Search Results (5,325)

In an effort to reduce global dependence on fossil-based polymers and advance toward a more sustainable materials industry, research over recent decades has increasingly focused on the development of bio-based polymers and broadening their potential applications. Within this context, the present study investigates nanocomposites based on poly(butylene succinate-co-butylene adipate) (PBSA), reinforced with two types of nanofillers: silicon dioxide nanoparticles (SiO₂ NPs) and cellulose nanofibrils (CNFs). The main objective of this work is to examine how the morphology, geometry, and chemical nature of the nanofillers influence the thermal, mechanical, and barrier properties of PBSA, as well as its biodegradability. For each nanofiller, three formulations were prepared, containing 1, 2, and 5 wt% of filler, respectively. Scanning electron microscopy (SEM) analysis confirmed good dispersion and minimal aggregation in the SiO₂-based systems, whereas marked aggregation was observed in the CNF-based samples. Thermal analysis indicated that the intrinsic thermal properties of neat PBSA were largely preserved. Mechanical testing revealed improvements in both the elastic modulus and elongation at break for most nanocomposite samples. In particular, CNFs provided the most consistent reinforcing effect, with enhancements of approximately 40% in the elastic modulus (495.4 vs. 356.4 GPa in neat PBSA) and 52% in elongation at the break (185.1 vs. 122.0% in neat PBSA) with 5 wt% loading. Additionally, the incorporation of nanofillers did not alter the surface hydrophilicity, but it did improve the oxygen barrier performance and enhanced disintegration under composting conditions. Overall, these findings demonstrate the promising potential of PBSA-based nanocomposites for sustainable rigid packaging applications. Full article

7xxx series aluminum alloys are critical structural materials in aerospace applications, but their susceptibility to hydrogen embrittlement (HE) poses significant challenges to service safety and durability. The effects of Si, Er, and Zr microalloying, combined with optimized heat treatments on the HE resistance of Al–Zn–Mg–Cu alloys, were systematically investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and mechanical testing. Three alloys—1# (AlZnMgCuZr), 2# (AlZnMgCuErZr), and 3# (AlZnMgCuSiErZr)—were subjected to single-stage or two-stage homogenization, followed by solution treatments at 470 °C/2 h and 540 °C/1 h, and peak aging at 125 °C. The hydrogen charging experiment was conducted by first applying a modified acrylic resin coating to protect the gripping sections of the specimen, followed by a tensile test. Results demonstrate that alloy 3# with Si addition exhibited the lowest RA_loss, followed by the 2# alloy, which effectively improved the alloys’ hydrogen embrittlement behavior. Compared with the solution in 470 °C/2 h, the 540 °C/1 h solution treatment enabled complete dissolution of Mg₂Si phases, promoting homogeneous precipitation and peak hardness comparable to alloy 2#. Two-stage homogenization significantly enhanced the number density and refinement of L₁₂-structured Al₃(Er,Zr) nanoprecipitates. Silicon further accelerated the precipitation kinetics, leading to more Al₃(Er,Zr) nanoprecipitates, finely dispersed T′/η′ phases, and lath-shaped GPB-II zones. The GPB-II zones effectively trapped hydrogen, thereby improving HE resistance. This work provides a viable strategy for enhancing the reliability of high-strength aluminum alloys in hydrogen-containing environments. Full article

Binder jetting additive manufacturing (BJAM) offers an effective approach for fabricating silicon carbide (SiC) parts with complex geometries; however, part quality is strongly influenced by process variables. Binder saturation and drying time are key process variables in BJAM, yet their individual influences on the density and dimensional deviation of SiC green parts remain underexplored. To address this gap, this study systematically investigates the effects of binder saturation and drying time on the dimensional deviation and density of SiC green parts by evaluating four binder saturation levels (60%, 80%, 100%, and 120%) and three drying times (15, 30, and 45 s). The results show that increasing binder saturation reduces green part density and increases dimensional deviation, whereas increasing drying time improves density and reduces dimensional deviation. Excessive drying, however, causes severe warpage, preventing the fabrication of dimensionally accurate parts. These findings highlight the need to optimize binder saturation and drying time to improve the density of printed parts while minimizing dimensional deviation. Full article

