Search Results (3,910)

This paper outlines the system engineering of a Lunar Robotic Construction System (LRCS) for the bagging and manipulation of Regolith Containment Units (RCUs) on the lunar surface. The lunar regolith is the most readily available material on the Moon’s surface, which can be utilized for the protection of structures, machines, and equipment from projectiles, thermal variations, and radiation. A mission scenario of employing the LRCS for the creation of a blast berm for landing pads is presented, and the subsystems are subsequently designed in detail. Structural and physical modeling of the LRCS is performed, including simulations of the regolith intake mechanism. An analysis of LRCS mass, power, and cost is also studied, completing its system engineering. Full article

The rapid expansion of artificial intelligence and cloud computing is straining terrestrial data center infrastructure, motivating exploration of space-based data centers (SBDCs) as a scalable and energy-efficient alternative. While orbital platforms offer unique advantages, including continuous solar energy, radiative cooling, and global coverage, their practical deployment is constrained by unresolved reliability challenges across the mission lifecycle. This study presents a lifecycle-oriented reliability and risk assessment for SBDCs spanning launch, orbital operation, maintenance, and end-of-life phases, using a structured systems-level analysis of failure modes and operational dependencies. This paper focuses on compute-centric SBDC architectures, treating storage solely as a supporting resource. We identify and classify space-environment-specific risks, including launch-induced mechanical stress, radiation-driven degradation, thermal extremes, and single points of failure in power and communication subsystems. By integrating engineering constraints with economic considerations, we develop a unified risk-chain framework that shows how reliability limitations propagate from component design to system cost and operational viability. The analysis reveals a critical trade-off: achieving terrestrial-grade reliability in orbit requires substantial redundancy and radiation hardening, increasing mass and cost and reducing economic feasibility, whereas lower-reliability designs introduce operational and financial risks that challenge sustainability. These findings establish reliability as the central determinant of SBDC viability, providing an applied foundation for fault-tolerant, modular, and lifecycle-aware design strategies essential for transitioning orbital cloud infrastructure from concept to scalable reality. Full article

Tracking agrivoltaic (TAV) systems represent a significant form of agrivoltaics, which optimize solar energy capture through the dynamic adjustment of photovoltaic (PV) panel tilt angles. However, there is limited research on the effects of TAV systems on the three-dimensional spatial distribution of the light environment within PV arrays and their impacts on agricultural production. Therefore, a comparative experiment was conducted between wheat production under a TAV system and traditional open-field cultivation. Solar radiation intensity sensors were deployed to continuously monitor the dynamic changes in solar radiation under and between the PV panels throughout the entire growth period. Simultaneously, a light environment model for the TAV system was constructed, and the photosynthetic parameters of wheat leaves, as well as yield, were measured. The results indicated that the light environment within the system exhibited significant gradient attenuation, with average light capture rates of 43.2% and 46.1% for the inter-panel and under-panel measurement points, respectively. The model results confirmed that the synergistic adjustment of panel tilt angle and solar altitude angle significantly affected the shading effects, leading to notable spatiotemporal heterogeneity in the light environment during the winter solstice, spring equinox, and summer solstice. This heterogeneity showed as regular variations in shadows and radiation, collectively forming a dynamic light–thermal environment that influences crop growth. Wheat yields under and between the panels decreased by 11.5% and 6.6%, respectively, compared to the open-field control, with yields of 4625.9 kg·hm⁻² and 4883.6 kg·hm⁻². Additionally, the photosynthetic characteristics of the leaves effectively reflected the yield differences. Overall, the comprehensive benefit assessment demonstrates that the TAV system can effectively mitigate the reduction in wheat yield in PV farmlands. This study provides a theoretical basis for optimizing the light environment in AV systems. Full article

The development of electronic substrates from locally available materials is critical for sustainable lunar infrastructure. This work investigates the synthesis, processing, and characterization of cyanate ester–lunar regolith simulant (CE-LRS) composites designed specifically for the extreme lunar environment. LRS were evaluated as functional fillers at loadings up to 55 wt.% with CE binder selected for its thermal stability (T_g > 230 °C), vacuum compatibility, and known radiation resistance from prior literature. A vacuum-assisted curing procedure was developed that utilizes the lunar environment as a processing advantage, reducing porosity from approximately 7% to less than 1% as quantified by X-ray micro-computed tomography. Dynamic mechanical analysis revealed that increased filler loading and vacuum processing enhanced the storage modulus and T_g through constraining polymer chain mobility at the filler-binder interface, confirming effective stress transfer and interfacial adhesion. Scanning electron microscopy also verified intimate polymer–filler wetting. Waveguide measurements in the microwave frequency range demonstrated that the composites remain non-magnetic while exhibiting moderately increased permittivity and low dielectric loss, meeting the requirements for radio-frequency substrate applications. Through material selection and process design that embraces, rather than ignores, lunar environmental constraints, this work establishes the CE-LRS composites that represent a viable pathway for the in situ fabrication of structural electronics on the Moon. Full article

