain current predictions. The optimization target is to keep an optimum balance between VSI-losses and electromagnetic torque ripple, using variable switching frequency (VSF). The primary objective with this article is the presented design methodology. Simulations are used to verify functionality as well as influence of different scaling factors. In addition, the NEDC driving cycle is used to further quantify the results for two different cost function setups.
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| 8. |
- Andersson, Jonas, 1977-, et al.
(författare)
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Effects of heavy endurance physical exercise on inflammatory markers in non-athletes
- 2010
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 209:2, s. 601-605
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Physical activity has beneficial effects on cardiovascular disease but the mechanisms are still somewhat unclear. One possible pathway may be through the anti-inflammatory effects attributed to regular physical activity. Our primary aim was to study the effects of endurance physical exercise on C-reactive protein (CRP), Interleukin-6 (IL-6), Tumor Necrosis Factor-alpha (TNFalpha) during the acute and recovery phases. Secondarily, we studied the impact of diet on these inflammatory markers.METHODS: Twenty men, aged 18-55 years, participated in a 14 days cross-country skiing tour. They traveled 12-30km per day corresponding to about 10h of heavy physical activity. The participants were randomized to a diet with either 30 or 40% of energy derived from fat. Inflammatory variables were analysed at week 0, after 1 and 2 weeks and during the recovery phase at week 6 and 8.RESULTS: CRP and TNFalpha increased significantly during the two weeks of exercise (1.4-5.0mg/l, p=0.00 and 6.8-8.4pg/ml, p=0.00). CRP levels were significantly lower during recovery (median 0.7mg/l) compared to baseline (median 1.4mg/l) and did not correlate to metabolic variables. There were no significant changes in IL-6 levels during the study period. For dietary groups significant CRP changes were observed only in the high fat group during recovery.CONCLUSIONS: CRP and TNFalpha increased significantly but reacted differently during heavy physical activity while there seemed to be no significant changes in IL-6. No significant differences regarding inflammatory variables were found between the dietary groups.
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