Nonlinear Hamiltonian dynamics of Lagrangian transport and mixing in the ocean

Methods of dynamical system's theory are used for numerical study of transport and mixing of passive particles (water masses, temperature, salinity, pollutants, etc.) in simple kinematic ocean models composed with the main Eulerian coherent structures in a randomly fluctuating ocean -- a jet-like current and an eddy. Advection of passive tracers in a periodically-driven flow consisting of a background stream and an eddy (the model inspired by the phenomenon of topographic eddies over mountains in the ocean and atmosphere) is analyzed as an example of chaotic particle's scattering and transport. A numerical analysis reveals a nonattracting chaotic invariant set $\Lambda$ that determines scattering and trapping of particles from the incoming flow. It is shown that both the trapping time for particles in the mixing region and the number of times their trajectories wind around the vortex have hierarchical fractal structure as functions of the initial particle's coordinates. Scattering functions are singular on a Cantor set of initial conditions, and this property should manifest itself by strong fluctuations of quantities measured in experiments. The Lagrangian structures in our numerical experiments are shown to be similar to those found in a recent laboratory dye experiment at Woods Hole. Transport and mixing of passive particles is studied in the kinematic model inspired by the interaction of a jet current (like the Gulf Stream or the Kuroshio) with an eddy in a noisy environment. We demonstrate a non-trivial phenomenon of noise-induced clustering of passive particles and propose a method to find such clusters in numerical experiments. These clusters are patches of advected particles which can move together in a random velocity field for comparatively long time

Numerical investigation of pulverized coal aero mixture combustion at the presence of flow swirling

Numerical investigation results of burning pulverized coal aero mixture in the presence of swirl flow have been presented. The mathematical model has been chosen allowing describing correctly the pulverized coal combustion processes in the furnace with a swirl burner

Numerical investigation of pulverized coal aero mixture combustion at the presence of flow swirling

Numerical investigation results of burning pulverized coal aero mixture in the presence of swirl flow have been presented. The mathematical model has been chosen allowing describing correctly the pulverized coal combustion processes in the furnace with a swirl burner

Experimental Study of Features of Thin-Walled Pipes Sizing in the Line of a Pipe Rolling Plant with an Automatic Mill

The aim of the study is to establish the actual level of working loads on the roll drive line of the sizing mill installed as part of the PRP-220 with an automatic mill, when switching to the production of steel pipes from increased strength group. The study is based on a complex experimental and theoretical analysis. After the processing of the results of experimental studies a comparison of the most loaded sizing route for a thin-walled pipe with a diameter of 244.5 mm and a wall thickness of 8.9 mm (D/S = 27.5) made of steel of strength group “D” was made with the route for a pipe with a diameter of 177.8 mm and a wall thickness of 9.2 mm (D/S = 19.3) from steel of strength group “E”. Graphs of the observed processes are presented, as well as calculated predictive values of sizing of thin-walled pipes for steel of strength group “E”, obtained on the basis of an experimental-theoretical analysis of the growth of flow stress. Recommendations have been given for improving the equipment of the PRP-220 sizing mill for the production of pipes with increased diameters from steels of increased strength groups

Comparative analysis of nondestructive ASSAY techniques for 235U and 239Pu in structural materials at a high gamma background level

Potential techniques to identify small quantities of fissionable materials (FM) (0.001% wt.) in conditions of a high gamma background level have been reviewed and compared, and the optimal possibility for the nuclear material (NM) control in spent fuel assemblies (SFA) has been selected. It was found through numerical simulation that a system based on a passive neutron control method could be used to detect FMs indirectly when the spent nuclear fuel (SNF) burn-up and cooling time are known. Two types of detectors have been compared: 3He counters and 235U-based fission chambers. Better application prospects of 3He counters, based on the SNM-18 neutron counter, have been shown and drawbacks of passive control technique have been pointed out. An active neutron control has been found to be the best way to address the problem considered. The system's computational model shows that the signal exceeds the triple background error (both for ambient and intrinsic background from Cm isotopes) more than twelvefold. To improve the signal recording efficiency, the system has been modified to allow for irregularities in the geometrical position of structural materials (SM) in the measuring chamber. The proposed procedure makes it possible to determine in a short time the content of 239Pu, 242Cm, and 244Cm in an SFA. After the quantity of 239Pu is determined, it is possible to estimate the content of other isotopes (Am, U, Np) due to the constancy of the 239Pu mass ratio to the mass of the actinide identified

Numerical investigation of pulverized coal aero mixture combustion at the presence of flow swirling

Numerical investigation results of burning pulverized coal aero mixture in the presence of swirl flow have been presented. The mathematical model has been chosen allowing describing correctly the pulverized coal combustion processes in the furnace with a swirl burner

Assessment of Risk Factors for Possible Toxocariasis Invasion in Lugansk Region Population

Toxocariasis — parasitosis-zoonosis which is widespread among animals and humans. The objective of study was to investigate factors that determine the possibility of toxocariasis invasion in population of Lugansk region. In the work we used information and statistical materials, data of state branch statistical forms, we analyzed the results of sanitary helminthological soil study for 2007–2011. Sanitary helminthological soil study were made using the N.A. Romanenko method. The study of various soil types demonstrates high degree of contamination by Toxocara canis eggs: highest contamination was detected in loamy (39–102 eggs per 1 kg of soil) and loam soil (53–64 eggs per 1 kg of soil). Black (39–40 eggs per 1 kg of soil) and sandy soil (17–39 eggs per 1 kg of soil) were less contaminated. Our observations relate to literature data: the most favorable for Toxocara canis eggs are loamy and clay soils, to a lesser extent — black soils, unfavorable for development are sandy soils. The study shows a high degree of possibility of toxocariasis invasion in population of Lugansk region. The findings once again confirm the need for creating national program for parasitosis-zoonosis prevention in Ukraine