In indoor thermal analyses, the effect of humid air as a radiatively participating medium that absorbs and emits energy is often neglected. This simplification can underestimate important values in the results. This study presents a numerical investigation of the humid air that participates radiatively in the conjugate heat and mass transfer convection into a room modeled as a two-dimensional square cavity with a semitransparent wall (glass). The governing equations for mass, momentum, energy, species transport, turbulence, and radiative heat transfer were solved using the Finite Volume Method and coupled with the SIMPLEC algorithm. Two scenarios were analyzed: a radiatively participating medium (RPM) and a non-participating medium (NPM), under two climatic conditions (hot and cold). Results show that considering the radiatively participating medium breaks the symmetric patterns observed in the case of NPM. The energy absorbed by humid air enhances turbulent viscosity, buoyant forces, and indoor temperature. Humid air absorbs approximately 30–32% of the incident energy entering the enclosure. Finally, a correlation for the average temperature is proposed. The results provide insight into the influence of radiatively participating humid air on indoor-like thermal behavior. The study focuses on the analysis of fundamental transport mechanisms. Full article

As a mountain–water city in the upper Yangtze River region, Chongqing is characterized by complex river-valley terrain, dense riverside development, extreme summer heat, high humidity, and frequent calm-wind conditions. Existing studies on waterfront thermal comfort mainly focus on plain cities, whereas mountainous riverside parks remain insufficiently understood. This study investigated summer thermal comfort in three riverside parks in Chongqing—Jiulongtan Park, Coral Park, and Jiangtan Park—through field measurements of air temperature, black globe temperature, wind speed, relative humidity, and Thermal Radiation, combined with thermal sensation vote (TSV) and thermal comfort vote (TCV) surveys. Results showed that the maximum air temperature reached 43.7 °C and the maximum black globe temperature reached 61.6 °C. The hydrophilic layer recorded the highest wind speed (1.64 ± 0.39 m/s), while the elastic layer showed high PET values (36.00–46.10 °C). Regression analysis indicated neutral PET values of 32.49–35.74 °C. Correlation analysis showed that PET, mean thermal sensation vote (MTSV), and mean thermal comfort vote (MTCV) were positively correlated with air temperature, black globe temperature, mean radiant temperature (T_mrt), and relative humidity. In contrast, PET was negatively correlated with wind speed. This study reveals the coupled effects of river-valley terrain, elevation stratification, waterfront microclimate, and landscape elements on outdoor thermal comfort, providing a scientific basis for optimizing shading, ventilation, and hydrophilic spaces in hot-humid mountain–water cities. Full article

The increasing complexity and extended operational lifetimes of modern space infrastructure have significantly intensified the demand for reliable structural health monitoring (SHM) systems. However, the extreme space environment, characterized by radiation exposure, microgravity, ultra-high vacuum, and severe thermal cycling, imposes critical limitations on conventional electrical sensing technologies, leading to reduced measurement accuracy, instability, and long-term degradation. This review presents a comprehensive analysis of fiber Bragg grating (FBG)-based sensing technologies as a promising solution for deformation monitoring in space infrastructure. The study investigates the fundamental operating principles of FBG sensors under space conditions and systematically classifies existing FBG-based SHM architectures, including point-based, multiplexed, long-distance, and hybrid sensing systems. Furthermore, the advantages of FBG sensors—such as immunity to electromagnetic interference, passive operation, and high-resolution multipoint sensing—are critically evaluated in comparison with traditional electrical sensors. In addition, key challenges affecting the performance of FBG systems in space environments are analyzed, including radiation-induced wavelength drift, temperature–strain cross-sensitivity, signal attenuation, and long-term stability issues. The paper also highlights recent advances in interrogation techniques and network architectures that enable reliable in situ and real-time deformation monitoring of space structures. The results demonstrate that FBG-based sensing systems provide a scalable and robust framework for SHM in extreme environments while also revealing existing limitations and open research challenges. This work establishes a structured foundation for the development of next-generation intelligent monitoring systems for space infrastructure. Full article

