Search Results (5,815)

Molten pool flow and keyhole status during Variable Polarity Plasma Arc (VPPA) welding directly affect the weld quality and stability. The lack of a clear correlation between them, however, prevents this process approach from being developed further. To investigate the keyhole morphology and liquid metal flow, the experimental examination of fluid flow by the X-ray imaging method and numerical simulation of plasma arc under the effect of the keyhole were carried out. By changing the tungsten electrode setback while keeping all other parameters, it is possible to vary the keyhole status and maintain the consistency of heat input to the base metal. This work establishes a dual-bifurcation flow model to characterize the keyhole molten pool, where the bifurcation point on the keyhole rear wall significantly affects the stability of the keyhole molten pool. The rear wall of the keyhole is divided into three sections from top to bottom, with the arc pressure in the middle section being significantly higher than in the upper and lower sections. As the degree of arc constriction increases—i.e., as arc stiffness or arc force increases—the middle section becomes more vertical. By the calculated distribution of driving forces, the arc pressure has a high possibility of being one of the dominances for the metal flow in keyhole welding of aluminum alloys. Arc pressure is also important for the bifurcation point position, which is closely related to the three welding states: blind keyhole, keyhole, and cutting. Full article

The genus Bizionia, a member of the Bacteroidota phylum, is considered a polyphyletic taxonomic group requiring a phylogenetic revision of its members. A novel strain 041-53-Ur-6^T was isolated from the cavity fluid of the sea urchin Strongylocentrotus intermedius from the Sea of Okhotsk. Analysis of the 16S rRNA gene sequence showed that 041-53-Ur-6^T belongs to the family Flavobacteriaceae, and its closest neighbor is [Bizionia] algoritergicola with 97.5% sequence similarity. Phylogenomic analysis confirmed the phylogenetic heterogeneity of the genus Bizionia and the clear separation of the genera “Algorimicrobium” and Hanstruepera. The inter-genus AAI values between them were 74.0–76.4%, which is slightly lower than the inter-species AAI values observed for each genus. The strain 041-53-Ur-6^T (= KMM 8389^T) formed a separated branch within the [B.] algoritergicola clade, demonstrating the highest ANI/AAI values of 80.1/81.0% with the strain [B.] algoritergicola APA-1^T. The dDDH values between strain KMM 8389^T and representatives of the genus “Algorimicrobium” ranged from 22.6% to 26.7%. Major fatty acids were iso-C_15:1 ω10c, iso-C_15:0 and iso-C_15:0 Δ2-OH. The polar lipids included a phosphatidylethanolamine, a phosphatidylglycerol, five unidentified lipids, two unidentified aminolipids, a phosphatidylcholine, and an unidentified aminophospholipid. The genome KMM 8389^T is a circular chromosome of 3,031,910 bp in size with a DNA G + C content of 33.5%. It comprises 2702 protein-coding genes and four rrn operons. Functional genomic analysis indicated the potential of KMM 8389^T for degrading starch, glycogen, and alginate due to the presence of genes encoding GH13, GH31, and GH65. Furthermore, KMM 8389^T possessed PLs 6, 7, 12, and 17, specialized for alginate, confirming the potential adaptation of this strain to algal substrates and surfaces. On the basis of the results of genotypic, chemotaxonomic, and phenotypic analyses, it is clear that the strain KMM 8389^T represents a novel species with [B.] algoritergicola, [B.] argentinensis, [B.] echini, [B.] hallyeonensis, [B.] myxarmorum, [B.] psychrotolerans, and [B.] sediminis as the nearest neighbors. These taxa are classified in a single novel genus, as Algorimicrobium algoritergicola gen. nov., comb. nov., A. argentinensis comb. nov., A. echini comb. nov., A. hallyeonensis comb. nov., A. myxarmorum comb. nov., A. psychrotolerans comb. nov., A. sediminis comb. nov., and Algorimicrobium bowmanii sp. nov. 041-53-Ur-6^T (=KMM 8389^T, =KCTC 72011^T). Full article

