Search Results (108)

The artificial ground freezing method (AGF) is widely used in underground construction to reinforce the ground and ensure construction safety. This study systematically evaluates the implementation of the artificial ground freezing method in the construction of a metro tunnel cross-passage, with a focus on analyzing the soil’s thermo-mechanical behavior and assessing safety performance throughout the construction process. A combined approach integrating field monitoring and refined three-dimensional numerical simulation using FLAC3D is adopted, considering critical factors, such as freezing pipe inclination, thermo-mechanical coupling, and ice–water phase transitions. Both field data and simulation results demonstrate that increasing the density of freezing pipes accelerates temperature reduction and intensifies frost heave-induced displacements near the pipes. After 45 days of active freezing, the freezing curtain reaches a thickness of 3.7 m with an average temperature below −10 °C. Extending the freezing duration beyond this period yields negligible improvement in curtain performance. Frost heave deformation develops rapidly during the initial phase and stabilizes after approximately 25 days, with maximum vertical displacements reaching 12 cm. Significant stress concentrations occur in the soil adjacent to the freezing pipes, with shield tunnel segments experiencing up to 5 MPa of stress. Thaw settlement is primarily concentrated in areas previously affected by frost heave, with a maximum settlement of 3 cm. Even after 45 days of natural thawing, a frozen curtain approximately 3.3 m thick remains intact, maintaining sufficient structural strength. The refined numerical model accurately captures the mechanical response of soil during the freezing and thawing processes under realistic engineering conditions, with field monitoring data validating its effectiveness. This research provides valuable guidance for managing construction risks and ensuring safety in similar cross-passage and cross-river tunnel projects, with broader implications for underground engineering requiring precise control of frost heave and thaw settlement. Full article

Ground-source heat pumps (GSHPs), despite their high efficiencies, are still not as cost-effective as air-source heat pumps, especially in urban environments, due to the necessity of drilling/excavation. Integrating GSHPs into existing geo-structures, such as underground tunnels, can play a vital role in reducing the overall costs of GSHP systems and promoting their use in cities. Tunnels can be realized through artificial ground freezing (AGF) by using probes for circulating the freezing fluid, which are left in the ground once the tunnel is completed. The novelty of the present work lies in the proposal of a sustainable reuse of AGF probes as ground heat exchangers (GHEs). The idea of converting AGF probes is both sustainable and cost-effective for GSHPs, as it can reduce installation costs by eliminating the drilling/excavation process. A test was performed for the first time in the Piazza Municipio metro station in Naples, Southern Italy, where several AGF probes, initially used for the construction of two tunnels, have then been converted into GHEs. The probes have been connected to a testing device called the energy box. The experiments included testing the heat transfer in the recovered AGF probes through cooling and heating operations. This work presents a numerical simulation of a test that has been validated against experimental results. Full article

From 2013 to 2021, 112 binucleate Rhizoctonia spp. (BNR) isolates were obtained from the strawberry, tomato, pepper, bean, apple, cherry, meadow grass, and soil previously cropped with strawberries from 16 locations in Serbia. Morphological and molecular analyses (ITS, LSU rDNA, RPB2, tef-1α, and atp6) confirmed infections caused by four BNR AGs: AG-G on the cherry (globally new host), bean, and tomato; AG-U on meadow grass (globally new host) and apple, AG-A on the strawberry (the most frequently isolated), and AG-F on pepper. ITS sequence analysis revealed 24 haplotypes within the worldwide population of BNR AG-A, with Serbian isolates belonging to nine. The aggressiveness of AG-A (ten isolates), AG-G (three isolates), AG-F (one isolate), and AG-U (two isolates) was tested on seedlings of 14 hosts from Poaceae, Brassicaceae, Solanaceae, Asteraceae, Fabaceae, Cucurbitaceae, Apiaceae, and Chenopodiaceae, and on detached leaf petioles of the strawberry, tomato, sunflower, and bean, as well as on two pea cultivars. Sunflower and sugar beet were the most susceptible, with AG-G being the most aggressive and AG-A the least aggressive. AG-A could not infect cabbage, while at least one isolate of each remaining AG infected all tested hosts. The consistency between seedling and petiole tests highlights the latter as a rapid method for evaluating the pathogenicity and aggressiveness of BNR isolates. Full article

