A small number of copepod species have adapted to an existence in the extreme habitat of hypersaline water. 13 copepod species have been recorded in the hypersaline waters of Crimea (the largest peninsula in the Blac...A small number of copepod species have adapted to an existence in the extreme habitat of hypersaline water. 13 copepod species have been recorded in the hypersaline waters of Crimea (the largest peninsula in the Black Sea with over 50 hypersaline lakes). Summarizing our own and literal_re data, the author concludes that the Crimean extreme environment is not an exception: copepod species dwell in hypersaline waters worldwide. There are at least 26 copepod species around the world living at salinity above 100; among them 12 species are found at salinity higher than 200. In the Crimea Cletocamptus retrogressus is found at salinity 360×10^-3 (with a density of 1 320 individuals/m^3) and Arctodiaptomus salinus at salinity 300×10^-3 (with a density of 343 individuals/m^3). Those species are probably the most halotolerant copepod species in the world. High halotolerance of osmoconforming copepods may be explained by exoosmolyte consumption, mainly with food. High tolerance to many factors in adults, availability of resting stages, and an opportunity of long-distance transportation of resting stages by birds and/or winds are responsible for the wide geographic distribution of these halophilic copepods.展开更多
This paper deals with the problem of theoretical identification of the residence time distribution (RTD) characteristics of a straight pipe at laminar pulsatile flow, if tracer diffusion can be neglected. This situa...This paper deals with the problem of theoretical identification of the residence time distribution (RTD) characteristics of a straight pipe at laminar pulsatile flow, if tracer diffusion can be neglected. This situation is typical for micro-apparatuses (e.g. fluidic element) and also for flow in large arteries. Residence time distribution based on velocity profiles at pulsatile flow of a Newtonian liquid in a rigid pipe will be derived theoretically and compared with the well known results for a constant flow rate E(τ) = τ-^2/2τ^3 at τ 〉 τ^-/2, where E (τ) is differential distribution, x is residence time and τ^- is the mean residence time. The following part of the paper deals stimulus response experimental techniques using tracers. The principal problem related to laminar and convection dominated pulsatile flows is discussed: Can the impulse response also be identified with the actual residence time distribution in the case of variable flow? The general answer is no, and differences between RTD and impulse responses are evaluated as a function of the frequency and amplitude of pulsatile flows.展开更多
文摘A small number of copepod species have adapted to an existence in the extreme habitat of hypersaline water. 13 copepod species have been recorded in the hypersaline waters of Crimea (the largest peninsula in the Black Sea with over 50 hypersaline lakes). Summarizing our own and literal_re data, the author concludes that the Crimean extreme environment is not an exception: copepod species dwell in hypersaline waters worldwide. There are at least 26 copepod species around the world living at salinity above 100; among them 12 species are found at salinity higher than 200. In the Crimea Cletocamptus retrogressus is found at salinity 360×10^-3 (with a density of 1 320 individuals/m^3) and Arctodiaptomus salinus at salinity 300×10^-3 (with a density of 343 individuals/m^3). Those species are probably the most halotolerant copepod species in the world. High halotolerance of osmoconforming copepods may be explained by exoosmolyte consumption, mainly with food. High tolerance to many factors in adults, availability of resting stages, and an opportunity of long-distance transportation of resting stages by birds and/or winds are responsible for the wide geographic distribution of these halophilic copepods.
文摘This paper deals with the problem of theoretical identification of the residence time distribution (RTD) characteristics of a straight pipe at laminar pulsatile flow, if tracer diffusion can be neglected. This situation is typical for micro-apparatuses (e.g. fluidic element) and also for flow in large arteries. Residence time distribution based on velocity profiles at pulsatile flow of a Newtonian liquid in a rigid pipe will be derived theoretically and compared with the well known results for a constant flow rate E(τ) = τ-^2/2τ^3 at τ 〉 τ^-/2, where E (τ) is differential distribution, x is residence time and τ^- is the mean residence time. The following part of the paper deals stimulus response experimental techniques using tracers. The principal problem related to laminar and convection dominated pulsatile flows is discussed: Can the impulse response also be identified with the actual residence time distribution in the case of variable flow? The general answer is no, and differences between RTD and impulse responses are evaluated as a function of the frequency and amplitude of pulsatile flows.