Tashkent State Transport University

Critical Markov Branching-Immigration Systems: Complete Classification of the State Space and Exact Rates of Convergence

We study a critical homogeneous continuous-time Markov branching-immigration system whose offspring and immigration generating functions regularly vary at point 1 of orders 1+ν and δ with ν,δ∈(0,1]. The slowly varying factors are controlled through their index functions, which ca...

Analysis and Design of a Double-Chamber Centrifugal-Gyratory Mill for Fine and Ultrafine Comminution

This study presents the analysis, design, and experimental–numerical evaluation of a double-chamber centrifugal-gyratory mill developed for the fine and ultrafine grinding of mineral raw materials. The operating principle is based on plane-parallel circular motion of two cylindri...

Advanced cathode engineering in sodium-ion batteries: doping, phase, and interface modulation from layer oxides to polyanionics

Abstract Sodium-ion batteries (SIBs) have attracted significant attention as viable alternatives to lithium-ion batteries; however, their practical advancement remains limited by cathode-related challenges, including sluggish Na + diffusion, structural degradation, and rapid capa...

Field-validated modelling of coupler forces during freight-train start-up on a steep gradient

Restarting a heavy freight train on a steep gradient produces transient tensile forces because locomotive tractive effort is transmitted through sequential coupler-slack closure and nonlinear draft-gear loading. This study develops a longitudinal multi-body model in MSC Adams for...

Optimal Methods for Approximating the Riemann–Liouville Fractional Integral in the Sobolev Space

We construct and analyze optimal quadrature formulas for the right-sided Riemann–Liouville fractional integral in the Sobolev space L2(m)(t,1), using φ,φ′,…,φ(m−1) at N+1 equally spaced nodes. The analysis is carried out through the Peano kernel of the error functional, for which...

Beyond Dissolved Oxygen: Integrated Assessment of Multistage Vortex Aeration Effects on Urban Reservoir Water Quality

Aeration is widely used to increase the oxygen concentration in urban reservoirs, but its broader effect on nutrients, organic matter, and integrated water quality status remains uncertain. This study evaluated the response of the Jangrim reservoir, Busan, South Korea, to a multi...

Optimization of multi-electrode surfacing technology for freight car axle box body repair

The paper studies the influence of temperature fields during single- and multi-electrode welding and surfacing treatment on deformations of the inner cylindrical surface of the body of the roller axle box of a freight car. The surfacing was performed using flux-cored electrodes o...

Multi-objectives approach for economic optimization in the smart electrical grid with demand response and electric vehicle

This paper presents an introduction to a multi-objective optimization framework that has been specifically designed to enhance the short-term operational scheduling of energy systems within smart parking lots. The innovative framework integrates the Improved Seagull Algorithm (IS...