TiO₂ mesoporous supports were obtained by the sol–gel method from different precursors (titaniumethoxide, isopropoxide, or butoxide) in the presence of nonionic, cationic, and anionic surfactants. Among these samples, those obtained from Ti isopropoxide, Brij58 w/o activated carbon (AC), were selected as supports. Photocatalysts were obtained by modifying these supports with Ag, Fe, and AgFe (each metal around 1% mass). The characterization results showed a stronger influence of titania precursors, surfactants, and AC on the texture and an insignificant effect on the crystalline structure and morphology of the obtained materials. X-ray photoelectron spectroscopy revealed the effects of AC and Fe on the Ag⁰ concentration and of Ag on Fe-reduced species. Based on this information, the results obtained by H₂-TPR, UV–Vis, Raman, and photoluminescence spectroscopy were explained. The performance of the photocatalysts was evaluated in the degradation of Congo Red (CR) and Crystal Violet (CV) dyes under UV and visible light. The Ag-TiO₂ sample exhibited the best activity in degrading CR at acidic pH and in degrading CV under basic conditions. In visible light, we observed the significant effects of the surface plasmon resonance, AC, Ag, and Fe on the activity in CR photodegradation. The proposed kinetics and mechanisms complete the study of the reactions. Full article

Reducing enteric methane emissions is critical for improving the sustainability of ruminant livestock production. In this study, we investigated the impact of the methane inhibitors 3-nitrooxypropanol (3-NOP) and canola oil, fed both individually and in combination, on the anaerobic gut fungi (AGF) of the rumen. Eight ruminally cannulated Angus heifers were used in a replicated double 4 × 4 Latin square over 28-day periods with a 2 (control, 3-NOP) × 2 (control, canola oil) factorial arrangement. Rumen samples were collected after 13 d dietary adaptation, and AGF communities were evaluated using amplicon sequencing of the D1/D2 region of the 28S rRNA (LSU) gene. Although 3-NOP reduced methane yield by approximately 32%, it did not substantially alter the diversity, composition, or overall abundance of the AGF community. In contrast, canola oil supplementation, either alone or combined with 3-NOP, markedly disrupted the fungal community. These treatments reduced overall fungal diversity and the abundance of key fiber-degrading taxa, such as Neocallimastix and Piromyces, while eliciting variable responses among less abundant genera. Furthermore, resilience analyses using control-diet-fed samples indicated that repeated perturbation impaired the recovery of some AGF taxa, leading to a shift in the composition of the fungal community. Overall, our findings suggest that 3-NOP offers a targeted methane mitigation strategy and does not alter the rumen AGF. In contrast, the addition of canola oil at levels that inhibit enteric methane emissions has a disruptive impact on the AGF community, contributing to reduced feed digestibility. Full article

