Search Results (94)

A cradle-to-gate life-cycle assessment (LCA) was conducted for an activated adsorbent produced from the non-metallic fraction (NMF) of waste printed circuit boards. The primary production reference was 1 kg of dry activated non-metallic fraction (ANMF) produced. Cradle-to-gate production impacts were subsequently normalized using previously reported equilibrium adsorption capacities for Pb²⁺, Cu²⁺, and Zn²⁺ to obtain performance-normalized production impacts per kilogram of theoretical metal uptake. Environmental impacts were quantified using the ReCiPe 2016 Midpoint (H) method together with cumulative energy demand (CED). Production of 1 kg of ANMF resulted in a climate change (CC) impact of 5.77 kg CO₂-eq and a CED of 140.03 MJ. After adsorption-capacity normalization, the CC impacts were 8.44, 31.35, and 43.05 kg CO₂-eq kg⁻¹ metal uptake, while the corresponding CED values were approximately 205, 761, and 1045 MJ kg⁻¹ metal uptake for Pb²⁺, Cu²⁺, and Zn²⁺, respectively. Commercial activated carbon (AC) exhibited slightly lower production impacts, but its lower representative Pb²⁺ adsorption capacity resulted in substantially higher normalized production burdens. These normalized indicators represent cradle-to-gate production impacts scaled by adsorption performance and do not include wastewater-treatment use-stage operations, regeneration, or management of spent adsorbent. The results demonstrate that adsorption performance substantially influences the interpretation of production-related environmental burdens and should therefore complement conventional mass-based assessment of adsorbents. Full article

To improve the practicality of water-inrush hazard identification in underground metal mines under complex hydrogeological conditions, this study develops a multi-source information fusion evaluation framework. An index system is established that encompasses water-source conditions, water-conducting pathway characteristics, mining-induced disturbance, and goaf-related hazards. Subjective and objective information are integrated through combined weighting based on the intuitionistic fuzzy analytic hierarchy process (IFAHP) and the entropy weight method (EWM). To characterize uncertainty and support hazard classification, a normal cloud model is introduced. The proposed method is applied to three stopes, namely 150701, 200-6-1, and 400-27-3, in a copper–iron mine in Anhui Province. The evaluation results classify the three stopes as Level III, Level II, and Level IV, respectively, which are consistent with the observed water inflows of approximately 28 m³/h, 17 m³/h, and 35 m³/h. These results indicate that the proposed method shows applicability in stope-scale water-inrush hazard assessment in the case mine and can provide a quantitative reference for risk identification and prevention under complex hydrogeological conditions. Full article

Non-proportional multiaxial loading is known to significantly affect the fatigue life of metallic materials. Although various non-proportionality parameters have been proposed, many of them rely on geometric or integral descriptions of the loading path and lack a direct physical connection to critical plane mechanisms. In this study, a new non-proportionality parameter is proposed based on the relationship between shear strain amplitudes evaluated on the critical planes of maximum shear and maximum normal strain. The proposed parameter effectively differentiates between proportional and non-proportional loading paths, and it exhibits correct limiting behavior for reference cases. The applicability of the proposed parameter is tested within the Itoh critical plane fatigue model by substituting it for the conventional integral non-proportionality parameter, allowing for a direct comparison of predictive accuracy. On a database of 15 metallic materials, the proposed parameter yields a mean log-life prediction error ∆ N ^ f = −0.33, standard deviation σ = 0.47, and coefficient of determination R 2 = 0.497, statistically indistinguishable from the integral Itoh (−0.35; 0.46; 0.495) and Borodii (−0.31; 0.48; 0.512) formulations, while offering a clearer physical interpretation and a simpler, non-integral computational procedure. Full article

