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Search Results (1,026)

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21 pages, 3850 KB  
Article
Vertical Ground-Motion Effects in Base-Isolated Buildings: Preliminary Observations from Twin Fixed-Base and Base-Isolated Structures During the 18 March 2025 Potenza Sequence
by Rocco Ditommaso and Felice Carlo Ponzo
Buildings 2026, 16(3), 482; https://doi.org/10.3390/buildings16030482 - 23 Jan 2026
Abstract
On 18 March 2025, a moderate earthquake with moment magnitude Mw 4.2 struck the Basilicata region in Southern Italy. The event occurred at 09:01:25 UTC with an epicentre located approximately 4 km northeast of the city of Potenza (PZ). The earthquake was clearly [...] Read more.
On 18 March 2025, a moderate earthquake with moment magnitude Mw 4.2 struck the Basilicata region in Southern Italy. The event occurred at 09:01:25 UTC with an epicentre located approximately 4 km northeast of the city of Potenza (PZ). The earthquake was clearly felt across the urban area and followed by a sequence of low-magnitude aftershocks. A few hours after the main shock, researchers from the University of Basilicata installed a temporary structural monitoring network to check the structural conditions of several buildings located in Potenza. This installation enabled the acquisition of accelerometric recordings of several aftershocks, providing a valuable dataset for preliminary observations on structural seismic response. The monitoring campaign focused on two adjacent twin buildings with similar geometry and structural layout but different seismic design strategies: one conventionally fixed at the base and the other equipped with seismic base isolation made by rubber bearings. Comparative analyses revealed distinct differences in dynamic response. The results highlight the need for refined regulatory tools to address near-epicentral conditions, particularly potential dynamic interactions among the vertical ground-motion component, the vertical vibration frequencies of the superstructure, and floor-system resonance. While not critical for ultimate limit states, these effects may influence comfort and performance in operational and damage limit states. Full article
17 pages, 3525 KB  
Article
Arsenic Trioxide and the MNK1 Inhibitor AUM001 Exert Synergistic Anti-Glioblastoma Effects by Modulating Key Translational, Cell Cycle, and Transmembrane Transport Pathways
by Yue Hao, Charles Shaffer, Nanyun Tang, Valerie DeLuca, Angela Baker and Michael E. Berens
Brain Sci. 2026, 16(2), 121; https://doi.org/10.3390/brainsci16020121 - 23 Jan 2026
Abstract
Background: The profound heterogeneity of glioblastoma and the often-limited efficacy of conventional treatments, including arsenic trioxide (ATO), underscore the urgent and critical demand for innovative combination strategies specifically designed to overcome treatment resistance. Methods: We evaluated the therapeutic effects of ATO as a [...] Read more.
Background: The profound heterogeneity of glioblastoma and the often-limited efficacy of conventional treatments, including arsenic trioxide (ATO), underscore the urgent and critical demand for innovative combination strategies specifically designed to overcome treatment resistance. Methods: We evaluated the therapeutic effects of ATO as a single agent and in combination with the MNK1 inhibitor AUM001 across patient-derived xenograft (PDX) models and investigated molecular determinants of sensitivity and synergy. Our results demonstrated that GBM models resistant to ATO, particularly those of the mesenchymal subtype, are more likely to show synergistic cytotoxicity when AUM001 is added. The combination significantly reduces the frequency of glioblastoma stem cells (GSCs) compared to either drug alone, especially in ATO-resistant models. Results: These observations suggest that targeting the MNK1 pathway in conjunction with ATO is a promising strategy to specifically eradicate GSCs, which are major drivers of GBM recurrence and therapeutic failure. Transcriptomic analyses revealed that ATO sensitivity correlated with activated translation-related pathways and cell cycle processes, while synergistic responses to the combination were driven by distinct molecular signatures in different GBM subtypes. Overall, synergistic response to the combination therapy is more associated with cellular organization, amino acid transmembrane transporter activity, ion channels, extracellular matrix organization and collagen formation. Conclusions: Our findings highlight that specific molecular pathways and their activities, including those involving translation, cell cycle and ion transport, appear to modulate the synergistic efficacy of the ATO and AUM001 combination, thereby offering potential biomarkers for improved patient stratification in future GBM clinical trials of such ATO-based treatments. Full article
(This article belongs to the Special Issue Brain Tumors: From Molecular Basis to Therapy)
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20 pages, 3589 KB  
Article
Comparison of Perceived and Measured Indoor Environmental Quality Across Home and Office Work Environments
by Young Joo Son, Zachary C. Pope, Kunjoon Byun and Meng Kong
Sustainability 2026, 18(3), 1144; https://doi.org/10.3390/su18031144 - 23 Jan 2026
Viewed by 72
Abstract
As remote and hybrid work arrangements become increasingly embedded in modern professional life, understanding indoor environmental quality (IEQ) in work-from-home (WFH) settings has become critical for supporting sustainable and healthy work environments. This study assessed both subjective perceptions and objective measurements of IEQ [...] Read more.