This paper addresses the axiom of balance in Flow Theory from a physiological-and-group-based approach by a quasi-experimental study using mixed methods across two action–research cycles, each divided into pre-test, intervention, and post-test phases. The study involved 56 students in two control and two experimental groups attending robotics and design STEAM courses in natural settings, wearing Polar H10 bands. Each group participated in nine one-hour sessions, with the same instructor. While flow in control groups was measured with intuition-based teacher actions, in experimental groups the teacher received support from a synchronous physiological flow advisory system. Data from these groups were analysed using nonlinear techniques, finding preliminary evidence that suggests (1) more quickly reaching of the Zone of Proximal Development when the teacher has physiological guidance, (2) mathematical physiologically-based support for the axiom of balance of Flow Theory, and (3) nonlinear analysis in group contexts offer quantification to the previously found contradictions in Flow Theory. Moreover, these findings propose new hypotheses and potential redefinitions in Flow Theory. Full article

To address the fluctuation and instability of renewable power generation and the steady-state demands of chemical processes, a single-channel, non-isothermal computational fluid dynamics 3D model was developed. This model explicitly incorporates the coupling effects of electrochemical reactions, two-phase flow, and heat transfer. Subsequently, the influence of key operating parameters on proton exchange membrane water electrolyzer (PEMWE) system performance was investigated. The model accurately predicts the current–voltage polarization curve and has been validated against experimental data. Furthermore, the CFD model was employed to investigate the coupled effects of several key parameters—including operating temperature, cathode pressure, membrane thickness, porosity of the porous transport layer, and water inlet rate—on the overall electrolysis performance. Based on the numerical simulation results, the evolution of the ohmic polarization curve under temperature gradient, the block effect of bubble transport under high pressure, and the influence mechanism of the microstructure of the multi-space transport layer on gas–liquid, two-phase flow distribution are mainly discussed. Operational strategy analysis indicates that the high-efficiency mode (4.3–4.5 kWh/Nm³) is suitable for renewable energy consumption scenarios, while the economy mode (4.7 kWh/Nm³) reduces compression energy consumption by 23% through pressure–temperature synergistic optimization, achieving energy consumption alignment with green ammonia synthesis processes. This provides theoretical support for the optimization design and dynamic regulation of proton exchange membrane water electrolyzers. Full article

Drought stress causes substantial yield losses in maize, posing a serious threat to food security. Leaf adaxial-abaxial polarity development is closely associated with drought tolerance. KANADI (KAN) genes play a pivotal role in leaf polarity establishment and are likely involved in regulating drought tolerance in maize. In this study, we identified 11 ZmKAN genes through sequence similarity analysis and functionally characterized one of them, ZmKAN1, in the context of drought response. The kan1-1 mutant exhibited enhanced drought tolerance compared to the wild-type B73. Transcriptome analysis revealed that differentially expressed genes in the mutant before and after drought stress were significantly enriched in pathways associated with drought tolerance, including “response to heat”, “secondary metabolite biosynthetic process”, and “plant hormone signal transduction”, suggesting that ZmKAN1 may modulate maize drought tolerance by regulating key processes such as heat response and plant hormone signaling. Furthermore, the differentially expressed genes in the wild type before and after drought stress were enriched in pathways such as “structural constituent of ribosome”, “mitochondrial respiratory chain complex I”, and “ribosome”, suggesting that drought stress may impair ribosomal and mitochondrial functions more severely in the wild type, along with other cellular organelles. In contrast, mutants exhibited relatively stable ribosomal and mitochondrial activities, enabling them to maintain higher survival rates and enhanced drought tolerance under drought conditions. Our findings provide important insights into the molecular mechanisms underlying drought tolerance in maize and offer valuable genetic resources for breeding drought-resistant maize cultivars. Full article

Vitamin D₃ (VD3) is an essential micronutrient, but its analytical determination in biological matrices is often hindered by structurally related metabolites and the limited selectivity of conventional analytical sorbents. The preparation of a molecularly imprinted polymer (MIP) using VD3 as a template is challenging due to its hydrophobic structure and lack of polar groups. Therefore, in this work, MIPs were prepared using the closely related structure hyodeoxycholic acid methyl ester as a template and tested for their adsorption capacity toward VD3. Several MIPs were first prepared using different functional monomers, and the results showed that 4-vinylpyridine (4VP) monomer in combination with divinylbenzene (DVB) as a crosslinker exhibited a relatively high binding capacity and imprinting factor. UV spectroscopy indicated an optimal VD3–monomer ratio of 1:4, while computational modeling further confirmed favorable interactions between VD3 and 4VP. The effect of incorporating styrene as a co-monomer with 4VP was also investigated, showing an enhancement in adsorption capacity with a slight increase in the imprinting factor. However, TGA analysis revealed that the thermal stability of the MIPs decreased with higher styrene content. Overall, the prepared MIPs demonstrated improved selectivity and recognition of VD3 compared to the non-imprinted polymers, offering a promising approach for its selective extraction and quantification. Full article