The objective of this study is to recover the transient out-of-plane displacement field of clamped circular plates subjected to blast loading using a single high-speed camera, as a low-cost alternative to stereo Digital Image Correlation (DIC) for the specific class of axisymmetrical structural responses of circular plates. The dynamic response of thin metal plates to blast loading is a fundamental problem in protective structural design, traditionally investigated through DIC. Although it provides full-field displacement measurements with high spatial resolution, it requires stereo camera arrangements, controlled illumination, speckle pattern preparation, and elaborate calibration procedures that significantly increase experimental cost and complexity. This study introduces a monocular optical method applicable to axisymmetrically defined material testing applications, such as the response of circularly supported isotropic plates under a uniform impulsive load, to recover the transient out-of-plane displacement field without using DIC. Clamped circular aluminum plates are subjected to blast loading generated by PG-3 charges of variable mass detonated at the closed end of a shock tube, with the exposed face matching the tube cross-section so as to enforce axisymmetric pressure load. A diametral reference line marked on the rear face of each specimen was recorded by a single high-speed camera, and a perspective correction derived from the axisymmetric deformed geometry was then applied to reconstruct the time-resolved displacement profile along the diameter. The permanent post-test deformed shape of each plate was subsequently digitized through 3D scanning and used as ground truth to validate the optical reconstruction. The reconstructed profiles closely matched the scans: for the conventional responses the root-mean-square error was 1.251 mm with a normalized mean residual of 6.57% (Case A) and 1.793 mm (9.20%, Case B), while for the anomalous counterintuitive response it was 1.043 mm (14.93%, Case C). Symmetry can thus be exploited as an active measurement principle to obtain quantitative blast-response data with substantially reduced experimental burden and without specialized stereo-optical instrumentation. Full article

The development of highly crystalline tungsten oxide nanomaterials remains challenging for catalytic applications due to the difficulty in achieving high phase purity without sacrificing metal oxide loading. This work addresses this limitation through an innovative fast hydrothermal synthesis at 100 °C for 4 h without autoclaves or surfactants, using citric acid as a critical structural directing agent. Such methodology reduces the synthesis time by 50–80% compared to existing hydrothermal routes. Citric acid was identified as the critical parameter controlling the nanosheet thickness (20 nm to 35 nm) and diameter (109 nm to 173 nm), acting as a coordinating ligand. The resulting nanosheets were used to prepare Pt/WO₃/Al₂O₃ catalysts with well-defined crystalline monoclinic WO₃ structures at 9.5% wt. loading. Normally, this phase is inaccessible by standard impregnation at equivalent loading. NH₃-TPD characterization confirmed that crystalline WO₃ generates strong acid sites absent in the reference wet impregnation catalyst. Glycerol hydrogenolysis tests revealed that the presence of monoclinic WO₃ reduces the average glycerol conversion rate by a factor of 3.8 and systematically shifts selectivity toward over-hydrogenolysis products (1-propanol and 2-propanol), despite identical WO₃ loading and surface densities below the literature optimum of 2.2 W atoms ${\mathrm{nm}}^{-2}$. These results demonstrate that the WO₃ crystalline phase is a primary determinant of catalytic performance, without taking into account increased loading. Such demonstration will be useful for the rational design of selective glycerol hydrogenolysis catalysts. Full article

Ionization potentials and electron affinities provide the energetic basis for several conceptual density functional theory descriptors, but their use in donor–acceptor maps requires careful distinction between physically bound anions, weak or borderline electron-affinity cases, and formally computed diagnostic states. In this work, a periodic donor–acceptor descriptor map was constructed for main-group atoms from H to Kr using a $\Delta$SCF-DFT framework. Neutral atoms, monocations, and formally defined monoanionic states were evaluated to obtain ionization potentials, electron affinities, and global reactivity descriptors, including electronegativity, chemical hardness, chemical potential, electrophilicity, electrodonating power, and electroaccepting power. The production dataset was calculated at the $\omega$B97X-D4/def2-QZVPPD level and benchmarked against reference atomic data. This protocol reproduced ionization potentials with a mean absolute error of 0.134 eV and electron affinities with a mean absolute error of 0.116 eV for the reference EA set, including the weak calcium case. A functional and basis-set sensitivity analysis using $\omega$B97X-D4/def2-TZVPPD, PBE0/def2-QZVPPD, and PBE0/def2-TZVPPD showed that ionization potentials are comparatively robust, whereas electron affinities are strongly affected by the quality of the diffuse basis set. The normalized donor–acceptor map reproduces chemically intuitive periodic trends, with alkali metals occupying the strong-donor region and halogens defining the strong-acceptor region. The analysis explicitly separates core validation atoms from weak or borderline electron-affinity cases and diagnostic finite-basis anionic states, emphasizing that formally computed negative electron affinities for unbound anions should not be interpreted as physical bound states. The resulting nonrelativistic dataset provides a reproducible atomic descriptor reference for interpreting donor–acceptor behavior in atoms, clusters, superatoms, doped materials, and charge-transfer systems. Full article