As remote and hybrid work arrangements become increasingly embedded in modern professional life, understanding indoor environmental quality (IEQ) in work-from-home (WFH) settings has become critical for supporting sustainable and healthy work environments. This study assessed both subjective perceptions and objective measurements of IEQ from three different working environments of home, employer offices, and simulated standard-compliant offices. Within the home environment, household characteristics resulted in significantly different measured IEQ: larger households and pet ownership were associated with higher CO2, VOC, and air temperature levels, while noise levels varied by childcare responsibilities and flooring type. IEQ perceptions also significantly differed: air temperature satisfaction was lower among those providing childcare, and overall environmental satisfaction varied by WFH frequency, with occasional WFH workers reporting the least satisfaction. Across the three working environments, participants were significantly more satisfied with thermal and acoustic conditions in WFH than employer offices, with simulated standard-compliant offices showing intermediate results. Notably, these perception patterns did not always align with measured environmental conditions. These findings demonstrate that both household characteristics and work context shape occupants’ IEQ perceptions, underscoring the importance of occupant-centered evaluation in advancing sustainable building design and remote work strategies. The results suggest that integrating both objective IEQ metrics and subjective experience is essential for promoting long-term environmental sustainability and occupant well-being across evolving work environments. Full article
(This article belongs to the Section Health, Well-Being and Sustainability)
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25 pages, 3260 KB  
Article
Research on Bearing Fault Diagnosis Method of the FPSO Soft Yoke Mooring System Based on Minimum Entropy Deconvolution
by Yanlin Wang, Jiaxi Zhang, Shanshan Sun, Zheliang Fan, Dayong Zhang, Ziguang Jia, Peng Zhang and Yi Huang
J. Mar. Sci. Eng. 2026, 14(2), 235; https://doi.org/10.3390/jmse14020235 - 22 Jan 2026
Viewed by 23
Abstract
The Soft Yoke Mooring (SYM) system is a critical single-point mooring method for Floating Production Storage and Offloading systems (FPSOs) in shallow waters. Its articulated thrust roller bearing operates long-term in harsh marine environments, making it prone to failure and difficult to diagnose. [...] Read more.
The Soft Yoke Mooring (SYM) system is a critical single-point mooring method for Floating Production Storage and Offloading systems (FPSOs) in shallow waters. Its articulated thrust roller bearing operates long-term in harsh marine environments, making it prone to failure and difficult to diagnose. To address the issues of non-stationary signals and fault features submerged in strong noise caused by the bearing’s non-rotational oscillatory motion, this paper proposes an adaptive improved diagnosis scheme based on Minimum Entropy Deconvolution (MED). By optimizing Finite Impulse Response (FIR) filter parameters to adapt to the oscillatory operating conditions and combining joint analysis of time-domain indicators and envelope spectra, precise identification of bearing faults is achieved. Research shows that this method effectively enhances fault impact components. After MED processing, the kurtosis value of the fault signal can be significantly increased from approximately 2.6 to over 8.6. Its effectiveness in noisy environments was verified through simulation. Experiments conducted on a 1:10 scale soft yoke model demonstrated that the MED denoising and filtering signal analysis method can effectively identify damage in the thrust roller bearing of the SYM system under marine conditions characterized by high noise and complex frequencies. This study provides an efficient and reliable method for fault diagnosis of non-rotational oscillatory bearings in complex marine environments, holding significant engineering application value. Full article
15 pages, 5081 KB  
Article
A Study on Super-Low-Energy Building Design Strategies Based on the Quantification of Passive Climate Adaptation Mechanisms
by Jiaohua Cheng, Yuanyi Zhang, Xiaohuan Liu and Rui Ding
Buildings 2026, 16(2), 456; https://doi.org/10.3390/buildings16020456 - 22 Jan 2026
Viewed by 13
Abstract
In response to the urgent need for developing super-low-energy buildings (SLEBs) under extreme climatic conditions, a critical research gap lies in scientifically quantifying the passive climate adaptation mechanisms of vernacular architecture and translating them into modern design strategies. To this end, this study [...] Read more.
