| 1. |
- Orsini, S., et al.
(författare)
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Inner southern magnetosphere observation of Mercury via SERENA ion sensors in BepiColombo mission
- 2022
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Mercury’s southern inner magnetosphere is an unexplored region as it was not observed by earlier space missions. In October 2021, BepiColombo mission has passed through this region during its first Mercury flyby. Here, we describe the observations of SERENA ion sensors nearby and inside Mercury’s magnetosphere. An intermittent high-energy signal, possibly due to an interplanetary magnetic flux rope, has been observed downstream Mercury, together with low energy solar wind. Low energy ions, possibly due to satellite outgassing, were detected outside the magnetosphere. The dayside magnetopause and bow-shock crossing were much closer to the planet than expected, signature of a highly eroded magnetosphere. Different ion populations have been observed inside the magnetosphere, like low latitude boundary layer at magnetopause inbound and partial ring current at dawn close to the planet. These observations are important for understanding the weak magnetosphere behavior so close to the Sun, revealing details never reached before.
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| 2. |
- Milillo, A., et al.
(författare)
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Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission
- 2020
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 216:5
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Forskningsöversikt (refereegranskat)abstract
- The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors.
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| 5. |
- Massetti, Matteo, et al.
(författare)
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Fully direct written organic micro-thermoelectric generators embedded in a plastic foil
- 2020
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Ingår i: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 75
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Tidskriftsartikel (refereegranskat)abstract
- Organic materials have attracted great interest for thermoelectric applications due to their tuneable electronic properties, solution processability and earth-abundance, potentially enabling high-throughput realization of low-cost devices for low-power energy harvesting applications. So far, organic thermoelectricity has primarily focused on materials development, with less attention given to integrated generators. Yet, future applications will require the combination of efficient generators architectures and scalable manufacturing techniques to leverage the advantages of such promising materials. Here we report the realization of a monolithic organic micro-thermoelectric generator (mu-OTEG), using only direct writing methods, embedding the thermoelectric legs within a plastic substrate through a combination of direct laser writing and inkjet printing techniques. Employing PEDOT:PSS for the p-type legs and a doped fullerene derivative for the n-type ones, we demonstrate a mu-OTEG with power density of 30.5 nW/cm(2) under small thermal gradients, proving the concrete possibility of achieving power requirements of low-power, distributed sensing applications.
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| 6. |
- Roth, Lorenz, et al.
(författare)
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Ganymede’s tenuous atmosphere
- 2024. - 1
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Ingår i: Ganymede. - Cambridge, UK : Cambridge University Press.
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Bokkapitel (refereegranskat)abstract
- Ganymede possesses a tenuous water-based atmosphere, thought to be produced by the solar and Jovian plasma irradiation of its icy surface. Observational evidence for Ganymede's atmosphere is provided by far-ultraviolet (FUV) emission from the atomic oxygen (O) and hydrogen (H) constituents. The relative strengths of the two observed FUV atomic oxygen emission multiplets, which are produced by electron-impact on the atmosphere, allow inference of molecular O2 and H2O components and their relative abundances. Minor species besides O and H have not been detected and the observational constraints can be considered loose overall, partly due to the inherent ambiguity and difficulty in relating the electron-excited emissions to atmospheric properties. Much of our understanding of the configuration of Ganymede’s atmosphere is based on modelling efforts. The modelling studies suggest that O2 is produced primarily through radiolysis and sputtering by the plasma precipitation in the icy polar regions. Since it does not condense, O2 is yet abundant everywhere and likely the dominant species over most of the surface. Ice sublimation increases the abundance of H2O near the sub-solar point, locally exceeding the O2 abundance. The high altitudes, in contrast, are expected to be primarily populated by the lighter H2 molecules everywhere. Inferred column densities for the primary molecules, O2 and H2O, are on the order of 1014 cm-2 to 1015 cm-2. In addition, models suggest that the atmosphere is collisional only up to a few tens of kilometers above the surface, particular in the dense sub-solar region.
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