Non-Terrestrial Networks (NTN), including Low Earth Orbit (LEO) satellite constellations, aim to provide connectivity remote and underserved areas. These networks now support complex network services leveraging Service Function Chaining (SFC), which sequences service functions such as firewalls load balances customize behavior. In this paper, a comprehensive system model for SFC deployment in NTN is presented. The problem regarded comprising two parts: routing VNF embedding. To improve the...

When an external short circuit occurs, the axial electromagnetic force increases dozens of times. Under effect short-circuit force, transformer windings vibrate violently. The spatial distribution disks is constantly changing during vibration, which can change temporal and distributions leakage magnetic field force. This process called strong coupling phenomenon structural field. In this article, a coupled magnetic-structural model proposed by using analysis method. equations, where...

Vitrimer, a class of covalent dynamic networks, is promising for polymeric applications requiring reshaping, recycling, and self-healing. The bonds in vitrimer can be reversibly broken reformed under thermal actuation. This work investigates the effects temperature on fracture toughness soft epoxy vitrimers. We measured above topology freezing temperature. Elevated temperatures reduce both stretch toughness, while they linearly increase modulus. Given invariant cross-linking density,...

For continuous or spiral windings which feature multiple continuously transposed conductors (CTC) wound in parallel, the transposition structure is commonly used to suppress circulation between conductors. This introduces a local asymmetry transformer windings. Fault analyses have shown that building an asymmetric transformers increases deformation risk these Researchers yet fully investigate this structure. study was conducted observe influence of 110 kV transformer. The conductor's...

Aim: As one of the most widely used anti-diabetic drug for type II diabetes, metformin has been shown to exhibit anti-cancer activity in recent years. Epidermal growth factor (EGF) and its receptor, EGFR, play important roles cancer metastasis various tumors, including breast cancer. Epithelial-mesenchymal transition (EMT) is a critical process invasion metastasis. In this study, we use EGF as metastatic inducer investigate effect on cell migration, EMT. Methods: Human MCF-7 cells were...

Burning state directly determines the clinker quality index in rotary kiln sintering process. A simulated feedback mechanism-based burning cognition intelligence method and a calculating model are explored for purpose of imitating human process with repeated comparison inference. The flame image feature space is optimized progressively using evaluation uncertain results different values demand to realize mode from global local. First, coupling operation training layer decision proposed,...

To pre-discover the insulating defects and avoid possible insulation failures, DC withstand voltage test with partial discharge (PD) measurements are routinely conducted before operation of a convertor transformer. However, "downward trend" PDs under studied in this paper indicates limitation current test. According to study, both PD magnitude repetition rate decrease applying time. At U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pdiv</sub>...

Previous studies indicate that cellulose bridges in oil-pressboard insulation are self-generating, and can influence the characteristics of partial discharges (PDs) under DC voltage. In this letter, further experiments based on an optical-electric experimental platform were conducted to determine generating sequence between PDs, provide visual evidence bridges' effects PD process. The results show generation be divided into three stages, which finished at a voltage lower than inception...

Short‐circuit forces, which result in violent vibration of power transformer windings, are induced by the interaction between short‐circuit currents and leakage magnetic induction. During vibration, rearrangements disks affect flux distribution, leads to time‐varying equivalent reactance further changes forces. When a accident occurs, these processes happen simultaneously constantly. In this article, influence circuit parameters on is analyzed. The strongly coupled phenomenon circuit, field...

Abstract Mechanical stability is one of the core capabilities power transformers. External short‐circuit accidents are main cause winding instability. International Electrotechnical Commission 60076‐5 standard recommends a method to calculate strength transformer windings by comparing stress within under effect maximum electromagnetic force with critical winding. This assumes that deformation will be produced force, which corresponds first peak waveform. However, owing interactions between...

Abstract Since 2018, there have been seven incidents of explosions and fires in ultra‐high voltage transformers China, which are caused by internal arc discharge transformer oil. Various pressure measurement experiments conducted to explore the laws pressure. However, differences experimental conditions, energy, current peak values led discrepancies power these experiments. Thus, it is crucial investigate relationship between An test platform was established measure waveforms based on RLC...

Recently, asteroid exploration becomes an important branch of human's deep space activities. In this paper, a piecewise linear optimal orbital maneuver strategy is designed for spacecraft soft landing on irregular-shaped asteroids. First, the around irregular converted into several grid units, and gravitational field linearly fitted in each unit. Then, soft-landing design problem formulated as problem, further transferred family two-point boundary value problems, which can be solved using...

Transformer oil has been used to electrically insulate a variety of electrical equipment including circuit breakers, cables and power transformers. Its insulation properties breakdown characteristics under impulse overvoltage is the key factor determine safety system. The configurations transformers reactors are affected by electrode surface area stressed volume. Therefore, it's great importance establish proper mathematical models cope with scale effects in transformer voltage. In order...

As the key equipment of power plants and substations, transformers carry heavy responsibility transmission, distribution transformation voltage levels. Recent years, with construction UHV projects, level in China has increased to more than 1000kV formed several networks, enhancing reliability efficiency supply. However, this also put stringent requirements on operation maintenance transformers. When a short-circuit fault occurs, current flowing through transformer windings will be bigger...

The safe operation of power transformers is critical for the stability grid. external short circuit one major threats transformers. When an occurs, transformer windings would endure large electromagnetic force and vibrate violently. Accurate calculation winding vibration necessary better designed with improved mechanical insulation strength. short-circuit consists DC component, fundamental frequency component double component. Different components have different amplitudes produce...

Lightning impulse withstand test is extremely important to the insulation examination of oil-immersed equipment, but increase entrance capacitance ultrahigh voltage equipment usually makes front time T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> impulses exceed upper limit regulated by IEC 60060-1. In order evaluate equivalency between tests under standard lightning and with longer (T <; 6 μs), as well explore effect wavefront on...

Winding transposition structures are commonly built into transformers to suppress winding circulation and minimize loss. They alter the distribution of transverse leakage magnetic field electromagnetic force. Researchers have not yet considered when investigating distribution. The relative position conductors in a structure is analyzed this paper, scale model experiment conducted verify effect structure. In meantime, finite element method which includes models established verified by...

The wavefront time T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> of lightning impulse plays an important role in the detection insulation defects metal enclosed gas insulated switchgear (GIS). Usually, a rod-plane electrode system with different geometric parameters is adopted to simulate local field enhancements GIS. But, for GIS, may occur on high-voltage which can not be properly simulated by electrode. To research influence...

Abstract Transformer winding turns often consist of multiple parallel strands. The spatial position variation each strand affects the leakage inductance branch, resulting in an uneven distribution short‐circuit currents within turns. And this unevenness persists even when transposition structures are implemented. Traditional methods transformer analysis frequently overlooked characteristics calculating electromagnetic forces. A frequency‐domain calculation method for analysing current was...

Abstract Accurately calculating axial electromagnetic force is essential to analyse transformer winding stability. Prior research has mainly focused on the effect of structure static and studying vibration by substituting in a time‐varying function. However, coupling between not been addressed, no calculation method for that considers both meso‐structures effects proposed. Previously authors presented an model characteristics, iterative algorithm magnetic‐structure calculation. Currently,...