10 research outputs found
Physical and dynamical characterization of the Euphrosyne asteroid Family
The Euphrosyne asteroid family occupies a unique zone in orbital element
space around 3.15 au and may be an important source of the low-albedo
near-Earth objects. The parent body of this family may have been one of the
planetesimals that delivered water and organic materials onto the growing
terrestrial planets. We aim to characterize the compositional properties as
well as the dynamical properties of the family. We performed a systematic study
to characterize the physical properties of the Euphrosyne family members via
low-resolution spectroscopy using the IRTF telescope. In addition, we performed
smoothed-particle hydrodynamics (SPH) simulations and N-body simulations to
investigate the collisional origin, determine a realistic velocity field, study
the orbital evolution, and constrain the age of the Euphrosyne family. Our
spectroscopy survey shows that the family members exhibit a tight taxonomic
distribution, suggesting a homogeneous composition of the parent body. Our SPH
simulations are consistent with the Euphrosyne family having formed via a
reaccumulation process instead of a cratering event. Finally, our N-body
simulations indicate that the age of the family is 280 Myr +180/-80 Myr, which
is younger than a previous estimate.Comment: 10 pages, 13 figures, accepted to be published in A&
Novel layered architecture based on Al
The paper is focused on a very hot topic of SMART materials and their architectures for energy conversion systems designed for conversion of mechanical to electrical energy using the piezoelectric effect. The aim of the study is to increase both the reliability and efficiency of electromechanical conversion compared to standard concepts. Our new design of piezoelectric cantilever is made with multi-layer ceramic composite, where piezoelectric layer BaTiO3 is covered by protective ceramics layers of different residual stresses, where Al2O3 and ZrO2 is used. Utilization of controlled residual stresses into new multi-layer architecture is the key idea and it is crucial for optimal design of the individual layers of the proposed concept. The multi-layer ceramic composite is fabricated by electrophoretic deposition, where the composite is assembled from different ceramic materials during processing and after sintering we get inseparable ceramic laminate consisting of piezoelectric and protective layers of ceramics. This approach of processing multi-layer ceramic material including lead free piezoelectric layers is innovative and has never been published before
Revised Set of Common Base Concepts, EuroWordNet-2 (LE-8328), Deliverable 2D001
En el contexto comunitario deben generarse tres tipos de acciones educativas correspondientes a la tripartición clásica del universo educativo: (1) la educación informal: la propia convivencia que ha de impregnar a los miembros de la comunidad estimulando la imitación creativa de conductas. (2) La educación formal: la escuela ha de potenciar la mediación de la evaluación moral en cualquier acto humano. Ha de contrastar y dar coherencia a los modelos formativos presentados con los modelos presentes en la comunidad y en la sociedad.(3) la educación no formal, la que permite concretizar más las actuaciones: intervenciones socioeducativas de tipo intergeneracional y multitemáticas como las de animación sociocultural que permitan espacios de encuentro, en la realizacion de actividades comunitarias, donde se ponga en juego, los modelos formativos definidos (la moral autónoma) y donde se potencien los valores de la convivencia
A study of the heavy fractions and residues from West Siberian crude oil by thermogravimetric and differential thermal analysis techniques
A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea
(10) Hygiea is the fourth largest main belt asteroid and the only known asteroid whose surface composition appears similar to that of the dwarf planet (1) Ceres1,2, suggesting a similar origin for these two objects. Hygiea suffered a giant impact more than 2 Gyr ago3 that is at the origin of one of the largest asteroid families. However, Hygeia has never been observed with sufficiently high resolution to resolve the details of its surface or to constrain its size and shape. Here, we report high-angular-resolution imaging observations of Hygiea with the VLT/SPHERE instrument (~20 mas at 600 nm) that reveal a basin-free nearly spherical shape with a volume-equivalent radius of 217 ± 7 km, implying a density of 1,944 ± 250 kg m− 3 to 1σ. In addition, we have determined a new rotation period for Hygiea of ~13.8 h, which is half the currently accepted value. Numerical simulations of the family-forming event show that Hygiea’s spherical shape and family can be explained by a collision with a large projectile (diameter ~75–150 km). By comparing Hygiea’s sphericity with that of other Solar System objects, it appears that Hygiea is nearly as spherical as Ceres, opening up the possibility for this object to be reclassified as a dwarf planet. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.P.V., A.D. and B.C. were supported by CNRS/INSU/PNP. M.Broz was supported by grant 18-04514J of the Czech Science Foundation. J.H. and J.D. were supported by grant 18-09470S of the Czech Science Foundation and by the Charles University Research Programme no. UNCE/SCI/023. This project has received funding from the European Union's Horizon 2020 research and innovation programmes under grant agreement nos 730890 and 687378. This material reflects only the authors' views, and the European Commission is not liable for any use that may be made of the information contained herein. TRAPPIST-North is a project funded by the University of Liege, in collaboration with Cadi Ayyad University of Marrakech (Morocco). TRAPPIST-South is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. E.J. and M.G. are F.R.S.-FNRS Senior Research Associates
What is the tensile strength of a ceramic to be used in numerical models for predicting crack initiation?
Novel layered architecture based on Al2O3/ZrO2/BaTiO3 for SMART piezoceramic electromechanical converters
Proceedings of The HKIE Geotechnical Division 42nd Annual Seminar: A New Era of Metropolis and Infrastructure Developments in Hong Kong, Challenges and Opportunities to Geotechnical Engineering
This seminar proceedings contain articles on the various research ideas of the academic community and practitioners presented at The HKIE Geotechnical Division 42nd Annual Seminar (GDAS2022). GDAS2022 was organized by the Geotechnical Division, The Hong Kong Institution of Engineers on 13th May 2022.
Seminar Title: The HKIE Geotechnical Division 42nd Annual SeminarSeminar Acronym: GDAS2022Seminar Date: 13 May 2022Seminar Location: Hong KongSeminar Organizers: Geotechnical Division, The Hong Kong Institution of Engineers
Link to the GDAS2021 Proceedings: Proceedings of The HKIE Geotechnical Division 41st Annual Semina