Search Results (251)

The electrooxidation (EO) of three important environmental contaminants, anticorrosive 1H-benzotriazole (BTA), plasticizer dibutyl phthalate (DBP), and non-ionic surfactant Triton X-100 (tert-octylphenoxy[poly(ethoxy)] ethanol, t-OPPE), was studied as a possible means to improve their elimination from wastewaters, which are an important emission source. EO was performed in a batch reactor with a boron-doped diamond (BDD) anode and a stainless steel cathode. Different supporting electrolytes were tested: NaCl, H₂SO₄, and Na₂SO₄. Results were analysed from the point of their efficacy in terms of degradation rate, kinetics, energy consumption, and transformation products. The highest degradation rate, shortest half-life, and lowest energy consumption was observed in the electrolyte H₂SO₄, followed by Na₂SO₄ with only slightly less favourable characteristics. In both cases, degradation was probably due to the formation of persulphate or sulphate radicals. Transformation products (TPs) were studied mainly in the sulphate media and several oxidation products were identified with all three contaminants, while some evidence of progressive degradation, e.g., ring-opening products, was observed only with t-OPPE. The possible reasons for the lack of further degradation in BTA and DBP are too short of an EO treatment time and perhaps a lack of detection due to unsuitable analytical methods for more polar TPs. Results demonstrate that BDD-based EO is a robust method for the efficient removal of structurally diverse organic contaminants, making it a promising candidate for advanced water treatment technologies. Full article

Terahertz metamaterial dual-band absorbers are used for multi-target detection and high-sensitivity sensing in complex environments by enhancing information that reflects differences in the measured substances. Traditional design processes are complex and time-consuming. Machine learning-based methods, such as neural networks and deep learning, require a large number of simulations to gather training samples. Existing design methods based on single-objective optimization often result in uneven multi-objective optimization, which restricts practical applications. In this study, we developed a metamaterial absorber featuring a circular split-ring resonator with four gaps nested in a “卍” structure and used the Multi-Objective Firefly Algorithm based on Multiple Cooperative Strategies to achieve fast optimization of the absorber’s structural parameters. A comparison revealed that our approach requires fewer iterations than the Multi-Objective Particle Swarm Optimization and reduces design time by nearly half. The absorber designed using this method exhibited two resonant peaks at 0.607 THz and 0.936 THz, with absorptivity exceeding 99%, indicating near-perfect absorption and quality factors of 31.42 and 30.08, respectively. Additionally, we validated the absorber’s wave-absorbing mechanism by applying impedance-matching theory. Finally, we elucidated the resonance-peak formation mechanism of the absorber based on the surface current and electric-field distribution at the resonance frequencies. These results confirmed that the proposed dual-band metamaterial absorber design is efficient, representing a significant step toward the development of metamaterial devices. Full article

Graphene oxide (GO) films have attracted significant attention due to their potential in separation and filtration applications. Based on their unique lamellar structure and ultrathin nature, GO films are difficult to maintain in a free-standing form and typically require substrate support. Consequently, understanding their film formation behavior and mechanisms on substrates is of paramount importance. This work employs commonly used nonwoven fibrous membranes as substrates and guided by the coffee-ring theory, systematically investigates the film formation behaviors, film morphology, and underlying mechanisms of GO films on fibrous membranes with varying wettability. Fibrous membranes with different wetting properties—hydrophilic, hydrophobic, and superhydrophobic—were prepared via electrospinning and initiated chemical vapor deposition (iCVD) surface modification techniques. The spreading behaviors, deposition dynamics, capillary effects, and evaporation-induced film formation mechanisms of GO suspensions on these substrates were thoroughly examined. The results showed that GO formed belt-like, ring-like, and circular patterns on the three fibrous membranes, respectively. GO films encapsulated more than the upper half, approximately the upper half, and the top portion of fibers, respectively. Pronounced wrinkling of GO films was observed except for those on the hydrophilic fibrous membrane. This work demonstrates that tuning the wettability of fibrous substrates enables precise control over GO film morphology, including fiber encapsulation, wrinkling, and coverage area. Furthermore, it deepens the understanding of the interactions between 1D nanofibers and 2D GO sheets at low-dimensional scales, laying a foundational basis for the optimized design of membrane engineering. Full article