The inevitable introduction of oxygen into Czochralski-method-grown single crystal silicon, facilitated by the use of quartz crucibles, can result in the failure of chips and devices. Both the size and position of the heater exert a significant influence on the oxygen concentration within the Czochralski-method-grown silicon. In this study, a novel short-type heater was designed and evaluated for its effect on melt temperature and oxygen diffusion during crystal growth. The silicon melt temperatures and oxygen diffusion coefficients in an MCZ furnace for several heater settings were simulated, and the results were implemented in experiments. From the examination of the growth process through computation, the heater and its positional adjustments were determined to be effective modulators of oxygen concentration during crystal growth, which was consequently reduced to below 4 ppma (ASTM F121-83). Finally, the simulations were validated experimentally, limitations in production were discussed, and possible improvements were outlined. Full article

This study reports the fabrication and characterization of copper–silicon carbide (Cu–SiC) metal matrix composites produced using powder metallurgy (PM) combined with thermo-compression processing (TCP), a dual route that remains limited in Cu–SiC research. Micro-sized SiC particles (1–25 wt.%) were incorporated into Cu, compacted, sintered, and subsequently subjected to sequential forging and annealing. Unlike conventional PM-only processing, TCP significantly reduced porosity, promoted more uniform reinforcement dispersion, and relieved residual stresses, creating a strong synergy between densification and microstructural refinement. SEM, EDS, XRD, and Raman analyses confirmed phase stability, homogeneous reinforcement distribution, and the absence of deleterious interfacial phases. The integrated PM + TCP route achieved an ultimate tensile strength of ~209 MPa, hardness of ~65 HRB, and toughness of ~35 MJ/m³ at approximately 3 wt.% SiC. The superior performance at this composition resulted not from the lowest porosity but from the combined effects of uniform particle dispersion, improved particle–matrix bonding, and deformation-driven refinement. These findings establish TCP as an effective post-sintering strategy that overcomes intrinsic porosity and interfacial limitations in Cu–SiC composites. Overall, powder metallurgy combined with the thermo-compression processing is identified as a promising processing pathway for developing high-strength, thermally stable Cu–SiC materials for structural and thermal management applications. Full article

As a non-invasive diagnostic technique, evolved gas analysis (EGA) holds significant value in assessing the insulation conditions of critical equipment such as power cables. Current analytical methods face two major challenges: insulation materials may undergo multiple aging mechanisms simultaneously, leading to interfering characteristic gases; and traditional approaches lack the multi-label recognition capability to address concurrent fault patterns when processing mixed-gas data. These limitations hinder the accuracy and comprehensiveness of insulation condition assessment, underscoring the urgent need for intelligent analytical methods. This study proposes a deep convolutional neural network (DCNN)-based multi-label classification framework to accurately identify the gas generation characteristics of five typical power cable insulation materials—ethylene propylene diene monomer (EPDM), ethylene-vinyl acetate copolymer (EVA), silicone rubber (SR), polyamide (PA), and cross-linked polyethylene (XLPE)—under fault conditions. The method leverages concentration data of six characteristic gases (CO₂, C₂H₄, C₂H₆, CH₄, CO, and H₂), integrating modern data analysis and deep learning techniques, including logarithmic transformation, Z-score normalization, multi-scale convolution, residual connections, channel attention mechanisms, and weighted binary cross-entropy loss functions, to enable simultaneous prediction of multiple degradation states or concurrent fault pattern combinations. By constructing a gas dataset covering diverse materials and operating conditions and conducting comparative experiments to validate the proposed DCNN model’s performance, the results demonstrate that the model can effectively learn material-specific gas generation patterns and accurately identify complex label co-occurrence scenarios. This approach provides technical support for improving the accuracy of insulation condition assessment in power cable equipment. Full article

Silicon carbide (SiC) ceramics are regarded as high-performance structural materials due to their excellent high-temperature strength, wear resistance, and thermal stability. However, their inherent high brittleness, low fracture toughness, and difficulty in densification have limited their wider application. To overcome these challenges, introducing a second phase and/or sintering aids is necessary. In this paper, SiC–AlN–VC multiphase ceramics were fabricated via spark plasma sintering at 1800 °C to 2100 °C. The interface, mechanical, and thermal properties were examined. It was found that the VC particles effectively pin the grain boundaries and suppress the abnormal growth of SiC grains. At temperatures exceeding 1800 °C, the N atoms released from the decomposition of AlN diffuse into the VC lattice, forming a V(C,N) solid solution that enhances both the toughness and strength of the ceramics. With increasing sintering temperature, the mechanical properties of the SiC multiphase ceramics first improve and then deteriorate. Ultimately, a nearly fully dense SiC multiphase ceramic is obtained. The maximum hardness, flexural strength, and fracture toughness of SAV20 are 28.7 GPa, 508 MPa, and 5.25 MPa·m^1/2, respectively. Furthermore, the room-temperature friction coefficient and wear rate are 0.41 and 3.41 × 10⁻⁵ mm³/(N·m), respectively, and the thermal conductivity is 58 W/(m·K). Full article

