Search Results (904)

Waste from the wind power and textile industries poses major environmental challenges. While the textile industry is a significant global contributor to waste, producing around 92 million tons of waste annually, and greenhouse gas emissions, wind power, although one of the cleanest energy sources during operation, still generates waste and associated CO₂ emissions, particularly associated with the end-of-life decommissioning of turbine blades. This waste can be reused, combined with bio-based binders, to reduce the construction sector’s long-term environmental impact. The present work identifies research trends and gaps in the use of these waste materials, either individually or combined, for the development of thermal and acoustic insulation solutions for the construction sector, by means of a combined bibliometric and content analysis of Scopus and Web of Science documents from 2014 to 2025. The study focuses on bibliometric indicators and reports on physical properties (thermal conductivity, density, mechanical strength, and acoustic performance) of the resulting composites, including those produced with bio-binders. Additionally, a qualitative review of life cycle assessment studies indicates that bio-based and waste-derived insulation materials can significantly reduce environmental impacts compared with conventional mineral or petrochemical insulators. Results reveal growing scientific interest in this subject, highlighting an annual publication growth of 5.09%. They emphasize the performance of natural textile fibers in thermal and acoustic insulation, the mechanical capacity of synthetic fibers, and the semi-structural potential of fiberglass composites. Meanwhile, bio-binders improve the upcycling of textile waste; however, they reveal a significant research gap in the integration of wind turbine blade waste into insulation composites. No indexed studies were found that simultaneously combine textile waste, blade-derived fibers, and bio-based binders in a single insulation system, despite projected cumulative blade waste of 43 million tons by 2050. These findings advocate hybrid innovations and standardized assessments to drive circular economy and low-carbon building solutions. Full article

This paper presents a multimodal transformer-based framework for the joint prediction of indoor thermal comfort and energy efficiency using real-world building management system (BMS) datasets. Unlike traditional comfort models that rely on fixed physical assumptions and subjective surveys, the proposed approach adopts physics-guided, data-driven learning to capture nonlinear and time-dependent interactions among environmental conditions, HVAC operation, and occupancy-related variables. Thermal comfort labels are computed using the PMV–PPD formulation defined by ASHRAE Standard 55, assuming standard metabolic rate and clothing insulation due to the lack of direct measurements in routine BMS data. A temperature-driven baseline HVAC energy proxy is derived using change-point regression. The proposed transformer architecture fuses multivariate temporal sequences to jointly predict both comfort and energy baseline targets through a dual-head regression formulation. The model is validated on two complementary datasets representing steady-state and dynamically perturbed thermal conditions. The proposed approach consistently outperforms linear regression, random forest, and LSTM baselines, achieving mean absolute errors below 0.03 and $R^2$ values exceeding 0.98 with corresponding RMSE values below 0.035 for both targets. Residual and calibration analyses confirm stable, unbiased prediction behavior across wide temperature ranges. The results highlight the strong potential of attention-based multimodal learning for future comfort-aware building energy optimization and digital twin integration. Full article

Thermal bridges at window installations significantly influence the energy performance and indoor comfort of buildings, particularly in nearly zero energy buildings (nZEB). This study investigates the impact of window mounting-position on thermal-bridge intensity at window-to-wall junctions using finite element method (FEM) simulations of representative junction configurations. Mounting depth, frame alignment relative to the insulation layer, and junction detailing were systematically varied to quantify their effect on linear thermal transmittance (ψ-values) and internal-surface temperatures. The results show that relatively small changes in mounting position can markedly reduce thermal-bridge effects; the most effective strategy combines installing the window within the insulation layer at an optimal depth of 7–12 cm. Across the studied configurations, ψ decreased from traditional installation values of 0.27 W/(m·K) to 0.02 W/(m·K) for installation in the insulation layer, and with frame overlap and frame extenders, the ψ-value can be further reduced, reaching 0.005 W/(m·K) in the best case. Applying external insulation increases the minimum internal-surface temperature by at least 2 °C compared with cases without frame covering. In the case study of a historical building retrofitted to Passive House (PH) standard, installing windows in the insulation layer reduced annual heating demand from 32 kWh/m² to 24 kWh/m². The additional investment is economically justified, with a simple payback period of about 25 years, decreasing to around 20 years assuming a 3% annual increase in energy prices. These findings demonstrate that optimised window positioning is an effective and economically viable measure to improve the energy performance, durability, and sustainability of high-performance buildings. Full article

