Search Results (11,182)

In this paper, a novel biobased phenol formaldehyde resin foam was fabricated. Specifically, lignosulfonate, a byproduct of paper and pulping, is hydroxymethylated with paraformaldehyde and then condensed with phenol to form lignosulfonate-based phenol formaldehyde (LPF) resin, subsequently undergoing foam technology to prepare LPF foam. The structures and properties of the intermediate and target products were characterized by ¹H nuclear magnetic resonance (¹H NMR) spectroscopy, gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry derivative thermogravimetry (TGA-DTG), scanning electron microscopy (SEM), compression performance test, limiting oxygen index test and thermal conductivity measurement. It was found that the prepared foam exhibited excellent mechanical and thermal properties. At a lignin substitution degree of 10%, the optimal thermal stability (at 800 °C), compressive strength (0.14 MPa) and thermal conductivity (0.0294 W/m·K) were achieved. As the lignosulfonate content gradually increases, the limit oxygen index initially showed a significant increase and then decreased. It is worth noting that when the LS substitution degree is increased to 30%, the limiting oxygen index of foam is up to 32.6%. These results underscore the application potential of industrial lignin as a promising biobased substitute in the synthesizing PF foam with excellent thermal insulation and flame-retardant properties. Full article

This study presents an environmental and circularity assessment of an integrated insulation-production system that valorises plastic waste and wood packaging waste as secondary material and energy resources. The analysis evaluates the recovery of incoming waste streams and their reintegration into a new production cycle, while the downstream end-of-life of the resulting insulation product remains outside the assessed system boundary. The process chain includes mechanical pre-treatment of wood (grinding, metal separation, and pelletising); thermochemical conversion via wood gasification and gas combustion; and post-combustion CO₂ capture. The captured CO₂ is used in the subsequent polymer processing stages, which comprise mixing, extrusion, thermal treatment, and cooling. Environmental impacts are evaluated through Life Cycle Assessment (LCA), while circularity indicators are assessed within the framework of EN 15804+A2. The results demonstrate the environmental and circularity potential of valorising wood packaging and plastic waste in the context of carbon capture and utilisation (CCU) and sustainable material development. Full article

This study presents a data-driven evaluation of recycled-aggregate gypsum composites by examining the relationships between dry density, mechanical performance, thermal conductivity, and formaldehyde adsorption. Analysis of published experimental data shows that dry density is the primary parameter governing overall material performance. Compressive strength increases with density, whereas lower-density composites provide superior thermal insulation. An optimal multifunctional performance range was identified at 900–1100 kg/m³, where a favorable balance between strength and insulation efficiency is achieved. Aggregate type also influences performance: polymer-based aggregates produce the greatest density reduction, biomass-derived aggregates offer a balanced combination of properties, and mineral-based aggregates generally maintain higher stiffness. Assessment of environmental functionality indicates that conventional gypsum composites possess limited formaldehyde and CO₂ adsorption capacity, although biochar and other bio-based modifications can significantly enhance adsorption performance. These findings provide a practical framework for designing sustainable gypsum composites with balanced structural, thermal, and indoor air quality benefits. Full article

High-efficiency industrial motors are increasingly important for reducing energy consumption, operating costs, and indirect carbon emissions. This study presents a comparative evaluation of IE2 and IE4 efficiency class induction motors with the same rated power and frame size through finite element analysis and prototype testing. Two-dimensional transient electromagnetic models were developed in ANSYS Maxwell to investigate magnetic flux distribution, torque behavior, losses, and steady-state performance, and the numerical results were experimentally validated according to IEC 60034-2-1 procedures. The results show that the IE4 motor provides a more balanced magnetic flux distribution, lower local saturation tendency, reduced torque ripple, and lower total losses than the IE2 motor. Experimental measurements confirmed the numerical predictions with good agreement, particularly at the rated operating point. In addition to higher efficiency, the IE4 motor exhibited stronger starting and breakdown torque characteristics, indicating superior load-handling capability. An economic assessment based on a representative duty cycle showed that the relative additional cost of the IE4 motor can be recovered within approximately 0.81 years, while lower annual electricity consumption also reduces indirect CO₂ emissions. Furthermore, the IE4 prototype operated at a lower thermal steady-state temperature, supporting longer insulation life and improved long-term reliability. Overall, the findings demonstrate that replacing conventional IE2 motors with IE4 alternatives is not merely an efficiency upgrade, but also a technically robust, economically justified, and environmentally effective strategy for sustainable industrial systems. Full article

