1,608 research outputs found
Unveiling the Intricate Symphony of Nonlinear Pulsation Mode Interactions in High-Amplitude Scuti Stars
People can diagnose the interiors of stars by sensing their pulsations.
Pulsation modes, which are determined by the internal state and structure of a
star, are typically considered stable over short timescales. These independent
pulsation modes have been used in asteroseismology to reconstruct the interior
structure of stars. Here, we report the discovery of peculiar pulsation mode
interaction details in the high-amplitude Scuti star KIC 6382916
(J19480292+4146558), challenging the reliability of independent pulsation modes
as indicators of the star's internal structure. Through analysis of archival
data, we found distinct variations in amplitudes and frequencies of three
independent pulsation modes and their harmonics/combinations over approximately
20 days. These variations can reach amplitudes of about 140% and frequency
variations of about 12%. Correlation analysis of amplitude and frequency
variations revealed additional pulsation mode interaction details and patterns.
Notably, our findings regarding the phenomena related to harmonics of
independent pulsation modes challenge the traditional understanding in this
area. These discoveries serve as cornerstones for future research and advance
nonlinear asteroseismology.Comment: 16 pages, 10 figures, 1 tabl
Solid reconstruction using recognition of quadric surfaces from orthographic views
International audienceThe reconstruction of 3D objects from 2D orthographic views is crucial for maintaining and further developing existing product designs. A B-rep oriented method for reconstructing curved objects from three orthographic views is presented by employing a hybrid wire-frame in place of an intermediate wire-frame. The Link-Relation Graph (LRG) is introduced as a multi-graph representation of orthographic views, and quadric surface features (QSFs) are defined by special basic patterns of LRG as well as aggregation rules. By hint-based pattern matching in the LRGs of three orthographic views in an order of priority, the corresponding QSFs are recognized, and the geometry and topology of quadric surfaces are recovered simultaneously. This method can handle objects with interacting quadric surfaces and avoids the combinatorial search for tracing all the quadric surfaces in an intermediate wire-frame by the existing methods. Several examples are provided
Using Hands-on Experiences including Various Forms of ARTS to Increase Ninth-Grade Female Students’ Interest in STEM – Final Results
Due to the ever-growing number of employment opportunities in the science technology engineering and math fields increasing emphasis is placed on STEM education at all levels This paper reports on research focused on increasing STEM interest and awareness in ninth- grade minority female students primarily from a low socioeconomic background Thirty-seven female students participated in this research study They attended fifteen hour-long sessions of STEM-infused hands-on workshops presented by university professors in the College of Education and the College of Arts and Sciences The workshops took place during school hours adding to their regular curriculum The school does not currently have an arts program although the founder of the school is a music artist Therefore the workshops incorporated the arts as the central theme while the lessons were delivered in biology chemistry engineering and mathematics The study is motivated by the need to close the achievement gap and improve the representation of women and minorities in STEM fields Data were collected through surveys assessments and interviews and analyzed using quantitative and qualitative methods The significance of the study lies in the potential to inspire underserved females to enter the STEM field
A description of the transverse momentum distributions of charged particles produced in heavy ion collisions at RHIC and LHC energies
By assuming the existing of memory effects and long-range interactions in the
hot and dense matter produced in high energy heavy ion collisions, the
nonextensive statistics together with the relativistic hydrodynamics including
phase transition is used to discuss the transverse momentum distributions of
charged particles produced in heavy ion collisions. It is shown that the
combined contributions from nonextensive statistics and hydrodynamics can give
a good description to the experimental data in Au+Au collisions at sqrt(s_NN )=
200 GeV and in Pb+Pb collisions at sqrt(s_NN) )= 2.76 TeV for pi^(+ -) , K^(+
-) in the whole measured transverse momentum region, and for p(p-bar) in the
region of p_T<= 2.0 GeV/c. This is different from our previous work, where, by
using the conventional statistics plus hydrodynamics, the describable region is
only limited in p_T<= 1.1 GeV/c.Comment: 14 pages, 3 figures, 2 table
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