To enhance the high-temperature resistance of silicone rubber and meet the application requirements of flexible conductive silicone rubber under elevated temperature conditions, this study adopts a chemical modification strategy by introducing phenyl groups into the molecular chains of silicone rubber to improve its thermal resistance. High-phenyl-content hydroxyl-terminated silicone oil (MPPS) was used as the polymer backbone, and vinylmethyldimethoxysilane (VDMS) served as the chain extender. Through a silanol condensation reaction, vinylmethylphenyl polysiloxane (VMPPS) with a crosslinkable structure was synthesized, providing reactive sites for subsequent vulcanization and molding. Subsequently, needle-like silver-coated glass fiber (AGF) conductive fillers were prepared via a green and environmentally friendly electroless silver plating method. These fillers were incorporated into the phenyl polysiloxane matrix to impart electrical conductivity to the phenyl silicone rubber while synergistically enhancing its thermal resistance. Finally, thermally resistant conductive silicone rubber was fabricated through high-temperature vulcanization, and the key properties of the material were systematically characterized. The synthesized phenyl polysiloxane exhibited a number-averaged molecular weight of up to 181,136, with a PDI of 2.43. When the loading of AGF reached 25 phr, the phenyl silicone rubber composite achieved the electrical percolation threshold, exhibiting a conductivity of 7.12 S/cm. With a further increase in AGF content to 35 phr, the composite demonstrated excellent thermal stability, with a 5% weight loss temperature of 478 °C and a residual mass of 37.36% at 800 °C. Moreover, after thermal aging at 100 °C for 72 h, the conductivity degradation of the phenyl silicone rubber was significantly lower than that of commercial silicone rubber, indicating outstanding electrical stability. This study provides an effective approach for the application of flexible electronic materials under extreme thermal environments. Full article

Medical imaging is crucial for disease diagnosis, but noise in CT and MRI scans can obscure critical details, making accurate diagnosis challenging. Traditional denoising methods and deep learning techniques often produce overly smooth images that lack vital diagnostic information. GAN-based approaches also struggle to balance noise removal and content preservation. Existing research has not explored tumor detection after image denoising; instead, it has concentrated on content and noise learning. To address these challenges, this study proposes the Adversarial Content–Noise Complementary Learning (ACNCL) model, which enhances image denoising and tumor detection. Unlike conventional methods focusing solely on content or noise learning, ACNCL simultaneously learns both through dual predictors, ensuring the complementary reconstruction of high-quality images. The model integrates multiple denoising techniques (DnCNN, U-Net, DenseNet, CA-AGF, and DWT) within a GAN framework, using PatchGAN as a local discriminator to preserve fine image textures. The ACNCL separates anatomical details and noise into distinct pathways, ensuring stable noise reduction while maintaining structural integrity. Evaluated on CT and MRI datasets, ACNCL demonstrated exceptional performance compared to traditional models both qualitatively and quantitatively. It exhibited strong generalization across datasets, improving medical image clarity and enabling earlier tumor detection. These findings highlight ACNCL’s potential to enhance diagnostic accuracy and support improved clinical decision-making. Full article

This study focuses on preparing and characterizing functionalized silver nanoparticle-based (Ag-F NPs) finishing agents for leather treatment. Ag-F NPs were synthesized and functionalized through a ligand exchange process with citric acid, enhancing their dispersion stability in aqueous media. The nanoparticles were incorporated into polyurethane- and nitroemulsion-based finishing formulations and applied to ovine and bovine leather via a spray coating process. Morphological (SEM, TEM), structural (XRD), thermal (TGA), and spectroscopic (FT-IR) analyses confirmed successful functionalization and uniform dispersion within the finishing layer. Leather samples treated with Ag-F NPs exhibited a significant improvement in antibacterial properties, with microbial growth reduction of up to 90% after 72 h. Additionally, accelerated aging tests demonstrated enhanced UV resistance, with a 30% lower color change (∆E) compared to control samples. The Ag-F NPs-based finishing layers also exhibited superior abrasion and micro-scratch resistance, maintaining a stable coefficient of friction over time. These findings demonstrate the potential of Ag-F NPs as multifunctional leather-finishing agents, making them highly suitable for applications in the automotive, footwear, and leather goods industries. Full article

The FLASH-COMP project aims to introduce novel inspection and monitoring technologies to develop a digital solution to predict defects during manufacturing, aiming to reach a zero-waste approach in composites manufacturing. Particularly, it’s studied the integration of two different Fiber Optic Sensor (FOS) technologies: Fiber Bragg Grating (FBG) and distributed All Grating Fiber (AGF^®), to retrieve relevant data during the preforming stage and later resin infusion process for aero-space materials. During the study, both FOS technologies were introduced into the materials, varying process conditions and the introduction of some artificial defects to evaluate the sensors response to correlate them after with their signals. Both systems can retrieve relevant information during the process such as vacuum, leaks and temperature changes, presence of voids and air bubbles, detection of dry zones, and resin flow monitoring. Further developments have to be focused on the scalability in the implementation, since FOS are fragile to handle and need specific training to use it in a more industrial field. Full article

