Search Results (2,896)

In this study, the effects of plasma assistance on the electron beam physical vapour deposition (EB-PVD) process were investigated using an industrial coater (Smart Coater ALD Vacuum Technologies GmbH) equipped with a dual hollow cathode system. This configuration enabled the generation of a plasma environment during the deposition of the ceramic top coat onto a metallic substrate. The objective was to assess how plasma assistance influences the microstructure and thickness distribution of 7% wt. yttria-stabilised zirconia (YSZ) thermal barrier coatings (TBCs). Coatings were deposited with and without plasma assistance to enable a direct comparison. The thickness uniformity and columnar morphology of the 7YSZ top coats were evaluated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical properties of the deposited coatings were verified by the scratch test method. The results demonstrate that, in the presence of plasma, columnar grains become more uniformly spaced and exhibit sharper, well-defined boundaries even at reduced substrate temperatures. XRD analysis confirmed that plasma-assisted EB-PVD processes allow for maintaining the desired tetragonal phase of YSZ without inducing secondary phases or unwanted texture changes. These findings indicate that plasma-assisted EB-PVD can achieve desirable coating characteristics (uniform thickness and optimised columnar structure) more efficiently, offering potential advantages for high-temperature applications in aerospace and power-generation industries. Continued development of the EB-PVD process with the assistance of plasma generation could further improve deposition rates and TBC performance, underscoring the promising future of HC-assisted EB-PVD technology. Full article

In this study, liquid-phase plasma electrolysis (LPE) was successfully employed to remove the sizing agent from T800 carbon fiber surfaces. Through systematic investigation of varying arcing voltages (185–215 V) and electrode spacings (10–20 mm), we determined that an optimal combination of 200 V and 10 mm spacing achieved near-complete sizing removal, as confirmed by SEM, TGA, and XPS analyses. Under this condition, plasma bombardment dominated the removal mechanism, eliminating sizing residues while exposing the underlying fiber grooves. TGA further demonstrated that in samples treated at a 10 mm interval, the weight loss of LPE samples before 300 °C was negligible, indicating that the sizing agent had been thoroughly removed. The results of XPS further confirmed the high efficiency of LPE in the removal of sizing agents (C-O bond content from 41.6% to 26.9%), and the retention of C-O also proved that LPE could maintain the surface activity of carbon fibers, confirming the effectiveness of LPE in decomposing the sizing agent. Meanwhile, based on the above test results, an attempt was made to explain the mechanism of LPE in removing sizing agents from the surface of carbon fibers. Full article

Urbanization affects bird communities by reducing habitat and fragmenting ecosystems. Urban parks can help counteract these effects. However, anthropogenic noise can further alter bird composition. We examined the distribution and abundance of bird species in nine urban parks in Mexico City. We used a ten minute fixed-radius (25 m) point-counting technique to count birds along their annual cycle, with ten minutes allocated for bird counts. The quality of green areas was analyzed in terms of vegetation (Normalized Difference Vegetation Index), park size, and mean noise level dB(A) (based on MIN and MAX values), and species were grouped into trophic guilds. A total of 108 bird species were recorded, 5 of which are under special protection; we grouped all species into 14 trophic guilds, showing different responses to environmental gradients. Redundancy analysis (RDA) explained 89.98% of the variance, with noise and park size being the most influential variables. Granivores and omnivores were more tolerant to noise, while insectivores and frugivores preferred quieter areas with more vegetation. A positive association was observed between the presence of winter resident species and the park size. On the other hand, mean noise level dB(A) was negatively related to permanent resident species, winter resident species, and those with protected status. Conservation efforts should focus on maintaining ample green spaces and reducing noise pollution, as recorded high mean noise levels (>53 dB(A)) exceed the recommended thresholds for avifauna conservation. Full article

With the development of subway transportation, how to excavate large-section tunnels and find more convenient and reliable support methods has become an issue that cannot be ignored. This paper addresses issues such as low construction efficiency of core rock columns during the construction of large-section subway tunnels in sandstone–mudstone interbedded geological conditions. It proposes an optimized support scheme that replaces traditional core rock columns with temporary steel supports (steel columns). Finite element analysis was used to compare the deformation of the surrounding rock when retaining the core rock columns, using temporary steel columns to replace the core rock columns, and not providing additional support. Five interlayer positions and four interlayer angles were analyzed to identify the most dangerous geological conditions. Based on this analysis, the reasonable spacing of the temporary steel columns was investigated. The results indicate that temporary steel columns and core rock columns can effectively reduce vertical deformation of the surrounding rock, with steel columns showing slightly better results. Replacing core rock columns with steel columns is feasible. To control tunnel rock mass deformation, this project should ensure that the spacing between temporary steel columns is maintained between 21.88 m and 56.80 m. However, in construction sections with good rock mass conditions, the spacing can be extended as long as safety is ensured. Full article