This article focuses on aspects related to the physical and thermal parameters of so-called thermal-insulating paints. These materials and systems are used in two different situations: first, as agents reducing surface temperature due to solar radiation, and second, as so-called “thermal-insulating” coatings. The paper focuses on the second aspect of the applications described by the manufacturers and presents the results of the author’s laboratory tests (using an insulated heating box with two different heat sources) and field tests (in situ) on a building façade. The research methodology focuses on contact and thermal imaging measurements to assess the effectiveness and properties of reflective thermal-insulating paints, as well as analyzing their impact on the surface temperature and heat transfer coefficient of building envelopes. The conducted research showed that the use of reflective thermal-insulating paints does not significantly improve the thermal insulation of building envelopes. Measurements of the heat transfer coefficient showed a reduction of 1–7% compared to the reference wall tested. In situ measurements using temperature sensors and thermographic studies confirmed the insignificant impact of reflective thermal insulation paints on the thermal protection of external walls. Full article

Both developed and developing countries are striving to reduce building energy consumption. Heating still accounts for an important share of the total energy used in buildings. Many studies compare different heating modes, but few take into account that, first of all, in heated rooms, similar operative temperatures should be provided. In this study, operative temperatures in different locations of a heated room have been analysed, assuming two different heating systems. In addition, the operative temperature distribution can be further disturbed by the room geometry (one or more external walls, or family house) and the room’s position in the building (ground floor, intermediate floor, or top floor). The operative temperature distribution was analysed at nine locations across 525 different room models for radiator and floor heating. The conducted research proved that, at the p = 0.05 significance level, the differences in operative temperatures across locations in a radiator-heated room are significant. Differences in operative temperatures across locations in a floor-heated room are significant and the number of external walls (one, two, or three) also have a significant effect on operative temperatures in a heated room. The differences in operative temperatures at the same location in a heated room with different dimensions can be significant. The differences between the mean operative temperatures in a room (radiator-heated or floor-heated) are not significant if the room has different positions in a multilevel building (ground floor, intermediate level, or top level). To compare two heating systems energetically, a complex analysis should be conducted, and efforts should be made to ensure similar operative temperatures at the most critical locations. Full article

Heating water in outdoor pools is common, particularly in regions with cool or temperate climates. Several factors, including solar radiation, ambient temperature, wind speed, and humidity, influence the pool water temperature. A key design challenge is to determine the collector surface area required to achieve the desired pool water temperature. In this study, a mathematical model was developed that accounts for the aforementioned factors. Under various operating conditions, thermal performance calculations were carried out. Climatic conditions at three locations across Europe, representing different climate regimes, were analyzed. The model was compared with results from the POLYSUN simulation software. Most of the calculations were performed for a pool surface area of 24 m². The calculations showed that wind speed above the pool water surface has a significant impact on heat losses. Locating the pool in a sheltered area results in a consistent reduction in heat losses. It was determined that, under the climatic conditions of Kraków, the installation of solar collectors with a surface area equal to 50% of the pool surface enables the maintenance of daytime water temperatures above 21 °C for approximately 100 days. In the absence of solar collectors, achieving such temperatures is not feasible. Full article

Electrolytic-plasma hardening of steel components requires reliable non-contact temperature monitoring, but traditional pyrometry is complicated by the variable emissivity of steel and the intense radiation of the plasma envelope. This work presents an approach that repurposes a compact multispectral AS7341 sensor into a virtual temperature sensor based on physically grounded spectral feature engineering and regularized machine learning. The use of logarithmic ratios of the near-infrared channel (940 nm) to the visible channels suppresses the plasma contribution and linearizes Wien’s radiation law. On a controlled dataset of 20 cycles, this increases the Pearson correlation with the peak temperature from r = 0.498 (raw NIR channel) to r = 0.781 for the log(NIR/Clear) feature. Current is identified as a confounding variable; normalizing the NIR/Clear ratio by the cycle-averaged current (r = 0.761) ensures correct signal interpretation under varying process conditions. Two narrow channels–NIR (940 nm) and F8 (680 nm)–provide accuracy equivalent to the broadband Clear channel (r = 0.778 vs. 0.781), thus simplifying hardware implementation. Ridge regression using three weakly correlated features (log(NIR/Clear), cycle duration, and initial temperature) achieves a mean absolute error of 91.4 °C under leave-one-out cross-validation (LOOCV) and 85.5 °C on an independent current-group test (R² = 0.536). Independent verification by scanning electron microscopy and Vickers microhardness on 30KhGSA steel confirms reliable separation of the three thermal regimes: underheating (<800 °C, 280–320 HV), optimal quenching (800–900 °C, 620–680 HV, fine-needle martensite), and overheating (>900 °C, 540–590 HV). The proposed set of spectral features provides a physically justified basis for a low-cost industrial temperature sensor for electrolytic-plasma processing. Full article