Magneto-optic surface plasmon resonances (MOSPRs) rely on the interaction of magnetic fields with surface plasmon polaritons (SPP) to modulate plasmonic bands with magnetic fields and enhance magneto-optical activity. In the present work, a study on the magnetoplasmonic behavior of Ag/Fe bilayers is carried out by VIS-NIR spectroscopy and backed with SQUID measurements, determining the thickness-dependent magnetization of thin-film samples. The MOSPR sensing properties of Ag/Fe planar bilayers are simulated using Berreman’s matrix formalism, from which an optimized structure composed of 15 nm of Ag and 12.5 nm of Fe is obtained. The selected structure is fabricated and characterized for refractive index (RI) sensitivity, reaching 4946 RIU⁻¹ and returning an effective enhancement of refractometric sensitivity after magneto-optical modulation. A new optimized and cobalt-free magnetoplasmonic Ag/Fe bilayer structure is studied, fabricated, and characterized for the first time towards refractometric sensing, to the best of our knowledge. This configuration exhibits potential for enhancing refractometric sensitivity via magneto-optical modulation, thus paving the way towards a simpler, more accessible, and safe type of RI sensor with potential applications in chemical sensors and biosensors. Full article

Adjusting freezing patterns is a critical technology in artificial ground freezing (AGF) projects to mitigate frost heave. The distribution of ice lenses formed under varying freezing patterns not only influences frost heave but also modifies the structure of thawed soil, thereby affecting the thaw settlement process. However, most existing research on freezing patterns has primarily focused on their impact on frost heave, with limited attention paid to thaw settlement. This study investigates the cooling rates at the cold side of open frozen systems, which are the key variables defining different freezing patterns, and examines their effect on the permeability coefficient of thawed soil. Experimental results demonstrate that the cooling rate significantly influences the soil permeability coefficient. This is specifically manifested as a 12.18-fold enhancement in permeability coefficients as cooling rates decrease from 0.5 °C/s to 0.005 °C/s. As the temperature gradient increases, the permeability coefficients increase. The minimum enhancement magnitude in the permeability coefficient was recorded at −75 °C. A decrease in the cooling rate leads to an increase in the permeability coefficient, particularly under high frozen temperature conditions. Utilizing the Kozeny–Carman permeability coefficient equation, a predictive model for the permeability coefficient of thawed soil was developed. In practical AGF projects, any freezing pattern can be represented as a combination of different cooling rates. By applying this predictive model, the permeability coefficient of thawed soil under any freezing pattern can be simulated using the corresponding combination of cooling rates. This study provides a valuable reference for predicting thaw settlement following artificial freezing construction. Full article

Hyperuricemia arises from imbalanced uric acid metabolism, contributing to gout and related chronic diseases. When traditional drugs are used to treat hyperuricemia, side effects are inevitable, which promotes the exploration of new bioactive compounds. Protein hydrolysates and peptides are gradually showing potential in the treatment of hyperuricemia. This study investigated the uric acid inhibitory activity of peptides extracted from Trachurus japonicus using in silico and in vitro methods. We employed in silico virtual enzymolysis and experimental validation to identify bioactive peptides from Trachurus japonicus proteins. Four peptides (DF, AGF, QPSF, and AGDDAPR) were comprehensively screened by molecular docking and database analysis. After solid-phase synthesis, the inhibitory effects of these peptides on hyperuricemia were further verified in vitro and at the cellular level. The results showed that all four peptides have good hyperuricemia-inhibiting activities. Molecular docking and molecular dynamics revealed that peptides DF and AGDDAPR affect the production of uric acid by binding to the active sites of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), and xanthine oxidase (XOD), while peptides QPSF and AGF mainly influence the XOD active site, confirming that it is feasible to rapidly screen hyperuricemia-inhibiting peptides by molecular docking. Full article

