Search Results (40,299)

The functional performance and structural integrity of natural rock materials under fluctuating environmental stressors are pivotal for their advanced applications. As a non-ionizing and radiation-free technology, terahertz (THz) spectroscopy offers a safe and promising alternative for non-destructive testing (NDT), uniquely capable of being deployed in open and unshielded environments. However, limited penetration depth, exacerbated by both the dense geological matrix and the extreme sensitivity of THz waves to moisture states, has long hindered its widespread application in rock characterization. This study establishes a quantitative Terahertz Time-Domain Spectroscopy (THz-TDS) framework to characterize four lithologies under drying–wetting cycles. Exponential signal attenuation across thicknesses was quantified based on the Beer–Lambert law, with attenuation coefficients ranging from 0.15 to 0.74 per millimeter. Planar transmission imaging successfully visualizes lithologic and moisture-dependent heterogeneity: limestone exhibits a dense, homogeneous structure with stable amplitude distribution; sandstone and purple sandstone show parallel statistical trends, reflecting uniform pore networks; and granite demonstrates the most pronounced imaging contrast under varying moisture states, driven by complex grain-boundary scattering. The findings reveal that THz transmission is dictated by the synergistic effects of mineral compositions and pore structures: scattering at grain boundaries and fractures leads to significant energy dissipation, whereas clay-rich lithologies exhibit the highest sensitivity to moisture variations due to water adsorption and interfacial polarization effects. As an exploration of THz technology in the non-destructive evaluation of rock materials, these findings establish an analytical framework for the quantitative assessment of microstructure evolution. Full article

Coal gasification fine ash (CGFA) is a carbon–mineral composite solid waste whose valorization is severely hindered by poor interfacial compatibility with organic media due to its highly polar surface. Here, we report a surface alkylation strategy using haloalkanes with variable chain lengths to systematically tune the surface chemistry and thermo-oxidative behavior of CGFA. Comprehensive spectroscopic characterizations (XPS, FTIR, and ¹³C NMR) confirm successful grafting of alkyl chains, which increases aliphatic C-H content from 24.8% to 43.9% while reducing polar carboxyl groups from 7.9% to 1.6%, with the mineral framework remaining intact. Thermogravimetric analysis reveals that alkylation lowers the onset decomposition temperature from 358 °C to 295 °C and enhances the maximum mass-loss rate. Kinetic analysis shows that grafted alkyl chains act as low-energy initiation sites, reducing the initial activation energy to 95 kJ/mol, while the later-stage oxidation becomes diffusion-limited. Notably, long straight-chain alkylation achieves the best performance, whereas branched chains are less effective due to steric hindrance and pore blockage. This work establishes a clear chain-length-dependent structure–thermal response relationship, positioning alkylated CGFA as a designable precursor for functional carbon materials, intelligent char-forming agents, and tunable components for energy or responsive material systems. Full article

Nanocomposite materials combine diverse material properties to form multifunctional structures, enhancing the efficiency of conventional applications. Particularly in environmental monitoring, such as water analysis, nanocomposites significantly improve sensitivity and lower costs associated with standard analysis methods. The SERS method is gaining popularity due to its operational simplicity, on-site applicability, and rapid results delivery. This study focused on the development of a multifunctional metal-chitosan-based nanocomposite utilizing an economical, eco-friendly approach as an SERS substrate. The resulting composite exhibits considerable preconcentration capabilities and will provide low detection limits (LOD) for future SERS applications. Specifically, magnetic nanoparticles (MNPs) were electrostatically combined with chitosan-coated silver nanoparticles (Chi-Ag NPs) to synthesize the MNPs@Chi-Ag NPs nanocomposite. CoFe₂O₄ NPs were prepared as MNPs. The resulting nanocomposite, which demonstrated colloidal stability after optimization, was characterized using various techniques, including UV-VIS and FTIR spectroscopy, XRD, TEM, SEM, and DLS. As a SERS substrate, the MNP@Chi-Ag NPs exhibited considerable analytical enhancement factors of (1.5 ± 0.4) × 10⁶, (7.0 ± 0.3) × 10⁶, and (1.2 ± 0.5) × 10⁶ for the detection of water contaminants BCB, CV, and MP, respectively. It was demonstrated that the substrate enhances precision and exhibits preconcentration. Finally, the MNPs@Chi-Ag NP nanocomposite demonstrates remarkable antibacterial activity, with larger inhibition zones observed at higher nanocomposite concentrations, indicating a concentration-dependent effect. Full article