The quality of Surface-Enhanced Raman Chemical Imaging (SER-CI) rely on several parameters, among which the uniform deposition of metallic nanoparticles impacts greatly the result. Optimizing deposition protocols for biological samples is challenging due to inherent spatial heterogeneity, preventing the distinction between deposition artefacts and true analyte distribution. However, to optimize the deposition parameters, it is necessary to have a controlled experimental model. This study presents the development of a repeatable dried gelatine–agarose hydrogel as a controlled analytical substrate with the uniform spatial homogeneity of diphenhydramine hydrochloride as the experimental model for further nanoparticle deposition optimization. With its skin-mimicking Raman fingerprint, the proposed hydrogel enables the systematic evaluation of deposition techniques without biological variability. Confocal Raman imaging performances are as follows: the normalization-based ratio (I₁₀₀₃/I₁₄₆₉) achieved an intra-day RSD of 3.6–8.2%, inter-day RSD of 6.5%, and intra-day pixel-wise RSD (%) of 8.3–12.3%. The Distribution Homogeneity Index (DHI) confirmed the analyte’s uniform distribution. Drying kinetics modelling revealed a diffusion-based dehydration process, with repeatable batch production. Application of dried hydrogels for SERS chemical imaging confirmed diphenhydramine hydrochloride detectability inside the polymeric matrix, with the proportionality of intensity based on the diphenhydramine hydrochloride concentration. A preliminary performance comparison of nanoparticle deposition by drop-casting and spray-coating demonstrates the applicability of the developed model. This standardized matrix provides a reference platform for evaluating deposition homogeneity, distinguishing method performance from sample artefacts and accelerating chemical imaging method development and performance through optimization. Full article

DNA damage requires repair via the endonuclease IV-mediated base excision repair (BER) pathway, which corrects apurinic/apyrimidinic (AP) sites. Chlamydophila pneumoniae AP endonuclease IV (CpEndoIV), the sole AP endonuclease in this pathogen, is crucial for genomic integrity. As humans lack a homologous protein, it represents a potential therapeutic target. In this study, we report the first crystal structure of CpEndoIV at 1.97 Å resolution. The structure reveals two Zn²⁺, one Mg²⁺, and a malonate molecule bound in the active site, marking the first observation of Mg²⁺ coordination in the EndoIV family. Compared to the three-Zn²⁺ model with a narrow, deep pocket for precise AP-site cleavage, the Zn²⁺/Mg²⁺-bound state has a wider, shallower pocket that might promote diverse catalytic activities. Combined with enzymatic assays, we suggest that the mixed Zn²⁺/Mg²⁺ model is better adapted for CpEndoIV to operate under host oxidative stress. Malonate binds to the metal ions, occupying the positions normally coordinated by water molecules. This binding mode may mimic the coordination of the substrate to the metal ions, and the protein conformation resembles that of the enzyme upon substrate binding at the active site. This study provides a structural basis for the functional characterization of CpEndoIV and offers a reference for the development of targeted inhibitors against diseases caused by Chlamydophila pneumoniae. Full article

In the fabrication process of pipelines for petrochemical and other industries, weld reinforcement is often excessive and adversely affects subsequent processes such as anticorrosion treatment and surface coating. Weld reinforcement must be removed through a grinding process. Welding deformation and fit-up errors often lead to highly irregular weld geometries, which makes robotic grinding difficult and causes the task to still heavily rely on manual operation. To address this issue, this study proposes an automatic weld recognition and grinding trajectory planning method based on 3D visualization and deep learning. A weld recognition network, termed WSR-Net, has been developed based on an improved PointNet++ architecture with a cross-attention mechanism, achieving a segmentation accuracy of 98.87% and a mean intersection over union of 90.71% on the test set. An intrinsic shape signature (ISS) key point selection algorithm with orthogonal slicing-based pruning optimization is developed to robustly extract key weld ridge points that characterize the weld trend on rugged weld surfaces. According to the height differences between the weld and the adjacent base metal surfaces, the grinding reference surface is fitted using the weld contour through the moving least-squares method. The ridge line points are projected onto the grinding reference surface along the local normal to generate the expected grinding trajectory points. The grinding trajectory that meets the process constraints is generated through reverse layer slicing. Grinding experiments demonstrate that the proposed WSR-Net achieves robust segmentation performance for both planar and curved surface welds. With the reverse layered trajectory planning method, the proposed method enables high-precision automatic grinding of complex spatially curved surface welds. The results show that the final grinding mean error is 0.316 mm, which satisfies the preprocessing requirements for subsequent processes. The proposed method provides a feasible technical method for the intelligent grinding of spatially curved surface welds. Full article

