Search Results (16,487)

Medical infrared thermography, which involves the use of infrared thermal cameras for the non-invasive assessment of skin surface temperature distribution, has gained increasing interest in recent years as a tool supporting diagnosis and treatment monitoring. The aim of this article is to present the historical background and critically reassess the current role of infrared thermography in medicine, with particular emphasis on standardization as a key determinant of its clinical utility. This Perspective highlights the fundamental impact of methodological variability on diagnostic performance and reproducibility. A structured framework for standardization is proposed, encompassing patient preparation, environmental conditions, device parameters and calibration, image acquisition protocols, region-of-interest definition and analysis, as well as reporting and clinical interpretation. The analysis demonstrates how inconsistencies at each of these levels reduce measurement reliability, limit inter-study comparability, and weaken clinical confidence in infrared thermography. The article also addresses the growing availability of mobile thermal imaging systems and their integration with artificial intelligence, while emphasizing the need for stronger evidence-based support across all methodological domains. The presented analysis suggests that, despite existing limitations, medical infrared thermography holds considerable potential as a supportive clinical tool. However, its broader clinical implementation remains limited by several factors, with the lack of standardized protocols constituting a major and practically addressable translational barrier. Wider adoption will require standardization efforts alongside rigorous validation studies and application-specific interpretative guidelines. Addressing these challenges through technological advances and coordinated international standardization may facilitate meaningful progress over the next decade. Full article

Porous ceramics have garnered widespread attention in high-temperature insulation, aerospace, and other fields due to their excellent thermal stability, low density, and superior thermal insulation performance. However, traditional preparation technologies suffer from limitations such as poor pore structure controllability, unstable mechanical properties, and long production cycles. In recent years, 3D printing (additive manufacturing) technology has emerged as a disruptive approach to address these challenges, enabling precise fabrication of porous ceramics with complex structures and tailored properties. This review comprehensively summarizes the research progress on 3D-printed porous ceramics, focusing on preparation technologies, structure optimization, and performance regulation. First, the principles and drawbacks of traditional preparation methods are analyzed. Then, four mainstream 3D printing technologies (Binder Jetting, Material Extrusion, Vat Photopolymerization, and Material Jetting) for porous ceramics are elaborated on in terms of forming mechanisms, process characteristics, typical cases, and performance advantages/disadvantages. Additionally, the structure–property optimization strategies, including the design of Triply Periodic Minimal Surface structures and the application of computational modeling and simulation, are discussed to achieve the balance between thermal insulation and mechanical properties. Finally, current challenges and future development trends of 3D-printed porous ceramics are prospected. This review provides a systematic reference for the rational selection of preparation technologies, structural design, and performance optimization of porous ceramics, promoting their engineering applications in high-value fields. Full article

Lead-free [(Ba_0.85Ca_0.15)_1−1.5xNd_x][(Zr_0.1Ti_0.9)_0.995Mn_0.005]O₃ (x mol% Nd/Mn BCZT, x = 0.05, 0.1, 0.5, 1 mol%) ceramics were prepared by the traditional solid-state reaction method, in which the synergistic effects of sintering temperature and Nd/Mn co-doping on the phase structure, microstructural evolution, and electrical properties were systematically investigated. All ceramics exhibit a pure perovskite structure, with the tetragonal (P4mm) phase dominating at room temperature as confirmed by the X-ray diffraction Rietveld refinement. The sintering temperature (1475–1520 °C) is found to be the primary factor governing densification and grain growth, with the relative density peaking at 91.7% for the x = 0.5 mol% sample sintered at 1505 °C. Within this optimized processing window, increasing the Nd content induces a gradual migration of the Curie temperature (T_C) toward lower temperatures, accompanied by enhanced relaxor behavior. A highlight of this work is the strategic balance between piezoelectric activity and mechanical quality factor through a “donor–acceptor” co-doping mechanism. Specifically, for the x = 0.5 mol% ceramics, an exceptionally high mechanical quality factor (Q_m = 424.5) is achieved for samples sintered at 1490 °C, which is proposed to be associated with the temperature-modulated formation of ${Mn}_{Ti}^{″}-V_O^{••}$ defect dipoles, while a peak inverse piezoelectric coefficient $d_{33}^{*}$ of 685.1 pm/V is maintained at a sintering temperature of 1520 °C. Full article

