2023
Autores
Hinkley, S; Lacour, S; Marleau, GD; Lagrange, AM; Wang, JJ; Kammerer, J; Cumming, A; Nowak, M; Rodet, L; Stolker, T; Balmer, WO; Ray, S; Bonnefoy, M; Molliere, P; Lazzoni, C; Kennedy, G; Mordasini, C; Abuter, R; Aigrain, S; Amorim, A; Asensio-Torres, R; Babusiaux, C; Benisty, M; Berger, JP; Beust, H; Blunt, S; Boccaletti, A; Bohn, A; Bonnet, H; Bourdarot, G; Brandner, W; Cantalloube, F; Caselli, P; Charnay, B; Chauvin, G; Chomez, A; Choquet, E; Christiaens, V; Clenet, Y; du Foresto, VC; Cridland, A; Delorme, P; Dembet, R; Drescher, A; Duvert, G; Eckart, A; Eisenhauer, F; Feuchtgruber, H; Galland, F; Garcia, P; Lopez, RG; Gardner, T; Gendron, E; Genzel, R; Gillessen, S; Girard, JH; Grandjean, A; Haubois, X; Heissel, G; Henning, T; Hippler, S; Horrobin, M; Houlle, M; Hubert, Z; Jocou, L; Keppler, M; Kervella, P; Kreidberg, L; Lapeyrere, V; Le Bouquin, JB; Lena, P; Lutz, D; Maire, AL; Mang, F; Merand, A; Meunier, N; Monnier, JD; Mouillet, D; Nasedkin, E; Ott, T; Otten, GPPL; Paladini, C; Paumard, T; Perraut, K; Perrin, G; Philipot, F; Pfuhl, O; Pourre, N; Pueyo, L; Rameau, J; Rickman, E; Rubini, P; Rustamkulov, Z; Samland, M; Shangguan, J; Shimizu, T; Sing, D; Straubmeier, C; Sturm, E; Tacconi, LJ; van Dishoeck, EF; Vigan, A; Vincent, F; Ward-Duong, K; Widmann, F; Wieprecht, E; Wiezorrek, E; Woillez, J; Yazici, S; Young, A; Zicher, N;
Publicação
ASTRONOMY & ASTROPHYSICS
Abstract
Aims. HD206893 is a nearby debris disk star that hosts a previously identified brown dwarf companion with an orbital separation of similar to 10 au. Long-term precise radial velocity (RV) monitoring, as well as anomalies in the system proper motion, has suggested the presence of an additional, inner companion in the system. Methods. Using information from ongoing precision RV measurements with the HARPS spectrograph, as well as Gaia host star astrometry, we have undertaken a multi-epoch search for the purported additional planet using the VLTI/GRAVITY instrument. Results. We report a high-significance detection over three epochs of the companion HD206893c, which shows clear evidence for Keplerian orbital motion. Our astrometry with similar to 50-100 mu arcsec precision a fforded by GRAVITY allows us to derive a dynamical mass of 12.7(+1:2) (-1:0) M-Jup and an orbital separation of 3.53(+0:08) (-0:06) au for HD206893c. Our fits to the orbits of both companions in the system use both Gaia astrometry and RVs to also provide a precise dynamical estimate of the previously uncertain mass of the B component, and therefore allow us to derive an age of 155 +/- 15 Myr for the system. We find that theoretical atmospheric and evolutionary models that incorporate deuterium burning for HD206893c, parameterized by cloudy atmosphere models as well as a '' hybrid sequence '' (encompassing a transition from cloudy to cloud-free), provide a good simultaneous fit to the luminosity of both HD206893B and c. Thus, accounting for both deuterium burning and clouds is crucial to understanding the luminosity evolution of HD206893c. Conclusions. In addition to using long-term RV information, this e ffort is an early example of a direct imaging discovery of a bona fide exoplanet that was guided in part by Gaia astrometry. Utilizing Gaia astrometry is expected to be one of the primary techniques going forward for identifying and characterizing additional directly imaged planets. In addition, HD206893c is an example of an object narrowly straddling the deuteriumburning limit but unambiguously undergoing deuterium burning. Additional discoveries like this may therefore help clarify the discrimination between a brown dwarf and an extrasolar planet. Lastly, this discovery is another example of the power of optical interferometry to directly detect and characterize extrasolar planets where they form, at ice-line orbital separations of 2 4 au.
2023
Autores
Vasconcelos, V; Bigotte, E; Marques, L; Almeida, R;
Publicação
Iberian Conference on Information Systems and Technologies, CISTI
Abstract
The 'Scratch4All' project aims to reduce school dropout rates by encouraging and motivating students in the 1st, 2nd, and 3rd cycles of elementary schools to achieve academic success. In addition, the project promotes true equality of opportunity in terms of educational resources. A learning environment that contributes positively to the improvement of educational results is created through the use of new technologies, specifically programming in the Scratch language and robotics. Impact indicators were developed and used as project evaluation tools based on Theory of Change. This paper presents and analyzes the changes observed from the perspective of the project's teachers' stakeholders during the 2020/2021 school year. This group of beneficiaries is critical to the project's success and continuation, not only because of the special relationship they have with the students, but also with their families and the school. The assessment of impact is very positive in terms of indicators such as school success and motivation, particularly in Mathematics and Portuguese Language, as well as in the reduction of inequalities, access to new technologies, and contribution to gender equality. © 2023 ITMA.
