Recovery of Boundary Functions on External and Internal Open Boundaries in an Open Sea Hydrodynamic Problem

2020 ◽  
Vol 60 (11) ◽  
pp. 1855-1871
Author(s):  
V. I. Agoshkov ◽  
N. R. Lezina ◽  
T. O. Sheloput
Author(s):  
J. Manning
Keyword(s):  

Author(s):  
Mateusz Lisak

The issue of discovery of a sea route to India is one of the most important questions about Indo-Roman trade relations and it has yet to be resolved. Historians tend to focus on who and when made the first open-sea journey, and whether it was a sudden change or a process. Conditions essential for discovery of a new route are not considered (not clear – are not considered here, in this paper?), nor are the circumstances that would have made this journey possible. Another issue (of what?) is the case of the Arabia Eudaimon port. The 1st-century AD Periplus Maris Erythraei states that the port had been ransacked and there was no direct connection between India and Egypt, but that all ships were forced to stop there. Thus the resumption of active trade with India necessitated the lifting of the tentative blockade of Arabia Eudaimon and discovering the trans-oceanic route. The nautical guide, however, does not describe the new repute in the context of the troubles in Bab el-Mandeb, but can we be really sure that these two events were not related? What were the circumstances and conditions that had to be met for it to be possible to discover a new route?


Author(s):  
Irina Mesenzeva ◽  
Irina Mesenzeva ◽  
Elena Sovga ◽  
Elena Sovga ◽  
Tatyana Khmara ◽  
...  

The ability of a bay and gulf ecosystems to self-purification was estimated and the current ecological state of the Sevastopol Bay in whole and the separated parts of the bay was given as an example. A zoning by type of anthropogenic impact subject to the water exchange with the open sea and an influence of the Chernaya River run-off were taken into account. A comparative analysis of assimilation capacity of the most environmentally disadvantaged part of the Sevastopol Bay (the Southern Bay) and the clean water area, bordering on the open sea, was carried out. The hydrodynamic regime of the Sevastopol Bay was described using numerical modelling. The prospect, opportunity and examples of the methodology for assessing the assimilation capacity of marine ecosystems are demonstrated.


2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Imran Talib ◽  
Thabet Abdeljawad

Abstract Our main concern in this article is to investigate the existence of solution for the boundary-value problem $$\begin{aligned}& (\phi \bigl(x'(t)\bigr)'=g_{1} \bigl(t,x(t),x'(t)\bigr),\quad \forall t\in [0,1], \\& \Upsilon _{1}\bigl(x(0),x(1),x'(0)\bigr)=0, \\& \Upsilon _{2}\bigl(x(0),x(1),x'(1)\bigr)=0, \end{aligned}$$ ( ϕ ( x ′ ( t ) ) ′ = g 1 ( t , x ( t ) , x ′ ( t ) ) , ∀ t ∈ [ 0 , 1 ] , ϒ 1 ( x ( 0 ) , x ( 1 ) , x ′ ( 0 ) ) = 0 , ϒ 2 ( x ( 0 ) , x ( 1 ) , x ′ ( 1 ) ) = 0 , where $g_{1}:[0,1]\times \mathbb{R}^{2}\rightarrow \mathbb{R}$ g 1 : [ 0 , 1 ] × R 2 → R is an $L^{1}$ L 1 -Carathéodory function, $\Upsilon _{i}:\mathbb{R}^{3}\rightarrow \mathbb{R} $ ϒ i : R 3 → R are continuous functions, $i=1,2$ i = 1 , 2 , and $\phi :(-a,a)\rightarrow \mathbb{R}$ ϕ : ( − a , a ) → R is an increasing homeomorphism such that $\phi (0)=0$ ϕ ( 0 ) = 0 , for $0< a< \infty $ 0 < a < ∞ . We obtain the solvability results by imposing some new conditions on the boundary functions. The new conditions allow us to ensure the existence of at least one solution in the sector defined by well ordered functions. These ordered functions do not require one to check the definitions of lower and upper solutions. Moreover, the monotonicity assumptions on the arguments of boundary functions are not required in our case. An application is considered to ensure the applicability of our results.


2021 ◽  
Vol 32 (3) ◽  
pp. 486-500
Author(s):  
Yong Yi Zhen ◽  
Ian G. Percival ◽  
Phil Gilmore ◽  
Jodie Rutledge ◽  
Liann Deyssing

Author(s):  
Marie V. Lebour
Keyword(s):  
The West ◽  
Open Sea ◽  

Several Gobius species and also Aphya and Crystallogobius are common near Plymouth, from up the estuaries in the neighbourhood of Saltash to the west and Chelson Meadow to the east, as far as the open sea, well beyond Rame Head and the Eddystone Lighthouse. It has, however, always been difficult to determine the young of the various species as they usually differ very little from one another and it is hoped that the following notes may be a help in the elucidation of the subject.


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