While recent research has extensively investigated the feasibility of incorporating various agricultural by-products as aggregate replacements in concrete, the specific potential of crushed date kernel (CDK) remains insufficiently characterized despite their abundance. This study evaluates the performance of concrete incorporating CDK as a partial replacement for fine aggregates at volumetric ratios ranging from 5% to 30%. The experimental program was oriented to find the major properties of the mixes, such as compressive strength, splitting tensile strength, flexural strength, and bonding, in addition to the Ultrasonic Pulse Velocity, water absorption, density, and thermal conductivity. The compressive strength of the standard mixture was 26.73 MPa, the flexural strength was 4.47 MPa, and the thermal conductivity was 1.99 W/m·K after 28 days. A compressive strength of 26.78 MPa was recorded for a 5% substitution, but the flexural strength of 4.85 MPa was greater, along with a reduction in the thermal conductivity of 1.86 W/m·K. Higher replacement ratios led to a gradual loss of mechanical strength, whereas 30% replacement gave a corresponding stress of 19.65 MPa. However, thermal conductivity continued to decrease to a value of 1.27 W/m·K, indicating a better insulation capacity. Furthermore, the TOPSIS multi-criteria decision-making analysis demonstrated a robust classification across multiple weighting combinations. The analysis identified the 5% replacement ratio as the optimum for operating and the 10% replacement as optimum on a sustainability basis. Full article

With the rapid development of electrified railways in high-altitude regions, section insulators in catenary systems frequently experience gap breakdown and surface flashover under low atmospheric pressure conditions, posing serious threats to safe train operation. This paper investigates the discharge mechanisms of section insulators in high-altitude environments and conducts research on discharge characteristics under extremely non-uniform electric fields, along with structural optimization. First, the physical mechanisms of gap discharge and surface flashover in section insulators are analyzed. A three-dimensional electric field simulation model of the section insulator is established, and numerical analysis is performed to reveal the electric field distribution characteristics. The results indicate that the electric field is predominantly concentrated at the junction between metal electrodes and insulators, as well as at the tip of the arcing horn. The local maximum field strength reaches 3.84 × 10⁵ V/m, exceeding the corona inception field strength of air, which readily induces discharge. Subsequently, power frequency and lightning impulse discharge tests are conducted in both plain region and regions at an altitude of 4300 m. The results show that under high-altitude conditions, the power frequency breakdown voltage decreases by 28%, and the 50% lightning impulse breakdown voltage decreases by 42%. The discharge voltages under standard atmospheric conditions are obtained through correction. Finally, optimization schemes involving arcing horn structural modification and surface coating application are proposed. Adjusting the arcing horn angle to 55° and adding a grading ring structure with a radius of 70 mm reduces the local maximum field strength by 26%. After applying an RTV insulating coating, the field strength at the junction decreases by 35.9%, effectively enhancing the insulation performance of section insulators in high-altitude regions. Full article

Improving the energy efficiency of the building envelope is critical for global decarbonization, yet a gap remains in the comprehensive thermophysical characterization of carbon-enhanced Expanded Polystyrene (EPS). This study evaluates the impact of expansion ratios and moisture content on the thermal behavior of two commercial EPS grades, EPS-A (12.7 ± 0.5 kg/m³) and EPS-B (16.0 ± 1.1 kg/m³), investigating the counterintuitive role of graphite (1.4–1.8 wt.%) in enhancing the thermal insulation properties. Thermal conductivity and diffusivity were independently determined via Transient Plane Source (TPS) and Heat Flow Meter (HFM) methods across a 10–50 °C range, while specific heat capacity (c_p) was analyzed using HFM and Differential Scanning Calorimetry (DSC) through the sapphire comparison method and Temperature-Modulated DSC (TOPEM^®). Methodologically, it was found that standard HFM protocols are unsuitable for c_p determination in low-density foams, yielding an average relative error of ±29%; conversely, the sapphire comparison method provided the most reliable results in agreement with theoretical expectations. Results indicate that the efficacy of graphite as a radiative shield is closely coupled with cellular morphology, proving significantly more effective in the higher expansion grade (EPS-A, 70 wt.% open porosity) than in the denser EPS-B. Furthermore, 30-day water immersion tests revealed that the higher open porosity of EPS-A facilitates increased water uptake of 144 ± 17 wt.% (compared to 97 ± 7 wt.% for EPS-B), causing the geometric densities of the two grades to converge and fundamentally altering thermal transport mechanisms. The study concludes that accurate thermal modeling of carbon-enhanced insulation requires careful selection of testing parameters, particularly when accounting for moisture-induced degradation in high-porosity systems. Full article

