scholarly journals Spreading Speed of Magnetopause Reconnection X-Lines Using Ground-Satellite Coordination

2018 ◽  
Vol 45 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Ying Zou ◽  
Brian M. Walsh ◽  
Yukitoshi Nishimura ◽  
Vassilis Angelopoulos ◽  
J. Michael Ruohoniemi ◽  
...  
2018 ◽  
Vol 45 (11) ◽  
pp. 5268-5273 ◽  
Author(s):  
B. M. Walsh ◽  
D. T. Welling ◽  
Y. Zou ◽  
Y. Nishimura

2016 ◽  
Vol 43 (10) ◽  
pp. 4716-4724 ◽  
Author(s):  
J. P. Eastwood ◽  
T. D. Phan ◽  
P. A. Cassak ◽  
D. J. Gershman ◽  
C. Haggerty ◽  
...  

Author(s):  
Ling Zhou ◽  
Shan Zhang ◽  
Zuhan Liu

In this paper we consider a system of reaction–diffusion–advection equations with a free boundary, which arises in a competition ecological model in heterogeneous environment. The evolution of the free-boundary problem is discussed, which is an extension of the results of Du and Lin (Discrete Contin. Dynam. Syst. B19 (2014), 3105–3132). Precisely, when u is an inferior competitor, we prove that (u, v) → (0, V) as t→∞. When u is a superior competitor, we prove that a spreading–vanishing dichotomy holds, namely, as t→∞, either h(t)→∞ and (u, v) → (U, 0), or limt→∞h(t) < ∞ and (u, v) → (0, V). Moreover, in a weak competition case, we prove that two competing species coexist in the long run, while in a strong competition case, two species spatially segregate as the competition rates become large. Furthermore, when spreading occurs, we obtain some rough estimates of the asymptotic spreading speed.


2007 ◽  
Vol 112 (A11) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. A. Fuselier ◽  
S. M. Petrinec ◽  
K. J. Trattner ◽  
M. Fujimoto ◽  
H. Hasegawa

2021 ◽  
Vol 166 (1) ◽  
pp. 9-13
Author(s):  
Christopher Neil Hulme-Smith ◽  
Vignesh Hari ◽  
Pelle Mellin

AbstractThe spreading of powders into thin layers is a critical step in powder bed additive manufacturing, but there is no accepted technique to test it. There is not even a metric that can be used to describe spreading behaviour. A robust, image-based measurement procedure has been developed and can be implemented at modest cost and with minimal training. The analysis is automated to derive quantitative information about the characteristics of the spread layer. The technique has been demonstrated for three powders to quantify their spreading behaviour as a function of layer thickness and spreading speed.


2017 ◽  
Vol 1 ◽  
pp. 1 ◽  
Author(s):  
Valaire Yatat ◽  
Yves Dumont

This paper deals with the problem of travelling wave solutions in a scalar impulsive FKPP-like equation. It is a first step of a more general study that aims to address existence of travelling wave solutions for systems of impulsive reaction-diffusion equations that model ecological systems dynamics such as fire-prone savannas. Using results on scalar recursion equations, we show existence of populated vs. extinction travelling waves invasion and compute an explicit expression of their spreading speed (characterized as the minimal speed of such travelling waves). In particular, we find that the spreading speed explicitly depends on the time between two successive impulses. In addition, we carry out a comparison with the case of time-continuous events. We also show that depending on the time between two successive impulses, the spreading speed with pulse events could be lower, equal or greater than the spreading speed in the case of time-continuous events. Finally, we apply our results to a model of fire-prone grasslands and show that pulse fires event may slow down the grassland vs. bare soil invasion speed.


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