Spacer fabrics are a breathable material option for wearable cushioning, but the cushioning performance is still not comparable to that of traditional elastomeric cushioning materials. The polymer-based connective structure of spacer fabrics largely affects fabric properties, compression, and mechanical performance, and this is a research gap that calls for the development of spacer fabrics with enhanced cushioning functions. This study develops a new square-wave inlay pattern and investigates the effects of the inlay structure and spatial frequency of the spacer course, as well as the effects of the silicone inlay on compression, impact force absorption, and vibration isolation of the spacer fabric. Twelve samples are designed and evaluated. The results show that the square-wave inlaid spacer fabric has higher energy absorption during compression. The square-wave pattern with a shorter transition distance between the front and back tuck stitches could increase the inclination angle close to a right angle, and extra tuck stitches on the surface float could secure the square-wave structure to enhance the impact force absorption ability. The increment in the spatial frequency of spacer courses provides a less stiff fabric with lower impact force absorption but higher vibration isolation ability. This study shows the innovative development of spacer fabric for enhancing cushioning properties. Full article

Background/Objectives: The clinical application of CAD/CAM restorative materials continues to evolve due to increasing demand for aesthetic, durable, and minimally invasive indirect restorations. Hybrid nanoceramics, such as Grandio disc (VOCO GmbH, Cuxhaven, Germany), are increasingly used in indirect restorative dentistry due to their favourable combination of mechanical strength, polishability, wear resistance, and bonding potential. One challenge associated with adhesive protocols for CAD/CAM materials lies in achieving durable bonds with resin cements. Extensive post-polymerization during fabrication reduces the number of unreacted monomers available for chemical interaction, thereby limiting the effectiveness of traditional adhesive strategies and necessitating specific surface conditioning approaches. This study aimed to evaluate, in a preliminary, non-inferential manner, the influence of several combined conditioning protocols on surface micromorphology, elemental composition, and descriptive SBS trends of a CAD/CAM hybrid nanoceramic. This work was designed as a preliminary pilot feasibility study. Due to the limited number of specimens (two discs per protocol, each providing two independent enamel bonding measurements), all bond strength outcomes were interpreted descriptively, without inferential statistical testing. This in vitro study investigated the effects of various surface conditioning protocols on the adhesive performance of CAD/CAM hybrid nanoceramics (Grandio disc, VOCO GmbH, Cuxhaven, Germany) to dental enamel. Hydrofluoric acid (HF) etching was performed to improve adhesion to indirect resin-based materials using two commercially available gels: 9.5% Porcelain Etchant (Bisco, Inc., Schaumburg, IL, USA) and 4.5% IPS Ceramic Etching Gel (Ivoclar Vivadent, Schaan, Liechtenstein), in combination with airborne-particle abrasion (APA), silanization, and universal adhesive application. HF may selectively dissolve the inorganic phase, while APA increases surface texture and micromechanical retention. However, existing literature reports inconsistent results regarding the optimal conditioning method for hybrid composites and nanoceramics, and the relationship between micromorphology, elemental surface changes, and adhesion remains insufficiently clarified. Methods: A total of ten composite specimens were subjected to five conditioning protocols combining airborne-particle abrasion with varying hydrofluoric acid (HF) concentrations and etching times. Bonding was performed using a dual-cure resin cement (BiFix QM) and evaluated by shear bond strength (SBS) testing. Surface morphology was examined through environmental scanning electron microscopy (ESEM), and elemental composition was analyzed via energy-dispersive X-ray spectroscopy (EDS). Results: indicated that dual treatment with HF and sandblasting showed descriptively higher SBS, with values ranging from 5.01 to 6.14 MPa, compared to 1.85 MPa in the sandblasting-only group. ESEM revealed that higher HF concentrations (10%) created more porous and irregular surfaces, while EDS indicated an increased fluorine presence trend and silicon reduction, indicating deeper chemical activation. However, extending HF exposure beyond 20 s did not further improve bonding, suggesting the importance of protocol optimization. Conclusions: The preliminary observations suggest a synergistic effect of mechanical and chemical conditioning on hybrid ceramic adhesion, but values should be interpreted qualitatively due to the pilot nature of the study. Manufacturer-recommended air abrasion alone may provide limited adhesion under high-stress conditions, although this requires confirmation in studies with larger sample sizes and ageing simulations. Future studies should address long-term durability and extend the comparison to other hybrid CAD/CAM materials and to other etching protocols. Full article