Efficient thermal management is a critical constraint for the performance, safety, and lifetime of electric vehicle (EV) batteries, particularly under transient high-power operation, where conventional dielectric coolants remain limited by the absence of thermal buffering. This Perspective examines PCM–dielectric hybrid coolants as a multiphase electro-thermal-fluid system, in which microencapsulated phase-change materials provide localized latent heat storage within a circulating insulating medium. Rather than proposing a new material concept, the work establishes a system-level engineering framework that links material properties, transport behavior, and electrical constraints to practical implementation. Key challenges, including dispersion stability, capsule durability under coupled stresses, dielectric reliability in heterogeneous media, and rheological limitations, are analyzed alongside quantitative design envelopes and validation pathways. A structured roadmap is presented, spanning multiphysics modeling, accelerated material qualification, system-level testing, and industrial integration, supported by techno-economic and lifecycle considerations. Full article

The increasing frequency of heatwaves and high-temperature events due to climate change intensifies heat stress and mortality risk in broiler production and necessitates reassessment of facility design and energy management. This study developed a machine learning surrogate model trained on BES-simulated heating and cooling loads to estimate future energy load changes in broiler houses under SSP climate scenarios. Training data were constructed using simulated energy load results under different insulation conditions combined with historical meteorological data (2011–2020). Four machine learning models, namely Linear Regression, Random Forest, Gradient Boosting, and XGBoost, were applied to compare their predictive performance for heating and cooling loads. Model performance was evaluated using five-fold cross-validation (K-fold cross-validation, K = 5). XGBoost and Random Forest showed the best performance for heating and cooling load prediction, respectively (R² > 0.99, MAPE < 10%). These models were applied to SSP1-2.6 and SSP5-8.5 climate scenarios. Results showed decreasing heating loads and increasing cooling loads across all scenarios, with cooling demand projected to increase by more than 150% relative to baseline levels under SSP5-8.5 by the late 21st century. This study demonstrates that simulation-trained machine learning can efficiently estimate long-term energy-demand changes, supporting climate-responsive facility design and energy management in livestock housing. Full article

The magnetic susceptibilities of various electrically insulating ordinary fluids depend on their local states, such as their density and temperature. When such fluids, which can be characterized as either paramagnetic or diamagnetic and occur commonly in nature, are subjected to magnetic field gradients, it induces an effective body force—the Kelvin force. This force, which depends on the susceptibility and the gradient of the square of the magnetic field strength, can become one of the effective mechanisms for modulating the flow and transport, particularly where terrestrial gravity becomes negligible, such as in free space or under microgravity conditions. For the first time, we developed a theoretical model demonstrating that a viscous current can be generated due to the contrasts between the magnetic susceptibilities of the intruding and ambient fluids in the presence of gradients in magnetic fields, analogous to the viscous gravity current in terrestrial situations. We derived similarity solutions for the two-dimensional and axisymmetric currents arising from a balance between the Kelvin buoyancy and viscous forces with a prescribed power law for the magnetic field strength. These determine the shape and various spreading relationships of the viscous current. For a prescribed time variation in the source flux, it is shown that a family of scaling laws exists for the spreading rate and the thickness of the current, which depend on the steepness of the magnetic field gradient. Unlike gravity, since the driving horizontal buoyancy arising from the Kelvin force is externally specified, it potentially offers a mechanism to control the characteristic shape and the rate of motion of the viscous current. Full article

