Results 61 to 70 of about 76,745 (212)

Immersion and Invariance Based Adaptive Backstepping Control for Body-Fixed Hovering Over an Asteroid

IEEE Access, 2019
An adaptive control law is proposed in this paper for body-fixed hovering over an asteroid with an unknown gravity field and an unknown rotation rate. The unknown parameters and irregular shape of an asteroid make the hovering problem challenging.
Bo Zhang, Yuanli Cai
doaj   +1 more source

Predicting Performance of Hall Effect Ion Source Using Machine Learning

Advanced Intelligent Systems, Volume 7, Issue 3, March 2025.
This study introduces HallNN, a machine learning tool for predicting Hall effect ion source performance using a neural network ensemble trained on data generated from numerical simulations. HallNN provides faster and more accurate predictions than numerical methods and traditional scaling laws, making it valuable for designing and optimizing Hall ...
Jaehong Park, Guentae Doh, Dongho Lee, Youngho Kim, Changmin Shin, Su‐Jin Shin, Young‐Chul Ghim, Sanghoo Park, Wonho Choe   +8 more
wiley   +1 more source

Pyroxene and Hydroxyl Signatures in Vesta Newly Calibrated Data from Dawn Mission

Universe, 2023
Thanks to the VIR spectrometer onboard NASA’s Dawn spacecraft, which orbited Vesta in 2011–2012, thousands of hyperspectral images of its surface have been collected.
Giuseppe Massa, Andrea Longobardo, Ernesto Palomba, Marianna Angrisani, Chiara Gisellu, Fabrizio Dirri, Maria Cristina De Sanctis, Andrea Raponi, Filippo Giacomo Carrozzo, Mauro Ciarniello   +9 more
doaj   +1 more source

Properties of rubble-pile asteroid (101955) Bennu from OSIRIS-REx imaging and thermal analysis

Nature Astronomy, 2019
Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces.
D. Dellagiustina, J. Emery, D. Golish, B. Rozitis, C. Bennett, K. Burke, R. Ballouz, K. Becker, P. Christensen, C. D. Drouet d’Aubigny, V. Hamilton, D. Reuter, B. Rizk, A. Simon, E. Asphaug, J. Bandfield, O. Barnouin, M. Barucci, E. Bierhaus, R. Binzel, W. Bottke, N. Bowles, H. Campins, B. C. Clark, B. Clark, H. Connolly, M. Daly, J. de León, M. Delbo', J. Deshapriya, C. Elder, S. Fornasier, C. Hergenrother, E. Howell, E. Jawin, H. Kaplan, T. Kareta, L. Corre, J.-Y. Li, J. Licandro, L. Lim, P. Michel, J. Molaro, M. Nolan, M. Pajola, M. Popescu, J. L. Rizos Garcia, A. Ryan, S. Schwartz, N. Shultz, M. Siegler, P. H. Smith, E. Tatsumi, C. Thomas, K. Walsh, C. Wolner, X.-D. Zou, D. Lauretta, the OSIRIS-REx Team   +58 more
semanticscholar   +1 more source

High atmospheric pressure rescues plant growth under humidity stress: A model for climate‐resilient deep underground agriculture

Deep Underground Science and Engineering, EarlyView.
High atmospheric pressure (120 kPa) in deep underground counteracts humidity‐induced physiological stress in plants, stabilizing water balance and enhancing antioxidative defenses. This synergy boosts biomass despite elevated humidity, demonstrating sustainable deep underground agriculture potential under climate uncertainty.
Yuxin He, Linglu Xu, Xiao Tan, Wenhua Zhuang, Naiwen Li, Chao Liu, Bo Tan   +6 more
wiley   +1 more source

Embryonic development of the Mediterranean starfish Hacelia attenuata

Developmental Dynamics, EarlyView.
Abstract Background Starfish play essential ecological roles as predators and ecosystem regulators; however, detailed developmental descriptions exist for only a handful of species, none of which are from the Mediterranean Sea. Results In this study, we provide the first full account of the development of the Mediterranean starfish Hacelia attenuata ...
Silvia Caballero‐Mancebo, Laurent Gilletta, Janet Chenevert, Stefania Castagnetti   +3 more
wiley   +1 more source

Thermochemical equilibrium calculations of high-temperature O2 generation on the early Earth: Giant asteroid impacts on land [PDF]

Journal of the Serbian Chemical Society, 2003
Earth’s atmosphere is composed primarily of N2 and O2. The origin of free O2 in the early Earth’s atmosphere is still subject of considerable debate.1 Theoretical models suggest that the initial form of free O2 in the atmosphere has been oceanic H2O ...
PAVLE I. PREMOVIC
doaj  

Thermochemical equilibrium calculations of high-temperature O2 generation on the early Earth: Giant asteroid impact on land [PDF]

Journal of the Serbian Chemical Society, 2003
Earth’s atmosphere is composed primarily of N2 and O2. The origin of free O2 in the early Earth’s atmosphere is still subject of considerable debate.1 Theoretical models suggest that the initial form of free O2 in the atmosphere has been oceanic H2O ...
Premović Pavle I.
doaj   +1 more source

Local Structures of Se and Br in Cretaceous–Paleogene Boundary Sediments and Concentration Effects of Ferrihydrite Originating From Impact Ejecta

Geological Journal, EarlyView.
Chemical states of Se and Br atoms in the KPg boundary sediments from Stevns Klint were studied using XAFS spectroscopy. The high concentrations of Se4+ could become an index of the degree to which the global environment was soiled with dust and ash derived from impact ejecta or volcanic eruptions.
Kei‐ichiro Murai, Akira Yoshiasa, Ginga Kitahara, Makoto Tokuda, Satoko Ishimaru, Toshihiro Moriga   +5 more
wiley   +1 more source

Heterogeneous mass distribution of the rubble-pile asteroid (101955) Bennu

Science Advances, 2020
The asteroid (101955) Bennu has a heterogeneous internal mass distribution with an underdense center and equatorial bulge. The gravity field of a small body provides insight into its internal mass distribution.
D. Scheeres, A. French, P. Tricarico, S. Chesley, Y. Takahashi, D. Farnocchia, J. McMahon, D. Brack, A. Davis, R.-L. Ballouz, E. R. Jawin, B. Rozitis, J. Emery, A. Ryan, R. Park, B. Rush, N. Mastrodemos, B. Kennedy, J. Bellerose, D. Lubey, D. Velez, A. T. Vaughan, J. Leonard, J. Geeraert, B. Page, P. Antreasian, E. Mazarico, K. Getzandanner, D. Rowlands, M. Moreau, J. Small, D. Highsmith, S. Goossens, E. Palmer, J. Weirich, R. Gaskell, O. Barnouin, M. Daly, J. Seabrook, M. A. Al Asad, L. Philpott, C. L. Johnson, C. Hartzell, V. Hamilton, P. Michel, K. Walsh, M. Nolan, D. Lauretta   +47 more
semanticscholar   +1 more source