| 1. |
- Karlsson, Hanna K., et al.
(författare)
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Evaluation of the effect of water on CO2 absorption in AMP and DMSO systems
- 2024
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Ingår i: Separation and Purification Technology. - 1873-3794. ; 341
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Tidskriftsartikel (refereegranskat)abstract
- Non-aqueous precipitating amine systems for carbon capture allows for CO2 desorption at lower temperatures than conventional aqueous amine systems and can potentially reduce the energy requirement for regeneration. In this work, the influence of water accumulation that may arise from humid gases entering the absorption column was investigated for absorption systems containing 2-amino-2-methyl-1-propanol (AMP) and dimethyl sulfoxide (DMSO). The physical solubility of CO2 decreased with increasing water concentration, as expected from the lower solubility of CO2 in water than in DMSO. The CO2 loading capacity was increased with the addition of water, resulting from formation of bicarbonate with water present in the system. Low lean loadings of 0.1 mol CO2/mol AMP and precipitation was observed in 23 wt% AMP/DMSO with 9 wt% added water, suggesting that some water accumulation might be tolerable while still maintaining the desired properties of the absorption system. NMR was used to study the CO2 reaction products at 30–88 °C. The results suggested that 88 °C can be used for regeneration of the system even with water accumulated in the system. At 80 °C formation of the tentatively assigned species 4,4-dimethyl-1,3-oxazolidin-2-one was observed, indicating that thermal degradation of AMP may occur above this temperature.
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| 2. |
- Mazur, Mikael, 1990, et al.
(författare)
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Field Trial of FPGA-Based Real-Time Sensing Transceiver over 524km of Live Aerial Fiber
- 2023
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Ingår i: Optical Fiber Communication Conference, OFC 2023. - 9781957171180
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Konferensbidrag (refereegranskat)abstract
- We perform fiber sensing over a 524 km live network using a real-time coherent transceiver prototype. Polarization and length changes from the link consisting exclusively of aerial fiber wound around high-voltage power cables are continuously monitored.
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| 3. |
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| 4. |
- Fridolfsson, Jonatan, 1992, et al.
(författare)
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Physical activity spectrum discriminant analysis—A method to compare detailed patterns between groups
- 2021
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 31:12, s. 2333-2342
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Tidskriftsartikel (refereegranskat)abstract
- Investigating physical activity (PA) patterns as a detailed intensity spectrum instead of crude intensity categories have improved the ability to analyze the relationship between measured PA and health variables. The aim of this methodological study was to introduce and investigate the utility of using detailed PA intensity spectrum compared to crude PA intensity categories for comparison of PA between groups and between repeated measures. The study sample consisted of two groups of children, where one group was scheduled for extended physical education (PE) by daily classes while the other group followed usual PE schedule. Accelerometer data was processed into traditional crude PA intensity categories and into detailed PA intensity spectrum. Multivariate partial least squares regression for discriminant analysis (PLS-DA) was applied for PA intensity spectrum group comparison and compared to traditional univariate statistical analysis. Repeated measures were investigated using independent PLS-DA as well as multilevel PLS-DA for paired analysis. While traditional analysis of crude PA intensity categories was unable to find any group differences, multivariate analysis of the PA intensity spectrum identified statistically significant differences. By the extension of multilevel PLS-DA for paired comparison, a clear difference in the PA intensity spectrum was demonstrated between repeated measures. In conclusion, analysis of detailed PA intensity spectrum demonstrates utility for comparing detailed PA data between groups and between repeated measures in interventional and observational research.
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| 5. |
- Karlsson, Hanna K., et al.