The changing structure of modern cities intensifies anthropopressure, resulting in the need to create plans for the protection of biodiversity in cities. This can be achieved by establishing lawns and flower strips along the streets and maintaining parks and squares in cities, creating green infrastructure and contributing to sustainable urban development. However, this vegetation also requires protection that is safe for the environment and city residents. Entomopathogenic fungi (EPF) are among the most well-known and effective microorganisms that infect plant pests and conduct the disease process leading to their death. The aim of the study was to conduct a comparative analysis of the generic composition of EPF and determine the density of their colony-forming units (CFUs) in soils from flower strips and lawns located along the main communication routes of the city of Siedlce (Poland). Soil samples collected from two sites and two habitats (a flower strip and a lawn directly adjacent to it)—Site No. 1, Wyszyńskiego Street; Site No. 2, Jagiełły Street—in the spring and autumn of 2021/2022 and 2024. At each site within the habitat, three zones (repeats) were designated, spaced approximately 10–15 m apart. Approximately six samples were collected from each replication, and then a mixed sample was prepared. Four genera of EPF were found in the soil samples: Beauveria, Metarhizium, Cordyceps, and Akanthomyces. The location, habitat type, and season had a significant effect on the diversity of individual genera of fungi and the density of colony-forming units (CFUs) in the studied soils. The dominant types of EPF, forming the most CFUs in the soils from the studied flower strips and the adjacent lawns, were Metarhizium spp. and Beauveria spp. It was found that EPF occurred in higher densities in the soil from the studied habitats (flower strips and lawns) in autumn than in spring. Both of these semi-natural habitats constitute forms of urban greenery that increase biodiversity and provide valuable ecosystem services that support sustainable urban development. Full article

The systematic attacks against the civilian population in Gaza, including educational institutions, constitute war crimes that violate the right to education and affect not only children but also an entire culture’s ability to recover post-conflict and maintain its identity. This document review analysed the reports issued by Nations agencies to identify the types of violence that occur in educational contexts, the victims of such violence, the impact on the rights to and within education, and the educational measures implemented in response. A thematic analysis guided by Karma Nabulsi’s concept of “scholasticide”, Rita Segato’s “pedagogy of cruelty”, and Sara Ahmed’s “witness” was conducted. The findings reveal that the attacks on educational spaces can be interpreted as ideological strategies against the Palestinian culture due to their critical role in cultural resilience and the recovery of the Palestinian people. The reports highlight significant limitations in recognising education as a priority dimension within the framework of international humanitarian aid. Finally, the analysed documents show that children in Gaza experience feelings of abandonment based on the inaction of the international community to guarantee their right to be free from all kinds of violence. Full article

Duct fan motors must provide high torque within limited space to maintain airflow while requiring low vibration characteristics to minimize fluid resistance caused by fan oscillation. Axial Flux Permanent Magnet Motor (AFPM) offers higher torque performance than Radial Flux Permanent Magnet Motor (RFPM) due to their large radial and short axial dimensions. In particular, the coreless AFPM structure enables superior low-vibration performance. Conventional AFPM typically employs a core-type stator, which presents manufacturing difficulties. In core-type AFPM, applying a multi-stator configuration linearly increases winding takt time in proportion to the number of stators. Conversely, a Printed Circuit Board (PCB) stator AFPM significantly reduces stator production time, making it favorable for implementing multi-stator topologies. The use of multi-stator structures enables various topological configurations depending on (1) stator placement, (2) magnetization pattern of permanent magnets, and (3) rotor arrangement—each offering specific advantages. This study evaluates and analyzes the performance of different topologies based on efficient arrangements of magnets and stators, aiming to identify the optimal structure for duct fan applications. The validity of the proposed approach and design was verified through three-dimensional finite element analysis (FEA). Full article

