The paper gives the results of mathematical modeling of movement of a loaded wagon with elastic suspension under viscous friction force equivalent to the dry friction force. Parameters of vertical relative forced vibrations have been found, which are stipulated by the wave of road irregularity.

This article explores issues related to the friction of the brake pads of a freight car. The coefficients of friction of composite and cast-iron pads of a new type, calculated for a range of different speeds, and the specific braking force during emergency braking are given. A sectional brake block for a freight car and a locomotive has been developed. The advantages of sectional brake pads have been scientifically substantiated. The obtained calculations allow us to recommend them for further study and implementation in operation on the railways.

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Background: Ectoparasites are known to transmit various pathogens that can cause numerous diseases in livestock, leading to detrimental effects such as skin damage, weight loss, anemia, reduced meat and milk production, and even mortality. Aim: This study aimed to investigate the species composition and prevalence of ectoparasites in domestic (dogs and cats) and wild predatory mammals (jackals, wolves, foxes, and reed cats) in Uzbekistan through regular parasite collections. Materials and Methods: A comprehensive surveillance was conducted to calculate the prevalence of ectoparasites in carnivorous mammals. Data on ectoparasite prevalence, including area, host, breed, species diversity, age, and seasonal infestation rate, were recorded and analyzed. This research represents the first investigation of ectoparasites in carnivorous mammals in Uzbekistan and encompassed 12 regions (Andijan,