Metal additive manufacturing relies on fine powders whose properties influence flow, spreading, and airborne release during processing, yet published data on powder characteristics, reuse effects, and emissions remain fragmented and difficult to compare. This study reviews quantitative measurements reported for metallic feedstocks used in laser powder bed fusion and directed energy deposition. A numerical evaluation model is developed to connect powder properties, process conditions, dispersion tendency, and material recovery. Particle size distribution values, density metrics, flow test results, reuse-related oxidation, and nanoparticle counts were compiled from the literature and normalized on a 0–1 scale. Four independent indices were defined: Material Fingerprint, process–powder interaction, airborne dispersion potential, and recovery. Adaptiveness refers to index sensitivity to changes in powder, reuse, and process conditions. The results indicate stable spreading for gas-atomized feedstocks, while wider particle size distributions and rougher surfaces increase cohesion and agglomeration, particularly under humid conditions and during reuse. Emission data indicate nanoparticle formation during processing, with recovery efficiency dependent on cyclone or high-efficiency particulate air filtration selection. The proposed model offers a screening approach for comparing powders and planning recovery strategies using data already available in the literature. Full article

Global climate change is increasing the impacts of abiotic stresses on plants. Vegetables are rich in vitamins, minerals, dietary fiber, and a variety of phytochemicals, and thus, are of great significance to human health. The growth of vegetable crops is regulated by a variety of abiotic stress factors, which not only affect their normal growth and metabolism but also lead to reduced yield and quality. Plant growth-promoting rhizobacteria (PGPR) can modulate the morphological or physiological characteristics of plants via nitrogen fixation, phosphorus dissolution, potassium dissolution, production of siderophores, secretion of secondary metabolites and hormones, and induction of plant stress resistance gene expression. This consequently increases the nutrient utilization rate in plants, improving their yield, quality, and stress resistance. In this review, the literature focused on how rhizosphere growth-promoting bacteria can improve the resistance of vegetable crops to drought, extreme temperature, heavy metals, and salt stresses is reviewed, and relevant application prospects and research directions provide a reference for further research on stress resistance and strategies to increase the yield of vegetable crops. Full article

Portland cement (PC) is widely regarded as a cost-effective and reliable binding material for the stabilization and solidification of municipal solid waste incineration fly ash (MSWI FA). However, the soluble salts and heavy metals present in MSWI FA retard PC hydration, thereby limiting the amount of fly ash that can be incorporated. The present study investigates the feasibility of normalizing the hydration of PC-based mixtures containing MSWI FA by applying a fly ash pre-granulation step with 25% PC, followed by coating the resulting granules with a geopolymer layer to reduce the release of harmful ions during the early stages of hydration. Isothermal calorimetry, TG/DTA, XRD, SEM, and mechanical testing were used to investigate the hydration characteristics of composites containing such granules and to assess their properties at 7, 28, and 90 days. It was found that a 20% substitution of PC with the studied FA disrupted PC hydration within the first 48 h. In contrast, both types of granules exhibited the main exothermic peak within the first 10–12 h, with hydration heat release (about 300 J/g) comparable to that of sand-containing references. Uncoated granules exhibited more active behavior with hydration kinetics similar to pure cement paste, whereas the effect of geopolymer-coated granules was close to sand. TG/DTA revealed reduced calcite content in mixtures containing granules, whereas uncoated granules promoted greater portlandite formation than the sand-based system. Hardening the samples under wet conditions resulted in the development of a dense cement matrix, firm integration of the granules, redistribution of chlorine and sulfur ions, and mechanical properties that reached at least 93% of those of the sand-containing reference, despite a lower density of ~4.5%. Full article