Background/Objectives: Emerging evidence suggests that hippocampal neuroinflammation (HNF) drives cognitive decline via dysregulation of the microbiota-gut-brain axis. Corylus heterophylla Fisch. male flower extract (CFE), a flavonoid-rich by-product of hazelnut processing, presents a promising yet unexplored neuroprotective candidate. This study investigated the preventive effects and mechanisms of CFE against HNF-induced cognitive decline. Methods: In the present study, mice were pretreated with CFE (200 mg/kg) before the Lipopolysaccharide (LPS) administration. Cognitive function, inflammation, core pathology, neuroplasticity, gut microbiota and serum metabolites were assessed. The chemical composition of CFE was analyzed by UHPLC-MS and its direct immunomodulatory effects were investigated in BV2 cells. Results: Behavioral assessments demonstrated significant therapeutic efficacy. This was evidenced by the recovery from hippocampal damage, accompanied by reduced levels of core pathological markers (Aβ1–42, Tau, p-Tau (Ser404), GSK-3β), decreased expression of pro-inflammatory mediators including IL-33, elevated levels of neurotrophic factors (BDNF and MAP2), and attenuated abnormal activation of astrocytes and microglia. The 16S rRNA analysis confirmed that CFE ameliorated gut microbial dysbiosis. Notably, CFE significantly increased the relative abundance of Muribaculaceae and Lachnospiraceae, while significantly decreased Staphylococcus and Helicobacter. Metabolomics revealed enhanced levels of α-linolenic acid (ALA), serotonin (5-HT) and acetic acid, which correlated positively with Muribaculaceae and Lachnospiraceae. Phytochemical analysis identified luteolin and kaempferol as the predominant flavonoids in CFE. In BV2 cells, CFE, luteolin and kaempferol shifted microglial polarization from the M1 phenotype toward the M2 phenotype. Conclusions: CFE alleviated HNF-induced cognitive decline by regulating microbiota-gut-brain axis and microglial M1/M2 polarization. Full article

Macrophages are versatile immune cells capable of modifying their functions based on their location and the specific requirements of the immune response. They polarize into the M1 phenotype when stimulated by inflammatory agents. In contrast to resolve inflammation and to facilitate tissue repair, macrophages polarize into the M2 phenotype. Polarization alters the cellular composition of the macrophages, including peroxisomes and peroxisome proliferator-activated receptors (PPARs). In macrophages, peroxisomes and PPARs perform at least three key roles: mediating inflammation, reducing oxidative stress, and regulating lipid metabolism. We review the functional role of peroxisomes and PPARs on macrophage biology focusing on adaptive mechanisms during these processes. The insights gained from this analysis are expected to lead to new advancements in treating inflammation and immune-related disorders, including autoimmune disorders, metabolic inflammation, and neurodegenerative conditions. Full article

Laser surface texturing (LST) is an effective method for enhancing surface functionality, but its effect on corrosion resistance highly depends on texture design and processing parameters. This study investigates the influence of two LST patterns—orthogonal ellipses and concentric octo-donuts—applied with 1 to 20 repetitions on the corrosion resistance of AISI 430 ferritic stainless steel. Corrosion behavior was evaluated using potentiodynamic polarization in a 3.5 wt.% NaCl solution at room temperature, complemented by SEM and EDS analysis. The results indicate that while a single laser pass can maintain good corrosion resistance, increasing the number of repetitions significantly degrades performance. This is attributed to the disruption of the protective oxide layer, the introduction of residual stress, and the creation of localized sites for galvanic corrosion. Consequently, the study concludes that a low number of laser repetitions is crucial for preserving the corrosion resistance of LST-processed AISI 430 steel. Full article

