| 1. |
- Hansson, Mats, et al.
(författare)
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A guide to barley mutants
- 2024
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Ingår i: Hereditas. - 0018-0661. ; 161
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Forskningsöversikt (refereegranskat)abstract
- Background: Mutants have had a fundamental impact upon scientific and applied genetics. They have paved the way for the molecular and genomic era, and most of today’s crop plants are derived from breeding programs involving mutagenic treatments. Results: Barley (Hordeum vulgare L.) is one of the most widely grown cereals in the world and has a long history as a crop plant. Barley breeding started more than 100 years ago and large breeding programs have collected and generated a wide range of natural and induced mutants, which often were deposited in genebanks around the world. In recent years, an increased interest in genetic diversity has brought many historic mutants into focus because the collections are regarded as valuable resources for understanding the genetic control of barley biology and barley breeding. The increased interest has been fueled also by recent advances in genomic research, which provided new tools and possibilities to analyze and reveal the genetic diversity of mutant collections. Conclusion: Since detailed knowledge about phenotypic characters of the mutants is the key to success of genetic and genomic studies, we here provide a comprehensive description of mostly morphological barley mutants. The review is closely linked to the International Database for Barley Genes and Barley Genetic Stocks (bgs.nordgen.org) where further details and additional images of each mutant described in this review can be found.
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| 2. |
- Sunjaq, Ahmed Marwan Mousa, 1996, et al.
(författare)
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Frequency control by BESS for smooth Island transition of a hydro-powered microgrid
- 2024
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Ingår i: IET Smart Grid. - 2515-2947. ; 7:1, s. 63-77
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Tidskriftsartikel (refereegranskat)abstract
- This paper develops a frequency control strategy for a battery energy storage system to facilitate the smooth island transition of a hydro-powered microgrid during unplanned grid outages. The proposed frequency control strategy uses a PI-based droop controller, where the tuning of the controller accounts for the limitations in the power response of a hydro generator and the required frequency quality of the microgrid. The effectiveness of the frequency control strategy is verified in Simulink using phasor simulations, and it is further validated in laboratory tests. The results demonstrate that the proposed PI-based droop and its tuning strategy fulfill the desired frequency quality requirement of the hydro-powered microgrid without over-dimensioning the size of the storage capacity as compared to the traditional proportional droop controller.
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| 3. |
- Tomas, Matthieu Tristan, 1993, et al.
(författare)
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Hydrogen-barrier coatings against dual-atmosphere corrosion for IT-SOFC interconnect applications
- 2024
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Ingår i: International Journal of Hydrogen Energy. - 0360-3199. ; 58, s. 852-862
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Tidskriftsartikel (refereegranskat)abstract
- A key component of a Solid Oxide Fuel Cell (SOFC) is the interconnect, which connects individual fuel cells in series to form a fuel cell stack. The interconnect is exposed to air and fuel in parallel; these so-called dual-atmosphere conditions cause severe corrosion on the air-side. This work investigates interconnect coatings that can mitigate this effect. Physical Vapour Deposition (PVD) coatings of Cr2O3, CeO2, YSZ, and Al2O3 on ferritic stainless steel (AISI 441) were exposed under dual-atmosphere conditions for up to 3000 h. The evolution of the corrosion products was evaluated using optical microscopy and Scanning Electron Microscopy (SEM) in combination with Energy-dispersive x-ray Spectroscopy (EDS). The SEM analysis showed that a chromia coating was not sufficient to reduce the dual-atmosphere effect, while other coatings on the fuel-side suppressed the dual-atmosphere effect by forming a barrier to hydrogen permeation. The best outcomes were observed with Al2O3 coatings on the fuel-side, which drastically reduced the dual-atmosphere effect. A 30 nm Al2O3 coating displayed acceptable Area-Specific Resistance (ASR).
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| 4. |
- Dellenmark-Blom, Michaela, et al.
(författare)
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Prevalence of Mental Health Problems, Associated Factors, and Health-Related Quality of Life in Children with Long-Gap Esophageal Atresia in Sweden
- 2023
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Ingår i: Journal of Pediatric Surgery. - : Elsevier. - 0022-3468 .- 1531-5037. ; 58:9, s. 1646-1655
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Tidskriftsartikel (refereegranskat)abstract
- Background: Children with long-gap esophageal atresia (LGEA) face a high risk of digestive and respiratory morbidity, but their mental health outcomes have not been investigated. We aimed to identify the prevalence of mental health problems in children with LGEA, associated factors and health-related quality of life (HRQOL).Methods: Twenty-six children with LGEA aged 3-17 were recruited nationwide in Sweden. One of their parents and adolescents aged 11-17 completed information on the child's mental health (Strength and Difficulties Questionnaire), generic (PedsQL 4.0) and condition-specific HRQOL (EA-QOL). Parents gave information on current child symptomatology. Mental health level was determined using validated norms; abnormal >= 90 percentile/borderline >= 80 percentile/normal. Elevated levels were considered borderline/abnormal. Data were analyzed using descriptives, correlation and Mann-Whitney-U test. Significance level was p < 0.05.Results: Twelve children with LGEA aged 3-17 (46%) had elevated scores of >= 1 mental health domain in parent-reports, whereas 2 adolescents (15%) in self-reports. In parent-reports, 31% of the children had elevated levels of peer relationship problems, with associated factors being child sex male (p = 0.037), airway infections (p = 0.002) and disturbed night sleep (p = 0.025). Similarly, 31% showed elevated levels of hyperactivity/inattention, and associated factors were male sex (p = 0.005), asthma (p = 0.028) and disturbed night sleep (p = 0.036). Elevated levels of emotional symptoms, seen in 20%, were related to swallowing difficulties (p = 0.038) and vomiting problems (p = 0.045). Mental health problems correlated negatively with many HRQOL domains (p < 0.05).Conclusions: Children with LGEA risk mental health difficulties according to parent-reports, especially peer relationship problems and hyperactivity/inattention, with main risk factors being male sex, airway problems and sleep disturbances. This should be considered in follow-up care and research, particularly since their mental health problems may impair HRQOL.