This proof-of-concept study proposes a photovoltaic transparent vacuum insulation panel (PV-TVIP) and evaluates its heat transfer and power generation characteristics with increased temperatures, and light transmission characteristics for visible light and ultraviolet wavelengths. The study was conducted with a climate-controlled chamber mimicking the common temperature range of Sapporo, Japan. The average TVIP heat flux was measured to be 65–75 W/m² with a U-value of 1.95–2.3 W/(m²∙K). Compared to earlier measurements to see the effect of seasonal atmospheric conditions to the quality of the TVIP, it was determined that the TVIP manufactured during winter conducted less heat, assumed to be caused by decreased humidity. Placing the PV between the TVIP and a glass pane increased the operating temperature by 26.06 °C and decreased power generation by 13%. Afterwards, the transparency of the TVIP and PV-TVIP were measured under a bright light therapy lamp, showing that TVIP reduced the amount of most visible light wavelengths by 50% and the PV-TVIP by 90%. UV radiation was respectively reduced by approximately 78% and 100%. The results show that while PV-TVIP shows potential as a BAPV window retrofit solution, its manufacturing requires optimized, low-humidity conditions during all phases of the manufacturing process. Full article

The anatase and rutile phases of titanium dioxide (TiO₂) have been widely studied for their photocatalytic and electronic properties, while the brookite phase is rarely explored. The investigations of intrinsic magnetotransport in mixed-phase systems are limited. Magnetic susceptibility and magnetotransport measurements were performed between 2 K and 300 K in magnetic fields up to 12 T. Both samples with different anatase–rutile–brookite ratios exhibit Curie–Weiss susceptibility. Transport measurements reveal an insulating behavior at low temperatures with activation energies 1–20 meV and signatures of variable-range hopping (VRH) conduction. Strong positive magnetoresistance at low temperatures obeys the Efros–Shklovskii VRH model. Full article

Diabetes mellitus comprises a group of heterogeneous metabolic disorders characterized by persistent hyperglycemia, progressive β-cell dysfunction, and multi-organ complications. Although type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have distinct pathogenic origins, both involve immune dysregulation, tissue stress, release of danger signals, and chronic inflammation. Dendritic cells (DCs), as antigen-presenting cells, integrate innate immune sensing, antigen presentation, cytokine production, T-cell regulation, and peripheral immune tolerance, placing them at a critical interface between autoimmunity and metabolic inflammation. In T1DM, DCs contribute to β-cell autoantigen presentation, tolerance breakdown, autoreactive T-cell activation, and insulitis amplification. In T2DM, DCs may contribute to adipose tissue inflammation, hepatic immunometabolic crosstalk, β-cell stress, vascular inflammation, and immune remodeling associated with diabetes-related complications. Here, we review the disease-specific roles of DC subsets in T1DM and T2DM and discuss shared molecular mechanisms, including pattern-recognition receptor signaling, metabolic reprogramming, inflammasome activation, cytokine networks, and the shift from immune tolerance to inflammation. We also evaluate therapeutic DC reprogramming strategies and their potential implications for targeted immunometabolic intervention in diabetes. Full article

This study investigates the influence of cold-working deformation on the electromotive force (EMF) calibration characteristics, hysteresis behavior, and long-term stability of the Type-K mineral-insulated metal-sheathed (MIMS) thermocouples used in Combination Fixed In-Core Detector Assemblies for pressurized water reactor nuclear power plants. Reduction ratios of 12%, 28%, and 38% were investigated, and samples were subjected to heating–cooling calibration and in situ aging tests. The results show that increased cold-working deformation leads to greater negative EMF deviation and larger heating–cooling hysteresis, mainly affected by the degradation of the positive KP thermoelement. Cold-working lowers the atomic diffusion activation energy and accelerates element migration, resulting in pronounced EMF drift during isothermal aging at 350 °C for 720 h. After aging below the order–disorder transition temperature, stable ordered structures form in the thermoelement alloys and hysteresis is significantly reduced. However, within the range investigated in this study, deformation above 28% imparts irreversible effects. The EMFs of 28% and 38% deformed samples remained lower than that of the undeformed state even after isothermal aging at 700 °C for 500 h. These findings reveal that excessive cold-working deformation severely impairs the measurement accuracy and long-term stability of the thermocouples, highlighting the necessity of the strict control of drawing deformation to ensure the reliability of nuclear-grade thermocouples under both normal and abnormal reactor operating conditions. Full article