2023
Autores
Pauperio, J; Gonzalez, LM; Martinez, J; Gonzalez, M; Martins, FM; Verissimo, J; Puppo, P; Pinto, J; Chaves, C; Pinho, CJ; Grosso-Silva, JM; Quaglietta, L; Silva, TL; Sousa, P; Alves, PC; Fonseca, N; Beja, P; Ferreira, S;
Publicação
BIODIVERSITY DATA JOURNAL
Abstract
BackgroundThe Trichoptera are an important component of freshwater ecosystems. In the Iberian Peninsula, 380 taxa of caddisflies are known, with nearly 1/3 of the total species being endemic in the region. A reference collection of morphologically identified Trichoptera specimens, representing 142 Iberian taxa, was constructed. The InBIO Barcoding Initiative (IBI) Trichoptera 01 dataset contains records of 438 sequenced specimens. The species of this dataset correspond to about 37% of Iberian Trichoptera species diversity. Specimens were collected between 1975 and 2018 and are deposited in the IBI collection at the CIBIO (Research Center in Biodiversity and Genetic Resources, Portugal) or in the collection Marcos A. Gonzalez at the University of Santiago de Compostela (Spain).New informationTwenty-nine species, from nine different families, were new additions to the Barcode of Life Data System (BOLD). A success identification rate of over 80% was achieved when comparing morphological identifications and DNA barcodes for the species analysed. This encouraging step advances incorporation of informed Environmental DNA tools in biomonitoring schemes, given the shortcomings of morphological identifications of larvae and adult Caddisflies in such studies. DNA barcoding was not successful in identifying species in six Trichoptera genera: Hydropsyche (Hydropsychidae), Athripsodes (Leptoceridae), Wormaldia (Philopotamidae), Polycentropus (Polycentropodidae) Rhyacophila (Rhyacophilidae) and Sericostoma (Sericostomatidae). The high levels of intraspecific genetic variability found, combined with a lack of a barcode gap and a challenging morphological identification, rendered these species as needing additional studies to resolve their taxonomy.
2023
Autores
Abolpour, R; Torabi, K; Dehghani, M; Vafamand, N; Javadi, MS; Wang, F; Catalao, JPS;
Publicação
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
Abstract
This article addresses the topic of frequency regulation of a single-area power system connected to an electric vehicle (EV) aggregator over a non-ideal communication network. It is considered that the command control action is received by the EV aggregator with constant delay and the power system includes uncertain parameters. Due to the presence of uncertainties and the delay term, the frequency regulation problem is non-convex and hard to solve. The present approaches in the literature convert the non-convex control design problem into a convex problem with a set of Linear Matrix Inequalities (LMIs), which is conservative and in many cases results infeasibility. In this paper, an innovative iterative algorithm, called direct search, is employed for the time-delayed system to design the unknown parameters of a pre-assumed controller. The controller choice is not limited and various controllers' structures can be assumed. Without loss of generality, a proportional-integral (PI) controller is designed. The novel direct search algorithm can determine a feasible solution whenever at least one solution lays in the design space. Hence, by selecting a wide design space, we can anticipate that the PI controller guarantees closed-loop stability. Numerical simulations are carried out to demonstrate the performance of the developed controller compared to the state-of-the-art approach.
2023
Autores
Shahrabadi, S; Gonzalez, D; Sousaa, N; Adao, T; Peres, E; Magalhaes, L;
Publicação
Procedia Computer Science
Abstract
2023
Autores
Moreno, T; Almeida, A; Toscano, C; Ferreira, F; Azevedo, A;
Publicação
PRODUCTION AND MANUFACTURING RESEARCH-AN OPEN ACCESS JOURNAL
Abstract
The manufacturing industry faces a new revolution, grounded on the intense digitalization of assets and industrial processes and the increasing computation capabilities imposed by the new data-driven digital architectures. This reality has been promoting the Digital Twin concept and its importance in the industrial companies' business models. However, with these new opportunities, also new threads may rise, mainly related to industrial data protection and sovereignty. Therefore, this research paper will demonstrate the International Data Spaces reference model's application to overcome these limitations. Following a pilot study with a Portuguese machine producer/maintainer enterprise, this paper will demonstrate the development of a cutting and bending machine Digital Twin, leveraged on an International Data Spaces infrastructure for interoperability, for the plastic and metal industry and its importance to introduce this machine manufacturing company in a new business-to-business marketplace from the EU project Market 4.0.
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