Search Results (6,180)

It has long been desired to achieve mechanical enhancement and structural health monitoring by introducing carbon nanotubes (CNTs) into traditional carbon fiber (CF) composites. Herein, the initiation of micro-damage and crack propagation has been investigated by utilizing in situ electrical resistance changes in interlaminar hybrid CNT network/CF composites during the shear loading process. The results show a clear relationship between the crack propagation and the electrical resistance response particularly when approaching the failure of the single-layer CNT network hybrid composites. Furthermore, the chemically modified CNT network exhibits evident enhancement on main mechanical properties of the CF composites, superior to the thermoplastic toughening method. The characterizations manifest that the multiscale interlayered CNT/CF structure can simultaneously resist the crack propagation along both the in-plane direction and the cross-plane direction, which consequently enhances the flexural and compressive strengths of the composite material. This discovery provides a novel idea for the potential application of CNT network/CF hybrid composites in the integration of mechanical reinforcement and structural health monitoring, namely, that the CNT network acts not only as a reinforcing phase but also as a sensor for the structural health monitoring of the composites. Full article

The Weishan rare earth element (REE) deposit, located in western Shandong, North China Block, is a typical carbonatite REE deposit and constitutes the third largest light REE resource in China. Its mineralization is closely related to the multi-stage evolution of a carbonatite magma–hydrothermal system. However, the mechanisms governing REE enrichment, migration, and precipitation remain insufficiently constrained from a mineralogical perspective, which hampers the understanding of the ore-forming processes and the establishment of predictive exploration models. Apatite is a pervasively developed REE phase in the Weishan deposit which occurs in multiple generations, and thus represents an ideal recorder of the magmatic–hydrothermal evolution. In this study, different generations of apatite hosted in carbonatite orebodies from the Weishan deposit were investigated using cathodoluminescence (CL), electron probe microanalysis (EPMA), and in situ LA-ICP-MS trace element analysis. Three types of apatite were identified. In paragenetic sequence, Ap-1 occurs as polycrystalline aggregates coexisting with calcite, is enriched in Na, Sr, and LREEs, and shows high (La/Yb)_N ratios, suggesting crystallization from an evolved carbonatite magma. Ap-2 and Ap-3 display typical replacement textures: both contain abundant dissolution pits and dissolution channels within the grains, which are filled by secondary minerals such as monazite and ancylite, and thus exhibit characteristic features of fluid-mediated dissolution–reprecipitation during the hydrothermal stage. Ap-2 is commonly associated with barite and strontianite, whereas Ap-3 is associated with pyrite and monazite and is characterized by relatively sharp grain boundaries with adjacent minerals. From Ap-1 to Ap-3, total REE contents decrease systematically, whereas Na, Sr, and P contents increase. All three apatite types lack Eu anomalies but display positive Ce anomalies. Discrimination diagrams involving LREE-Sr/Y and log(Ce)-log(Eu/Y) indicate that apatite in the Weishan REE deposit formed during the magmatic to hydrothermal evolution of a carbonatite, and that the dissolution of early magmatic apatite, followed by element remobilization and mineral reprecipitation, effectively records the progressive evolution of the ore-forming fluid. Full article

In temperate freshwater ecosystems, zooplankton play a crucial role in the pelagic food web and act as sensitive indicators of environmental change. They respond to shifts in water temperature, hydrodynamic mixing, and short-term meteorological events. This study investigated the epilimnetic zooplankton fauna of Lake Karamurat (Bolu, Türkiye), a small tectonic temperate lake, with a specific focus on the influence of rainfall events and wind speed on community structure. The samples were taken seasonally and horizontally using a plankton net (55 µm mesh size) and were analyzed alongside in situ physico-chemical measurements and meteorological data. In total, 74 zooplankton taxa were identified, comprising 54 rotifer species and 20 crustacean species (16 Cladocera and 4 Copepoda). Testudinella greeni was recorded for the first time in Türkiye, representing a new addition to the Turkish Rotifera fauna. Multivariate analyses revealed that electrical conductivity, water temperature, dissolved oxygen, precipitation, and wind speed were key drivers shaping community composition. The findings suggest that wind-driven surface mixing and episodic rainfall events enhanced vertical redistribution, leading to dominance of rotifers and small-bodied cladocerans in the epilimnion. These findings underscore the critical role of sampling strategy in shallow lakes under dynamic conditions and provide new faunistic insights into the zooplankton diversity of Anatolian lakes. Full article

