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Research on Blocking Ion Channels in Cell Membranes Under the Action of Electromagnetic Field

Thu, 01 Jan 2026 00:00:00 GMT

Назва: Research on Blocking Ion Channels in Cell Membranes Under the Action of Electromagnetic Field Автори: Kundenko, Mykola; Мардзявко, Віталій Анатолійович; Mardziavko, Vitalii; Мардзявко, Катерина Олександрівна; Mardziavko, Katerina; Яблуновська, Катерина Олександрівна; Yablunovska, Katerina; Руденко, Андрій Юрійович; Rudenko, Andrii Короткий огляд (реферат): The article investigates the effect of ultrahigh frequency electromagnetic radiation on the functioning of ion channels in fruit cell membranes, which determine the intensity of ion transport and the level of cellular respiration. Based on the electrodiffusion equation and the stochastic model of ion channel operation, a system of equations was constructed that describes the probabilities of the channel being in different functional states. Analytical expressions were obtained for the flow of ions through the membrane under the action of an external microwave field and it was established that electromagnetic influence at ultrahigh frequencies significantly increases the probability of channel blockage, reducing the permeability of the membrane. This leads to a noticeable decrease in the intensity of cellular respiration, which is a key factor in slowing down the physiological aging of fruits. The results confirm the prospects of using electromagnetic methods for controlled regulation of ion channel operation and extending the shelf life of fruits without the use of chemicals. Опис: Повний текст статті доступний з сайту видавця за посиланням: https://ieeexplore.ieee.org/document/11632291

The Digital State in the Context of Systemic Instability: Institutional Challenges and Innovative Solutions

Thu, 01 Jan 2026 00:00:00 GMT

Назва: The Digital State in the Context of Systemic Instability: Institutional Challenges and Innovative Solutions Автори: Іванов, Геннадій Олександрович; Ivanov, Gennadiy; Solodka, Olena; Shepeta, Olena; Zaitsev, Yurii; Kravchenko, Milena Короткий огляд (реферат): Due to the increasing demand for digital infrastructure in public administration, the digital state has become a crucial element of governance during systemic instability. In times of cyber threats, fragmentation of coordination, external technological dependence, and lack of public confidence, digital sovereignty and information security are constitutive preconditions of institutional continuity, and developing them is a key to enabling the resilience of the state. This paper aims to identify the major institutional challenges and innovative solutions, i.e., the key populating objects of the digital state. By examining the major figures of the digital state through qualitative comparative-analytical research rooted in conceptual analysis, problem-oriented synthesis, and structured comparison of crisis-driven institutional response, the article finds that the interaction between strategic sovereignty, institutional capacity, and operational security affects success in digital transformation. External platform dependence, a lack of interoperability, fragmented governance, and institutional capacity gaps impose substantial limitations on digital administration. This study also shows that resilience is not enough if not transformed into institutional restructuring through secure infrastructure, flexible coordination, and accountability-driven reform, thus promoting the continuity, sovereignty, and confidence of the public sector.

Numerical and Experimental Analysis of Free Vibrations of Thick-Walled Cylindrical Shell

Thu, 01 Jan 2026 00:00:00 GMT

Назва: Numerical and Experimental Analysis of Free Vibrations of Thick-Walled Cylindrical Shell Автори: Grigorenko, Alexander; Müller, Wolfgang; Borysenko, Maksym; Бойчук, Олена Володимирівна; Boychuk, Olena Короткий огляд (реферат): Free vibrations of an isotropic thick-walled circular cylindrical shell with one end rigidly clamped, and the other free, are investigated numerically and experimentally. The natural frequencies and corresponding mode shapes are determined using the finite element method within a three-dimensional elasticity formulation, employing solid finite elements. The article focuses on constructing a reliable finite element model, including selecting element types and mesh density based on accuracy, convergence, and computational efficiency. In the article, solve a test problem to verify the numerical model and present a detailed convergence analysis. An experimental study of free vibrations based on stroboscopic interferometry, which allows full-field visualization of vibration mode shapes and determination of natural frequencies with sufficient accuracy. A comparison between numerical and experimental results demonstrates good agreement, confirming the reliability of the proposed modeling approach. The research study has been used in the design and analysis of thick-walled cylindrical shell structures in engineering applications, as well as for validating numerical and analytical methods for the vibration analysis of shell systems.

Methodology for investigating the interference immunity of satellite navigation antenna arrays using ansys hfss

Thu, 01 Jan 2026 00:00:00 GMT

Назва: Methodology for investigating the interference immunity of satellite navigation antenna arrays using ansys hfss Автори: Slyusar, Vadym; Атаманюк, Ігор Петрович; Atamanyuk, Igor; Sliusar, Ihor; Shelemin, Zakhar; Sidenko, Ievgen; Kondratenko, Yuriy Короткий огляд (реферат): This paper presents an HFSS-based procedure for quantifying the interference resilience of satellite-navigation antennas on autonomous platforms that employ digital antenna arrays and controlled reception pattern antennas (CRPAs). An individual element is first simulated to determine the operating band under the VSWR<2 criterion and to select the analysis frequency. The complete array is then solved with in-phase excitation to obtain the zenith peak gain P. Next, a phase distribution that enforces a zenith null is identified, the associated gain depression D is measured, and interference suppression is expressed as P−D. The workflow is demonstrated on navigation CRPAs of several topologies. A six-element ring yields a relative null depth of about 36.5 dB, whereas a seven-element ring provides up to 45 dB of suppression. The strongest performance is achieved by a dual-ring 16-element array, reaching a 53 dB null depth. A square 4×4 array is lower by 8.5 dB. In further research, it would be advisable to experimentally test the influence of phase errors and also to extend this approach to other electromagnetic simulators.