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| 5. |
- Imgart, Paul, 1990, et al.
(författare)
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Stability Limits and Improved Robustness of Grid-Forming Converters With External Inertia-Emulation Loop
- 2023
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Ingår i: 2023 25th European Conference on Power Electronics and Applications, EPE 2023 ECCE Europe. - 9789075815412
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Konferensbidrag (refereegranskat)abstract
- An external inertia emulation loop (IEL) prevents instability in grid-forming converters during frequency disturbances. This paper investigates IEL stability limits and compares three alternatives to improve IEL performance under power limitation. Simulations confirm the IEL’s robustness and the effectiveness of the proposed solution in avoiding undesired active-power injection at the disturbance end.
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| 6. |
- Mohtat, Sohrab, 1993, et al.
(författare)
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Impact of pole-to-pole DC voltage on energy requirement of FB YY-MMC
- 2023
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Ingår i: 2023 25th European Conference on Power Electronics and Applications, EPE 2023 ECCE Europe.
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Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to investigate the impact of pole-to-pole DC voltage on the energy requirements of a modular multilevel converter with full-bridge submodules (FB-MMC). With focus on energy-storage equipped FB-MMCs, the relation between the pole-to-pole voltage and the peak-to-peak energy variations in the MMC's arms is derived. Unlike MMC with half-bridge (HB) submodules (SM), in a FB-MMC the pole-to-pole DC voltage can be selected independently of the AC voltage; this allows for reduced energy requirements as well as lower number of FB SMs and capacitors for the same converter ratings. Furthermore, the impact of the converter's circulating current on the MMC's energy requirements is investigated. A guideline for the converter design is provided. Theoretical findings are validated via time-domain simulations.
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| 7. |
- Narula, Anant, 1993, et al.
(författare)
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Voltage-based Current Limitation Strategy to Preserve Grid-forming Properties Under Severe Grid Disturbances
- 2023
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Ingår i: IEEE Open Journal of Power Electronics. - 2644-1314. ; 4, s. 176-188
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Tidskriftsartikel (refereegranskat)abstract
- Grid-forming (GFM) converters are a promising solution to enable large scale integration of renewable energy sources into the power system. However, due to the intrinsic voltage-source behaviour of GFM converters, current limitation during large grid disturbances is challenging. This paper presents a novel limitation strategy that preserves the GFM properties of the converter and at the same time effectively limits the converter current to the desired value. Through the limitation of the converter's internal voltage, stable operation even during faults and in case of large frequency disturbances in the grid is achieved. Experimental results show the effectiveness of the proposed current limitation strategy in case of various grid disturbances.
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| 8. |
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| 9. |
- Reddy, Mareddy, 1993, et al.
(författare)
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11–23% Cr steels for solid oxide fuel cell interconnect applications at 800 °C – How the coating determines oxidation kinetics
- 2023
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Ingår i: International Journal of Hydrogen Energy. - : Elsevier BV. - 0360-3199. ; 48:34, s. 12893-12904
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Tidskriftsartikel (refereegranskat)abstract
- The present work investigates the low-cost steels AISI 441, AISI 430, and AISI 444 against the tailor-made high Cr steel Crofer 22 APU (22.9 wt% Cr) at 800 °C in simulated solid oxide fuel cell (SOFC) cathode conditions. Furthermore, a low Cr steel, AISI 409 (11.4 wt% Cr) is included in the study. The oxidation, chromium evaporation, and area-specific resistance (ASR) of the uncoated and Ce/Co-coated steels are studied for up to 3000 h. Ce/Co-coated steels showed significant improvement in behaviour compared to their uncoated counterparts. The oxidation and chromium evaporation behaviour between the uncoated steels varied substantially while the Ce/Co coated steels exhibited highly similar behaviour. The area-specific resistance of the coated low-cost steels was on par with Crofer 22 APU. However, 430 formed a continuous silica layer, resulting in a higher ASR after 3000 h. Cross-sections of the uncoated and Ce/Co-coated steels were analysed using a scanning electron microscope and energy dispersive X-ray spectroscopy.
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| 10. |
- Reddy, Mareddy, 1993, et al.
(författare)
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Experimental review of the performances of protective coatings for interconnects in solid oxide fuel cells
- 2023
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 568
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Tidskriftsartikel (refereegranskat)abstract
- Ferritic stainless steel interconnects are used in solid oxide fuel cells; however, coatings are required to improve their performance. Although several types of coatings have been proposed, they have been scarcely investigated under similar conditions. This study compares the characteristics of uncoated Crofer 22 APU and eight different coatings on Crofer 22 APU for up to 3000 h at 800 °C. The coatings were deposited at various research laboratories around the world, and the experiments were performed at Chalmers University of Technology, Sweden. Cross-sections of the samples were analysed using scanning electron microscopy and energy-dispersive x-ray spectroscopy. The (Co,Mn)-based coated steels showed more than 50-fold lower chromium evaporation and at least 3 times thinner Cr2O3 scale thickness compared to uncoated steel. The coated steel samples showed lower area-specific resistance (ASR) values than the uncoated steel after 3000 h of exposure, irrespective of the coating thickness, composition and deposition method.
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