Approximate system of equations for describing nonstationary natural concentration convection in binary gas mixtures

1980 ◽  
Vol 15 (5) ◽  
pp. 679-683 ◽  
Author(s):  
D. A. Nikulin ◽  
G. S. Potekhin ◽  
M. Kh. Strelets
Keyword(s):  
Gas Mixtures ◽  
System Of Equations ◽  
Natural Concentration ◽  
Approximate System ◽  
Concentration Convection

scholarly journals FEATURES OF ISOTHERMAL MULTICOMPONENT MIXING OF GAS MIXTURES CONTAINING METHANES AT CONVECTIVE INSTABILITY

2020 ◽  
Vol 71 (3) ◽  
pp. 118-122
Author(s):  
V.N. Kossov ◽  
◽  
V. Mukamedenkyzy ◽  
А. Zhussanbayeva ◽  
◽  
...  
Keyword(s):  
Convective Instability ◽  
Vertical Channel ◽  
Initial Mixture ◽  
Gas Mixtures ◽  
Convective Mixing ◽  
Boundary Relation ◽  
Concentration Convection ◽  
Calculation Results ◽  
The Difference ◽  
Rayleigh Numbers

The features of the change in the regimes "diffusion-gravitational concentration convection" in isothermal ternary gas mixtures have been studied experimentally and numerically. It is shown that, at a certain pressure, due to the difference in the diffusion coefficients of the components, an instability of mechanical equilibrium arises, leading to the appearance of structured convective formations. Calculation results are compared with experimental data on the location of the instability boundaries in the studied gas mixtures. Intensity of convective mixing is also influenced by the content of the component with the highest molecular weight in the initial mixture. In terms of Rayleigh numbers, a boundary relation is obtained that determines the regime change. The solution of the problem of multicomponent mixing in a cylindrical vertical channel of finite height with solid and impermeable boundaries for the substance made it possible to determine the concentration distribution along the length.

On the structural organization of biological pumps and channels

1984 ◽  
Vol 42 ◽  
pp. 138-141
Author(s):  
G. Zampighi ◽  
M. Kreman
Keyword(s):  
Active Transport ◽  
Transport System ◽  
Plasma Membranes ◽  
Transport Proteins ◽  
Molecular Organization ◽  
Passive Transport ◽  
Concentration Gradients ◽  
Cell Functions ◽  
Natural Concentration ◽  
Active Transport System

The plasma membranes of most animal cells contain transport proteins which function to provide passageways for the transported species across essentially impermeable lipid bilayers. The channel is a passive transport system which allows the movement of ions and low molecular weight molecules along their concentration gradients. The pump is an active transport system and can translocate cations against their natural concentration gradients. The actions and interplay of these two kinds of transport proteins control crucial cell functions such as active transport, excitability and cell communication. In this paper, we will describe and compare several features of the molecular organization of pumps and channels. As an example of an active transport system, we will discuss the structure of the sodium and potassium ion-activated triphosphatase [(Na+ +K+)-ATPase] and as an example of a passive transport system, the communicating channel of gap junctions and lens junctions.

Canonical Submersion and Lie Homomorphisms Normal Subgroup

2020 ◽  
Vol 23 (1) ◽  
pp. 97-101
Author(s):  
Mikhail Petrichenko ◽  
Dmitry W. Serow
Keyword(s):  
Normal Subgroup ◽  
Canonical System ◽  
System Of Equations ◽  
Core Group ◽  
The Core ◽  
Switch Group

Normal subgroup module f (module over the ring F = [ f ] 1; 2-diffeomorphisms) coincides with the kernel Ker Lf derivations along the field. The core consists of the trivial homomorphism (integrals of the system v = x = f (t; x )) and bundles with zero switch group Lf , obtained from the condition ᐁ( ω × f ) = 0. There is the analog of the Liouville for trivial immersion. In this case, the core group Lf derivations along the field replenished elements V ( z ), such that ᐁz = ω × f. Hence, the core group Lf updated elements helicoid (spiral) bundles, in particular, such that f = ᐁU. System as an example Crocco shown that the canonical system does not permit the trivial embedding: the canonical system of equations are the closure of the class of systems that permit a submersion.

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