Silicon (Si) application is recognized for its beneficial roles in crop growth. This study examines the effects of two forms: zeolite and sodium metasilicate (SMS), on rice under hydroponic (EP I) and soil (EP II) conditions. Four treatments were used at the early stage of rice: 4 ppm and 2 ppm of Si from zeolite, 4 ppm of Si from SMS, and a control. In EP I, only 4 ppm of SMS significantly improved root traits: total root length (36%), surface area (34%), root volume (23%), tips (46%), and forks (34%) by day seven compared to the control. Zeolite-based Si had minimal effects, except on the average diameter. However, in EP II, all Si forms enhanced root traits: total root length (50–73%), surface area (51–58%), average diameter (32–50%), root volume (54–72%), tips (29–68%) and increased shoot and root dry weights by 19–24% and 79–106%, respectively, compared to the control. In EP II, starting from the first and fifth day of treatment, the Si applied groups showed a significant increase in photosynthetic traits and vegetative indices, respectively. On the last day of treatment, particularly for 2 ppm of Si zeolite, the electron transport rate increased by 5 times, the apparent transpiration by 3 times, total conductance and stomatal conductance by around 50%, normalized difference vegetative index by 6–8%, and photochemical reflectance index by 14–33%. These results suggest that the effectiveness of Si is highly dependent on the growth medium and the type of Si, with soil enabling better Si availability, uptake, and physiological response compared to hydroponics. The superior performance of zeolite in EP II indicates its potential as a slow-release Si source that enhances root development and photosynthetic efficiency over time. Thus, it is concluded that zeolite has more potential in soil, and soluble silicon sources should be selected in hydroponics. Full article

The Silicon Alley model is enhancing neighborhood competitiveness through cultural and technological innovation, while the living experience of its inhabitants serves as a critical foundation for sustainable development. This study investigates neighborhoods developed under the Silicon Alley framework. It explores theoretical models and practical pathways that use inclusive design to enhance public facilities and service strategies, ultimately aiming to build a sustainable living experience system. Utilizing a combined LDA-DEMATEL-ISM-MICMAC methodology, the research first identifies seven key factors influencing living experience from multi-source texts, spanning social, technological, emotional, and governance dimensions. It then reveals the cause-effect relationships, hierarchical structure, and driver-dependency mechanisms among these factors. The findings indicate that sustainable collaborative governance acts as a fundamental driver, diversified community experience and urban attractiveness serve as intermediate transmission factors, while Elderly-Friendly Livelihood Experience, Digital Block Experience, Artistic Life Scene Experience, and Local Cultural and Historical Experience function as surface-level outcome factors. The study proposes short-term priorities focusing on collaborative governance and social integration, and long-term strategies emphasizing livelihood services and cultural identity. These recommendations are intended to enhance neighborhood living experience, promote inclusive and sustainable urban renewal, and provide both theoretical insights and practical guidance for achieving sustainable neighborhood development. Full article

In this study, we investigate the relationship between the progressive lowering of the silicon (Si) anode potential during lithiation and the accompanying crystallization reaction to enable in situ electrochemical detection in Si-based full cells. Si–Li half cells were first analyzed by differential capacity (dQ/dV), revealing a crystallization feature near 0.05 V vs. Li⁺/Li, commonly associated with crystallization to Li₁₅Si₄. In the initial cycle, this signal was obscured by a dominant amorphization peak near 0.1 V; however, once amorphization was completed and the end-of-lithiation potential dropped below ~0.05 V in later cycles, a distinct crystallization peak became clearly resolvable. Under capacity-limited cycling that mimics full-cell operation, degradation-induced lowering of the Si-anode potential led to the appearance of the crystallization signal when the anode potential crossed this threshold. Based on these results, we extended the analysis to LiFePO₄–Si three-electrode full cells and, by reparameterizing dQ/dV as a function of charge time, separated electrode-specific contributions and identified the Si crystallization feature within the full-cell response when N/P ≈ 1. A simple degradation-modeling scenario further showed that in cells initially designed with N/P > 1, loss of anode active material can reduce the effective N/P, drive the Si potential into the crystallization window, and introduce a new peak in the full-cell dQ/dV curve associated with Si crystallization. These combined experimental and modeling results indicate that degradation-driven lowering of the Si-anode potential triggers crystallization and that this process can be detected in full cells via dQ/dV analysis. Practically, the emergence of the Si-crystallization feature provides an in situ marker that the effective N/P has drifted toward unity due to anode-dominated aging and may inform charge cut-off strategies to mitigate further Si-anode degradation. Full article

