| 1. |
- Osborn, H. P., et al.
(författare)
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The PDS 110 observing campaign - photometric and spectroscopic observations reveal eclipses are aperiodic
- 2019
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 485:2, s. 1614-1625
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Tidskriftsartikel (refereegranskat)abstract
- PDS 110 is a young disc-hosting star in the Orion OB1A association. Two dimming events of similar depth and duration were seen in 2008 (WASP) and 2011 (KELT), consistent with an object in a closed periodic orbit. In this paper, we present data from a ground-based observing campaign designed to measure the star both photometrically and spectroscopically during the time of predicted eclipse in 2017 September. Despite high-quality photometry, the predicted eclipse did not occur, although coherent structure is present suggesting variable amounts of stellar flux or dust obscuration. We also searched for radial velocity (RV) oscillations caused by any hypothetical companion and can rule out close binaries to 0.1Ms. Asearch of Sonneberg plate archive data also enabled us to extend the photometric baseline of this star back more than 50 yr, and similarly does not re-detect any deep eclipses. Taken together, they suggest that the eclipses seen in WASP and KELT photometry were due to aperiodic events. It would seem that PDS 110 undergoes stochastic dimmings that are shallower and of shorter duration than those of UX Ori variables, but may have a similar mechanism.
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| 2. |
- Murali, Damu, et al.
(författare)
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Experimental assessment of a solar photovoltaic-thermal system in a livestock farm in Italy
- 2024
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Ingår i: Solar Energy Advances. - : Elsevier. - 2667-1131. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents an experimental evaluation of the performance of a solar photovoltaic-thermal (PVT) system in a swine farm at Mirandola in Italy. In this project named RES4LIVE, funded by the EU’s Horizon 2020 program, a PVT system is installed to replace fossil fuel consumption in one of the barns on the farm. The electrical energy from the collectors is utilized to operate the heat pump and provide electricity to the barn, whereas the thermal energy from the collector is stored in a borehole thermal energy storage (BTES) for further use by a 35 kW heat pump. The hybrid solar field consists of 24 covered PVT flat plate collectors (7.68 kWel and 25 kWth) with a total aperture area of 39.3 m2, which can increase the temperature of the heat transfer fluid (HTF) to up to 40 °C. The PVT system is connected to a modular solar central (SC) with a standardized design that can also be used for other similar applications. The hybrid solar system complemented by energy storage is expected to save approximately 20,850 kg CO2/year . The data collected from the PVT system, SC, and BTES are rigorously analyzed to evaluate its overall performance. A comprehensive performance assessment reveals the capability of the solar system to reduce carbon emissions and effectively replace fossil fuel consumption in the agricultural sector.
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