In this work, we present and analyze a fishery model with a price variation. We take into account the evolution in time of the fish biomass and the harvesting effort, while the price of fish is dependent on supply and demand. Assuming that the price variation occurs at a fast time scale. We assume that the stock and the effort evolution follow a slow time scale.
The purpose of this work was to study the process of adsorption of phosphate on natural and synthesized sorbents, such as aluminosilicates. The sorption properties of natural zeolite for phosphate under static and dynamic conditions were investigated. The zeolite on the basis of the coal fly ash of Dobrotvorskaya heat power plant was synthesized and modified. The equilibrium values of adsorption capacity were determined, and the corresponding isotherms were constructed at a temperature of 20° C. The kinetics of adsorption under mechanical mixing conditions was investigated.
The application of thermodynamic analysis for studying the equilibrium of chemical reactions between components of architectural monuments made of stone and air components of large cities is considered. In order to evaluate the possibility of a chemical reaction, it is necessary to calculate the change in enthalpy, entropy, and Gibbs energy. The heat effect of the reaction (change of the en-thalpea) and the change of entropy have a secondary value for the course of such reactions. The proven values of ΔCр allow us to verify the correctness of the calculations ΔН0Т and ΔS0Т.
Heavy metals in the environment are a source of some concern because of their potential reactivity, toxicity, and mobility in the soil. Zeolites have been used as a adsorbents to prevent potentially toxic metal contamination stemming from mining waste disposal. These materials are characterized by a high cation exchange capacity (CEC) and a predominance of negative charges, favoring their potential utilization in metal cation immobilization. It is widely used in laboratory research and industrial applications. Many physical and chemical processes occur at different interfaces.
The aim of this work was studying the process of phosphate adsorption on natural and synthesized adsorbents such as aluminosilicates. Sorption properties of natural zeolite concerning phosphates in static and dynamic conditions were investigated. It was found that phosphates were absorbed better in an acidic environment. Zeolites based on fly ashes of Dobrotvir heat power plant were synthesized and modified. The equilibrium values of adsorption capacity were established and the proper isotherms at a temperature 20 °C were built.
Statics and kinetics of ammonium nitrogen absorption on natural zeolite were investigated experimentally under periodic conditions. A mathematical kinetics model was developed and a counterion diffusion coefficient was defined. The influence of phosphate compounds and protein on equilibrium and a rate of ammonium ion sorption was investigated
In this paper the basic thermodynamic parameters that have the greatest impact on the efficiency of the separation processes of gas-liquid mixtures and phase equilibrium in such systems are considered. The general characteristics of separation processes based on phase equilibrium are given. The main approaches to the calculation of phase equilibrium and coupled heat are analyzed. Possible ways of gas separation technology improvement and development are explored.