In the oil and gas pipeline industry, numerous small-diameter branch pipe fillet welds exist, which are prone to stress concentration because of diverse geometric shapes. The internal welding defects within these welds pose severe hazards to safe production. Specifically, the irregular geometry often leads to internal root defects where the weld metal fails to fully penetrate the joint or fuse with the base material (referred to as incomplete penetration and incomplete fusion). This study developed a GF-CF-GF (CF is carbon fiber, GF is glass fiber) sandwich composite reinforcement structure for pipe fittings with these specific internal defects (main pipe: Φ323.9 × 12.5 mm; branch pipe: Φ76 × 5 mm) through a combination of finite element analysis (FEA) and burst test verification. The inherent correlation between structural factors and pressure-bearing capacity was revealed by analyzing the influence of defect sizes. Based on FEA, the repair layer coverage should be designed to be within 400 mm from the defect along the main pipe wall direction and within 100 mm from the defect along the branch pipe wall direction, with required thicknesses of 5.6 mm for incomplete penetration and 3.2 mm for incomplete fusion. Analysis of the actual burst test pressure curve showed that the elastic-plastic transition interval of the repaired pipes increased by approximately 2 MPa compared to normal undamaged pipes, and their pressure-bearing capacities rose by 1.57 MPa (incomplete penetration) and 1.76 MPa (incomplete fusion). These results demonstrate the feasibility of the proposed reinforcement design, which has potential applications in the safety and integrity of oil and gas transportation. Full article

Low-cost miniaturized gas sensors are increasingly considered for outdoor air quality monitoring, yet their performance under real-world environmental conditions remains insufficiently characterized. This work evaluates the dynamic gas response of the Bosch BME688 sensor, whose metal oxide sensing layer is based on tin dioxide (SnO₂) material, focusing on its sensitivity, selectivity, and dynamic response to four representative air pollutants: nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), and isobutylene. This study provides both quantitative performance metrics and a physicochemical interpretation of the sensing mechanism. Controlled experiments were conducted in a custom test chamber to facilitate the precise regulation of temperature, humidity, and gas concentrations in the ppm to sub-ppm range. Despite large variability in the baseline resistance across devices, normalization yields consistent behavior, enabling cross-sensor comparability. The results show that the optimum operating temperatures fall in the range of 360–400 °C, where response and recovery times are reduced to a few minutes, compatible with mobile sensing requirements. Moreover, humidity strongly influences sensor behavior: it generally decreases sensitivity but improves kinetics, and in the case of CO, it enables enhanced responses through additional hydroxyl-mediated pathways. These findings confirm the feasibility of deploying BME688 sensors in distributed outdoor monitoring platforms, provided that humidity and temperature effects are properly addressed through calibration or compensation strategies. In addition, the variability observed in baseline resistance highlights the need for normalization and, consequently, individual calibration steps for each sensor under reference conditions in order to ensure cross-sensor comparability. The findings provided in this study provide support for the design of robust, low-cost air monitoring networks. Full article

The use of ammonia-fueled solid oxide fuel cells (NH3-SOFC) in shipping has emerged as a key area of research for advancing zero-carbon transportation. This study integrates and analyzes a novel ship design powered by NH3-SOFCs to quantify its environmental impact across its entire life-cycle, from production to disposal. A 200 TEU ammonia-fueled container ship operating on the Yangtze River is used as the reference vessel. Comprehensive technical analysis and modeling of the ship’s construction, operation, and Decommissioning stages are conducted. By utilizing life-cycle assessment and the ReCiPe 2016 method for calculations, 19 environmental impact indicators were obtained, weighted, and normalized. Life-cycle characterization results reveal that ecosystem and human health impacts are predominantly influenced by the operation stage. Thus, focusing on environmental protection measures and technological innovations during operation is crucial to mitigate these impacts. Conversely, resource depletion is mainly driven by the construction stage, underscoring the need for optimized design, production processes, and the use of eco-friendly materials to reduce resource consumption. A comparative analysis between diesel-powered and ammonia-powered ships shows that while ammonia SOFC ships have a slightly higher environmental load in terms of metal consumption, diesel-powered ships exhibit higher overall environmental loads in other impact indicators. This demonstrates the superior environmental and social benefits of ammonia SOFC ships compared to traditional diesel power systems. Full article