Aim: To compare caregiver satisfaction and children’s acceptance of silver fluoride/potassium iodide (AgF + KI) treatment (Riva Star Aqua^®, SDI Limited, Victoria, Australia) and glass-ionomer cement (GIC) application (Ionostar Plus + Easy Glaze, VOCO, Germany) in reducing hypersensitivity in permanent molars affected by molar incisor hypomineralisation (MIH) with the MIH treatment need index (MIH-TNI) 3 and 4 immediately after its application and after 12 weeks. Materials and Methods: This prospective, comparative, clinical study recruited schoolchildren with at least one hypersensitive MIH molar with a Schiff cold air sensitivity score (SCASS) of 2 and 3. Caregivers in both groups (AgF + KI and GIC + glaze) answered a questionnaire (5-Point Likert Scale) regarding the perception of the treatment immediately (15 min post application) and in the 12 weeks follow-up. Children’s behaviour during both applications was assessed using FBRS (Frankl Behaviour Rating Scale). Results: A total number of 47 children (n = 22 for AgF/KI and n = 25 for GIC) with a mean age of 8.6 ± 1.42 were recruited. A high proportion of the children in both arms (n = 40 out of 44; 90.1%) reported a reduction in hypersensitivity in the last 12 weeks. On average, children (n = 39; FBRS ≥ 3) in both groups showed positive behaviour, with a significantly more definitely positive behaviour in the GIC group (p < 0.05, independent student t-test). Caregiver satisfaction with both study procedures was high after immediate assessment (n = 19 out of 22, 86.4% for AgF/KI and n = 19 out of 25, 76.0% for GIC application) and in 12 weeks of follow-up (n = 17 out of 20, 85.0% for AgF/KI and n = 22 out of 24, 91.6% for GIC application). However, the taste AgF/KI is more frequently considered not acceptable for the child (n = 10; 45%) than smell (n = 2; 9%). Interestingly, there was a statistically significant difference in caregivers’ preference toward alternative desensitisation treatment (tooth restoration coverage, desensitisation paste, stainless steel crown and fluoride varnish) in both treatment groups (p < 0.05, Mann–Whitney U test). Conclusions: Both GIC and AgF/KI applications can be considered acceptable approaches to reduce hypersensitivity in permanent molars affected by MIH both immediately and in long-term follow-up for schoolchildren based on caregivers’ assessments. Full article

Ammonia is one of the common inorganic pollutants in surface waters. It can come from a wide range of sources through the discharge of wastewater (industry, agriculture, and municipal waters). Catalytic ozonation reaction can efficiently remove ammonia nitrogen without introducing other pollutants and improve the nitrogen selectivity of reaction products by controlling the reaction conditions. Catalysts based on silver nanoparticles (Ag NPs) have shown excellent O₃ decomposition performance; therefore, they are promising catalysts for catalytic ammonia ozonation due to their high reactivity, stability, and selectivity to N₂. In this study, we synthesized well-defined silver nanoparticles (Ag NPs) using a modified alkaline polyol method and then dispersed them on solid oxide supports (Fe₃O₄, TiO₂, and WO₃). Before being deposited on the oxide support, the silver nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-VIS spectroscopy. The obtained catalysts, Ag_Fe₃O₄, Ag_TiO₂, and Ag_WO₃ were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area analysis, UV-VIS spectroscopy, temperature-programmed reduction (H₂-TPR), and temperature-programmed desorption (TPD) of CO₂ and NH₃. It has been demonstrated that the nature of the support significantly influences the physicochemical properties of the catalysts, as well as their catalytic performance in ammonia ozonation reaction. Full article