Proton exchange membrane fuel cells (PEMFCs) have been widely studied as an efficient and environmentally friendly energy conversion technology in recent years. However, the high cost, easy poisoning and complex synthesis methods of noble metal catalysts have hindered their commercialization. Therefore, in this paper, a non-noble metal composite catalyst CuFeCo/C for the oxygen reduction reaction (ORR) was prepared by using a facile liquid-phase reduction method. The ORR kinetic performance of CuFeCo/C was evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and rotating ring-disk electrode (RRDE) tests. The results show that the oxygen reduction peak of CuFeCo/C appears at about 0.64 V, the half-wave potential is about 0.73 V, the limiting current density is about −16.51 A·m⁻², and the Tafel slope is about −0.08. The 10,800 s chronoamperometry test shows that the catalyst has a very good long-term cycle stability. This indicates that the CuFeCo/C composite catalyst has strong stability, good conductivity and ORR catalytic activity under alkaline conditions, which can promote the large-scale commercial application of PEMFCs. Full article

Background: Percutaneous screw fixation has increasingly been used for pelvic ring fracture fixation. In older adult patients, especially in patients with a fragility fracture of the pelvis (FFP), minimally invasive techniques followed by early ambulation have been promoted in order to regain pre-injury levels of mobility and independence. The purpose of this study was to evaluate patient-centered outcomes, including post-operative pain relief, functional performance, and satisfaction, in older adults with pelvic ring fractures treated with percutaneous screw fixation and to assess injury characteristics, complications, and return-to-home rates. Methods: In this retrospective cohort study, patients 50 years and older who had their pelvic fracture treated in the Amsterdam UMC location AMC between January 2019 and December 2022 were identified. After a minimum follow-up period of 6 months, a questionnaire was conducted by phone to evaluate the pain, current living situation, and mobility of the patients. Results: A total of 51 patients were included in this study with a median age of 74 years (IQR 62–82), and the vast majority were female (n = 40, 78%). Over half of the pelvic fractures were caused by low-energy trauma (n = 29, 57%). Unilateral or bilateral sacral fractures with unilateral anterior ring fractures were the most common fracture pattern. The interoperative complication rate was 4%, and the in-hospital complication rate was 23%. Forty-five patients were reached to complete the questionnaire. Forty patients (91%) returned to an acceptable level of mobility after treatment, and almost all (n = 44, 98%) were pleased with the results of the surgery. Conclusions: Percutaneous screw fixation of pelvic fractures in older adult patients is a safe and effective operating technique. Most patients preserve their pre-morbid functionality and are able to return to their previous place of residence after admission. Furthermore, patients are almost unanimously very pleased with the results of the surgery despite some residual pain complaints. Full article

In response to the urgent need for innovative fungicides to ensure food security and safety, a series of twenty-three novel trifluoromethylpyridine compounds were designed and synthesized using a scaffold hopping strategy derived from dehydrozingerone. This approach involved converting the α, β-unsaturated ketone moiety into a pyridine ring. Bioassay results indicated that the majority of these compounds exhibited promising in vitro antifungal activity, particularly against Rhizoctonia solani and Colletotrichum musae. Notably, compound 17 showed the highest efficacy and broad-spectrum activity, with median effective concentrations (EC₅₀) ranging from 2.88 to 9.09 μg/mL. Phenoxytrifluoromethylpyridine derivatives, including compound 17, exhibited superior antifungal activity compared to benzyloxytrifluoromethylpyridine derivatives. In vivo tests revealed that both compounds 17 and 23 exhibited moderate control effects against C. musae. The degradation half-lives of compounds 17 and 23 in bananas were determined to be 176.9 h and 94.8 h, respectively, indicating the stability of their structures in the environment. Molecular docking studies indicated that compound 23 interacts with succinate dehydrogenase, offering valuable insights for the structural optimization of compound 23. Full article

Vegetation transpiration (Tr) is crucial for the water cycle, regional water balance, and plant growth but remains challenging to estimate at large scales. Sun-induced chlorophyll fluorescence (SIF) provides a novel method for estimating Tr, but its effectiveness is limited by species specificity, requiring continuous tower-based observations for comprehensive analysis across diverse ecosystems. In this study, SIF and Tr were simultaneously monitored in Chinese cork oak (ring-porous), poplar (diffuse-porous), and arborvitae (non-porous) plantations in northern China, and the SIF–Tr relationship was further analyzed. The results showed that SIF and Tr shared similar diurnal dynamics, although Tr exhibited midday saturation. SIF and Tr were closely correlated, and the correlation strengthened as the temporal scale aggregated. Environmental factors had nonlinear impacts on SIF and Tr. Therefore, the SIF–Tr relationship deteriorated to some extent at midday, with short-term stress reducing the correlation by 0.1–0.23. Compared to the linear empirical model, the inclusion of environmental factors improved the accuracy of SIF-based Tr estimation, increasing the R² value by 0.12 to 0.37. At the same level of accuracy, the number of environmental variables required was higher at the half-hour scale than at the daily scale. This study demonstrated the species-specific influence of environmental factors on SIF and Tr in different plantations, enhanced the understanding of the SIF–Tr relationship, and provided theoretical and data support for future large-scale Tr predictions using satellite-based SIF. Full article

