Research and Mathematic Simulation of the Pollution Particle Motion Process in the Fluid Stream under Effluents Treatment

The article covers the issues of the mathematic simulation of the pollution particle motion process in the fluid stream, and there are defined the options influencing the process of the sweat. There are also analysed the challenging problems of the effluent water dispose. There is also devoted attention to the updating of the sedimentation process by the use of constrained features which exclude sediments in the objectionable points of the cleansing system and etc.

Numerical Simulation of Fluid Flows in Rotary Discs

The object of this paper is to model the complex fluid motion that is caused by the rotational motion of rotary disks. In doing so, the rotary disk occupied a normal or parallel position with respect to the fluid flow axis. Various designs of rotary bodies were also applied, with the introduction of fluid through the central opening inside the impeller of the rotating bodies and with the introduction of fluid on the outer surfaces of these impellers (surfaces limited by the largest diameters of the rotary discs). During the modeling, different initial conditions for different structures and positions of rotating bodies were adopted. For each individual stream, flow diagrams are given through a cylindrical fluid stream whose translational motion is complicated by the rotational motion of the friction disks in its flow. The results obtained give a clear picture of the disturbances and changes in the front of the fluid motion wave which can be used as a necessary experience in the design of circulating technological systems.

Determining the type of mudflow mixture using the Gibbs–Roseboom diagram

The Gibbs–Roseboom diagram was used in determining and generalizing the type of mudflow mixture as well as new boundaries between viscous stream and fluid stream were determined in the article. The latter is due to the percentage of solid-liquid component in the mudflow, as well as from fractions of less than one millimeter.Thus, the typification of mudflows is convenient and expedient, since the structure of the mixture is determined by clay-colloidal fractions, and not by the amount of water components in it. Using the proposed diagrams, it is possible to determine the type of mudflow still in the outbreaks and take appropriate preventive measures.

Why Is the GFR So High?: Implications for the Treatment of Kidney Failure

The high GFR in vertebrates obligates large energy expenditure. Homer Smith’s teleologic argument that this high GFR was needed to excrete water as vertebrates evolved in dilute seas is outdated. The GFR is proportional to the metabolic rate among vertebrate species and higher in warm-blooded mammals and birds than in cold-blooded fish, amphibians, and reptiles. The kidney clearance of some solutes is raised above the GFR by tubular secretion, and we presume secretion evolved to eliminate particularly toxic compounds. In this regard, high GFRs may provide a fluid stream into which toxic solutes can be readily secreted. Alternatively, the high GFR may be required to clear solutes that are too large or too varied to be secreted, especially bioactive small proteins and peptides. These considerations have potentially important implications for the understanding and treatment of kidney failure.

Experimental Study of Flow Structure in Converging–Diverging Axisymmetric Geometry

Control valves, nozzles, and other mechanical flow constricting constructions often introduce highly turbulent flow downstream of vena contracta. When solid particles are present in the fluid stream erosion can occur due to the high fluid velocity and turbulence, both in the converging and diverging section of a constriction. This paper presents an experimental study of such flow structure in a converging–diverging valve geometry. The purpose of the study is to obtain velocity profiles downstream of vena contracta by the use of particle image velocimetry measurements. Profiles and flow structure, with and without introduced swirl component, is investigated and discussed with respect to erosion in such specific geometries.