Olive pomace biochar, obtained through the pyrolysis of lignocellulosic biomass, has emerged as a sustainable and multifunctional additive for polymer composites. Its physicochemical properties, including porosity, surface area, and electrical conductivity, can be tailored by controlling feedstock type and pyrolysis conditions. Although mechanical reinforcement and thermal stability improvements are well documented, the influence of biochar on surface-related properties such as wettability and contact angle remains insufficiently explored for environmentally relevant composite systems. In this study, epoxy-based composites containing biochar synthesized at 750 °C were evaluated in terms of their water interaction behavior by monitoring the evaporation dynamics of ultra-pure water droplets (10 μL, 0.055 mS/cm conductivity) at eight time intervals between 20 and 580 s using high-resolution digital microscopy. Image enhancement and segmentation were performed prior to Discrete Cosine Transform (DCT) analysis to describe droplet geometry in the frequency domain. Time-dependent variations in the standard deviations of DCT coefficients were optimized using the Bat Algorithm, resulting in mathematical models capable of accurately representing droplet evolution and surface–fluid interactions. The primary novelty of this study lies in the development of a hybrid experimental–computational framework that integrates droplet-based wettability measurements with signal-domain analysis and metaheuristic optimization. Unlike conventional studies focusing solely on material characterization, this approach establishes quantitative relationships between surface behavior and numerical descriptors derived from DCT and the Bat Algorithm. The proposed methodology provides a data-driven tool for predicting wettability trends in biochar-reinforced composites and supports the development of moisture-resistant materials for coatings, packaging, and thermal insulation applications within the context of sustainable composite design. Full article

This study takes the relevant literature published in the past decade as the research object, screens the literature by setting clear inclusion and exclusion criteria, and systematically reviews the thermal insulation performance, durability, and prospects for engineering applications of bio-based thermal insulation materials by means of qualitative integration and comparative analysis. With the advantages of low energy consumption, renewability, and biodegradability, bio-based thermal insulation materials have emerged as a green alternative to traditional thermal insulation materials. This paper systematically reviews the research progress of such materials, which are classified into two categories: natural biomass (e.g., straw bales and cork boards) and bio-based composites. The core thermal insulation indicators include thermal conductivity, thermal resistance, and thermal storage coefficient, and the performance is affected by factors such as component ratio, pore structure, temperature, and humidity. The thermal conductivity of some bio-based materials is comparable to that of expanded polystyrene (EPS) and mineral wool. In terms of durability, temperature–humidity cycling, corrosion, biological erosion, and mechanical action are the main causes of performance degradation, and composite modification can effectively improve their stability. Current engineering applications face challenges such as thermal insulation performance being susceptible to humidity, poor construction compatibility, high costs, and a lack of relevant standards. Future research should focus on the development of high-performance composite systems, the investigation of long-term durability mechanisms, the innovation of low-cost green preparation technologies, and the establishment of unified standards, so as to promote the large-scale application of bio-based thermal insulation materials in the construction industry and contribute to the achievement of carbon neutrality goals. Full article

The growing demand for environmentally sustainable technologies is driving the adoption of increasingly stringent energy regulations across Europe. The residential sector is particularly impacted, not only through requirements for highly insulated buildings but also through stricter standards for household appliances. Among these, domestic ovens represent a critical target, requiring manufacturers to develop technologies that support laboratory testing while reducing energy consumption. This work proposes a tool to support manufacturers during laboratory testing by applying a multi-objective optimisation approach using the Pareto front method. The code was developed in MATLAB^® and aims to minimise final consumption by acting exclusively on the management of the heating element. The results obtained from the code are first tested in the Simulink^® digital model of the oven and then through experimental testing. The results demonstrate that the proposed tool, specifically tailored for these systems, provides outcomes consistent with real operating conditions, while enabling a substantial reduction in laboratory testing time. Full article