(författare)
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Chemical absorption of carbon dioxide in non-aqueous systems using the amine 2-amino-2-methyl-1-propanol in dimethyl sulfoxide and N-methyl-2-pyrrolidone
- 2021
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Ingår i: Separation and Purification Technology. - : Elsevier BV. - 1383-5866. ; 256
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Tidskriftsartikel (refereegranskat)abstract
- Non-aqueous amine systems have been suggested as energy-efficient alternatives to conventional aqueous amine systems in post-combustion carbon capture, as low regeneration temperatures can be achieved. The solubility of CO2 and heat of absorption in non-aqueous systems were studied using the sterically hindered amine 2-amino-2-methyl-1-propnaol (AMP) in the organic solvent dimethyl sulfoxide (DMSO). 13C NMR was used to study the product species in solution as CO2 reacts with AMP in either DMSO or N-methyl-2-pyrrolidone (NMP). The solubility of CO2 in AMP/DMSO showed that low loadings could be achieved at 80–88 °C, indicating that regeneration can be carried out at lower temperatures than in conventional aqueous systems. Precipitation occurred at 25 wt% AMP in DMSO, increasing the overall capacity of the system. The heat of absorption decreased with increasing temperature, and was explained by physical absorption dominating the absorption mechanism at higher temperatures. This was also confirmed by the results of NMR, as less chemically absorbed species were observed at higher temperatures. The reaction products observed in AMP/DMSO and AMP/NMP were identified as the AMP carbamate, bicarbonate from water impurities, and the AMP carbonate from CO2 reacting with the hydroxyl group of AMP.
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| 6. |
- Li, Jianqiang, 1983, et al.
(författare)
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Transmission of 1.936 Tb/s (11 x 176 Gb/s) DP-16QAM superchannel signals over 640 km SSMF with EDFA only and 300 GHz WSS channel
- 2012
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Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 20:26, s. B223-B231
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Tidskriftsartikel (refereegranskat)abstract
- With an improved receiver-side spectral shaping technique by introducing and optimizing one tap coefficient in the intermediate response, we successfully transmitted 1.936 Tb/s (11 x 176 Gb/s) DP-16QAM superchannel signal over 8 x 80 km SSMF with EDFA-only and two 280 GHz wavelength selective switches (WSSs) in support of future 1.6 Tb/s Ethernet with up to 20% forward error correction overhead. The 280 GHz 3-dB bandwidth of the WSS passband permits a sufficient guardband if the 1.936 Tb/s superchannel signals are placed in a 300 GHz WSS channel.
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| 7. |
- Aidanpää, Jan-Olov, et al.
(författare)
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Developments in rotor dynamical modeling of hydropower units
- 2009
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Ingår i: Proceedings of the IUTAM Symposium on Emerging Trends in Rotor Dynamics. - Dordrecht : Encyclopedia of Global Archaeology/Springer Verlag. - 9789400700192
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Konferensbidrag (refereegranskat)
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| 8. |
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| 9. |
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| 10. |
- Karlsson, P, et al.
(författare)
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Low-Density Cellulose-Based Foams: Preparation, Characterization and Biodegradation
- 2023
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Ingår i: Book of Abstracts EPNOE 2023. - : Graz University of Technology. ; , s. 345-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The demands for alternatives to fossil-based materials for the packaging and building sector is rapidly increasing as new regulations and laws are set. The usage of such materials in low- density applications is increasingly questioned since only a small amount is recycled and a large part ends up in the environment where it has a very long decomposition time and contributes to the emergence of microplastics in our marine eco systems. Alternatives to fossil- based low-density materials has been demonstrated using e.g., starch [1] and cellulose [2] as raw materials. However, challenges remain regarding the process parameters and properties such as strength and water integrity. To fulfil these properties requested by the specification owners, understanding is needed regarding which tools that are available for incorporating wet-integrity and hydrophobicity without causing the wet foam to collapse during the foaming or drying process. It is also of highest importance to have an early understanding of how such materials can be recycled and/or bio-degraded to fit a circular economy. In this study two different cross-linkers and two different types of hydrophobisers are used to obtain a wet stable and a water repelling low-density material. The wet foams are characterized by measuring the foamability and foam stability and the dry foams are characterized in terms of structure, porosity and degradability. Two demonstrators have been produced based on the most promising material composition and the up-scaling processes of the developed foaming technology to both batch-wise and continuous fabrication of composite foams is underway. Finally, a biodegradation study was conducted and evaluated.[1] S. Chaireh, P. Ngasatool, and K. Kaewtatip, “Novel composite foam made from starch and water hyacinth with beeswax coating for food packaging applications,” Int. J. Biol. Macromol., vol. 165, pp. 1382–1391, 2020[2] C. Qin, M. Yao, Y. Liu, Y. Yang, Y. Zong, and H. Zhao, “MFC/NFC-based foam/aerogel for production of porous materials: Preparation, properties and applications,” Materials (Basel)., vol. 13, no. 23, pp. 1–21, 2020
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