Functionally graded aluminum matrix composites are of interest for applications requiring region-dependent mechanical and tribological performance. In this study, the micro-structure, hardness, and abrasive wear properties of functionally graded Al/ZrB₂ compo-site materials produced by an in situ centrifugal casting method were investigated. The ZrB₂ reinforcement phase was synthesized in situ within the molten aluminum matrix, and functional grading was achieved through the action of centrifugal force during solidification. Samples taken from cylindrical castings were characterized using optical microscopy, scanning electron microscopy (SEM), X-Ray diffraction (XRD), density measurements, Brinell hardness testing, and abrasive wear experiments. Phase analyses con-firmed the successful in situ formation of ZrB₂ and verified that the phase distribution in-creased toward the direction of centrifugal force. Hardness increased with reinforcement content, rising from approximately 28 HB in the matrix-rich region to 68 HB and 72 HB in regions reinforced with 12% and 15% ZrB₂, respectively. Abrasive wear behavior was evaluated using the pin-on-disk method, and a Taguchi L (3⁵) orthogonal array was employed for experimental design. Statistical analyses showed that the composite region was the most influential parameter affecting wear performance, followed by abrasive particle size and applied load, while sliding distance and sliding speed were not statistically significant. These findings demonstrate that in situ centrifugal casting is an effective approach for producing functionally graded Al/ZrB₂ composites with improved hardness and wear resistance. Full article

Understanding how plants respond to water limitation is increasingly important under accelerating climate change. Lycoris aurea, a widely distributed ornamental and medicinal bulbous plant, frequently inhabits environments with fluctuating soil moisture, yet its molecular drought-response mechanisms remain largely unexplored. In this study, we investigated L. aurea growing under field-based, in situ soil moisture regimes, comparing low (~20% soil water content) and high (~40% soil water content) conditions. We combined soil property assessments with high-resolution transcriptomic and untargeted metabolomic profiling to characterize the adaptive responses of bulb tissues under contrasting soil water conditions. Although total nitrogen, phosphorus, and potassium levels were comparable across treatments, soil moisture, representing the primary contrasting field condition, and soil pH, a correlated environmental factor, were significantly associated with variation in gene expression and metabolite accumulation (p < 0.05, n = 3). Transcriptome analyses identified a total of 1034 differentially expressed genes enriched in pathways related to amino acid metabolism, cuticle formation, cell wall modification, and osmotic adjustment. Metabolomic analysis identified a total of 1867 differentially expressed metabolites belonging to carboxylic acids and prenol lipids, showing alterations involved in amino acids, lipids, phenolic acids, and alkaloids associated with osmoprotection, membrane stabilization, and structural reinforcement under low soil moisture. Pathway-based integration analysis highlighted four core pathways, including “alanine, aspartate and glutamate metabolism” (p = 0.00371) and “cutin, suberine and wax biosynthesis” (p = 0.00873), as central hubs linking transcriptional regulation with metabolic reconfiguration. Gene-metabolite-soil correlation networks further demonstrated that drought adaptation arises from tightly coordinated biochemical and structural adjustments rather than shifts in nutrient acquisition. Together, this species-specific study provides a comprehensive multi-omics framework for understanding drought tolerance in L. aurea, reveals key molecular targets associated with plant resilience, and offers potential targets and insights for the conservation of drought-resilient Lycoris cultivars. Full article