The motivation for this work is to study the cause and present mitigation for some challenges faced in preparing porous silicon. This enables benefiting from the appealing benefits of porous silicon that offers a wide range, simple technique for varying the refractive index. Such challenges include the refractive index values, sensitivity to oxidation, some fabrication parameters, and other factors. Additionally, highly doped p-type silicon is preferred to form porous silicon, but it causes high losses, which necessitates its detachment. We investigate some possible causes of refractive index change, especially after detaching the fabricated layers from the silicon substrate. Thereby, we could recommend simple but essential precautions during fabrication to avoid such a change. For example, the native oxide formed in the pores has a role in changing the porosity upon following some fabrication sequence. Oppositely, intrinsic stress doesn’t have a significant role. On another aspect, the effect of differing etching/break times on the filter’s responses has been studied, along with other subtle details that may affect the lateral and depth homogeneity, and thereby the process success. Solving such homogeneity issues allowed reaching thick layers not suffering from the gradient index. It is worth highlighting that several approaches have been reported; unlike these, our method doesn’t require sophisticated equipment that might not be available in every lab. To well characterize the thin films, it has been found essential that freestanding monolayers are used for this purpose. From which, the wavelength-dependent refractive index and absorption coefficient have been determined in the near infrared region (1000–2500 nm) for different fabricated conditions. Excellent fitting with the measured interference pattern has been achieved, indicating the accurate parameter extraction, even without any ellipsometry measurements. This also demonstrates the refractive index homogeneity of the fabricated layer, even with a large thickness of over 16 µm. Subsequently, multilayer structures have been fabricated and tested, showing the successful nano-manufacturing methodology. Full article

This study presents the development of high-performance polymer composites designed for operation under extreme conditions. The research aimed to investigate the influence of laser ablation parameters on the synthesis of carbon nanotubes (CNTs) and to evaluate their efficacy as electrically conductive fillers. CNTs were synthesized using a 200 W laser ablation setup, with the graphite-to-ferrocene ratio in the target varied from 3:1 to 8:1 at a constant pulse duration of 0.1 s. Comprehensive analysis by Raman spectroscopy and scanning electron microscopy (SEM) demonstrated that this method enables the production of nanotubes with controlled morphology and diameters ranging from 20 to 70 nm. It was established that varying the target composition serves as an effective tool for managing the specific surface area and structure of the synthesized CNTs. The obtained nanotubes exhibited high efficiency in forming conductive networks within polymer matrices (exemplified by silicone), thereby imparting the composites with tailored electrophysical properties. A key finding of the work is the identified dependence of the positive temperature coefficient of resistance (PTCR) of the composites on the morphology and composition of the carbon filler. This property opens prospects for creating “smart” self-regulating heating elements based on the developed materials, including for anti-icing systems. Thus, the study results confirm that the targeted synthesis of CNTs via laser ablation and their subsequent incorporation into polymer matrices constitutes an effective strategy for expanding the functional capabilities of composite materials in modern technical applications. Full article

Aerinite is a rare blue aluminosilicate mineral whose identification as a pigment in Pyrenean medieval artworks typically requires invasive microsampling. This study evaluates portable X-ray fluorescence spectroscopy (pXRF) as a noninvasive screening tool for aerinite in Alto Aragón (Spain) cultural heritage. Elemental compositions of aerinite and lapis lazuli references, ceramics, polychromed capitals, and thirteenth- to fifteenth-century painted panels were measured with a Niton XL3t GOLDD+ spectrometer. Data were analyzed using log-ratio linear discriminant analysis (LDA), with silicon as an internal normalizer. Aerinite references showed Cu and Co levels below instrumental detection limits, along with Fe (6.99 ± 1.04 wt%), Al (4.91 ± 1.38 wt%), and Si (15.95 ± 1.60 wt%). High-confidence aerinite classifications were obtained for Cu-free and Co-free blue pigments in the Barbastro Chrismon, the Buira altar frontal, and other panels. Extension of the protocol to green pigments revealed that two samples—from the Saint Anthony Abbot panel and Portaspana retable—were also classified as aerinite, providing the analytical evidence for “verde de Juseu” as a naturally occurring greenish aerinite variety. Despite known pXRF limitations, this technique effectively screens candidate aerinite-containing passages for subsequent microanalytical confirmation. Full article