In response to the urgent need for developing super-low-energy buildings (SLEBs) under extreme climatic conditions, a critical research gap lies in scientifically quantifying the passive climate adaptation mechanisms of vernacular architecture and translating them into modern design strategies. To this end, this study proposes a multidimensional “Monitoring–Visualization–Quantification” analytical method. Using the Aijing Zhuang building in central Fujian, China, as a case study, this method systematically analyzed its passive regulatory performance through high-frequency monitoring and spatial-interpolation techniques. This research revealed a distinct “Gradient-Buffering-and-Dynamic-Adjustment” mechanism: a maximum indoor–outdoor temperature difference of 5.7 °C was achieved, with indoor temperature variability reduced by 62%. The courtyard, functioning as a “Thermal Buffer” and “Ventilation Hub”, orchestrated the internal climatic gradients. This study provides systematic quantitative evidence for the modern translation of traditional wisdom, and the revealed mechanism can be directly transformed into design strategies for SLEBs adapted to extreme climates. Full article
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19 pages, 2755 KB  
Article
Fractional Modelling of Hereditary Vibrations in Coupled Circular Plate System with Creep Layers
by Julijana Simonović
Fractal Fract. 2026, 10(1), 72; https://doi.org/10.3390/fractalfract10010072 (registering DOI) - 21 Jan 2026
Viewed by 56
Abstract
This paper presents an analytical model for the hereditary vibrations of a coupled circular plate system interconnected by viscoelastic creep layers. The system is represented as a discrete-continuous chain of thin, isotropic plates with time-dependent material properties. Based on the theory of hereditary [...] Read more.
This paper presents an analytical model for the hereditary vibrations of a coupled circular plate system interconnected by viscoelastic creep layers. The system is represented as a discrete-continuous chain of thin, isotropic plates with time-dependent material properties. Based on the theory of hereditary viscoelasticity and D’Alembert’s principle, a system of partial integro-differential equations is derived and reduced to ordinary integro-differential equations using Bernoulli’s method and Laplace transforms. Analytical expressions for natural frequencies, mode shapes, and time-dependent response functions are obtained. The results reveal the emergence of multi-frequency vibration regimes, with modal families remaining temporally uncoupled. This enables the identification of resonance conditions and dynamic absorption phenomena. The fractional parameter serves as a tunable damping factor: lower values result in prolonged oscillations, while higher values cause rapid decay. Increasing the kinetic stiffness of the coupling layers raises vibration frequencies and enhances sensitivity to hereditary effects. This interplay provides deeper insight into dynamic behavior control. The model is applicable to multilayered structures in aerospace, civil engineering, and microsystems, where long-term loading and time-dependent material behavior are critical. The proposed framework offers a powerful tool for designing systems with tailored dynamic responses and improved stability. Full article
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39 pages, 3761 KB  
Review
From Perception to Adaptation: A Comparative Study of Plant Regulatory Networks in Response to Heat and Waterlogging Stress
by Javed Iqbal, Sikandar Amanullah, Chengyue Li, Xiaohui Qin, Pengbo Yu, Xuanyang Chen and Dongliang Qiu
Plants 2026, 15(2), 328; https://doi.org/10.3390/plants15020328 - 21 Jan 2026
Viewed by 40
Abstract
Heat and waterlogging are critical abiotic stresses that threaten crop productivity, especially as climate change intensifies their frequency and severity. While both stresses independently disrupt essential physiological functions such as photosynthesis, respiration, and nutrient uptake, their underlying mechanisms and adaptive strategies exhibit key [...] Read more.
