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This study presents a segmentation framework for images of 220 kV cable insulation that addresses sample scarcity and blurred boundaries. The framework integrates data augmentation using the Wasserstein Generative Adversarial Network with Gradient Penalty (WGAN-GP) and the TransUNet architecture. Considering the difficulty and high cost of obtaining real cable images, WGAN-GP generates high-quality synthetic data to expand the dataset and improve the model’s generalization. The TransUNet network, designed to handle the structural complexity and indistinct edge features of insulation layers, combines the local feature extraction capability of convolutional neural networks (CNNs) with the global context modeling strength of Transformers. This combination enables accurate delineation of the insulation regions. The experimental results show that the proposed method achieves mDice, mIoU, MP, and mRecall scores of 0.9835, 0.9677, 0.9840, and 0.9831, respectively, with improvements of approximately 2.03%, 3.05%, 2.08%, and 1.98% over a UNet baseline. Overall, the proposed approach outperforms UNet, Swin-UNet, and Attention-UNet, confirming its effectiveness in delineating 220 kV cable insulation layers under complex structural and data-limited conditions.

The article aims to present the modified structural composition of the sub-ballast layers of the railway substructure, in which a part of the natural materials for the establishment of sub-ballast or protective layers of crushed aggregate is replaced by thermal insulation and reinforcing material (layer of composite foamed concrete and extruded polystyrene board). In this purpose, the experimental field test was constructed and the bearing capacity of the modified sub-ballast layers’ structure and temperature parameters were analyzed. A significant increase in the original static modulus of deformation on the surface of composite foamed concrete was obtained (3.5 times and 18 times for weaker and strengthen subsoil, respectively). Based on real temperature measurement, it was determined the high consistency of the results of numerical analyses and experimental test (0.002 m for the maximum freezing depth of the railway line layers and maximum ±0.5 °C for temperature in the railway track substructure–subsoil system). Based on results of numerical analyses, modified railway substructure with built-in thermal insulating extruded materials (foamed concrete and extruded polystyrene) were considered. A nomogram for the implementation of the design of thicknesses of individual structural layers of a modified railway sub-ballast layers dependent on climate load, and a mathematical model suitable for the design of thicknesses of structural sub-ballast layers of railway line were created.

As the number of tunnels continues to increase, there are more and more tunnels crossing the high geothermal strata. This study aims to address the issue of heat damage caused by high geotemperature in tunnels that cross such strata. Field tests were conducted to reveal the temperature variation law of high temperature tunnels during construction. Numerical simulation was employed to identify the influence characteristics of air volume and temperature on ambient temperature in tunnels. A ventilation system that adjusts according to the change of ambient temperature was designed, wherein the air supply volume and temperature can be modified based on monitoring of the tunnel environment and the temperature variation law. To minimize the diffusion of tunnel surrounding rock temperature into the tunnel, the study investigated the impact of insulation layer thickness and thermal conductivity on the tunnel's air temperature and proposed a rational layout of the insulation layer. Based on the above research, we obtained comprehensive control measures for tunnel high geothermal involve both an insulation layer and ventilation cooling system.

One of the most important goals in developing centrifugal pumps for liquid hydrogen transport is to minimize the temperature rise of the working fluid caused by internal and external heat sources during operation. In this paper, as part of our evaluation of the internal insulation characteristics of a centrifugal pump for liquid hydrogen transport, we removed the external vacuum insulation layer and installed a Teflon insulation layer inside the pump. We investigated the process of heat transfer from the outside to the working fluid due to internal heat flow loss during the pumping process and the resulting temperature rise of the working fluid through CHT (Conjugate Heat Transfer) analysis. The results show that, compared to a pump without a Teflon insulation layer, increasing the insulation layer thickness to 10 mm reduces external heat input from about 1300 W to 300 W. Furthermore, the Teflon insulation layer reduces the heat generated by internal heat flow losses during pump operation from approximately 37 W to 11 W.

A spacecraft is a vehicle designed for accomplishing a mission for military, scientific and commercial purposes. While designing a spacecraft, scientists face some challenges, one of which is the design of a thermal subsystem. A spacecraft is exposed to internal and external thermal loads during its lifetime. External heat loads are solar flux, Earth IR radiation, and albedo flux. The significance of these external loads varies depending on the orbit type. Internal loads are heat dissipation induced by the electrical and mechanical equipment. Thermal control systems must be developed carefully to keep spacecraft subsystems within operating temperatures until the end of their operating life. Thermal control can be performed with two methods: passive and active. This article mainly focuses on passive thermal control systems that have been designed and tested before. This type of thermal systems do not exert any power from a system, and they are more robust. Typical passive control hardware are thermal control coatings, multilayer insulation systems, radiators, louvers, thermal interface materials, and passive heat pipes. Here, we summarize some of the most recent developments in passive thermal protection system testing and design.

