Parametric decay of Alfvén waves at parallel and oblique propagation: Kinetic effects and transverse couplings

2012 ◽  
Author(s):  
L. Matteini
Keyword(s):  
Parametric Decay ◽  
Oblique Propagation ◽  
Kinetic Effects ◽  
Propagation Kinetic

scholarly journals On the parametric decay of waves in magnetized plasmas

2009 ◽  
Vol 75 (1) ◽  
pp. 9-13 ◽  
Author(s):  
G. BRODIN ◽  
L. STENFLO
Keyword(s):  
General Theory ◽  
Magnetized Plasmas ◽  
Wave Interactions ◽  
Parametric Decay ◽  
Cold Plasmas ◽  
Kinetic Effects

AbstractWe reconsider the theory for three-wave interactions in cold plasmas. In particular, we demonstrate that previously overlooked formulations of the general theory are highly useful when deriving concrete expressions for specific cases. We also point out that many previous results deduced directly from the basic plasma equations contain inappropriate approximations leading to unphysical results. Finally, generalizations to more elaborate plasma models containing, for example, kinetic effects are given.

scholarly journals Parametric decay of parallel and oblique Alfvén waves in the expanding solar wind

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
L. Del Zanna ◽  
L. Matteini ◽  
S. Landi ◽  
A. Verdini ◽  
M. Velli
Keyword(s):  
Solar Wind ◽  
Background Field ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Parametric Decay ◽  
Direct Excitation ◽  
Oblique Propagation ◽  
Polarized Waves ◽  
Parallel Propagation ◽  
Local Background

The long-term evolution of large-amplitude Alfvén waves propagating in the solar wind is investigated by performing two-dimensional MHD simulations within the expanding box model. The linear and nonlinear phases of the parametric decay instability are studied for both circularly polarized waves in parallel propagation and for arc-polarized waves in oblique propagation. The non-monochromatic case is also considered. In the oblique case, the direct excitation of daughter modes transverse to the local background field is found for the first time in an expanding environment, and this transverse cascade seems to be favored for monochromatic mother waves. The expansion effect reduces the instability growth rate, and it can even suppress its onset for the lowest frequency modes considered here, possibly explaining the persistence of these outgoing waves in the solar wind.

Intrinsic kinetic effects during martensitic transformations

2003 ◽  
Vol 112 ◽  
pp. 133-137 ◽  
Author(s):  
A. Fraile-Rodriguez ◽  
P. P. Rodriguez ◽  
R. B. Pérez-Saez ◽  
A. Lopez-Echarri ◽  
J. San Juan
Keyword(s):  
Martensitic Transformations ◽  
Kinetic Effects ◽  
Intrinsic Kinetic

The Kinetic Effects, Caused by Thickness Fluctuations of Quantum Semiconductor Wire

2017 ◽  
Vol 9 (2) ◽  
pp. 02024-1-02024-4
Author(s):  
M. A. Ruvinskii ◽  
◽  
B. M. Ruvinskii ◽  
O. B. Kostyuk ◽  
◽  
...  
Keyword(s):  
Quantum Semiconductor ◽  
Kinetic Effects

Unraveling Kinetic Effects during Photoelectrochemical Mineralization of Phenols. Rutile:Anatase TiO2 Nanotube Photoanodes under Thin-Layer Conditions

2020 ◽  
Author(s):  
Dalia Leon ◽  
Alberto Maimone ◽  
David Carvajal ◽  
Lorean Madriz ◽  
Benjamín R. Scharifker ◽  
...  
Keyword(s):  
Thin Layer ◽  
Tio2 Nanotube ◽  
Kinetic Effects

scholarly journals Modelling of Microstructure Evolution during Laser Processing of Intermetallic Containing Ni-Al Alloys

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1051
Author(s):  
Mohammad Amin Jabbareh ◽  
Hamid Assadi
Keyword(s):  
Additive Manufacturing ◽  
Rapid Solidification ◽  
Microstructure Evolution ◽  
Phase Field ◽  
Laser Processing ◽  
Field Model ◽  
Phase Field Model ◽  
Intermetallic Phases ◽  
Al Alloy ◽  
Kinetic Effects

There is a growing interest in laser melting processes, e.g., for metal additive manufacturing. Modelling and numerical simulation can help to understand and control microstructure evolution in these processes. However, standard methods of microstructure simulation are generally not suited to model the kinetic effects associated with rapid solidification in laser processing, especially for material systems that contain intermetallic phases. In this paper, we present and employ a tailored phase-field model to demonstrate unique features of microstructure evolution in such systems. Initially, the problem of anomalous partitioning during rapid solidification of intermetallics is revisited using the tailored phase-field model, and the model predictions are assessed against the existing experimental data for the B2 phase in the Ni-Al binary system. The model is subsequently combined with a Potts model of grain growth to simulate laser processing of polycrystalline alloys containing intermetallic phases. Examples of simulations are presented for laser processing of a nickel-rich Ni-Al alloy, to demonstrate the application of the method in studying the effect of processing conditions on various microstructural features, such as distribution of intermetallic phases in the melt pool and the heat-affected zone. The computational framework used in this study is envisaged to provide additional insight into the evolution of microstructure in laser processing of industrially relevant materials, e.g., in laser welding or additive manufacturing of Ni-based superalloys.

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