There is a growing trend to promote circular economy practices and reduce petroleum-derived product consumption in the paving sector. In this context, a liquid lignin-rich industrial waste was incorporated at 0% (control), 5%, 10%, 15%, and 20% into a bitumen emulsion to manufacture a lignin-based biobinder for half-warm-mix asphalt (HWMA). The mix of the bitumen emulsion and the industrial waste was made using an Ultra-turrax device, with the final mixing temperature monitored using a thermographic camera. Microstructure analysis was conducted using scanning electron microscopy (SEM). The bitumen was extracted and characterized using needle penetration tests at several temperatures. Additionally, the ring-and-ball softening point, penetration index, and ductility were assessed. Incorporating up to 5% of lignin-rich industrial waste led to a lignin-based biobinder that could be used for a more sustainable and bitumen-efficient HWMA production. Full article

Vector beams (VBs) with longitudinally varying polarization states provide a new dimension for light field manipulation, and promote the advancements of related areas such as optical metrology, longitudinal depth detection, and classical and quantum communications. In this study, we propose a half-wave plate dielectric metasurface based on a spatial partitioning method, realizing the longitudinal manipulation of the polarization states of higher-order Poincaré (HOP) beams by changing the elliptical polarization state of the incident light and selecting the appropriate propagation distances. The metasurface is composed of two sub-metasurfaces, and the two sets of a-Si:H meta-atoms are uniformly arranged on concentric rings of different radii with an equal interval. The propagation and Pancharatnam–Berry phases are utilized to construct the axicon and helical phase profiles. As a result, two sub-metasurfaces, respectively, generate the first- and second-order VBs with longitudinally varying polarization states. The polarization states of generated VBs correspond to points on different meridians of nth-order HOP spheres from the south pole to the north pole. The consistency between the theoretical and simulated results demonstrates the feasibility and practicability of the proposed method. This study provides an innovative strategy to extend the modulation of light fields from two-dimensional to three-dimensional space. Full article

The heterogeneous integration of ferroelectric thin films on silicon- or silicon nitride-based platforms for photonic integrated circuits plays a crucial role in the development of nanophotonic thin film modulators. For this purpose, an ultrathin seed film was recently introduced as an integration method for ferroelectric thin films such as BaTiO₃ and Pb(Zr,Ti)O₃. One issue with this self-orienting seed film is that for non-planarized circuits, it fails to act as a template film for the thin films. To circumvent this problem, we propose a method of planarization without the need for wafer-scale chemical mechanical polishing by using hydrogen silsesquioxane as a precursor to forming amorphous silica, in order to create an oxide cladding similar to the thermal oxide often present on silicon-based platforms. Additionally, this oxide cladding is compatible with the high annealing temperatures usually required for the deposition of these novel ferroelectric thin films (600–800 °C). The thickness of this silica film can be controlled through a dry etch process, giving rise to a versatile platform for integrating nanophotonic thin film modulators on a wider variety of substrates. Using this method, we successfully demonstrate a hybrid BaTiO₃-Si ring modulator with a high Pockels coefficient of $r_{wg}=155.57\pm 10.91$ pm V⁻¹ and a half-wave voltage-length product of $V_{\pi }L=2.638\pm 0.084$ V cm, confirming the integration of ferroelectric thin films on an initially non-planar substrate. Full article

The compounds targeting the bromo and extra terminal domain proteins (BET), such as the JQ1, present potent anti-cancer activity in preclinical models, however, the application of JQ1 at the clinical level is limited by its short half-life, rapid clearance, and non-selective inhibition of BET family proteins, leading to off-target effects and resistance. To address these challenges, the optimization of JQ1 delivery has been accomplished through polylactide (PLA) nanoparticles. PLA derivatives with varying molecular weights were synthesized via ring-opening polymerization using a zinc-based initiator and characterized using thermogravimetric analysis, differential scanning calorimetry, and infrared spectroscopy. PLA nanoparticles (NPs) were subsequently formulated, and the effects of key parameters—including PLA molecular weight, organic phase concentration, and surfactant concentration—on particle size, polydispersity index (PDI), and encapsulation efficiency were systematically investigated. PLA molecular weight and organic phase concentration mainly influenced the NPs size whilst the thermodynamic state of the NPs was unaffected by these two parameters. The surfactant concentration is correlated to the encapsulation efficacy of JQ1 as well as the release profile, suggesting the potential tool that the variation of these parameters represent for customizing the release of JQ1 according to specific needs. Full article