Measuring spin polarization (P) of materials is essential for understanding their fundamental properties and for their application in spintronics. Point contact Andreev reflection (PCAR) spectroscopy is a straightforward yet powerful technique for measuring P. However, conventional analysis methods depend on iterative fitting procedures that are time-consuming, subjective, and often lead to non-unique solutions. This complexity arises from the interplay of multiple physical parameters with pressure, including temperature, superconducting gap, and interfacial barrier strength. Here, we present a machine learning (ML) approach that utilizes convolutional neural networks (CNNs) to facilitate the rapid and automated extraction of P from PCAR spectra. We validate the ML model by analyzing experimental PCAR spectra from various materials reported in the literature. The predicted parameters by the CNN model show excellent agreement with the literature values, demonstrating its robust performance across a wide range of materials and parameter sets. This approach significantly reduces analysis time while maintaining accuracy, providing a practical tool for material characterization, thus accelerating materials discovery for spintronics. Full article

Amorphous nano zero-valent iron (A-nZVI) was synthesized via liquid-phase reduction and ethylenediamine (EDA) modification to enhance trichloroethylene (TCE) dechlorination. A-nZVI showed a cauliflower-like morphology, where 20–50 nm primary particles formed 500–1000 nm secondary agglomerates with a high surface area. Compared with crystalline nZVI (C-nZVI), A-nZVI exhibited higher electron transfer efficiency and stronger reducing capability (potentiodynamic polarization analysis). TCE removal followed a two-stage model: a rapid adsorption–reduction phase (pseudo-second-order; q_e = 9.48 mg/g, R² = 0.998) and a slower degradation phase (pseudo-first-order; k = 0.0125 h⁻¹, R² = 0.994). No toxic intermediates (e.g., dichloroethylene or vinyl chloride) were detected; products were mainly acetylene, ethylene, and ethane. The electron utilization efficiency increased from 8.47% (C-nZVI) to 15.32% (A-nZVI), while hydrogen evolution decreased by 32%. EDA formed Fe–N coordination bonds that facilitated electron transfer and stabilized the amorphous structure. A-nZVI retained 40% of its activity after four cycles under neutral to alkaline conditions. Full article

This study reports the first molecularly confirmed occurrence of Phlegmacium herculeum in Algeria, identified through morphological features and ITS sequence analysis (GenBank accession: PQ133121). Phytochemical profiling revealed a diverse composition of metabolites. SPME–GC–MS analysis detected volatile aldehydes (butanal, pentanal), organic acids (butanoic, pentanoic), terpenoids (limonene, 1,8-cineole), phenolics, and long-chain alkanes. Furthermore, the macrofungus has been extracted with organic solvents, and the obtained extracts have been analyzed via NMR and GC–MS, revealing the presence of organic acids (lactic, succinic, azelaic), fatty acids (palmitic, linoleic), and phenolic acids (protocatechuic, 4-hydroxybenzoic). DPPH-based analysis indicated that the antioxidant response of the crude extracts strengthened as the dose increased, with the ethyl acetate (EtOAc) extract exhibiting the highest inhibition and lowest IC₅₀, attributed to its rich phenolic content. The chloroform (CHCl₃) extract showed moderate activity, consistent with its composition of less polar metabolites such as fatty acids and terpenoids. Antibacterial assays revealed extract-specific effects: CHCl₃ strongly inhibited Staphylococcus aureus (18 mm), while EtOAc was more effective against Gram-negative strains, including Escherichia coli (18 mm) and Pseudomonas aeruginosa (13 mm). Cytotoxicity testing using Saccharomyces cerevisiae confirmed that both extracts were non-toxic, maintaining ≥90% cell viability. These findings highlight P. herculeum as a novel source of bioactive metabolites with antioxidant and antibacterial potential. Full article

