The article presents the results of a study of the resistance of carbon fiber felt “Carbopon-B-22”, actively used as highly effective broadband electromagnetic radiation screens and radio-absorbing materials, to oxidation under the influence of molecular oxygen during seven years of storage at room temperature. Felt samples annealed at temperatures from 600 to 720 °C were studied to obtain the surface resistance of the material “Carbopon-B-22” from 1100 to 100 Ohm. An increase of 1.7–1.8 times in surface resistance compared to the initial value was noted. The obtained data on the long-term stability and reliability of the properties of the material “Carbopon-B-22” can contribute to new research and development in its application in various fields.

A three-dimensional nonlinear mathematical model of induction heating for forming ball terminals using the Flip-Chip technology has been developed. The study was conducted at frequencies of 300, 732, and 900 kHz with a heating power of 20–100 W. The use of a ferrite core focusing the magnetic field and an eddy current concentrator allowed us to establish optimal thermal profiles for forming ball terminals for mounting integrated circuits with a heating rate of 2.0 to 5.5 °C/s. When analyzing the results obtained from the experiments, the option of locating the concentrator at the bottom of the board turned out to be optimal. In this case, heating the solder balls at the selected frequencies reached the melting temperature of the ball terminals of 230–250 °C, which is sufficient for their reflow.

Features of formation of amplitude-frequency characteristics of resonant amplifier stages with double autotransformer inclusion are considered. The amplitude-frequency characteristic of the resonant cascade was simulated using the Multisim circuit design program. The transfer function of the circuit is analyzed and the factors influencing the formation of the frequency response of the cascade in a wide frequency range are revealed. Attention is drawn to the undesirable distortion of the shape of the amplitude-frequency response of the cascade outside the operating frequency band, leading to a decrease in attenuation and deterioration of selectivity on the side channels of reception. Recommendations are given for improving the shape of the amplitude-frequency characteristics outside the operating frequency band by parallel connection of autotransformers.

Currently, uncooled thermal detectors are among the most popular photodetectors, since they combine acceptable optical characteristics without the need to maintain the desired temperature. The main advantage of uncooled thermal detectors over cooled ones is the relative cheapness of manufacture. This also implies the main disadvantage - a decrease in sensitivity due to the effect of the ambient temperature on the device. Changing the thickness of the structural layers of the active elements of the microbolometric matrix is one of the most easily accessible ways to increase sensitivity. By modeling the absorption spectra and then calculating the integral absorption coefficient in the wavelength range from 8 to 14 μm, it was found that this coefficient increases from 60 to 81 % with a decrease in the thickness of the absorbing NiCr layer from 10 to 4 nm. The results obtained can be used to improve the optical characteristics of manufactured uncooled thermal detectors of the bolometric type.

The declared increase in area traffic capacity of mobile communications to 107 bit/s/m2 in 5G systems and to 109 bit/s/m2 in 6G systems may cause an unacceptable increase in the level of electromagnetic background, especially in indoor hot spots, where the intensity of wireless public information services is maximum. A methodology for analyzing and assessing the average electromagnetic background levels in various configurations of the typical 5G scenario Indoor Hotspot-eMBB at frequency ranges FR1 and FR2 is proposed, indicating a significant contribution of subscriber terminal radiations to the average levels of the generated radio frequency electromagnetic background. The possibilities of safe implementation of this scenario for the population are ana­ lyzed, associated with the use of MIMO technology and base station antennas that provide adaptive formation of narrow beams in the direction of the subscriber terminals being served.

Microstrip patch antennas are used in wireless networking due to their flexibility, light weight, and ease of fabrication. This article discusses the designed and simulated microstrip patch antenna for WBAN networks using professional CST Studio Suite 2020 software. The antenna operating frequency was 2.5 GHz, and its substrate was made of FR-4 (lossy) and Rogers RT/Duroid 5880 PCB materials with permittivity of 4.3 and 2.2, respectively. Both materials showed good results, but Rogers RT/Duroid was better with an efficiency of 94.4% because it has excellent performance characteristics that make it more suitable for use in wearable devices. The antenna substrate and ground plane were made of copper with a substrate height of 1.58 mm for Rogers RT/Duroid and 2.8 mm for FR-4. During the research process, an antenna with low return loss and a standing wave ratio value as close as possible to unity was created.

A methodology based on the use of ionospheric and magnetospheric monitoring system data to reduce systematic errors in radar measurements was developed. A comparison between experimental monitoring data and calculations was made using the international reference ionospheric model IRI-2020 for two scenarios: disturbed (September 12, 2024) and quiet (September 14, 2024) ionosphere. It was found that during pe­ riods of ionospheric disturbances, model IRI-2020 can understate systematic range errors by 1.5–2 times, espe­ cially for VHF and UHF bands, where errors may reach 7.0–10.0 and 1.0–1.2 km respectively at low elevations. It was shown that radial velocity and elevation errors also significantly depend on the ionospheric state. The use of real-time ionospheric monitoring data provides a substantial improvement in the accuracy of radar measurements, particularly for low-frequency bands and during periods of geophysical disturbances.