A frequency-reconfigurable MIMO antenna with high gain, low mutual coupling and highly suppressed side lobe level (SLL) for applications in 24 GHz ISM band sensing and automotive radar systems was designed, modeled, and simulated. The reconfigurability feature was modeled with the implementation of a varactor diode in the model to alter the frequency in a wide band around 24 GHz. The design features 2- and 4-port MIMO antenna each comprising a 1 × 8 microstrip patch array. At the core of achieving both a high gain of 16 dBi and high isolation of 38.4 dB at a resonance frequency of 24.120 GHz lies the integration of a metamaterial absorber, comprising an optimized split-ring unit cell to effectively mitigate interference among the MIMO elements. Noteworthy impedance bandwidths of the sensor antenna span from 23.8 to 24.3 GHz, catering to diverse frequency requirements. The proposed sensor antenna feature a half-power beamwidth of 74° in the E-plane and 11° in the H-plane and an SLL of −24 dB at 24.120 GHz showing its robust performance characteristics across multiple operational dimensions. Full article

This study focuses on the analysis of the spectral response of all-pass micro-ring resonators (MRRs), which are essential in photonic device applications such as telecommunications, sensing, and optical frequency comb generation. The aim of this work is to generate a synthetic dataset that explores the spectral characteristics of the expected transmission spectra of MRRs by varying their structural parameters. Using numerical simulations, the dataset will allow the optimization of MRR performance metrics such as free spectral range (FSR), full width at half maximum (FWHM), and quality factor (Q-factor). The results confirm that variations in geometric configurations can significantly affect MRR performance, and the dataset provides valuable insights into the optimization process. Furthermore, machine learning techniques can be applied to the dataset to automate and improve the design process, reducing simulation times and increasing accuracy. This work contributes to the development of photonic devices by providing a broad dataset for further analysis and optimization. Full article

Carbon Fiber Reinforced Polymers (CFRPs) are widely used in aerospace, automotive, and other sectors for their high strength-to-weight ratio and adaptability. In order to reach high mechanical performance and quality for CFRP components in which a thermosetting resin is used, the curing process plays a key role, and the optimal conditions have to be identified. In this context, the present study aims to study the effect of heat-shrinkable tape application on the mechanical performance of CFRP tubular components obtained by a filament winding process. To this purpose, CFRP hoop-wound components were realized with a laboratorial filament winding machine. Half of them were directly cured in a muffle oven, while the other half were cured after the application of heat-shrinkable tape around the external surface of the component. To evaluate the effect of the heat-shrinkable tape use on the mechanical properties of the CFRP wound parts, ring specimens, obtained by the tubular components according to the ASTM D2290 standard, were subjected to ring tensile tests. The thickness uniformity and void content of the components were evaluated by means of X-ray computed tomography, whilst the fracture surfaces were observed using scanning electron microscopy. It was demonstrated that the heat-shrinkable tape application around the external surface of the CFRP tubular components allows for improved mechanical performance of the wound parts due to the enhanced material compaction, resulting in stronger and more cohesive structures characterized by a uniform thickness and reduced void content. Full article

The aim of this study was to establish a standardized and unified method for identifying and evaluating jujube fruit texture quality and to provide a theoretical basis for determining the texture quality of jujube germplasm resources. The texture of 56 jujube germplasms was characterized via the texture profile analysis (TPA) method, and the texture and anatomical structure of three each of the hard- and soft-fleshed germplasms were analyzed. Cluster analysis was used to categorize the 56 germplasms into hard- (17) and soft-fleshed jujubes (39). Significant positive correlations were found between all other textural parameters of jujube fruits except adhesiveness. The hardness, springiness, and chewiness of the full-red period hard- and the soft-fleshed jujube fruit were lower than those of the half-red period. The hardness, adhesiveness, and chewiness of the hard-fleshed jujube fruits in the full-red period were 2.13–3.57, 3.00–4.99, and 4.39–9.58 times higher than those of the soft-fleshed jujube fruits, respectively. The findings of this study provide a theoretical foundation for the evaluation and classification of the texture and quality of jujube fruits and a basis for the breeding of new, high-quality jujube varieties with distinctive characteristics. Full article