Heat and waterlogging are critical abiotic stresses that threaten crop productivity, especially as climate change intensifies their frequency and severity. While both stresses independently disrupt essential physiological functions such as photosynthesis, respiration, and nutrient uptake, their underlying mechanisms and adaptive strategies exhibit key differences. This review presents a systematic comparison of plant responses to heat and waterlogging stress, focusing on both their shared and distinct impacts on plant physiology, biochemistry, and molecular regulation. We synthesize recent insights from omics technologies, including transcriptomic and metabolomics, to explore regulatory pathways, hormonal crosstalk (e.g., ABA–ethylene interactions), and metabolic shifts (e.g., fermentation vs. chaperone induction) that drive stress tolerance. This comparative analysis similarly demonstrates that effective plant resilience to climate extremes depends on the coordinated optimization of shared stress management hubs, such as antioxidant defense systems and hormonal crosstalk, together with the deployment of stress-specific adaptive strategies, including molecular chaperone induction under heat stress and anaerobic metabolic reprogramming under waterlogging. By integrating convergent and divergent regulatory pathways, this framework provides a mechanistic and conceptual guide for breeding and engineering crops with durable tolerance to multiple, increasingly co-occurring abiotic stresses. Full article
(This article belongs to the Special Issue Biochemical Responses of Horticultural Crops to Abiotic Stresses)
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39 pages, 1175 KB  
Article
Beyond Digital Natives: A System-Level Analysis of Institutional Barriers and Teacher Experience in Secondary School ICT Integration
by Athanasia Regli, Hera Antonopoulou, Grigorios N. Beligiannis, George Asimakopoulos and Constantinos Halkiopoulos
Sustainability 2026, 18(2), 1108; https://doi.org/10.3390/su18021108 - 21 Jan 2026
Viewed by 72
Abstract
(1) Background: Information and Communication Technology (ICT) integration in secondary education remains a critical challenge despite substantial investments in teacher training and infrastructure. This study investigated ICT certification levels, implementation patterns, and barriers among Greek secondary school teachers to understand the disconnect between [...] Read more.
(1) Background: Information and Communication Technology (ICT) integration in secondary education remains a critical challenge despite substantial investments in teacher training and infrastructure. This study investigated ICT certification levels, implementation patterns, and barriers among Greek secondary school teachers to understand the disconnect between policy aspirations and classroom realities. (2) Methods: A quantitative cross-sectional survey design was employed with 108 secondary teachers (61.1% female; mean age 47.3 years; 70.4% with >10 years’ experience) in the Prefecture of Ilia, Greece (response rate: 87.7%). Participants were permanent secondary school teachers employed in public schools during the 2021–2022 academic year; substitute teachers and private school staff were excluded. A three-section structured questionnaire was developed through literature review, expert validation (n = 3), and pilot testing (n = 10). Section A assessed demographics (5 items), Section B measured perceived barriers using a 7-item Likert scale, and Section C assessed implementation practices using a 10-item frequency scale (Cronbach’s α = 0.942). Data were analyzed using descriptive statistics, Mann–Whitney U tests, Kruskal–Wallis tests, and correlation analyses. (3) Results: While 74.1% of teachers held Level A certification, only 25.9% achieved Level B, with overall implementation remaining moderate (M = 2.92/5.00). Leadership support deficiency emerged as the primary barrier (76.9%), followed by inadequate technical support (74.1%). Younger teachers (24–35 years) demonstrated significantly higher ICT implementation than their older colleagues (56+ years), and teachers with less experience showed greater implementation frequency than veteran teachers—a finding that paradoxically challenges the “digital natives” assumption, given the barriers they face. Teachers preferred flexible Internet resources to formal educational software, indicating strategic adaptation to institutional constraints. Key limitations include convenience sampling, cross-sectional design, self-reported measures, and regional specificity. (4) Conclusions: The certification–implementation gap reveals that individual competencies cannot overcome unsupportive institutional environments. Effective ICT integration requires systemic transformation, encompassing leadership development, technical support, and structural reforms beyond traditional teacher training approaches. Full article
(This article belongs to the Section Sustainable Education and Approaches)
33 pages, 2502 KB  
Review
A Review of Heat Wave Impacts on the Food–Energy–Water Nexus and Policy Response
by Manman Wang, Sze Yui Lu, Hairong Xin, Yuxuan Fan, Hao Zhang, Sujata Saunik and Rajib Shaw
Climate 2026, 14(1), 27; https://doi.org/10.3390/cli14010027 - 21 Jan 2026
Viewed by 114
Abstract
Heat waves have emerged as an escalating climate threat, triggering cascading disruptions across food, energy, and water systems, thereby undermining resilience and sustainability. However, reviews addressing heat wave impacts on the food–energy–water (FEW) nexus remain scarce, resulting in a fragmented understanding of cross-system [...] Read more.