Cancer continues to present a profound challenge due to high mortality and the inherent limitations of conventional treatments, including suboptimal targeting, systemic toxicity, and difficulty in overcoming physiological barriers. Micro/nanorobots (MNRs) offer a promising enhanced precision and efficacy in cancer therapy. This review systematically analyzes recent advancements in MNR applications, establishing a consistent framework that interlinks their diverse material compositions, propulsion strategies, and therapeutic functions. We critically compare various materials (inorganic, organic/polymeric, and biological/hybrid materials), elucidating their respective trade-offs in biocompatibility, biodegradability, and stimulus responsiveness. This paper further examines both internal (chemical and biological) and external (magnetic, light, and ultrasound) propulsion mechanisms, highlighting their strengths in overcoming biological barriers and enabling complex in vivo navigation, while also discussing their inherent limitations in control, fuel dependency, and tissue penetration. We then synthesize the therapeutic capabilities of MNRs across targeted drug delivery, phototherapy, radiotherapy, and immunotherapy, emphasizing common advantages like enhanced tumor specificity and reduced systemic side effects. A forward-looking perspective was also provided on the remaining challenges, particularly focusing on in vivo controllability, long-term biosafety, manufacturing scalability, and the significant hurdles in clinical translation. By offering a more critical and integrated analysis, this review underscores the immense potential of MNRs to revolutionize personalized precision cancer treatment, while candidly addressing the complex obstacles that must be surmounted for their successful clinical adoption. Full article

To satisfy the requirements of channel-type ultra-low penetration air (ULPA) filters for high filtration efficiency, low pressure drop, and good corrugation processability, a three-layer composite filter medium with a bast-fiber surface layer/glass wool–lyocell blended core layer/bast-fiber surface layer structure was designed and prepared. The effects of surface-layer material, core-layer fiber composition, surface-layer basis weight, and processing conditions on the overall performance of the medium were systematically investigated. Bast-fiber paper exhibited the best corrugation processability and mechanical performance and was selected as the surface layer. The optimal core-layer composition was 25 wt.% 475-79 glass wool fibers, 30 wt.% 475-59 glass wool fibers, and 45 wt.% lyocell fibers, yielding an original-sheet filtration efficiency of 99.9996% and a pressure drop of 381 Pa. Further optimization showed that a bast-fiber surface layer with a basis weight of 15 g/m² provided the best balance among pleat retention, structural stability, and low-resistance characteristics. Under optimized corrugation conditions of 120 °C roller temperature, 10 m/min roller speed, and 0.480 mm roller gap, a desirable pleat morphology suitable for channel-type structures was obtained. The resulting channel-type ULPA filter maintained a filtration efficiency of 99.99954%, while increasing the effective filtration area by 51.6% and reducing the pressure drop by 26.1% compared with a conventional pleated filter with the same dimensions. These results provide a useful reference for the design and application of low-resistance, high-efficiency filter media for channel-type ULPA filters. Full article

This study develops a ternary Fe-based geopolymer system composed of metakaolin (MK), red mud (RM), and fly ash (FA) for the preparation of sustainable water-retaining subgrade materials for sponge-city roadbed applications. Unlike conventional formulations primarily designed for structural strength or rapid permeability, the proposed MK–FA–RM system was designed to improve water-storage capacity while maintaining adequate mechanical support and environmental compatibility. In this ternary system, MK provides highly reactive aluminosilicate species for geopolymer network formation, RM introduces Fe-bearing phases and enhances industrial solid-waste utilization, and FA contributes to particle packing, workability, and resource efficiency. A constrained ternary mixture design implemented using Design-Expert software was adopted to optimize precursor proportions. Within the investigated compositional range, the fitted first-order mixture model showed acceptable statistical adequacy for preliminary composition screening (R² = 0.86). The optimal blend (60% MK, 30% RM, and 10% FA) achieved a 7-day compressive strength of 8.37 MPa and a water retention rate of 35.3% under ambient curing conditions, satisfying the strength requirement considered for the target subgrade/base-layer application. Microstructural and phase analyses suggest that the synergistic interaction of the three precursors promoted Fe-modified aluminosilicate gel formation together with conventional geopolymer gel products, while improving matrix continuity and preserving interconnected pore space for water storage. This multiscale structural effect helps explain how the material achieved a balance between water retention capacity and mechanical support. Under the tested conditions, the material maintained acceptable residual strength after short-term exposure to water, acid, and sulfate-containing solutions. Life-cycle assessment indicated a 70% reduction in CO₂ emissions compared with ordinary Portland cement, while pilot-scale cost analysis showed a 39% lower production cost than MetaMax-based geopolymer materials. Pilot-scale application further demonstrated the constructability and water-regulation potential of the material in practical environments. Overall, the proposed ternary Fe-based geopolymer demonstrates that Fe-rich industrial wastes can be engineered into low-carbon and economically viable water-retaining subgrade materials that balance hydraulic regulation, structural adequacy, and sustainability. Nevertheless, long-term durability, cyclic loading performance, and direct nanoscale characterization of Fe-bearing gel evolution still require further investigation. Full article