There are differences in imaging characteristics between infrared and visible light images: visible light images can provide rich texture and color information, but imaging is limited in harsh weather conditions. Infrared images are based on the target’s thermal radiation characteristics and have the ability to resist environmental interference but lack details and background information. Effectively integrating the two can significantly enhance scene understanding ability and improve environmental perception and target recognition performance in applications such as intelligent driving. However, existing fusion methods still face challenges, especially in complex scenes where it is difficult to balance the full preservation of target information with the complete presentation of background details, often resulting in difficulties in extracting differentiated features from different modalities. This article proposes a target detection method based on the visible light infrared fusion diffusion model. This method introduces the Stable Diffusion architecture and designs a target perception spatial fusion weight module that can adaptively generate a spatial fusion weight map based on modal differences. By implementing a multi-stage dynamic fusion strategy, the fusion ratio is automatically adjusted at different diffusion stages. A full-step multi-step prediction mechanism is adopted to improve fusion quality and stability. Compared with existing methods, the method proposed in this article has significant advantages. Experiments on multiple publicly available datasets have shown that this method outperforms existing mainstream methods in key metrics such as Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE), and ean Absolute Error (MAE) and also demonstrates good detection performance in downstream tasks for object detection. Full article

The phenomenon related to urban heat islands is becoming severe. Besides the concrete building walls in cities, the urban surface also includes a large amount of asphalt pavement, whose thermal properties play a significant role in influencing the urban heat island. Therefore, it is necessary to examine the thermal characteristics of different asphalt aggregates and to enhance their effect on mitigating the urban heat island effect by applying radiative cooling to the aggregate components. Through indoor scaled experiments, we produced 30 × 30 × 5 cm asphalt concrete specimens, including conventional asphalt concrete (dense mix) and basic oxygen furnace slag (BOF) asphalt concrete with 100% aggregate replacement. The asphalt concrete specimens were heated in an oven until they reached the same temperature as the actual asphalt pavement and then subjected to 24 h radiation heat release cooling observation, to record temperature, humidity, and heat flux. The measured data were then verified against the theoretical values. The results showed that asphalt concrete with BOF aggregate had a higher heat capacity and a more pronounced radiative cooling effect than conventional asphalt. Such properties enable the localized cooling of the surrounding air. The results of this study provide a basis for the development of aggregate asphalt to boost the radiative cooling performance of surface materials and reduce the urban heat island effect. Full article

Land surface temperature (LST) and its diurnal variation are critical for understanding the surface energy balance and water cycle processes. Traditional diurnal temperature cycle (DTC) models are widely used to reconstruct continuous temperature sequences from sparse satellite observations. However, these models rely on the idealized assumption of an isotropic surface and ignore the thermal radiation directionality caused by viewing geometry, which introduces substantial errors over heterogeneous surfaces. Thus, incorporating angular effects into DTC modeling has become an effective approach to improving LST simulation accuracy. This review traces the progress of DTC models from isotropic to anisotropic representations. First, we summarize the development and inherent limitations of conventional isotropic DTC models. Then, we synthesize representative angular-coupled models, ranging from early simple component-based models to recent kernel-driven coupling methods, and compare their physical assumptions, data requirements, parameter complexity, and applicable scenarios. Although these coupled models can significantly improve fitting accuracy over heterogeneous surfaces, they still face challenges. These include strict data requirements, limited all-weather applicability, a lack of nighttime angular correction, and incomplete validation systems. Future research can advance through multi-source data fusion, hybrid modeling strategies, and robust validation systems. These are key to generating high-precision, spatiotemporally consistent LST data. Full article

Rockfall events are significant natural hazards on fractured rock cliffs, often driven by environmental forcing, including thermal variations that induce stress and fatigue in rocks. This study presents the first application of Ground-Based Interferometric Synthetic Aperture Radar (GB-InSAR) for high-resolution monitoring of sub-millimeter thermally induced displacements on a rock slope. An eight-day pilot experiment conducted at the La Cornalle molasse cliff (Vaud, Switzerland) revealed cyclic displacement signals with a clear 24 h periodicity, identified through Fourier and wavelet analyses, with a mean amplitude of 5 × 10⁻⁴ m. Simultaneously, infrared thermography (IRT) and a weather station recorded rock surface and air temperature variations, allowing a first estimation of the time lag between thermal forcing and mechanical response, with delays of 1–8 h relative to air temperature and 1–6 h relative to solar radiation. An analytical deformation model based on thermal diffusion predicts a daily displacement amplitude of 4.2 × 10⁻⁵ m, highlighting a significant difference with GB-InSAR observations and emphasizing the influence of structural complexity and thermo-hydro-mechanical processes in rock slopes. These results demonstrate the capability of combined high-resolution remote sensing techniques to quantify thermo-mechanical behavior in rock masses and provide a methodological framework for future investigations of rockfall-prone slopes. Full article