Heat waves have emerged as an escalating climate threat, triggering cascading disruptions across food, energy, and water systems, thereby undermining resilience and sustainability. However, reviews addressing heat wave impacts on the food–energy–water (FEW) nexus remain scarce, resulting in a fragmented understanding of cross-system interactions and limiting the ability to assess cascading risks under extreme heat. This critical issue is examined through bibliometric analysis, scoping review, and policy analysis. A total of 103 publications from 2015 to 2024 were retrieved from Web of Science and Scopus, and 63 policy documents from the United States, the European Union, Japan, China, and India were collected for policy analysis. Bibliometric analysis was conducted to identify the most influential articles, journals, countries, and research themes in this field. The scoping review indicates that agricultural losses are most frequently reported (32), followed by multiple impacts (19) and cross-sectoral disruptions (18). The use of spatial datasets and high-frequency temporal data remains limited, and community-scale studies and cross-regional comparisons are uncommon. Mechanism synthesis reveals key pathways, including direct system-specific stress on food production, water availability, and energy supply; indirect pressures arising from rising demand and constrained supply across interconnected systems; cascading disruptions mediated by infrastructure and system dependencies; and maladaptation risks associated with uncoordinated sectoral responses. Policy analysis reveals that most countries adopt sector-based adaptation approaches with limited across-system integration, and insufficient data and monitoring infrastructures. Overall, this study proposes an integrated analytical framework for understanding heat wave impacts on the FEW nexus, identifies critical research and governance gaps, and provides conceptual and practical guidance for advancing future research and strengthening coordinated adaptation across food, energy, and water sectors. Full article
(This article belongs to the Special Issue Climate Change and Food Sustainability: A Critical Nexus)
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38 pages, 4734 KB  
Article
Robust Disturbance-Response Feature Modeling and Multi-Perspective Validation of Compensation Capacitor Signals
by Tongdian Wang and Pan Wang
Mathematics 2026, 14(2), 316; https://doi.org/10.3390/math14020316 - 16 Jan 2026
Viewed by 143
Abstract
In high-speed railways, the reliability of jointless track circuits largely hinges on the operational integrity of compensation capacitors. These capacitors are periodically installed along the track to mitigate rail inductive impedance and stabilize signal transmission. The induced voltage response, referred to as the [...] Read more.
In high-speed railways, the reliability of jointless track circuits largely hinges on the operational integrity of compensation capacitors. These capacitors are periodically installed along the track to mitigate rail inductive impedance and stabilize signal transmission. The induced voltage response, referred to as the compensation-capacitor signal, serves as a critical diagnostic indicator of circuit health. Yet it is often distorted by electromagnetic interference and structural resonance, posing significant challenges for robust feature extraction. To address this challenge, we propose a Disturbance-Robust Feature Distillation (DRFD) framework that performs multi-perspective modeling and validation of robust features. The framework formulates a unified multi-objective optimization model that jointly considers statistical significance, environmental stability, and structural separability. These objectives are harmonized through an adaptive Bayesian weighting mechanism, enabling automatic identification of disturbance-resistant and discriminative features under complex operating conditions. Experimental evaluations on real-world datasets collected at a 100 kHz sampling rate from roadbed, tunnel, and bridge environments demonstrate that the DRFD framework achieves 96.2% accuracy and 95.4% F1-score, outperforming the best-performing baseline by 4.2–7.8% in accuracy and 6.5% in F1-score. Moreover, the framework achieves the lowest cross-condition relative variance (RV < 0.015), confirming its high robustness against electromagnetic and structural disturbances. The extracted core features—Root Mean Square (RMS), Peak Factor (PF), and Center Frequency (CF)—faithfully capture the intrinsic electromagnetic behaviors of compensation capacitors, thus linking statistical robustness with physical interpretability for enhanced reliability assessment of railway signal systems. Full article
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36 pages, 4293 KB  
Article
AI-Based Health Monitoring for Class I Induction Motors in Data-Scarce Environments: From Synthetic Baseline Generation to Industrial Implementation
by Duter Struwig, Jan-Hendrik Kruger, Henri Marais and Abrie Steyn
Appl. Sci. 2026, 16(2), 940; https://doi.org/10.3390/app16020940 - 16 Jan 2026
Viewed by 98
Abstract
Condition-based maintenance strategies using AI-driven health monitoring have emerged as valuable tools for industrial reliability, yet their implementation remains challenging in industries with limited operational data. Class I induction motors (≤15 kW), which power critical equipment in industries such as grain handling facilities, [...] Read more.