This study characterizes novel cross-linked polymeric composites based on bisphenol A glycerolate dimethacrylate (BPA.DM) as the primary matrix, incorporating 1-vinyl-2-pyrrolidone (NVP) or 2-hydroxyethyl methacrylate (HEMA) as active diluents, and modified with antimicrobial agents: zinc oxide (ZnO), copper(II) sulfate (CuSO₄), nanosilver (Ag), and benzethonium chloride (BEN). Release kinetics of active components into water and LH medium were measured over 20 days using HPLC (bisphenol A, benzethonium chloride), GF AAS (Cu, Zn, Ag), and GC–MS, revealing highest silver release from HEMA+Ag composites (1671 µg/L), substantial copper release from HEMA (354 mg/L) and NVP (319 mg/L) systems, while benzethonium chloride exhibited significantly lower migration. The effect of NVP- and HEMA-containing composites on the metabolism of the Cerrena unicolor was also assessed. Scanning electron microscopy (SEM) and optical profilometry confirmed extensive surface degradation by C. unicolor mycelium, manifesting as cracks, increased porosity, and altered surface across HEMA- and NVP-based composites after 21-day incubation. Biochemical analysis of the fungus post-culture liquids demonstrated that both composite types markedly enhanced extracellular laccase activity at all tested time points (7, 14, 21 days), with ethanol-sterilized samples inducing a slower-migrating laccase isoform identified via zymography. These materials also increased total protein concentration and superoxide anion radical levels while reducing phenolic compounds relative to controls. The findings demonstrate that antimicrobial-modified BPA.DM composites not only undergo controlled biodegradation by C. unicolor but crucially serve as potential laccase inducers, highlighting their dual utility in bioactive material design and fungal enzyme biotechnology. Full article

Additive manufacturing by Fused Filament Fabrication (FFF) enables the fabrication of complex polymer components, although limitations in surface quality and dimensional accuracy often require post-processing. Abrasive water jet machining (AWJM) is a non-thermal technique suitable for improving surface integrity in polymers and composites without inducing thermal damage. This study investigates the AWJM performance on FFF-printed polylactic acid (PLA) and carbon-fiber-reinforced PLA (PLA–CF), focusing on the influence of water pressure (WP), traverse feed rate (TFR), and abrasive mass flow rate (AMFR). A full factorial design was implemented, and surface integrity was evaluated through surface roughness (Ra) and kerf taper (T), considering their variation across characteristic cutting regions: initial damage region (IDR), smooth cutting region (SCR), and rough cutting region (RCR). Results show that WP and TFR are the dominant parameters, while AMFR has a limited effect within the studied range. The SCR exhibits the lowest roughness, whereas the RCR shows significant degradation due to energy loss. Both materials present similar behavior, with only minor improvements in PLA–CF. ANOVA confirms that process parameters have a stronger influence than material type, providing useful criteria for AWJM optimization in FFF polymers. Full article