Due to the small size of defects, partial occlusion, and cluttered background, insulator defect detection in transmission lines remains challenging. To address these issues, this paper proposes an improved Single Shot MultiBox Detector (SSD) framework. Firstly, a feature pyramid network is introduced for bidirectional multi-scale feature fusion to enhance the representation of small defects. Secondly, after fusing the feature maps, a convolutional block attention module is embedded to suppress background interference and highlight responses related to defects. Thirdly, focus loss replaces the original confidence loss to alleviate the imbalance of foreground and background during the training process. The proposed method achieved 99.03% insulator AP, 98.27% defect AP, and 98.65% mAP on a self-built dataset, which is 9.97 percentage points higher than the baseline SSD. The ablation study confirmed the complementary contributions of the three modules. The proposed detector significantly improves the detection reliability and robustness in complex detection scenarios, providing effective technical support for intelligent maintenance of transmission equipment. Full article

This work evaluates a high-voltage stacked piezoelectric actuator designed for high force and high power, via silicone oil as both the primary dielectric insulator and thermal management medium. The proposed stacked actuator consists of 10 active lead zirconate titanate (PZT) discs, each 2 mm thick and 50 mm in diameter, wired in parallel and mechanically stacked in series. Quasi-static displacement measurements confirm successful operation up to 2.5 kV/mm with a measured free displacement of 25 µm at 5000 V, in agreement with the constitutive displacement relationship, demonstrating that silicone oil provides effective dielectric insulation at the intended field level. Steady-state thermal measurements across drive conditions ranging from 600 V to 1000 V and 2000 Hz to 5000 Hz show consistent surface temperature reductions of 5 °F to 15 °F with the addition of static silicone oil compared to air. Additional results and discussion are disclosed. Full article

Polymer/Silica aerogel (SA) composites improve mechanical properties strategically, but the mixing process disrupts the aerogel’s structure, reducing its efficiency due to polymer chains filling the pores. Pre-vulcanized natural rubber latex (PVNRL) with a higher crosslink density can strain the moving chains, thereby preserving the SA-porous structure in the bulk composite for thermal insulation materials. This study aimed to investigate the effects of PVNRL pre-vulcanization time and SA-immersion time in PVNRL. For PVNRL/SA composite preparation, various PVNRL, from 0 days to 8 days of pre-vulcanization time, were mixed with a fixed SA content of 20 parts per hundred of rubber (phr) using a latex compounding method. Subsequently, the PVNRL/SA slurries were cast on glass plates with 0, 3, and 6 days to obtain the PVNRL/SA composite. Considering the effect of pre-vulcanization time, the crosslink density of the composite increased and revealed a peak at PVNRL/SA with 8-day PVNRL by 7.277 ± 0.881 μmol , corresponding to the closest percentage of pore area in the SA’s structure to the pristine SA, and eventually a 42.41% lower thermal conductivity than the PVNRL/SA with 0-day PVNRL exhibited. In addition, the thermal conductivity increased more slowly over immersion time with the presence of 8-day PVNRL. The proposed correlation states that increasing the pre-vulcanization improves the thermal insulation performance of PVNRL/SA composites, emphasizing the reduction of filled SA’s pore with unvulcanized NR chains. Furthermore, the PVNRL/SA composite with 8-day PVNRL maintains thermal stability at 387.3 °C, and can be flexed at room temperature. These fascinating discoveries may be advantageous for further applications related to thin-film and flexible thermal insulation materials. Full article

Unidirectional glass fiber reinforced polymer (GFRP) composite insulators are widely used in extra-high voltage (EHV) and ultra-high voltage (UHV) transmission lines due to their outstanding electrical and mechanical performance. However, the accurate prediction of the critical buckling load is crucial to satisfy the high reliability requirement under complex operations. In this paper, an improved Perry–Robertson theory to predict the critical buckling loads of GFRP composite insulators with different slenderness is proposed. Firstly, initial imperfection is expressed as a function of the insulator strut length, which enables the critical load to be formulated as a function of slenderness explicitly. It also allows for convenient comparisons with other theories, such as Euler and Johnson’s, and easy calibration with the magnitude of initial imperfections. Secondly, the nonlinear material behavior of the GFRP composite insulator strut, resulting from changes in glass fiber orientation in relation to the loading direction during buckling, is considered to further enhance the prediction accuracy. The predicted results with current theory were validated through compression tests of GFRP composite insulators with solid and hollow struts and different slenderness and boundary conditions, which shows an accuracy of over 85%. Thus, the proposed improved Perry–Robertson theory can be also applied in other fiber-reinforced composite buckling analyses. Full article