The optical properties, electronic structure and morphology of thin films of the polymer donor PTB7-Th blended with either the fullerene acceptor PC70BM or the non-fullerene acceptor ZY-4Cl were systematically investigated to evaluate their annealing-induced evolution. Thin films were characterized using UV–Vis–NIR absorption spectroscopy, spectroscopic ellipsometry, ATR-FTIR spectroscopy, atomic force microscopy (AFM), and nano-IR analysis. In situ stepwise thermal annealing revealed distinct changes in absorption edge parameters, indicating thermally induced modifications in the electronic structure of the blend films. Ellipsometric analysis showed that elevated temperatures significantly affect the refractive index and extinction coefficient spectra. AFM measurements demonstrated markedly different surface morphology evolution for the two blend systems, with pronounced needle-shaped crystallites formation observed in PTB7-Th:ZY-4Cl films after annealing at 100 °C. Nano-IR characterization identified these crystallites as predominantly PTB7-Th, indicating phase separation driven by thermal treatment. The combined optical and structural results reveal distinct annealing-induced changes in the blend. Finally, BHJ solar cells, based on PTB7-Th:PC70BM and PTB7-Th:ZY-4Cl active layers, were fabricated, and their photovoltaic response was demonstrated. Full article

Background: Intrachromosomal rearrangements in birds play a subtle but important role in shaping genomic evolution, phenotypic diversity and speciation. However, the avian sex chromosome system (homogametic ZZ males; heterogametic ZW females) remains relatively understudied, and evolutionary rearrangements of the Z chromosome have not been mapped in most species. To address this, we employed universally hybridizing avian Z chromosome probes to metaphases of 11 avian species from South America. Methods: Chromosome preparations were obtained from fibroblast cell cultures of 11 birds representing nine different orders; four bacterial artificial chromosome (BAC) probes were used in our interspecies fluorescence in situ hybridization (FISH) experiments. We identified chromosomal rearrangements in the species investigated, tracing the evolution of the Z chromosome in these species through comparison with reptiles from Southeast Asia (three snake species used as an outgroup), along with two reference species: chicken (Galliformes) and zebra finch (Passeriformes). Results: We observed high rates of intrachromosomal rearrangements in the avian Z chromosome, with most species showing different patterns from chicken and zebra finch. Nannopterum brasilianum (Suliformes) and Jacana jacana (Charadriiformes) showed the same BAC order as chicken, but centromere repositioning was evident. Apart from Piciformes, all other species exhibited a conserved Z chromosome size. The corresponding Z chromosome sequences were homologous to regions of the long arms of Chromosome 2 and W in snakes but not on the Z chromosomes. Conclusions: Comparative analysis of the Z chromosome across avian orders provides important insights into the dynamics of avian sex chromosomes and the evolution of sex chromosome systems in general. Full article

Mass spectrometry imaging (MSI) is an innovative analytical technique that integrates chemical analysis with spatial localization, enabling label-free, in situ detection and visualization of diverse biomolecules within tissue sections. This review summarizes the recent advances in the application of MSI to neurological disorders, with a focus on Parkinson’s disease, Alzheimer’s disease, schizophrenia, and traumatic brain injury. Studies have demonstrated that MSI can delineate the spatial heterogeneity of disease-related molecules—such as neurotransmitters, lipids, and metabolites—thereby providing new perspectives for understanding the pathological mechanisms of neurodegenerative and psychiatric diseases. Platforms including MALDI-MSI and DESI-MSI have been effectively employed for visualizing drug distribution, characterizing lipid metabolic pathways, and identifying spatial biomarkers. Although challenges remain in quantitative accuracy, spatial resolution, and the detection of low-abundance molecules, advances in high-resolution mass spectrometry, single-cell-level imaging, and multi-omics integration are expected to further enhance the utility of MSI in the investigation of brain diseases. Full article

Mapping coastal landforms is critical for the sustainable management of ecosystems influenced by both natural dynamics and human activity. This study investigates the application of Transformer-based semantic segmentation models for pixel-level classification of key surface types such as water, sandy shores, rocky areas, vegetation, and built structures. We utilize a diverse, multi-resolution dataset that includes NAIP (1 m), Quadrangle (6 m), Sentinel-2 (10 m), and Landsat-8 (15 m) imagery from U.S. coastlines, along with high-resolution aerial images of the Greek coastline provided by the Hellenic Land Registry. Due to the lack of labeled Greek data, models were pre-trained on U.S. datasets and fine-tuned using a manually annotated subset of Greek images. We evaluate the performance of three advanced Transformer architectures, with Mask2Former achieving the most robust results, further improved 11 through a coastal-class weighted focal loss to enhance boundary precision. The findings demonstrate that Transformer-based models offer an effective, scalable, and cost-efficient solution for automated coastal monitoring. This work highlights the potential of AI-driven remote sensing to replace or complement traditional in-situ surveys, and lays the foundation for future research in multimodal data integration and regional adaptation for environmental analysis. Full article