Condition-based maintenance strategies using AI-driven health monitoring have emerged as valuable tools for industrial reliability, yet their implementation remains challenging in industries with limited operational data. Class I induction motors (≤15 kW), which power critical equipment in industries such as grain handling facilities, represent a significant portion of industrial assets but lack established healthy vibration baselines for effective monitoring. A fundamental challenge exists in deploying AI-based health monitoring systems when no historical performance data is available, creating a ’cold-start’ problem that prevents industries from adopting predictive maintenance strategies without costly pilot programs or prolonged data collection periods. This study developed a data-driven health monitoring framework for Class I induction motors that eliminates the dependency on long-term historical trends. Through extensive experimental testing of 98 configurations on new motors, a correlation between vibration amplitude at rotational frequency and motor power rating was established, enabling the creation of a synthetic signal generation algorithm. A robust Health Index (HI) model with integrated diagnostic capabilities was developed using the JPCCED-HI framework, trained on both experimental and synthetically generated healthy vibration data to detect degradation and diagnose common failure modes. The regression analysis revealed a statistically significant relationship between motor power rating and healthy vibration signatures, enabling synthetic generation of baseline data for any Class I motor within the rated range. When implemented at an operational grain silo facility, the HI model successfully detected faulty behavior and accurately diagnosed probable failure modes in equipment with no prior monitoring history, demonstrating that maintenance decisions could be made based on condition data rather than reactive responses to failures. This framework enables immediate deployment of AI-based condition monitoring in industries lacking historical data, eliminating a major barrier to adopting predictive maintenance strategies. The synthetic data generation approach provides a cost-effective solution to the data scarcity problem identified as a critical challenge in industrial AI applications, while the successful industrial implementation validates the feasibility of this approach for small-to-medium industrial facilities. Full article
(This article belongs to the Special Issue AI-Based Machinery Health Monitoring)
32 pages, 107231 KB  
Article
Simulation and Experimental Study of Vessel-Borne Active Motion Compensated Gangway for Offshore Wind Operation and Maintenance
by Hongyan Mu, Ting Zhou, Binbin Li and Kun Liu
J. Mar. Sci. Eng. 2026, 14(2), 187; https://doi.org/10.3390/jmse14020187 - 16 Jan 2026
Viewed by 224
Abstract
Driven by global initiatives to mitigate climate change, the offshore wind power industry is experiencing rapid growth. Personnel transfer between service operation vessels (SOVs) and offshore wind turbines under complex sea conditions remains a critical factor governing the safety and efficiency of operation [...] Read more.