This paper presents the results of numerical modelling of the influence of various factors (geometrical layout of the structural layers of the railway track, climatic factors and ballast fouling) on the freezing of railway track structure with a built-in thermal insulation layer of extruded polystyrene (Styrodur). At the same time, the suitability and expediency of incorporating the thermal insulation layer at the sub-ballast upper surface level (i.e. below the rail ballast construction layer), or at the level of subgrade surface are discussed. Numerical modelling results in the main factors that should be taken into account in the dimensioning of the sub-ballast layers with a built-in thermal insulation layer. Based on the data on the depth of freezing of the railway track structure obtained from numerical modelling, a design nomogram for dimensioning was created and subsequently the influence of the changes of climatic characteristics on the freezing of the railway track structure was then mathematically expressed.

Annual energy consumption has surged due to suboptimal energy efficiency, resulting in an electricity supply shortage in Sulaimani, an Iraqi city in a temperate climate zone. This mixed-methods study aims to optimise energy efficiency in Sulaimani’s office buildings using IDA Indoor Climate and Energy (IDA ICE) dynamic simulation software v4.8. First, we collected data and developed 204 scenarios based on three prevalent plan typologies, linear (T1), concentric (T2), and courtyard (T3), utilising common materials such as Alucobond (M1), cement plaster (M2), Styropor (M3), and a curtain wall (M4). Afterwards, we performed relevant analyses employing External Venetian Blinds (EVBs) to reduce cooling load and/or Expanded Polystyrene (EPS) to reduce heating load. Notably, the results proved that EPS was more effective than EVBs in reducing both heating and cooling loads in the temperate climate zone, achieving reductions of up to 38% for T1. Meanwhile, EPS contributed to a heating load reduction of up to 52% for T3, and this adversely impacted overall energy consumption. Both EVBs and EPS could reduce total energy consumption by up to 30% in T2. In conclusion, the total energy consumption increased in temperate climate zones when EVBs were utilised, but this effect varied based on the various typologies of office buildings.

The unreasonable setting of thermal insulation layer in high cold tunnels not only increases the maintenance cost of tunnels, but also weakens the anti-freezing and cold resistance of the tunnels. In order to optimize the setting of thermal insulation layer in an Alpine tunnel, relying on Dabanshan tunnel in Qinghai Province, three schemes of radial and longitudinal thermal insulation region of thermal insulation layer were adopted, and the temperature field of the surrounding rock was numerically analyzed. The results show that the uneven region scheme of 9 cm-8 cm-7 cm and 10 cm-9 cm-8 cm insulation layer can effectively reduce the freezing area of the lining and the surrounding rock, the freezing region at the tunnel entrance is significantly reduced, and there is no lining freezing region within the depth of 30–750 M. The research results can provide guidance for the partition wall setting of radial and longitudinal insulation layers of Alpine tunnels. In addition, it has considerable economic advantages for the reduction in engineering construction costs.

Under the influence of plate collision, the high geothermal is a widespread phenomenon within the region of Tibet. Due to the aforementioned high geothermal, lining cracking is a common disaster in Sangzhuling tunnel during construction period. This paper presented the mechanical behaviour of tunnel lining under high geothermal temperature, which is studied by thermo-mechanical numerical method. The results both from field investigation and numerical analysis demonstrate that high geothermal temperature can cause the tunnel lining cracking and the variation of the stress of the tunnel lining. Thus, a novelty sandwich composite lining supporting scheme is proposed to overcome such geothermal temperature effects, in which a thermal insulation layer between primary supporting and secondary supporting is designed. The numerical analysis results indicate that the insulation layer can significantly improve the mechanical characteristics of the lining structure. In addition, the effect of the insulation layer is not linear with its thickness. For this reason, the optimum insulation thickness of the insulation layer is chosen as 0.06 m, which was optimized by a numerical parametric analysis. The research can provide a reliable reference for tunnelling works in high geothermal regions.

A theoretical model for describing the heat transfer characteristics of a turbine-based combined cycle (TBCC) engine cabin was established in Matlab/Simulink to quickly predict the thermal protection performance for engine accessories. The model’s effectiveness was verified by comparing the numerical results with the experimental data. The effects of different heat insulation layer thicknesses and fuel temperatures on the thermal protection performance are discussed; based on these effects, the heat insulation layer of 5 mm and fuel of 353 K were chosen to design the thermal protection cases. Nineteen different thermal protection cases were proposed and evaluated by using the model. Two representative accessories were chosen for the evaluation of the thermal protection performance of these cases. For accessory 1 with an internal heat source of 1000 W and internal fuel access, the thermal protection effect of adding a heat insulation layer and ventilation was the best, which decreased the accessory temperature by 43 K. For accessory 2 without an internal heat source, the thermal protection effect of adding a heat insulation layer to the casing and fuel cooling was the most ideal, which decreased the accessory temperature by 190 K. In addition, a comprehensive assessment was made to compare the performances of thermal protection cases.