With the shift in advanced packaging toward 3D integration and flexible electronics, it is becoming critical to produce high-quality silicon nitride films under low thermal budgets. To overcome the limitations of low-temperature deposition, this study compares two gas mixtures—SiH₄/NH₃/N₂ and SiH₄/N₂—in plasma-enhanced chemical vapor deposition of silicon nitride coatings. We systematically evaluated how the NH₃ precursor affects deposition kinetics, chemical bonds, non-uniformity, optical properties, and internal stress at different RF powers and electrode gaps. The test results show that NH₃, with its lower dissociation energy, avoids the high activation barrier associated with pure N₂ plasma, leading to a higher reactive nitrogen flux and a doubled deposition rate. In the SiH₄/NH₃/N₂ system, raising RF power from 300 W to 900 W reduced hydrogen content from 23.58% to 12.25%. This suppression of hydrogen promoted structural densification, shifting the mechanical stress from 173.3 MPa to −989.7 MPa. At a larger electrode gap of 19 mm, NH₃’s better diffusion characteristics offset the electric field sensitivity typical of N₂ systems, reducing large-area film non-uniformity by 28.7% compared to a 13 mm gap. This work offers a practical, mass-production-friendly approach for depositing robust, low-hydrogen, highly uniform silicon nitride films at low temperatures. Full article

Adsorption is a promising technology for phosphate removal to alleviate eutrophication. In this study, thermally modified calcium aluminate decahydrate (TCAH) was prepared via low-temperature thermal treatment of calcium aluminate decahydrate (CAH₁₀) to develop a cost-effective and high-performance phosphate adsorbent. The optimal modification temperature was determined to be 120 °C, which reduced the crystallinity of CAH₁₀, enhanced its porosity, and induced the formation of amorphous calcium aluminate phases. Batch adsorption experiments showed that TCAH exhibited a maximum adsorption capacity of 199.80 mg P/g at 25 °C. The adsorption kinetics followed the pseudo-second-order model, while the adsorption isotherms were well fitted by the Redlich–Peterson model. TCAH maintained high removal efficiency over a wide pH range of 3.0–11.0 and showed high selectivity against common coexisting anions. Characterizations using SEM-EDS, XRD, FTIR and XPS suggested that phosphate removal by TCAH was dominated by synergistic amorphous precipitation and inner-sphere complexation. In tests with real phosphorus-releasing liquor derived from excess sludge, TCAH achieved nearly complete phosphate removal at a dosage of 5 g/L within 6 h. Owing to its readily available raw materials, low preparation temperature, and outstanding phosphate capture performance, TCAH is a promising candidate for efficient phosphate capture and recovery from wastewater. Full article

Asymmetric SiC membranes with surface pore sizes ranging from 0.12 to 0.31 μm at a constant open porosity of approximately 42% were fabricated by dip-coating SiC support followed by sintering from 1700 to 2000 °C. The effect of membrane structural constants (hydraulic resistance (k₁), pore size exponent (k₂), and shape factor (k₃)) on PWP were evaluated by comparing the symmetric and asymmetric structures. In addition, the experimentally determined values of PWP were quantitatively analyzed by comparing with theoretically predicted values obtained using the Kozeny–Carman (K–C) and Hagen–Poiseuille (H–P) models. Despite having a smaller pore size, the asymmetric membranes exhibited high PWP (1257-3883 LMH) due to decreased flow resistance (low k₁), enhanced pore size effect (high k₂), and improved flow network (high k₃) as compared to symmetric membranes. The hydrophilicity of the prepared membranes improved remarkably, with increasing average surface roughness (102.3 nm to 161.0 nm) due to an increase in pore size, which also caused a decrease in water contact angle (WCA) from approximately 27.44° to 21.67° with increasing sintering temperature (1700–2000 °C). Furthermore, the prepared membrane separation performance was found to be affected by its pore size, and the 1900 °C sintered SiC membrane showed optimal gradient profile and pore structure, demonstrating its practical reusability and scalability for O/W wastewater treatment. Full article