Driven by global initiatives to mitigate climate change, the offshore wind power industry is experiencing rapid growth. Personnel transfer between service operation vessels (SOVs) and offshore wind turbines under complex sea conditions remains a critical factor governing the safety and efficiency of operation and maintenance (O&M) activities. This study establishes a fully coupled dynamic response and control simulation framework for an SOV equipped with an active motion-compensated gangway. A numerical model of the SOV is first developed using potential flow theory and frequency-domain multi-body hydrodynamics to predict realistic vessel motions, which serve as excitation inputs to a co-simulation environment (MATLAB/Simulink coupled with MSC Adams) representing the Stewart platform-based gangway. To address system nonlinearity and coupling, a composite control strategy integrating velocity and dynamic feedforward with three-loop PID feedback is proposed. Simulation results demonstrate that the composite strategy achieves an average disturbance isolation degree of 21.81 dB, significantly outperforming traditional PID control. Validation is conducted using a ship motion simulation platform and a combined wind–wave basin with a 1:10 scaled prototype. Experimental results confirm high compensation accuracy, with heave variation maintained within 1.6 cm and a relative error between simulation and experiment of approximately 18.2%. These findings demonstrate the framework’s capability to ensure safe personnel transfer by effectively isolating complex vessel motions and validate the reliability of the coupled dynamic model for offshore operational forecasting. Full article
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19 pages, 3366 KB  
Article
Observed Change in Precipitation and Extreme Precipitation Months in the High Mountain Regions of Bulgaria
by Nina Nikolova, Kalina Radeva, Simeon Matev and Martin Gera
Atmosphere 2026, 17(1), 93; https://doi.org/10.3390/atmos17010093 - 16 Jan 2026
Viewed by 158
Abstract
Precipitation in high mountain areas is of critical importance as these regions are major sources of freshwater, supporting river basins, ecosystems, and downstream communities. Changes in precipitation regimes in these regions can have cascading impacts on water availability, agriculture, hydropower, and biodiversity. The [...] Read more.
Precipitation in high mountain areas is of critical importance as these regions are major sources of freshwater, supporting river basins, ecosystems, and downstream communities. Changes in precipitation regimes in these regions can have cascading impacts on water availability, agriculture, hydropower, and biodiversity. The present study aims to give new information about precipitation variability in high mountain regions of Bulgaria (Musala, Botev Peak, and Cherni Vrah) and to assess the role of large-scale atmospheric circulation patterns for the occurrence of extreme precipitation months. The study period is 1937–2024, and the classification of extreme precipitation months is based on the 10th and 90th percentiles of precipitation distribution. The temporal distribution of extreme precipitation months was analyzed by comparison of two periods (1937–1980 and 1981–2024). The impact of atmospheric circulation was evaluated by correlation between the number of extreme precipitation months and indices for the North Atlantic Oscillation (NAO) and Western Mediterranean Oscillation (WeMO). Results show a statistically significant decrease in winter and spring precipitation at Musala and Cherni Vrah, and a persistent drying tendency at Cherni Vrah across all seasons. The frequency of extremely wet months in winter and autumn has sharply declined since 1981, whereas extremely dry months have become more common, particularly during the cold season. Precipitation erosivity also exhibits station-specific responses, with Musala and Cherni Vrah showing reduced monthly concentration, while Botev Peak retains pronounced warm-season erosive rainfall. Circulation analysis indicates that positive NAOI phases favor dry extremes, while positive WeMOI phases enhance wet extremes. These findings reveal a shift toward drier and more seasonally uneven conditions in Bulgaria’s alpine zone, increasing hydrological risks related to drought, water scarcity, and soil erosion. The identified shifts in precipitation seasonality and intensity offer essential guidance for forecasting hydrological risks and mitigating soil erosion in vulnerable mountain ecosystems. The study underscores the need for adaptive water-resource strategies and enhanced monitoring in high-mountain areas. Full article
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22 pages, 3507 KB  
Article
Extending ImmunoSpot® Assays’ Sensitivity for Detecting Rare Antigen-Specific B Cells to One in a Million—And Possibly Lower
by Greg A. Kirchenbaum, Noémi Becza, Lingling Yao, Alexey Y. Karulin and Paul V. Lehmann
Vaccines 2026, 14(1), 88; https://doi.org/10.3390/vaccines14010088 - 15 Jan 2026
Viewed by 395
Abstract
Background/Objectives: Despite clonal expansion during a primary immune response, or after subsequent antigen encounters, the frequency of memory B cells (Bmem) specific for an antigen remains low, making their detection difficult. However, unlike serum antibodies, which have a short half-life [...] Read more.
