Results 61 to 70 of about 1,037 (263)

White-Dwarf Asteroseismology With the Kepler Space Telescope

Frontiers in Astronomy and Space Sciences, 2020
In the course of their evolution, white-dwarf stars go through at least one phase of variability in which the global pulsations they undergo allow astronomers to peer into their interiors, making it possible to shed light on their deep inner structure ...
Alejandro H. Córsico, Alejandro H. Córsico   +1 more
doaj   +1 more source

Excitation and damping of solar and stellar oscillations [PDF]

Symposium - International Astronomical Union, 1988
Variable stars can be broadly classified into two categories: (a) High amplitude pulsators like Cepheids and RR Lyrae variables, (b) Low amplitude pulsators like Sun and Sun-like stars. The study of stellar pulsations has opened the possibility of using the oscillatory modes to probe the internal structure and dynamics of these stars.
openaire   +1 more source

Optimization of the Production of Rubber Compounds Using Mathematical Models

Advanced Engineering Materials, EarlyView.
Rubber compounds were mixed in a batch internal mixer, and symbolic regression was used to derive mathematical models linking recipe and process parameters to ram path, torque, and mixing quality (incorporation, dispersion, distribution). Subsequent optimization with evolutionary algorithms identified operating conditions that reduce specific energy ...
Anke Bardehle, Andreas Limper, Ulrich Giese, Carlos Lucke, Mario Beiner, Christoph Gögelein, Lisa Leuchtenberger‐Engel, Christian Hopmann   +7 more
wiley   +1 more source

Wave topology of stellar inertial oscillations

Physical Review Research
Inertial waves in convective regions of stars exhibit topological properties linked to a Chern number of 1. The first of these is a unique, unidirectional, prograde oscillation mode within the cavity, which propagates at arbitrarily low frequencies for ...
Armand Leclerc, Guillaume Laibe, Nicolas Perez   +2 more
doaj   +1 more source

Stellar oscillations in TeVeS

Journal of Physics: Conference Series, 2010
In this work we examine the oscillation spectra of neutron stars in TeVeS. As a result with Cowling approximation, we find that the frequencies of fundamental modes in TeVeS could become lager than those expected in general relativity, while the dependence of frequency of higher overtone on gravitational theory is stronger than that of lower modes ...
openaire   +1 more source

Additive Manufacturing of Alumina‐Reinforced Elastomers

Advanced Engineering Materials, EarlyView.
Vat‐photopolymerized elastomers reinforced with platelet‐shaped alumina exhibited preferential orientation, reduced porosity, and significantly enhanced mechanical performance. A 3 wt% platelet loading increased tensile strength from 12.4 to 45.7 MPa, highlighting the critical role of filler morphology in elastomeric VPP composites.
Majid Barzegar Keyvani, Zongwen Fu, Robert Göstl, Hamed Shokri, Carmine Putignano, Gianluca Percoco, Bilal Gökce   +6 more
wiley   +1 more source

High-order Gravity-mode Period Spacing Patterns of Intermediate-mass (1.5 M⊙ < M < 3 M⊙) Main-sequence Stars. I. Perturbative Analysis

The Astrophysical Journal
Theoretical study of the high-order gravity-mode period spacing (Δ P _g ) pattern is relevant to a better understanding of the internal properties of intermediate-mass (1.5 M _⊙  
Yoshiki Hatta, Takashi Sekii
doaj   +1 more source

Stellar Oscillations Network Group – SONG

Journal of Physics: Conference Series, 2008
The Stellar Oscillations Network Group (SONG) is an initiative which aims at designing and building a ground-based network of 1 m telescopes dedicated to the study of phenomena occurring in the time domain. In particular the study of stellar oscillations and the search for and characterisation of extra-solar planets. There will be eight identical nodes
Grundahl, Frank, Arentoft, T., Christensen-Dalsgaard, J., Frandsen, S., Kjeldsen, H., Rasmussen, Per Kjærgaard   +5 more
openaire   +3 more sources

Uniform Amorphization of Crystalline Silicon Surfaces Enabled by Deep Ultraviolet Femtosecond Laser Pulses

Advanced Engineering Materials, EarlyView.
Deep‐UV (258 nm) femtosecond pulses enable uniform amorphous silicon writing on Si(100)/(111) with a six‐fold larger fluence amorphization window than NIR methods. Optimized fluence and overlap yield 20–45 nm uniform and continuous amorphous layers. Microscopy shows sharp interfaces, and real‐time reflectivity reveals nanosecond melt–resolidification ...
Wissal Benali, Magali Gregoire, Matys Guyard, Tatiana Itina, David Grojo, Pol Sopeña   +5 more
wiley   +1 more source

Antisolar Differential Rotation May Have Revived Magnetic Braking in the Subgiant 31 Aquilae

The Astronomical Journal
Recent observations have shown that sufficiently slow rotation disrupts the organization of large-scale magnetic field in older main-sequence stars, leading to weakened magnetic braking (WMB) and a collapse in the efficiency of the global stellar dynamo.
Travis S. Metcalfe, Jennifer L. van Saders, Thomas R. Ayres, Derek Buzasi, Jeremy J. Drake, Ricky Egeland, Rafael A. García, Oleg Kochukhov, Steven H. Saar, Keivan G. Stassun, Sarbani Basu, J. M. Joel Ong, Amalie Stokholm, Timothy R. Bedding, Sylvain N. Breton, Ilya V. Ilyin, Pascal Petit, Marc H. Pinsonneault, Klaus G. Strassmeier   +18 more
doaj   +1 more source