Insulation deterioration is the leading cause of premature failures in high-voltage (HV) power equipment, with partial discharge (PD) serving as a key indicator of insulation health. This study introduces a novel compact PD sensor assembly that integrates fiber Bragg grating (FBG) with an exponential acoustic horn to enhance the sensitivity of PD detection. The horn’s geometry effectively collects ultrasonic emissions from the PD, concentrating the acoustic energy to amplify the force on the FBG located at its focal point. To further enhance signal transduction, the FBG is mounted on a fixed solid structure engineered to resonate at higher ultrasonic frequencies that closely align with the dominant acoustic components generated by PD activity, ensuring improved strain amplification and optimal sensitivity. This results in measurable wavelength shifts, which are used for PD detection. A fiber Bragg grating analyzer interrogates the reflected spectra, providing real-time PD detection during HV operations. The effectiveness of the system was validated against the IEC 60270 standard method using laboratory models that emulated corona and surface discharge. The laboratory experiments demonstrated a significant sensitivity of 2.2 pm/Pa and a favorable signal-to-noise ratio of ~21 dB for the proposed sensor module. The dielectric construction of the sensor module, lightweight design, and resistance to electromagnetic interference make it suitable for harsh HV environments and the long-term condition monitoring of HV power equipment. Full article

While sustainability is set as a goal by a broad range of international organizations, its definition varies, and there is still a lack of practical criteria for product designers to evaluate the degree of (un)sustainability in the design phase. Life cycle assessment (LCA) can allow quantification of the environmental impacts of a product but is often carried out post-design, when the manufacturing process is already settled. Finally, while significant advances have been made towards standardizing LCA calculations by providing product category rules, large uncertainties remain in the calculation results due to a lack of transparency regarding the choices of databases, system boundaries, allocation, cut-off rules, and level of data granularity. A practical way to improve in those areas is to share with the semiconductor community a parametrizable life cycle inventory (LCI) model based on a target device to (1) identify knowledge gaps in LCA methods for such products, (2) identify the main process variables, and (3) provide a starting point for LCA calculations by the designers themselves. With this aim, a parametrizable cradle-to-gate manufacturing LCI model was developed based on the peer-reviewed process flow of a trench field-stop silicon insulated gate bipolar transistor (IGBT) semiconductor power device. The model allows computation of the environmental impacts of the IGBT manufacturing process based on different tunable parameters such as die size, wafer diameter, manufacturing yield, abatement efficiency, wafer fab throughput, wafer fab location, and associated electricity mix. Embedding a high level of data granularity, it helps identify, at elementary process levels, key environmental hotspots and associated technical levers for their reduction. Analysis of the IGBT manufacturing process tends to demonstrate the importance of an impact assessment approach considering multiple environmental categories, going beyond the sole focus on greenhouse gas emissions and accounting for potential transfers of impact. With an open-source mindset and in a continuous improvement prospective, the manufacturing inventory model and its associated tools are freely available from a public GitHub repository and open for comments and consolidation from users. Full article

The insulation condition of oil-pressboard insulating bushings is commonly evaluated by measuring the dielectric loss factor and capacitance at power frequency. However, systematic investigations into the influence of aging and moisture defects on frequency-domain dielectric spectroscopy (FDS) characteristics are still insufficient. To address this issue, a 10 kV high-voltage FDS measurement system was independently developed. The system has an output voltage range of 0~10 kV and a test frequency band of 1 mHz~10 Hz, with excellent measurement stability and high test accuracy. The standard deviation of dielectric loss of the system is on the order of 10⁻⁴ and the relative error is less than 5%. It also features reliable weak current detection capability and thermal stability. Based on this system, the dielectric spectral characteristics of oil-pressboard insulation models with different moisture contents and aging levels were investigated under various temperatures and applied voltages. The results indicate that the dielectric spectrum shifts toward higher frequencies with increasing temperature. Moreover, the low-frequency dielectric loss of degraded insulation increases linearly with the applied voltage, and the rate of increase shows a positive correlation with both moisture content and aging duration. As insulation degradation becomes more severe, the voltage-dependent characteristic frequency moves toward higher frequencies. This frequency refers to the characteristic frequency where the dielectric loss of insulation presents an obvious linear variation with the change of applied voltage. Unaged and dry bushings exhibit only weak voltage dependence at 0.01 Hz, whereas bushings aged for 28 days with a moisture content of 4.121% demonstrate pronounced voltage dependence at 10 Hz. These results provide a valuable technical basis for diagnosing coupled aging and moisture defects in oil-pressboard insulated bushings. Full article