Axial flux motors, characterized by compact axial dimensions and high torque density, are well-suited for space-constrained applications such as in-wheel drives and flying vehicles. However, conventional axial flux permanent magnet synchronous motors (AFPMSMs) face challenges such as high-temperature demagnetization, reduced efficiency at high speeds, and elevated manufacturing costs. Electrically excited synchronous motors (EESMs) offer a promising alternative, providing high-temperature reliability and superior high-speed capability while maintaining high torque density. In this paper, a novel composite-cooled axial flux electrically excited synchronous motor (AFEESM) is proposed. From an electromagnetic design perspective, the effects of key parameters such as shaft-to-outer-diameter ratio, inner-to-outer-diameter ratio, slot depth, and yoke thickness on output performance are systematically investigated, and a dedicated design procedure is established. Through multi-objective optimization, the motor’s torque output is increased by 19.6%. Comparative simulations are conducted to evaluate differences in torque density, efficiency, and cost between the proposed AFEESM, a conventional radial flux EESM, and an AFPMSM. To address the cooling requirements of double-sided windings on both the stator and rotor, a dual-channel composite cooling structure is developed, integrating internal–external double-loop water cooling for the stator and axial through-hole air cooling for the rotor, reducing the peak temperature by over 36%. Finally, a prototype is manufactured, and no-load characteristics and load efficiency validate the effectiveness of the electromagnetic design and the structural reliability of the motor. Full article

The use of commercial off-the-shelf smart devices in digital signage for sentient spaces is emerging as a promising solution within smart city environments. In such scenarios, these devices are often required to execute resource-intensive applications despite limited local computational capacity. Although cloud and fog infrastructures have been proposed to offload demanding workloads, they are not always suitable due to privacy and security concerns. As a result, executing sentient space applications directly on smart devices may exceed their processing capabilities. To address this limitation, state-of-the-art solutions have introduced load balancing techniques for smart devices. However, these approaches typically rely on centralized coordination or require extensive system profiling, making them unsuitable for sentient spaces, where device availability is intermittent and cooperative behavior must remain lightweight, adaptive, and decentralized. This paper proposes a distributed load balancing strategy tailored for sentient spaces that operate without reliance on cloud or fog infrastructures. The approach is based on reactive cooperation among neighboring devices and employs a local feasibility-check mechanism to determine when to offload computation and which neighboring devices are available to process it. The proposed solution is evaluated in a laboratory setting that emulates a real-world sentient space scenario within a commercial mall. Experimental results show the effectiveness of the proposed approach in maintaining real-time performance and mitigating local computational overload without relying on centralized infrastructure. Even under dynamic operating conditions, the system achieves a load balancing execution time of 5 ms on an ARM Cortex-A53 processor integrated in an AMD Zynq UltraScale+ platform. Full article

The cellular envelope of Gram-negative bacteria is a space where processes that are extremely important for the proper functioning of bacteria and determining their virulence take place. The extracytoplasmic protein quality control system, which includes chaperones, protein-folding catalysts, and proteases, is responsible for maintaining homeostasis in this cellular compartment. This system has been well studied in the model bacterium Escherichia coli, but little is known about its function in other bacteria. In bacteria evolutionarily distant from Enterobacteriaceae, the protein quality control system appears to function differently. For example, in the phylum Campylobacterota, a number of homologs of folding factors and proteases, whose functions are important for maintaining homeostasis in the periplasm of E. coli, have not been identified. Instead, there are quality control components that have no similar counterparts in the Enterobacteriaceae. In this review, we present the current state of knowledge on the extracytoplasmic protein quality control system in the model Campylobacterota, C. jejuni and H. pylori. Full article

Based on field studies, this study contributes the new physical data of winter indoor thermal conditions of the indoor spaces with four different dust mite allergen levels in New Zealand houses. This study provides a new method to identify the relationships between indoor thermal conditions and indoor dust mite allergen levels. This study found that the indoor mean relative humidity (RH) close to the floor must be controlled below 70%, and there must be less than 30% of time in winter when indoor RH close to the floor is higher than or equal to 75% to maintain indoor dust mite allergens at an undetectable level; and the indoor mean RH close to the floor must be controlled below 75%, and there must be less than 50% of time in winter when indoor RH close to the floor is higher than or equal to 75% to maintain indoor dust mite allergens at a low (acceptable) level. This study also identified the relationship between indoor thermal conditions for dust mites to thrive and for mould spores to germinate. This study provides a strategy or guideline for preventing indoor allergies related to dust mites and mould under the temperate climate zone; the winter is mild and humid. Full article

Solving math word problems automatically is a critical task in the field of natural language processing. Due to the insufficient size of existing MWP datasets, recent models have reached a performance bottleneck. Large-scale and high-quality training examples are crucial for training a robust math solver, but existing high-quality datasets have limited scale, and annotating or synthesizing vast MWPs explicitly is highly expensive. To address these issues, we propose a novel hidden space-based retrieval augmentation self-distillation method, named RASD, to improve the mathematical reasoning performance of MWP solvers with semantic representation augmentation and self-distillation learning. RASD enhances problem representations by retrieving and merging similar ones. It then inputs both the original and augmented representations into the decoder for solution reasoning. A self-distillation objective is used to maintain reasoning consistency between them. Extensive experiments on five popular math word problem-solving benchmarks, including MAWPS, Math23K, ASDiv-A, SVAMP, and GeoQA, show the effectiveness and universality of our RASD on improving the math reasoning ability of multiple popular baseline solvers. Full article