Bone tissue engineering requires biomimetic materials; however, pure polylactic acid (PLA) exhibits limited osteoinductivity and produces acidic byproducts upon degradation. To address these limitations, this study fabricated PLA scaffolds using fused-deposition modeling (FDM) with four distinct lattice structures (rectangular, triangular, gyroid, and 3D honeycomb) and incorporated hydroxyapatite (HA) at 0, 10, 20, and 30 wt% via injection molding. Mechanical properties were evaluated via compression, three-point bending, and tensile testing. The results revealed that increasing HA content significantly reduced structural strength and increased brittleness across all test modes. Specifically, specimens with 30 wt% HA exhibited a 70.8% reduction in bending strength relative to pure PLA (from 58.60 MPa to 17.07 MPa), while tensile strength decreased by 46.1% at just 10 wt% HA (from 37.54 MPa to 20.23 MPa). Although the triangular lattice achieved the highest absolute compressive load, the rectangular lattice provided a superior load-to-weight ratio and greater plastic deformation capacity before fracture. Consequently, these findings indicate that the rectangular pattern at 70% infill density combined with HA addition limited to ≤10 wt% represents the most mechanically balanced design for bone defect repair applications. Based on the mechanical characterization performed in this study, and drawing on published evidence regarding the biological properties of PLA/HA composites, these scaffolds represent a mechanically promising candidate for further evaluation in bone tissue regeneration. Biological validation through in vitro and in vivo studies is required before clinical relevance can be established. Full article

Chronic kidney disease (CKD) is a progressive and irreversible disorder affecting over 850 million individuals globally and is associated with significant morbidity, mortality, and healthcare burden. Conventional diagnostic approaches rely on intermittent laboratory measurements, including serum creatinine, estimated glomerular filtration rate (eGFR), and urinary albumin, which provide limited temporal resolution and fail to capture dynamic physiological changes. Recent advances in wearable biosensing technologies offer new opportunities for continuous, non-invasive monitoring of biochemical and physiological markers relevant to renal function. This review provides a comprehensive analysis of wearable biosensors for CKD monitoring, focusing on sensing mechanisms (electrochemical, optical, and field-effect transistor), biofluid interfaces (sweat, interstitial fluid, and saliva), and materials engineering strategies enabling flexible, high-performance devices. Emphasis is placed on biofluid transport dynamics, analytical performance across sampling matrices, and system-level integration with wireless communication and digital health platforms. Key challenges limiting clinical translation, including biofouling, enzymatic instability, and variability in biofluid composition, are examined—alongside emerging solutions such as antifouling interfaces, synthetic recognition elements, and multimodal sensing architectures. Finally, regulatory pathways and the role of artificial intelligence in digital nephrology are discussed. This review highlights the potential of wearable biosensors to transform CKD management through continuous monitoring, early detection, and personalized therapeutic intervention. Full article

Bone fractures are often treated using invasive methods involving osteosynthesis plates. These plates are typically made of metallic materials such as titanium or steel. However, their high stiffness relative to bone tissue can contribute to the undesirable stress shielding effect. Therefore, there is a growing interest in developing new, more friendly biocompatible materials with improved mechanical properties. A promising candidate is a polymer composite made of high-strength PEEK reinforced with carbon fibers, which was the subject of this study. The aim of this work was a numerical analysis of osteosynthesis plates made from conventional materials and from PEEK-CF composite. The study also included geometric modification of the composite plate using topology optimization methods to reduce the stress shielding effect. The obtained results confirmed that the use of a geometrically optimized composite osteosynthesis plate can reduce bone unloading and ensure an appropriate stress distribution in the implant–bone system. Full article

Forsythia suspensa flowers are a promising raw material for herbal infusions, but the effects of drying on their flavor and chemical composition remain unclear. Four drying methods, freeze-drying (FD), indoor shade drying (ID), sun drying (SD), and hot-air drying (HAD), were evaluated using an electronic nose, an electronic tongue, HS-GC-MS, LC-MS, sensory evaluation, and correlation analyses. Significant differences in aroma, taste, and overall acceptability scores were observed between drying treatments. HAD samples showed stronger sweetness, bitterness, and umami responses, whereas FD samples showed higher W1W (mainly responsive to terpenes) and W2W (mainly responsive to aromatic compounds) sensor responses. In total, 72 volatile and 148 non-volatile compounds were identified. Aldehydes were the main volatile class, showing the highest relative abundance in SD, whereas terpenes were highest in HAD. OAV analysis revealed 38 volatile compounds with OAV > 1, with nonanal as the major contributor in all groups. LC–MS screened 62 differential non-volatile compounds across the four drying treatments. Pairwise comparisons with FD showed 46 differential compounds, with HAD showing the most distinct changes. Overall, the flavor differences across drying treatments were closely associated with changes in volatile and non-volatile compounds, and HAD showed better potential for standardized processing. Full article

