Convective instability of directional crystallization in a forced flow: The role of brine channels in a mushy layer on nonlinear dynamics of binary systems

2011 ◽  
Vol 54 (5-6) ◽  
pp. 1144-1149 ◽  
Author(s):  
D.V. Alexandrov ◽  
A.P. Malygin
Keyword(s):  
Nonlinear Dynamics ◽  
Convective Instability ◽  
Binary Systems ◽  
Forced Flow ◽  
Mushy Layer ◽  
Directional Crystallization

scholarly journals Solute Driven Transient Convection in Layered Porous Media

2021 ◽  
pp. 3-9
Author(s):  
Emmanuel E. Luther ◽  
Seyed M. Shariatipour ◽  
Michael C. Dallaston ◽  
Ran Holtzman
Keyword(s):  
Convective Instability ◽  
Onset Time ◽  
Fluid Phase ◽  
Deep Saline Aquifer ◽  
Research Attention ◽  
Storage Security ◽  
Permeability Distribution ◽  
Layered Porous Media ◽  
Geological Formations

AbstractCO2 geological sequestration has been proposed as a climate change mitigation strategy that can contribute towards meeting the Paris Agreement. A key process on which successful injection of CO2 into deep saline aquifer relies on is the dissolution of CO2 in brine. CO2 dissolution improves storage security and reduces risk of leakage by (i) removing the CO2 from a highly mobile fluid phase and (ii) triggering gravity-induced convective instability which accelerates the downward migration of dissolved CO2. Our understanding of CO2 density-driven convection in geologic media is limited. Studies on transient convective instability are mostly in homogeneous systems or in systems with heterogeneity in the form of random permeability distribution or dispersed impermeable barriers. However, layering which exist naturally in sedimentary geological formations has not received much research attention on transient convection. Therefore, we investigate the role of layering on the onset time of convective instability and on the flow pattern beyond the onset time during CO2 storage. We find that while layering has no significant effect on the onset time, it has an impact on the CO2 flux. Our findings suggest that detailed reservoir characterisation is required to forecast the ability of a formation to sequester CO2.

scholarly journals Microtubules: A network for solitary waves

2017 ◽  
Vol 82 (5) ◽  
pp. 469-481 ◽  
Author(s):  
Slobodan Zdravkovic
Keyword(s):  
Nonlinear Dynamics ◽  
Differential Equation ◽  
Nonlinear Differential Equation ◽  
Solitary Waves ◽  
Discrete Approximations ◽  
Mathematical Methods ◽  
In Cells

In the present paper we deal with nonlinear dynamics of microtubules. The structure and role of microtubules in cells are explained as well as one of models explaining their dynamics. Solutions of the crucial nonlinear differential equation depend on used mathematical methods. Two commonly used procedures, continuum and semi-discrete approximations, are explained. These solutions are solitary waves usually called as kink solitons, breathers and bell-type solitons.

scholarly journals Eccentric grazing envelope evolution towards Type IIb supernova progenitors

2020 ◽  
Vol 497 (1) ◽  
pp. 855-864
Author(s):  
Dmitry Shishkin ◽  
Noam Soker
Keyword(s):  
Parameter Space ◽  
Binary Systems ◽  
Circular Orbits ◽  
High Eccentricity ◽  
Mass Removal ◽  
Common Envelope ◽  
Hydrogen Mass ◽  
Very High ◽  
Initial Orbit

ABSTRACT We simulate the evolution of eccentric binary systems in the frame of the grazing envelope evolution (GEE) channel for the formation of Type IIb supernovae (SNe IIb), and find that extra mass removal by jets increases the parameter space for the formation of SNe IIb in this channel. To explore the role of eccentricity and the extra mass removal by jets, we use the stellar evolutionary code mesa binary. The initial primary and secondary masses are M1, i = 15 and M2, i = 2.5 M⊙. We examine initial semimajor axes of 600–1000 R⊙, and eccentricities of e = 0–0.9. Both Roche lobe overflow (RLOF) and mass removal by jets, followed by a wind, leave a hydrogen mass in the exploding star of MH, f ≈ 0.05 M⊙, compatible with an SN IIb progenitor. When the initial orbit is not circular, the final orbit might have a very high eccentricity. In many cases, with and without the extra mass removal by jets, the system can enter a common envelope evolution (CEE) phase, and then gets out from it. For some ranges of eccentricities, the jets are more efficient in preventing the CEE. Despite the large uncertainties, extra mass removal by jets substantially increases the likelihood of the system to get out from a CEE. This strengthens earlier conclusions for circular orbits. In some cases, RLOF alone, without mass removal by jets, can form SN IIb progenitors. We estimate that the extra mass removal by jets in the GEE channel increases the number of progenitors relative to that by RLOF alone by about a factor of 2.

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