The article considers a pulsating loop thermosyphon as the most promising heat-transfer device for coo­ ling heat-loaded miniature semiconductors, which has minimal evaporator dimensions and demonstrates a heat removal density of more than 120 W/cm2. The main disadvantage of this type of thermosyphons is high thermal resistance. To improve the efficiency of heat transfer, ultra-thin powder capillary structures were studied, which intensify the evaporation process in the evaporator of the loop thermosyphon. It has been shown that the use of a 140 μm thick powder capillary structure made from a fraction of copper powder PMS-N with particle sizes of 63–100 μm to reduces the thermal resistance of a loop thermosyphon by three times and increases the heat flux density to 220 W/cm2. The pulsating loop thermosyphon can be used in efficient cooling systems for server stations, industrial computers, telecommunication equipment, where it is necessary to remove heat from miniature semiconductor components in a limited space of a dense arrangement.

Modern use of vacuum microwave resonators covers many areas of science, technology and industry. These devices, due to their ability to effectively generate, amplify and filter microwave signals, are used in many scientific fields. Resonators of complex shape, which allow obtaining improved electrodynamic characteristics of interaction with an electron flow, are investigated. The calculation of the H_mnp and E_mnp modes in a resonator with an azimuthally-longitudinally irregular cross-section is presented. The obtained solutions are based on projection methods during verification with an electrodynamic solution in the certified international CST Studio Suite package.

The paper presents the architecture of a prototype system for detecting network traffic anomalies. The system is based on a three-tier architecture using the Flask web framework to create a RESTful API. Anomaly detection is implemented using the Isolation Forest unsupervised machine learning algorithm (100 estimators, contamination factor 0.05) from the scikit-learn library, which processes data pre-normalized using StandardScaler in one-hour windows. The analysis results, including a multi-level classification of anomaly severity (with norma­ lized scores in the range of 0–1, where values greater than 0.8 correspond to the critical level) and ensuring compatibility with SIEM systems, are interactively visualized using Chart.js. Key theoretical and practical challenges, such as data quality, feature selection, scalability (algorithmic complexity O(n log n)), parameter optimization, and interpretability of results, are discussed.

The electrodynamic and photothermal properties of spherical silver nanoparticles with a diameter of 31 nm and a shell corresponding to the optical-electrical parameters of succinic acid in a phosphate buf­fered saline medium were simulated. It was found that such nanoparticles are capable of enhancing the electric field near the surface by up to 37 times. The electric field strength enhancement coefficient significantly depends on the distance between the nanoparticles and decreases by 10 times with a change in the distance from 1 to 30 nm. It was shown that an increase in the thickness of the shell of succinate ions of succinic acid leads to a shift in the resonance wavelength of silver nanoparticles to a longer-wavelength region. Irradiation of nanoparticles in the mode of excitation of localized surface plasmon resonance causes heating of nanoparticles to 86 °C, and the presence of a succinic acid shell contributes to an increase in the heating temperature above 100 °C with increasing thickness.

An algorithmic approach to the analysis of kinematic parameters of running in children using markerless motion capture systems is presented. Key aspects of the efficiency of running locomotion are analyzed, algorithms for calculating temporal and spatial parameters of running based on the matrices of coordinates of biokinematic landmarks of the human body are developed. The proposed data analysis technique provides highly accurate quantitative indicators, which, in turn, contributes to a more in-depth biomechanical study of sports movements in children. This approach not only increases the reliability of the results obtained, but also opens up new horizons for further research in the field of physical education and sports medicine.

The article presents the results of a study of the influence of color schemes on the perception of web resources within the visual part of the product (UI) and the overall perception and sensations of the user when interacting with the product (UX). The features of the construction and selection of the color scheme of the web resource are analyzed using the example of a bank, taking into account the user’s perception. Using Figma AI, a generative design of the resource was obtained, an analysis of the proposed color scheme of the site’s elements was carried out, and the shortcomings of the algorithmic approach to the selection of color solutions on the perception of content by users were identified.

Accurate trajectory prediction of multiple agents is a critical task in the fields of autonomous driving, human-computer interaction, and behavior analysis. However, the dynamic and interactive nature of agent behavior poses significant challenges, since it requires the formation of complex spatio-temporal dependencies and dynamically evolving interactions between agents. A novel approach is proposed for modeling dynamic relational graphs, the core component of which is the attention focus block, taking into account the relative positions of graph-based agents. By considering objects in a scene (e.g., vehicles and road elements) as graph nodes and their interactions as edges, the proposed approach effectively captures both local and global dependencies in a scene and makes a prediction about the future trajectory. The presented approach is evaluated using the Argoverse1 trajectory prediction dataset. Experimental results show that this model outperforms existing methods.