Porous ceramics have shown great application potential in aerospace, electronics, and lithium-ion battery thermal management due to their low density, high specific strength, and excellent thermal insulation. Material Jetting (MJ), a high-precision 3D printing technology, enables the fabrication of porous ceramics with tailored pore structures, but the synergistic effects of pore structure parameters (configuration, porosity, and number of periods) on their thermal insulation performance remain insufficiently explored. This study systematically investigates the thermal insulation behavior of zirconia porous ceramics fabricated by MJ through experimental tests and numerical simulations. Three typical lattice configurations (Octet, Schwarz, and Gyroid) were selected, and samples with varying porosities (40%, 50%, 60%) and numbers of periods (1, 2, 3) were prepared. The results indicate that the Octet configuration (60% porosity, 3 periods) exhibits the optimal thermal insulation performance, with a minimum cold-end temperature of 58.5 °C (experiment) and 59.21 °C (simulation), attributed to its strut-based structure that forms a more tortuous heat conduction path. For the Gyroid configuration, thermal insulation performance improves with increasing porosity (reducing solid conduction dominance under non-forced convection) and decreases with decreasing number of periods (due to inhomogeneous pore distribution extending heat transfer paths). Notably, the trend of porosity affecting thermal insulation is opposite to that of compressive performance. Numerical simulation results are consistent with experimental data in both values and trends, verifying the reliability of the model. This work clarifies the key factors regulating the thermal insulation of MJ-fabricated porous ceramics and provides practical structural design guidelines for applications such as lithium-ion battery thermal runaway management. Full article

To address the application bottlenecks of organic phase change materials characterized by low thermal conductivity and susceptibility to liquid leakage, this study utilized natural poplar wood as a raw material to construct a three-dimensional carbon/silver heterogeneous porous skeleton via delignification, gradient carbonization, and in situ electroless silver plating. Polyethylene glycol (PEG) was then vacuum-encapsulated within this structure to prepare form-stable composite phase change materials (CPCMs). The regulatory effects of carbonization temperature and metal interface modification on the microscopic morphology and thermophysical properties of the materials were systematically investigated. The results indicate that the skeleton carbonized at 800 °C achieves an optimal balance between pore distribution and skeleton rigidity, ensuring the uniform conformal growth of silver nanoparticles and endowing the material with excellent anti-leakage performance. The thermal conductivity of the optimal sample reaches as high as 0.683 W/(m·K), with the melting latent heat maintained at 133.9 J/g, while also demonstrating an agile and stable photothermal conversion response. Non-equilibrium molecular dynamics (NEMD) simulations further confirm that the silver nanoparticle modification layer smooths the phonon vibration frequency mismatch between the carbon substrate and organic segments, significantly reducing the interfacial thermal resistance. This research provides an important reference for the structural design and microscopic heat transfer mechanism analysis of high-performance phase change energy storage materials. Full article

Rapid rewarming is the most conventional and primary treatment for frostbite, yet effective adjunctive strategies remain absent. Conventional wound dressings, such as therapeutic hydrogels, tend to freeze and lack the necessary rewarming ability, rendering them unsuitable for direct application. Herein, we engineered an environmentally tolerant photothermal hydrogel, named 5A-Gel, featuring anti-swelling, anti-pressure, antioxidant, anti-freezing, and anti-drying capacities, for the treatment of frostbite. 5A-Gel was formed via dynamic crosslinking between gelatin and tea polyphenols in a glycerol/water solvent system. The incorporation of glycerol endowed the hydrogel with superior anti-swelling, anti-freezing, and anti-drying performance (remaining flexible at −20 °C and 37 °C for at least 60 days), along with concentration-dependent antioxidant activity due to tea polyphenols. Furthermore, 5A-Gel exhibited excellent photothermal effects, maintaining stable temperature and softness under 808 nm laser irradiation with robust cyclic durability. In addition, 5A-Gel showed slow degradability, excellent hemocompatibility, and favorable in vivo biosafety. Functionally, in a mouse frostbite wound model, photothermal rewarming therapy using 5A-Gel markedly expedited frostbite healing, promoting re-epithelialization, enhancing collagen deposition, alleviating inflammatory response, and stimulating neovascularization. Therefore, the as-prepared 5A-Gel serves as a competent therapeutic platform for in situ frostbite treatment and offers innovative principles for the rational engineering of high-performance hydrogel systems targeting frostbite tissue injuries. Full article

