INTEGRATION OF THE NUMERICAL SOLUTION MODULE OF THE KINETIC EQUATION INTO THE CFD PACKAGE FOR THE VOLUME CONDENSATION PROBLEM OF THE VAPOR-GAS MIXTURE FLOW THROUGH A NOZZLE

Objective. Integrating the numerical solution module of the kinetic equation for the droplet size distribution function in a CFD package. Application of the module to volumetric condensation at the supersonic flow of a vapor-gas mixture through a nozzle in a two-dimensional formulation, comparison of the results with experimental data of third-party authors.Methods. In this paper, the problem of volume condensation in the supersonic flow of a vapor-gas mixture through a nozzle is solved by finite element methods in a two-dimensional formulation using user-defined functions.Results. A module for the numerical solution of the kinetic equation for the droplet size distribution function is presented as a user-defined function integrated into the calculated CFD package.Conclusion. The module application to volumetric condensation for a vapor-gas mixture flow through the nozzle gave a qualitative agreement in all areas and a quantitative agreement in the area of intense condensation with measurement data. The distributions of temperatures, pressures, and the degree of supersaturation are presented both along the central axis and on the plane bounded by the contour of the computational domain. It is shown that the module does not depend on the solver type (stationary or non-stationary).

Cl − and K + channels and their role in primary brain tumour biology

Profound cell volume changes occur in primary brain tumours as they proliferate, invade surrounding tissue or undergo apoptosis. These volume changes are regulated by the flux of Cl − and K + ions and concomitant movement of water across the membrane, making ion channels pivotal to tumour biology. We discuss which specific Cl − and K + channels are involved in defined aspects of glioma biology and how these channels are regulated. Cl − is accumulated to unusually high concentrations in gliomas by the activity of the NKCC1 transporter and serves as an osmolyte and energetic driving force for volume changes. Cell volume condensation is required as cells enter M phase of the cell cycle and this pre-mitotic condensation is caused by channel-mediated ion efflux. Similarly, Cl − and K + channels dynamically regulate volume in invading glioma cells allowing them to adjust to small extracellular brain spaces. Finally, cell condensation is a hallmark of apoptosis and requires the concerted activation of Cl − and Ca 2+ -activated K + channels. Given the frequency of mutation and high importance of ion channels in tumour biology, the opportunity exists to target them for treatment.