In situ measurements of ambient dose equivalent rates were conducted across the territory of Macedonia at five-year intervals in 2010, 2015, and 2020. Data were collected from 68 uniformly distributed locations in 2010 and from 72 locations in both 2015 and 2020, ensuring representative spatial coverage. The main objective of this study was to establish a baseline dataset of outdoor gamma dose rates, evaluate their potential temporal variations, and identify the dominant factors influencing their spatial variability. The results indicate a high degree of temporal stability over the investigated decade, with mean values of 113 nSv/h in 2010 and 110 nSv/h in both 2015 and 2020. Following descriptive statistical analysis, spatial distribution maps were created, revealing that the observed dose rate variability is primarily associated with the country’s diverse geology rather than anthropogenic sources. These findings confirm the reliability of direct in situ monitoring and provide a robust reference framework for assessing environmental and atmospheric contributions to external gamma radiation exposure in Macedonia. Full article

Antimicrobial resistance (AMR) is a major global health concern, which complicates treatment of microbial infections and wounds. Conventional therapies are no longer effective against drug resistant microbes; hence, novel antimicrobial approaches are urgently required. Silver nanoparticles (AgNPs) offer stronger antimicrobial activity, and in situ synthesis improves stability, uniformity, cost efficiency, and bioactivity while minimising contamination. These features make AgNPs well-suited for incorporation into textiles and wound dressings. Red wine extract (RW-E), rich in antioxidant and anti-inflammatory compounds was used to hydrothermally synthesise RW-AgNPs and RW-AgNPs-loaded on cotton (RWALC) by optimising pH and RW-E concentration. Characterisation was performed using UV–Vis spectroscopy, dynamic light scattering (DLS), and High Resolution and Scanning electron microscopy (HR-TEM and SEM). Antibacterial activities were evaluated against human pathogens through agar disc diffusion assay for RWALC and microdilution assay for RW-AgNPs. RWALC showed higher potency against both Gram-negative and Gram-positive bacteria, with inhibition zones of 12.33 ± 1.15 to 23.5 ± 5.15 mm, that surpassed those of ciprofloxacin (10 ± 3 to 19.17 ± 1.39 mm at 10 μg/mL). RW-AgNPs exhibited low minimum inhibitory concentrations (MIC: 0.195–3.125 μg/mL) and minimum bactericidal concentrations (MBC: 0.78–6.25 μg/mL). Preincubation with β-mercaptoethanol (β-ME) inhibited the antibacterial activity of RWALC, suggesting that thiolated molecules are involved in AgNPs-mediated effects. This study demonstrated that green-synthesised RW-AgNPs, incorporated in situ into cotton, conferred strong antibacterial properties, warranting further investigation into their mechanisms of action. Full article

Spatial openness affects the subjective evaluation of soundscape, landscape, and thermal perceptions, leading to various restoration effects and recreational behaviors. However, the literature lacks studies investigating the effects of multisensory interactions under different levels of spatial openness in plazas on users’ behaviors in urban greenways. Thus, this study contributes to the enhancement of recreational experiences and the environmental design of urban greenways by examining the interaction between multisensory evaluations and recreational behaviors in greenway plazas with different levels of spatial openness. Three types of plazas (enclosed, semi-enclosed, open) were selected along an urban greenway to analyze interactions through in situ measurements, questionnaires, and behavior observation. The results showed that people rated the environment as the quietest and coolest in enclosed plazas, although the sound pressure level of these plazas was the highest. Furthermore, the visual evaluation (VE) was mostly correlated with acoustic evaluation (AE) in plazas with high openness, while the correlation effect between AE and thermal evaluation (TE) was only significant in enclosed plazas. In other words, AE was the key factor targeting the improvement in comfort in greenway plazas. Secondly, improving AE was more effective for stimulating the frequency of interactive activities in enclosed plazas, compared to improving TE. However, AE had a negative effect on the time that people were willing to spend on interactive activities in semi-enclosed plazas. Finally, these findings provide corresponding strategies for creating comfortable audio, visual, and thermal environments in greenway plazas with different levels of openness, as well as strategies for enhancing the recreational experiences of visitors. Full article

