ОЦІНЮВАННЯ ГЕОМЕТРИЧНИХ ПАРАМЕТРІВ ПОЛЮСНОЇ СИСТЕМИ МАТРИЦІ ЕЛЕКТРОМАГНІТНОГО СЕПАРАТОРА

Purpose. The choice of the geometric dimensions ratios of system of matrix poles of electromagnetic polygradient separator to increase productivity with maintaining the reliability of extracting of ferromagnetic impurities from bulk material.Methodology. To solve the dynamic problem of motion of a ferromagnetic body in the working gap of pole system of matrix of polygradient separator under the influence of an external magnetic field the known methods of solving linear inhomogeneous differential equations are used. To confirm the reliability of obtained results the method of experimental research is used.Findings. The formulation of dynamic problem of movement of ferromagnetic body in the working gap of plate pole system of matrix of polygradient separator is carried out. Parametric equation for the trajectory of ferromagnetic body removal and a calculated relation connecting the main geometric dimensions of the system of matrix poles are obtained. The calculation results are confirmed experimentally and by operating practice of known magnetic separating devices.Originality. The mathematical description of working process of a polygradient electromagnetic separator with a plate matrix was further developed, which made it possible to obtain an analytical expression that takes into account the main geometric dimensions of the working space of matrix of separator.Practical value. Accounting of obtained analytical dependences between the length of separation zone and air gap, which characterizes the thickness of the separated material layer through which the ferromagnetic body must pass during the separation process, will ensure the necessary purity and productivity of separation.

Control Performance, Stability Conditions, and Bifurcation Analysis of the Twelve-Pole Active Magnetic Bearings System

The active magnetic bearings system plays a vital role in high-speed rotors technology, where many research articles have discussed the nonlinear dynamics of different categories of this system such as the four-pole, six-pole, eight-pole, and sixteen-pole systems. Although the twelve-pole system has many advantages over the eight-pole one (such as a negligible cross-coupling effect, low power consumption, better suspension behaviors, and high dynamic stiffness), the twelve-pole system oscillatory behaviors have not been studied before. Therefore, this article is assigned to explore the effect of the magneto-electro-mechanical nonlinearities on the oscillatory motion of the twelve-pole system controlled via a proportional derivative controller for the first time. The normalized equations of motion that govern the system vibrations are established by means of classical mechanics. Then, the averaging equations are extracted utilizing the asymptotic analysis. The influence of all system parameters on the steady-state oscillation amplitudes is explored. Stability charts in a two-dimensional space are constructed. The stable margin of both the system and control parameters is determined. The obtained investigations reveal that proportional gain plays a dominant role in reshaping the dynamics and motion bifurcation of the twelve-pole systems. In addition, it is found that stability charts of the system can be controlled by simply utilizing both the proportional and derivative gains. Moreover, the numerical simulations showed that the twelve-poles system can exhibit both quasiperiodic and chaotic oscillations besides the periodic motion depending on the control parameters’ magnitude.

A Parametric Study of a Deep Reinforcement Learning Control System Applied to the Swing-Up Problem of the Cart-Pole

In this investigation, the nonlinear swing-up problem associated with the cart-pole system modeled as a multibody dynamical system is solved by developing a deep Reinforcement Learning (RL) controller. Furthermore, the sensitivity analysis of the deep RL controller applied to the cart-pole swing-up problem is carried out. To this end, the influence of modifying the physical properties of the system and the presence of dry friction forces are analyzed employing the cumulative reward during the task. Extreme limits for the modifications of the parameters are determined to prove that the neural network architecture employed in this work features enough learning capability to handle the task under modifications as high as 90% on the pendulum mass, as well as a 100% increment on the cart mass. As expected, the presence of dry friction greatly affects the performance of the controller. However, a post-training of the agent in the modified environment takes only thirty-nine episodes to find the optimal control policy, resulting in a promising path for further developments of robust controllers.

PAX2 variant associated with bilateral kidney agenesis and broad intrafamilial disease variability

Pathogenic variants in PAX2 have previously been associated with renal coloboma syndrome. Here we present a novel variant c.68T>C associated with bilateral kidney agenesis, minimal change nephropathy, ureteropelvic junction obstruction, duplex kidney with hydronephrosis of upper pole system and bilateral kidney hypoplasia within the same family. Additionally, two family members were found to have optic nerve abnormalities further supporting the impact of the PAX2 variant. This is the first report of a PAX2 variant associated with bilateral kidney agenesis.

Landscape Economic Attractiveness: An Integrated Methodology for Exploring the Rural Landscapes in Piedmont (Italy)

The present paper focuses on an integrated evaluation methodology aimed at measuring the attractiveness of rural landscapes. The landscapes under observation are two exceptional contexts in Piedmont (Italy): The Moraine Amphitheatre of Ivrea and the vineyard landscape of Langhe, Roero and Monferrato, which have recently been included in the UNESCO World Heritage List. The proposed investigation tool consists of the use of a system of landscape indicators, from which a synthetic index called the landscape economic attractiveness index has been obtained, and the integration of the results in a dynamic model, considering the synthetic index as a factor of people mobility in a multi-pole system. This integrated approach aims at supporting the decision-making process in the definition and orientation of landscape and territorial transformation policies, respecting the landscape components.