This study investigated the effect of MoS₂/graphite lubricant composition on the high-temperature compaction behavior, local mechanical uniformity, and microstructural characteristics of Fe–5.0 wt.%Si SMCs. Nine lubricant compositions were prepared by varying MoS₂ and graphite contents, and their friction behavior, Vickers hardness, and compaction behavior were evaluated experimentally and by FEA. One-way ANOVA confirmed that lubricant composition significantly affected the Vickers hardness response (F = 4.245, p = 0.000273). The measured friction coefficients were applied as interface friction conditions in FEA, and the relative density, effective strain, and absolute hydrostatic stress distributions were compared. Among the investigated compositions, C3, containing 1.0 wt.% MoS₂ and 0.3 wt.% graphite, showed the lowest friction coefficient and Vickers hardness standard deviation. In FEA, C3 also showed balanced relative density, effective strain, and hydrostatic stress distributions. XRD confirmed the α-Fe-based bcc Fe–Si matrix, while SEM-EDS indicated locally distributed lubricant-derived residual regions. Therefore, C3 was selected as the most balanced lubricant composition within the investigated range. Future studies will evaluate electromagnetic properties, including core loss and magnetic permeability. Full article

Desert ecosystems harbor microbial communities adapted to extreme environmental conditions, including water scarcity, elevated temperatures, and intense UV radiation. Among these microorganisms, microalgae represent promising resources for agricultural applications. In this study, microalgae isolated from desert soils in Mexico were characterized by molecular (rbcL) and phylogenetic analysis, and morphological observations. They were identified as Chlorella sp. (RAD3), Nannochloris-related isolate (RAD4), and Chlorella cf. variabilis (RAD5). The effects of microalgal biomass on maize (Zea mays L.) germination and early seedling development were evaluated using a seed-priming approach. Microalgal treatments significantly improved (p < 0.05) germination-related traits, seedling vigor, shoot height, root length, and fresh and dry biomass, as compared with the control. Chlorella cf. variabilis (RAD5) was associated with reduced germination time, whereas Nannochloris-related isolate (RAD4) consistently produced the strongest responses in vigor and growth parameters. Although some variables reached their highest numerical values at 10⁸ cells/mL, similar responses were usually observed at 10⁷ cells/mL. Overall, the evaluated desert-derived microalgal preparations were associated with improved early maize seedling performance, under the evaluated conditions. Full article

Kimchi fermentation involves dynamic physicochemical and microbial changes; however, conventional monitoring methods are generally dependent on intermittent measurements, resulting in limitations in the real-time detection of abnormal fermentation. In this study, a Wireless Sensor Network (WSN)-based Fermentation Monitoring System (WFMS) and a Long Short-Term Memory (LSTM)-based Anomaly Detection System (LADS) were developed to continuously monitor internal pressure changes during kimchi fermentation. Kimchi samples were prepared under normal fermentation conditions (CON) and glucose-added conditions (GLU-6). Pressure data were collected at 10 min intervals using 15 psi and 30 psi pressure sensors connected to an Arduino Nano 33 IoT board and were transmitted to the ThingSpeak platform. During the fermentation period, pressure data were collected stably, while the external temperature was maintained at approximately 25 °C. Both CON and GLU-6 samples exhibited a rapid increase in internal pressure during the early fermentation stage, followed by a gradual decrease. However, relatively larger pressure fluctuations were observed in the middle and late fermentation stages of the GLU-6 samples. An LSTM autoencoder model trained using CON data established a reconstruction error-based threshold of 0.0025 and successfully detected anomalies in the GLU-6 samples. Anomalies were mainly identified during the initial fermentation stage and between fermentation days 2 and 4. These results demonstrate that pressure-based real-time monitoring combined with LSTM autoencoder analysis can be effectively applied for the non-destructive tracking of kimchi fermentation and the early detection of abnormal fermentation patterns. Full article