When cold waves occur in winter, the entire vineyard greenhouse is completely covered with plastic film to improve heat insulation. However, differences in vertical stratification of soil faunal communities between pre-sealing (PSP) and sealing periods (SP) have not been fully quantified. We compared soil fauna communities and hydrothermal nutrient conditions between PSP and SP in standardized protected vineyards, sampling 0–10, 10–20, and 20–30 cm soil layers. Community traits were analyzed via paired Wilcoxon tests and mixed-effects models, while compositional differentiation was assessed using PCoA/PERMANOVA, NMDS/ANOSIM, and redundancy analysis with hierarchical partitioning. Soil fauna abundance decreased significantly in SP, with sharp declines in 0–10 and 20–30 cm layers, whereas the 10–20 cm layer showed minimal shifts. Taxon richness and alpha-diversity indices exhibited no consistent stage-specific variations. Inter-layer compositional differentiation intensified in SP, indicating enhanced vertical community stratification. Depth-specific analysis revealed the main drivers of community shifts: SOC and C: N in 0–10 cm, pH and C: N in 10–20 cm, and moisture and temperature in 20–30 cm. Overall, we observed layer-dependent shifts in soil microenvironments and faunal communities between PSP and SP, suggesting that soil depth should be considered in protected vineyard management. Full article

The textile industry is seeking alternative coloration methods to comply with the global demands for eco-friendly and non-hazardous dyes, as synthetic colorants are costly and substantially toxic in nature, having deleterious effects on the environment as well as ecosystems. This research aimed to develop a printed functional cotton fabric using a new bio-based pigment from acacia wood waste (Acacia nilotica) charcoal. Acacia charcoal was ground into fine powder and added into pigment paste with polyacrylic binder and screen printed on cotton fabric, followed by drying and curing. The printed fabric was tested for color strength (K/S), colorfastness, flame resistance, contact angle (for checking the hydrophobicity), thermal insulation, and tensile strength following standard testing protocols. Using different charcoal concentrations (in the range of 0.5–5%), the samples presented light to dark gray color and the K/S value gradually increased from 1.85 (0.5%) to 12.31 (5%), demonstrating stronger color depth. The printed fabrics revealed good results in terms of color fastness ratings (washing 3–5, dry rubbing 3–5, wet rubbing 3–5), satisfactory flame resistance, good thermal insulation, and excellent hydrophobicity. The obtained results contribute to sustainable and durable textile development for achieving better performance. Full article

The construction sector faces increasing pressure to reduce the embodied energy of building materials while valorizing industrial waste streams. This study evaluates the direct incorporation of post-industrial textile waste (100% cotton and cotton–polyester blends) in its native form to develop high-performance cementitious ceiling sheets. Composites were fabricated under a controlled hydraulic compaction pressure of 2.0 MPa, optimized to achieve matrix densification while preserving the integrity of the fibrous network. Viscoelastic recovery of the compressed fibers induced a hierarchical double-porosity architecture characterized by macro-voids and hollow fiber lumens. This microstructural evolution reduced thermal conductivity to 0.091 W/m·K, approximately 50% lower than commercial cement–fiber benchmarks—without compromising mechanical compliance. Scanning Electron Microscopy (SEM) revealed a mechanistic decoupling between water absorption and dimensional stability. Although the CP15 formulation (15 wt.% cotton–polyester) exhibited high moisture uptake (~21%), thickness swelling remained limited to 1.35%. This dimensional stability is attributed to the hydrophobic polyester framework, which bridges microcracks and constrains hygroscopic expansion within the cellulosic phase. The optimized CP15 composite achieved a Modulus of Rupture (MOR) of 8.75 MPa, exceeding ISO 8336 Category C, Class 2 requirements. Despite increased thickness, the areal density (10.84 kg/m²) remains compatible with standard gypsum-grade suspension systems, eliminating the need for structural modification. These findings establish a scalable, direct-valorization strategy for circular construction materials delivering enhanced thermal insulation and robust performance under tropical climatic conditions. Full article