scholarly journals Problems with the Pulsation Mode Selection Mechanism in the Lower Instability Strip (Observations and Theory)

2002 ◽  
Vol 185 ◽  
pp. 388-391
Author(s):  
M. Breger ◽  
A.A. Pamyatnykh
Keyword(s):  
Kinetic Energy ◽  
Mode Selection ◽  
Simple Rule ◽  
Selection Mechanism ◽  
Outer Envelope ◽  
Instability Strip ◽  
Perfect Agreement ◽  
Pulsation Mode ◽  
Scuti Stars ◽  
Selection Of

AbstractWe examine the severe disagreement between the number of predicted and observed pulsation modes for δ Scuti stars. The selection of nonradial modes trapped in the outer envelope is considered on the basis of kinetic energy arguments. The trapped l = 1 modes for the star 4 CVn are in good, but not perfect agreement with the observations. The trapping of the l = 2 modes is weaker, so that this simple rule of mode selection may apply to l = 1, and possibly not to l = 2 modes.

scholarly journals Mode selection mechanism in traveling and standing waves revealed by Min wave reconstituted in artificial cells

2022 ◽  
Author(s):  
Sakura Takada ◽  
Natsuhiko Yoshinaga ◽  
Nobuhide Doi ◽  
Kei Fujiwara
Keyword(s):  
Mode Selection ◽  
Standing Waves ◽  
Reaction Diffusion ◽  
Wave Mode ◽  
Spatiotemporal Pattern ◽  
Selection Mechanism ◽  
Artificial Cells ◽  
Pattern Formations ◽  
Selection Of ◽  
Wave Modes

Reaction-diffusion coupling (RDc) generates spatiotemporal patterns, including two dynamic wave modes: traveling and standing waves. Although mode selection plays a significant role in the spatiotemporal organization of living cell molecules, the mechanism for selecting each wave mode remains elusive. Here, we investigated a wave mode selection mechanism using Min waves reconstituted in artificial cells, emerged by the RDc of MinD and MinE. Our experiments and theoretical analysis revealed that the balance of membrane binding and dissociation from the membrane of MinD determines the mode selection of the Min wave. We successfully demonstrated that the transition of the wave modes can be regulated by controlling this balance and found hysteresis characteristics in the wave mode transition. These findings highlight a novel role of the balance between activators and inhibitors as a determinant of the mode selection of waves by RDc and depict a novel mechanism in intracellular spatiotemporal pattern formations.

Harmony as licensing

2018 ◽  
Author(s):  
Harry van der Hulst
Keyword(s):  
Vowel Harmony ◽  
Selection Mechanism ◽  
Phonological Structure ◽  
Explicit Theory ◽  
Selection Of

This chapter develops an explicit theory of vowel harmony based on unary elements and lateral and positional licensing which is embedded in a general dependency-based theory of phonological structure (called ‘Radical CV Phonology’). Harmony is analyzed in terms of a licensing requirement, which results in ‘agreement’, both intra-morphemically and inter-morphemically, that is, within the domain of the word In essence, the view put forward is that lexical vowel harmony involves the selection of lexically listed allomorphs. Licensing will be the selection mechanism for the proper allomorph. The chapter discusses the treatment of morpheme-internal harmony, trigger and targets in harmony, and the notion of cyclicity.

scholarly journals Non-Adiabatic Seismic Study of The Thin Convective Envelope of δ Scuti Stars

2004 ◽  
Vol 193 ◽  
pp. 470-473
Author(s):  
M.-A. Dupret ◽  
A. Grigahcène ◽  
R. Garrido ◽  
J. Montalban ◽  
M. Gabriel ◽  
...  
Keyword(s):  
Instability Strip ◽  
Full Spectrum ◽  
Convective Envelope ◽  
Theoretical Predictions ◽  
Mode Stability ◽  
Different Color ◽  
Mixing Length Theory ◽  
Scuti Stars ◽  
Δ Scuti Stars ◽  
Phase Differences

AbstractFor δ Sct stars, the theoretical predictions of a non-adiabatic pulsation code are very dependent on the characteristics of the thin convective envelope of the models (Balona & Evers 1999). The treatment of the non-adiabatic interaction between convection and pulsation also has a significant impact on the results, particularly near the red edge of the instability strip. The non-adiabatic theoretical predictions can be tested upon observations by comparing them to the amplitude ratios and phase differences as observed in different color passbands (Dupret et al. 2003). In the first part of this paper, we compare the results obtained by adopting different treatments of convection in the interior and atmosphere models: mixing-length theory (MLT) and full spectrum of turbulence (FST) (Canuto et al. 1996, CGM). In the second part, we examine the problem of the interaction between convection and pulsation and compare the mode stability obtained with and without including time-dependent convection in our non-adiabatic code.

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