All articles. Humanities of BMSTU

Simulation of shortwave communication equipment units using open-source software

Thu, 15 Oct 2026 00:00:00 +0400

This article discusses methods for mathematical modeling of shortwave electronic device components using the QUCS-S (Quite Universal Circuit Simulator) computer-aided design system. This modeling system is based on the Ngspice computational kernel and enables frequency-domain analysis of electronic circuits, including calculation of scattering parameters. The paper describes an approach to modeling electronic devices based on their representation as two-port networks and S-parameter analysis. Simulations were performed to determine the frequency characteristics of key components of an amateur shortwave transceiver, including mixers, band-pass filters, and amplifier stages. Methods for calculating key parameters of high-frequency circuits, such as reflection coefficient and standing wave ratio, are also presented.

Development of an NDIR gas analyzer: engineering implementation and testing

Thu, 15 Oct 2026 00:00:00 +0400

One of the most significant tasks of modern environmental monitoring is the rapid and highly accurate monitoring of changes in greenhouse gas concentrations, such as water vapor and carbon dioxide, in the atmosphere. This article presents an engineering implementation of the NDIR (Non-dispersive infrared) gas analyzer with an innovative discrete infrared radiation generation scheme based on pulse width signal modulation. Among other things, it describes the testing of the developed device as part of an ecological and climatic station at the Bauman Moscow State Technical University training base in the village of Kamshilovka (Moscow region) in combination with a three-axis ultrasonic anemometer for the implementation of the turbulent pulsation method.

Comparative analysis of intrusive and non-intrusive methods for computing polynomial chaos expansion coefficients: a case study of the heat equation

Thu, 15 Oct 2026 00:00:00 +0400

This paper considers the heat equation under a formulation that accounts for the stochastic nature of the thermal diffusivity coefficient and randomness in the initial condition. Uncertainty is represented using the Polynomial Chaos Expansion method. The analytical solution is compared with two stochastic approximations: the non-intrusive least-squares method and the intrusive Galerkin method implemented together with the Crank — Nicolson scheme. Statistical simulations are performed, mean temperature trajectories and their three-dimensional visualizations are constructed, and errors between the methods are evaluated. The results demonstrate a high degree of consistency between the numerical approaches and the analytical solution, confirming the practical suitability of the proposed methods.

Abstraction levels in electronic computing systems

Thu, 15 Oct 2026 00:00:00 +0400

The article presents information-processing computing systems and highlights their specific characteristics regarding design across the various levels of the hierarchical abstraction model—ranging from the physical to the software level. The tasks associated with each level are described in detail, accompanied by illustrative examples. The distribution of responsibilities among different specialists is demonstrated, and the mutual influence of adjacent levels is examined (for example, the relationship between the properties of electronic components at the analog level and the speed of logic circuits), along with the impact of level alignment on architectural decisions. It is shown that maximum system-wide efficiency is achieved only through high-quality, in-depth analysis and development across all levels of the system

Analysis of promising areas in the production of space truss structures

Thu, 15 Oct 2026 00:00:00 +0400

The article reviews historical and modern approaches to creating truss structures for orbital stations and large space structures. Design solutions are analyzed, from manual assembly of individual elements in orbit to modular and deployable systems and advanced composite technologies that make it possible to create large-diameter structures directly in space. Three classes of structural materials — carbon-fiber-reinforced polymer, aluminum alloys, and an aluminum-based metal composite reinforced with silicon carbide — are compared in terms of density, specific strength and stiffness, thermal stability, resistance to cyclic thermal loads, radiation resistance, and manufacturability of large-size elements. Each material has both advantages and limitations in open-space conditions. Based on the analysis, a technical solution for a hybrid carbon-fiber truss with metal end fittings is proposed and substantiated. The truss geometry and reinforcement scheme of the composite rods are selected to provide maximum stiffness at minimum mass. The relevance of this solution for future space projects is demonstrated.

Determination of the repair diameter for restoring the lead screw of a screw-cutting lathe

Thu, 15 Oct 2026 00:00:00 +0400

The technical and geometric parameters of lead screws of screw-cutting lathes are analyzed, the critical importance of their accuracy for the quality of cut threads is substantiated, and the consequences of wear are considered. Cutting a repair-size thread is proposed as the most effective restoration method because it preserves the mechanical properties of the material and is technologically simple. The main limitation of the method is the permissible reduction of the screw outside diameter by no more than 10 %. Repair-size restoration makes it possible to use the equipment resource rationally and to reduce costs and machine downtime compared with complete replacement of the screw–nut pair.