In this work, the characteristic temperatures (solidus and liquidus) of selected lead blast furnace slags were investigated using in situ high-temperature optical microscopy. The effects of the basicity of the slag (CaO/SiO₂), the Fe/SiO₂ ratio, and the Zn content were investigated. The deformation temperature associated with the rounding of the sample edges and the temperature at which 75% of the sample height decreases were experimentally considered as the solidus and liquidus temperatures, respectively. The pseudoternary phase diagrams CaO-SiO₂-Fe_0.63Zn_0.37O and FeO-Ca_0.54Si_0.46O_1.46-ZnO were calculated, along with the crystallization curves, using the thermodynamic software FactSage to estimate the characteristic temperatures and phase evolution during the cooling of the slag. The difference between the calculated and experimental solidus and liquidus temperatures was about 70 °C. The results of XRD, SEM, and DSC analysis at high temperatures showed that spinel (ZnFe₂O₄), melilite (Ca₂ZnSi₂O₇), and andradite (Ca₃Fe₂Si₃O₁₂) were the base crystals for all slag samples. The liquidus temperature increases with decreasing slag basicity (CaO/SiO₂), while the liquidus temperature increases with increasing Fe/SiO₂ ratio or Zn content. Full article

The COREX smelting-reduction route is a representative non-blast furnace technology, but its scale-up is hindered by insufficient gas and liquid permeability in the melter gasifier. To improve the gas and liquid permeability of the melter gasifier, coke is charged together with an iron-bearing material to partly replace lump coal to increase the burden voidage. The charged coke undergoes successive physical and chemical attacks that progressively weaken its strength, finally reducing the coke particle size and impairing overall burden permeability. Drilling “in situ” coke samples from the tuyere zone is an effective method to study coke behaviors inside a working melter gasifier. This work obtained tuyere coke samples by direct coke sample drilling during a melter gasifier blow-out and then systematically investigated the coke deterioration behaviors in the melter gasifier. The results show that the mean particle size decreased from an initial 50.3 mm to 31.6 mm at the tuyere, evidencing the severe fragmentation of coke. Basic oxides and alkali metals in the coke ash increased, indicating alkali recycling and enrichment occurred in the melter gasifier. Microcrystalline structure analysis of coke revealed a high degree of graphitization. Furthermore, coke degradation was further accelerated by both alkalis trapped in the coke pores and slag infiltration into the pores. This study clarifies the properties of the coke in the tuyere of the COREX melter gasifier and provides a theoretical basis for its operational optimization. Full article

Laboratory-scale cryogenic X-ray microtomography was employed for the first time to investigate the early structural evolution of polyurethane (PU) foams. This method enables ex situ studying the internal morphology of the frozen reactive mixture at various times before cell impingement. In this work, the precision of the method was evaluated by studying the early bubble formation and growth under different blowing agents and catalyst contents. It was detected that tripling the catalyst weight content doubled cell nucleation density, from 8.9 × 10⁵ to 1.8 × 10⁶ cells cm⁻³. Yet, doubling the water content has lesser impact on nucleation but leads to fast speeds of cell growth and, in turn, lower relative density at equal reaction times. Overall, it is demonstrated that laboratory cryogenic microtomography can be used to democratise the 3D investigation of the internal structure of foams which was until now only possible in synchrotron facilities. In addition, this method can help elucidate the mechanisms of nucleation and degeneration via directly measuring the density of bubbles and distance between them in the reactive mixture. Finally, this methodology could be extended to recent laboratory nanotomography systems utilizing X-ray tubes with nanometric spot sizes, thereby enabling the confident identification of nucleation events. Full article