The optical stability and aesthetic performance of dental polymers are critical for the longevity of restorative treatments. This study aims to evaluate the influence of different polymerisation conditions and maintenance protocols—specifically the use of charcoal pastes and brushes—on the Whiteness Index for Dentistry (WID) of polymer samples. Four groups of polymer samples (Optiprint Lumina, Dentona, AG) were prepared under various conditions: Group I (Standard: 7 min, 22 °C), Group II (Thermal: 7 min, 60 °C), Group III (Extended: 20 min, 22 °C), and Group IV (Glycerin barrier: 7 min, 22 °C). The protocol consisted of brushing with standard or carbon-infused toothpastes and brushes for a period of 2 min. Between brushing, the samples were stored in artificial saliva at 37 °C to simulate the oral environment. The samples were divided into groups. The first group was brushed with a standard paste and a standard brush; the second group was brushed with a simple paste and a carbon brush; the third group was brushed with carbon paste and a standard brush; and the fourth group was brushed with carbon paste and a carbon brush. Changes in the Whiteness Index for Dentistry (WID) were recorded and analysed statistically using a paired t-test and Pearson correlation. Results: All groups showed a statistically significant increase in the WID (p = 0.0191). Group IV (glycerin barrier + carbon paste/brush) exhibited the highest increase, with a WID = 2.0, demonstrating a synergistic effect between oxygen inhibition control and activated charcoal. In contrast, Group II (thermal polymerisation) showed the highest chromatic stability (ΔWID = 0.6), remaining below the Whiteness Perceptibility Threshold (WPT = 0.72). No significant correlation was found between polymerisation time and WID changes (r = 0.087, p = 0.913), indicating that temperature and surface treatment are the primary drivers of optical modification. Conclusions: The heat parameter did not reveal a significant difference in the optical properties. Furthermore, the combination of a glycerin barrier and carbon-based hygiene products maximises the whitening effect while remaining within the Whiteness Acceptability Threshold (WAT < 2.60), providing valuable insights for both material processing and patient maintenance protocols. Full article

This study employed sodium acetate trihydrate as the phase-change matrix and used a binary nucleating agent composed of disodium hydrogen phosphate dodecahydrate (DHPD) and borax (BX) to suppress supercooling. Sodium carboxymethyl cellulose (CMC) was used as a thickener to mitigate phase separation, and expanded graphite (EG) was introduced as a supporting matrix to enhance thermal conductivity. The composite phase-change material was prepared via melt blending. By means of thermal storage and release performance tests, differential scanning calorimetry and thermal conductivity tests, the effects of the binary nucleating agent ratio, CMC content and EG addition amount on phase-change thermal storage performance, supercooling degree, phase stability and thermal conductivity of the system were systematically investigated. The results indicated that the addition of 3.0 wt% DHPD and 2.0 wt% BX as the binary nucleating agent reduced the supercooling temperature from 20.52 °C to 1.92 °C; 1 wt% CMC effectively suppressed phase separation during thermal cycling; and the incorporation of 3.0 wt% EG increased the thermal conductivity of the composite to 2.92 times that of the pure hydrated salt. Full article

Studies on the relationships between structure and thermal stability, as well as on the pyrolysis behavior of cross-linked citronellyl methacrylate/hexyl acrylate and geranyl methacrylate/hexyl acrylate copolymers, are presented. These insoluble and highly chemically resistant polymeric materials exhibited glass transition temperatures (T_g) ranging from −55.2 °C to 7.6 °C, depending on their composition. The thermal stability of the prepared copolymers also depended on their composition and decreased with increasing geranyl methacrylate or citronellyl methacrylate content. The highest thermal stability was achieved for copolymers containing 20 wt% methacrylate and 80 wt% hexyl acrylate. The corresponding decomposition temperatures were 167 °C for citronellyl methacrylate-based copolymers and 190 °C for geranyl methacrylate-based copolymers. The thermal decomposition of the investigated copolymers proceeded in at least three stages, involving simultaneous pyrolysis processes and chemical reactions between the decomposition products. As a result, a mixture of low-molecular-weight saturated and unsaturated volatile compounds, as well as CO, CO₂, and H₂O, evolved. Based on the gaseous FTIR analysis, the pyrolysis pathways of the tested copolymers and the structures of the emitted saturated and unsaturated volatile products were proposed. Full article