The Colombian Orinoquia was shaped within a tectonic and sedimentary framework linked to the uplift of the Andean cordilleras during the Oligocene–Miocene. This orogenic event generated two tectonic fronts and facilitated extensive fluvial sedimentation across a broad alluvial geosyncline. The present geomorphological configuration reflects the cumulative interaction of tectonic and erosional processes with Quaternary climatic dynamics, which together produced complex landscape assemblages characterized by plains with distinctive drainage patterns. To delineate and characterize geomorphological units, we employed multidimensional imagery and Machine Learning techniques within the Google Earth Engine platform. The classification model integrated dual polarizations of synthetic aperture radar (L-band) with key topographic variables including elevation, slope, aspect, convexity, and roughness. The analysis identified three major physiographic units: (i) the Foothills and the Floodplain, both dominated by fluvial environments; (ii) the High plains and Serranía de La Macarena (Macarena Mountain Range), where denudational processes predominate; and (iii) localized aeolian environments embedded within the Floodplain. These contrasting dynamics have generated a broad spectrum of landforms, ranging from terraces and alluvial fans in the Foothills to hills and other erosional features in La Macarena. The Floodplain, developed over a sedimentary depression, illustrates the combined action of fluvial and aeolian processes, whereas the High plains is characterized by rolling plains and peneplains formed through the uplift and erosion of Tertiary sediments. Such geomorphic heterogeneity underscores the interplay between tectonic activity, climatic forcing, and surface processes in shaping the Orinoquia landscape. The geomorphological classification using Random Forest demonstrated high effectiveness in discriminating units at a regional scale, with accuracy levels supported by confusion matrices and associated Kappa indices. Nevertheless, some degree of classificatory overlap was observed in fluvial environments, likely reflecting their transitional nature and complex sedimentary dynamics. Overall, this methodological approach enhances the objectivity of geomorphological analysis and establishes a replicable framework for assessing landform distribution in tropical sedimentary basins. Full article

Mild steel readily corrodes in acidic environments, and most industrial corrosion inhibitors are synthetic, often toxic, and environmentally harmful. In this study, electrocatalytically active Cd–Cs mixed oxide nanocomposites were synthesized via a green route using an aqueous extract of Trachyspermum ammi (ajwain) seeds as a natural reducing, stabilizing, and capping agent. This eco-friendly method eliminates harsh chemicals while producing nanomaterials with active surfaces capable of facilitating electron transfer and scavenging free radicals. Incorporation of cesium introduces basic, electron-rich sites on the Cd–Cs oxide surface, serving as inhibition promoters that enhance charge transfer at the metal/electrolyte interface and assist in the formation of an adsorbed protective film on steel. The nanocomposites were optimized by adjusting precursor ratios, pH, temperature, and reaction time, and were characterized by UV–Vis, FTIR, XRD, SEM–EDS, HR-TEM EDS, BET, DLS, XPS, and zeta potential analyses. Strong antioxidant activity in ABTS and DPPH assays confirmed efficient catalytic quenching of reactive radicals. Corrosion inhibition potential, evaluated by using potentiodynamic polarization, electrochemical impedance spectroscopy, and gravimetric analysis in 0.5 M HCl, shows an inhibition efficiency of 90–91%. This performance is associated with an electrocatalytically active, adsorbed barrier layer that suppresses both anodic dissolution and cathodic hydrogen evolution, which depicts mixed-type inhibition. Overall, the biosynthesized Cd–Cs mixed oxide nanocomposites function as promising green synthesized nanomaterial with dual antioxidant and corrosion-inhibiting functions, underscoring their potential for advanced surface engineering and corrosion protection. Full article

The rise in social media has transformed Online Travel Agencies (OTAs) into platforms where users actively share their experiences and opinions. However, conventional opinion mining approaches often fail to capture nuanced emotional expressions or connect them to user influence. To address this gap, this study introduces an ontology-driven opinion mining framework that integrates multi-class emotion classification, aspect-based analysis, and influence modeling using Indonesian-language discussions from the social media platform X. The framework combines an OTA-specific ontology that formally represents service aspects such as booking support, financial, platform experience, and event with fine-tuned IndoBERT for emotion recognition and sentiment polarity detection, and Social Network Analysis (SNA) enhanced by entropy weighting and TOPSIS to quantify and rank user influence. The results show that the fine-tuned IndoBERT performs strongly with respect to identification and sentiment polarity detection, with moderate results for multi-class emotion classification. Emotion labels enrich the ontology by linking user opinions to their affective context, enabling the deeper interpretation of customer experiences and service-related issues. The influence analysis further reveals that structural network properties, particularly betweenness, closeness, and eigenvector centrality, serve as the primary determinants of user influence, while engagement indicators act as discriminative amplifiers that highlight users whose content attains high visibility. Overall, the proposed framework offers a comprehensive and interpretable approach to understanding public perception in Indonesian-language OTA discussions. It advances opinion mining for low-resource languages by bridging semantic ontology modeling, emotional understanding, and influence analysis, while providing practical insights for OTAs to enhance service responsiveness, manage emotional engagement, and strengthen digital communication strategies. Full article