Background/Objectives: Despite clonal expansion during a primary immune response, or after subsequent antigen encounters, the frequency of memory B cells (Bmem) specific for an antigen remains low, making their detection difficult. However, unlike serum antibodies, which have a short half-life in vivo and thus require continuous replenishment to maintain stable titers, circulating Bmem are long-lived; they preserve immunological preparedness through their ability to rapidly engage in recall responses and differentiate into antibody-secreting cells (ASCs) upon antigen encounter. To this end, development of assays suited for the reliable detection of rare antigen-specific Bmem is critical and can provide insights into an individual’s antigen exposure history and immune status beyond that offered by traditional serum antibody measurements alone. Methods: ImmunoSpot® has emerged as a suitable technique for the detection of individual antigen-specific B cells through visualizing their antibody-derived secretory footprints. Here, we report the theoretical and practical foundations for detecting rare antigen-specific Bmem in human peripheral blood mononuclear cells (PBMC). Leveraging the unique availability of verifiably naïve vs. antigen-experienced human samples, we used SARS-CoV-2 Spike (S-) and Nucleocapsid (NCAP) antigens to interrogate the presence of Bmem with these respective specificities. Results: While 100% diagnostic accuracy was achieved for both antigens, detection of NCAP-specific Bmem required reducing the lower detection limit of the standard assay. Specifically, this was achieved by testing a total of 2 million PBMC across multiple replicate assay wells and assessing the cumulative number of secretory footprints detected. Conclusion: The protocols described here should facilitate the reliable detection of ASCs present at varying precursor frequencies and serve as guidance for routine immune monitoring of rare Bmem with specificity for any antigen. Full article
(This article belongs to the Special Issue Human Immune Responses to Infection and Vaccination)
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18 pages, 4862 KB  
Article
Research on Mechanical Characteristics of Multi-Stage Centrifugal Pump Rotor Based on Fluid–Structure Interaction
by Haiyan Zhao, Yi Gao, Xiaodi Zhang, Zixing Yang and Wei Li
Water 2026, 18(2), 229; https://doi.org/10.3390/w18020229 - 15 Jan 2026
Viewed by 248
Abstract
This study investigates the mechanical characteristics of a multi-stage centrifugal pump rotor through fluid–structure interaction (FSI) analysis. A two-stage centrifugal pump equipped with back vanes on the trailing impeller is selected as the research object. Numerical simulations are performed based on the continuity [...] Read more.
This study investigates the mechanical characteristics of a multi-stage centrifugal pump rotor through fluid–structure interaction (FSI) analysis. A two-stage centrifugal pump equipped with back vanes on the trailing impeller is selected as the research object. Numerical simulations are performed based on the continuity equation and Reynolds-averaged Navier–Stokes (RANS) equations, with experimental data utilized to validate the numerical model’s accuracy. The internal flow field mechanisms are analyzed, and the effectiveness of two axial force calculation methods—formula-based and numerical simulation-based—for the rotor system is comprehensively evaluated. Employing an FSI-based modal analysis approach, the governing differential equations of motion are established and decoupled via Laplace transformation to introduce modal coordinates. Modal analysis of the pump rotor system is conducted, revealing the first six natural frequencies and corresponding vibration modes, along with critical speed calculations. The findings demonstrate that when the flow field near the back vanes exhibits complex characteristics, the formula-based axial force calculation shows reduced accuracy. In contrast, without back vanes, the hydraulic motion in the impeller rear chamber remains relatively stable, resulting in higher accuracy for formula-based axial force predictions. The calculation error between the two conditions (with/without back vanes) reaches 27.6%. Based on vibration mode characteristics and critical speed analysis, the pump is confirmed to operate within a safe region. The rotor system exhibits two similar adjacent natural frequencies differing by less than 1 Hz, with perpendicular vibration mode directions. Additionally, rotational speed fluctuations in the rotor system induce alternating critical speed phenomena when operating in this region. This study establishes a coupled analysis framework of “flow field stability–axial force calculation accuracy–rotor dynamic response”, quantifies the axial force calculation error patterns under different flow field conditions of a special pump type, supplements the basic data on axial force calculation accuracy for complex structure centrifugal pumps, and provides new theoretical insights and reference benchmarks for the study of hydraulic–mechanical coupling characteristics of similar fluid machinery. In engineering applications, it avoids over-design or under-design of thrust bearings to reduce manufacturing costs and operational risks. The revealed rotor modal characteristics, critical speed distribution, and frequency alternation phenomena can provide direct technical support for the optimization of operating parameters, vibration control, and structural improvement of pump units in industrial scenarios, thereby reducing rotor imbalance, bearing wear, and other failures. Full article
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