High-temperature sintered conductive silver paste serves as a critical material in the fabrication of electronic components, with its performance directly influencing device reliability and integration density. In this work, conductive silver paste was prepared via a ball milling method by dispersing silver powder (conductive filler), glass powder (binder), and ethyl cellulose (EC, thickener) in an organic carrier composed of α-terpineol, diethylene glycol butyl ether acetate (DBA), and dimethyl phthalate (DMP) at specific ratios. The effects of the formulation composition and preparation process on the rheological properties of the paste as well as the electrical and mechanical properties of the resulting films were systematically investigated. The results indicated that sintering time and temperature exerted regular effects on the resistance of the silver paste; ball milling speed and duration influenced the particle size distribution, thereby affecting the resistance behavior; thixotropy significantly impacted the resistance characteristics. Under optimal conditions, where the organic carrier consisted of α-terpineol, DBA, and DMP at a ratio of 6:3:1, with 30 wt.% silver powder, 18 wt.% glass powder, and 4 wt.% EC, combined with a sintering temperature of 500 °C for 50–60 min, a ball milling speed of 500–600 r/min, and a ball milling time of approximately 1.5 h, the obtained silver paste exhibited pronounced shear-thinning behavior and excellent thixotropy, indicating favorable processability. The corresponding silver paste film demonstrated the lowest resistivity, superior bending resistance, and good adhesion to both PET and glass substrates. This study provides valuable insights for the design and preparation of high-performance, high-temperature sintered conductive silver pastes. Full article

This study proposes and investigates a modular assembled steel–ultra-high-performance concrete (UHPC) composite cable support bridge consisting of upper prefabricated UHPC ducts and a steel truss underneath. Finite element (FE) analysis is conducted to investigate the mechanical performance of the medium-span (L = 36 m) cable support bridge under service-loading conditions. The FE results indicate that under combined action of vertical and horizontal loads, the tensile damage in the UHPC ducts reaches approximately 10%, mainly concentrated near the end-support sections. The peak stress in the steel truss is far below its yield strength. The peak vertical displacement of the bridge is approximately L/225, below the allowable limit of L/150, and the peak horizontal displacement is negligible. A parametric analysis is performed for web sections in the midspan and end of the cable support bridge. Results show that the peak stress located at the lower chord increases with larger midspan web section. The increase in the midspan web section triggered a stress redistribution in the end webs and, consequently, a rise in the peak stress under the same load case; the peak vertical displacement decreases while the horizontal displacement exhibits marginal change. Appropriately scaling down the end diagonal web sections optimizes the material distribution, achieving a reduction in self-weight with negligible impact on the overall structural performance. Full article

Carbon capture and storage (CCS) is widely recognized as a key technology for reducing carbon dioxide (CO2) emissions from large industrial sources. Among the stages of the CCS chain, CO2 transportation plays a decisive role in determining overall system safety, reliability, and economic viability. CO2 transportation through pipelines is generally preferred for large-scale, long-distance applications and is commonly operated under dense or supercritical conditions to maximize efficiency. However, internal corrosion of pipeline steels remains a major integrity concern, with corrosion accounting for approximately 45% of reported CO2 pipeline failures. This review provides a comprehensive assessment of internal uniform and localized corrosion phenomena in CO2 pipelines operating under supercritical CO2 environments. The influence of key CO2 stream impurities, including H2O, O2, H2S, SOx, and NO2, is examined, considering their individual and synergistic effects on corrosion mechanisms, corrosion morphology, corrosion products, and severity ranking. In addition, an in-depth analysis of operating parameters such as temperature, pressure, flow conditions, and exposure time is presented alongside material-related factors, including steel grade, internal surface roughness, and welded regions. Corrosion mitigation approaches are also reviewed, with particular emphasis on organic, inorganic, and composite corrosion inhibitors. The review concludes by identifying key knowledge gaps and outlining future perspectives for improving corrosion control in CO2 transport systems supporting large-scale CCS deployment. Full article