Urbanization in China and the proliferation of high-rise office buildings have led to increased demand for daylighting and thermal comfort. These requirements often result in reliance on active systems, including heating, cooling, and artificial lighting, which increase energy consumption. Existing studies have often focused on individual cases or room-scale models, which makes it difficult to generalize findings to the design of various high-rise office building types. Therefore, in this study, parametric prototype building models for high-rise office buildings were developed based on surveys of completed and under-construction projects. These surveys reflected actual design practices and were used to support systematic performance evaluation and typology-level optimization. Building performance was simulated using Grasshopper and Honeybee to generate large-scale datasets, and stacking ensemble learning models were used as surrogate predictors for energy use, daylighting, and thermal comfort. Multi-objective optimization was conducted using the non-dominated sorting genetic algorithm III (NSGA-III), followed by strategy formulation. The results revealed the following: (1) the proposed prototype model establishes clear parameter ranges for geometry, envelope design, and thermal performance, offering reusable models and data; (2) the stacking ensemble model outperforms individual models, improving the coefficient of determination (R²) by 0.5–16.1%, with mean squared error (MSE) reductions of 4.4–70.6%, and mean absolute error (MAE) reductions of 2.8–45.8%; (3) space length, aspect ratio, usable area ratio, window U-value, and solar heat gain coefficient (SHGC) were identified as primary performance drivers; and (4) optimized solutions reduced energy use by 3.79–11.81% and enhanced daylighting comfort by 40.16–50.32% while maintaining thermal comfort. The proposed framework provides localized, data-driven guidance for early-stage performance optimization in high-rise office building design. Full article

Intra-specific variation in functional traits and their inter-relationships reflect how plants allocate resources, adapt, and evolve in response to environmental changes. This study investigated eight functional traits—leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), chlorophyll content (CHL), leaf nitrogen content (LNC), leaf phosphorus content (LPC), twig tissue density (TTD), and wood density (WD)—in Cunninghamia lanceolata plantations of three stand ages (15, 30, and 50 years), using a space-for-time substitution approach. We examined differences in trait values, intra-specific variation, and trait correlations across forest ages and diameter classes. The results showed that (1) Functional traits exhibited varying degrees of intra-specific variation, with LA having the highest coefficient of variation (21.66%) and LPC is lowest (9.31%). (2) Forest age had a stronger influence on trait variation than diameter class, with all traits differing significantly across ages, while only WD varied significantly among diameter classes. (3) PC1 (25.5%) and PC2 (19.4%) together explained approximately 44.9% of the total variation, with PC1 primarily reflecting functional trait changes driven by forest age. PCA results showed that LA and CHL tended to exhibit higher values in young forests, whereas SLA, LDMC, LPC, and LNC had relatively higher values in mature forests. This pattern suggests a shift in functional trait expression from resource acquisition to resource conservation strategies with increasing forest age. (4) Significant positive correlations between LNC and LPC, and negative correlations between SLA and LDMC, were observed in most groups, except in large-diameter trees at the over-mature stage. C. lanceolata adjusts trait combinations to enhance fitness across developmental stages. Juvenile trees adopt traits favoring efficient light and nutrient use to support rapid growth and competition. Middle-aged trees prioritize balanced water and nutrient use to maintain productivity and resist disturbances. Mature trees focus on sustained resource use and offspring protection to support ecosystem stability and regeneration. These findings reveal age-specific adaptive strategies and provide insights into the coordination and trade-offs among traits in response to environmental conditions. Full article

UAV airborne network intrusion detection faces challenges due to highly imbalanced datasets, where normal samples significantly outnumber intrusion instances. This paper proposes an improved stratified sampling and ensemble learning (ISSEL) method to address this issue. The method improves upon traditional stratified sampling by clustering normal samples and performing distance-based sampling from cluster centers to ensure better feature space representation. Subsequently, five tree models, namely, decision tree, extra tree, random forest, gradient boosting tree, and XGBoost, are utilized to train each subset. The model prediction results are then integrated using an adaptive weighting strategy based on the F1 score. The experimental results on the MIL-STD-1553B data bus demonstrated that the ISSEL method maintained a high accuracy rate of 99.42% while significantly enhancing the recognition ability for minority-class attacks. The precision, recall, and F1 score reached 98.94%, 97.62%, and 98.28%, respectively. These results validate the effectiveness of the ISSEL method in handling imbalanced datasets, highlighting its potential application in the field of airborne network intrusion detection. Full article