Search Results (5,060)

The integration of photovoltaic (PV) systems into DC motor drives has prompted the enhancement of motor performance. This study explores the application of photovoltaic generators (PVs) to independently power and excite a Separately Excited Direct-Current (SEDC) system by utilizing a proportional open-circuit voltage method as a strategy for tracking the maximum power point. This approach offers an effective means of optimizing energy output from PV systems. The primary aim was to optimize power output from photovoltaic generators across varying solar intensity levels. This paper describes the nonlinear current/voltage behaviour of PV generators under different levels of irradiation, along with the magnetic characteristics of the core material in an SEDC motor, utilizing advanced polynomial equations for accurate mathematical representation. Furthermore, we conducted a dynamic analysis of the SEDC motor, powered by the PV generators, under varying solar intensities. This study investigates the operational performance of the SEDC motor under varying solar irradiance levels by developing a realistic model using MATLAB software, R2022a, for numerical simulations, followed by implementation on high-performance computing platforms, including a real-time simulator and testbed, using a real-time digital simulator (RTDS). Full article

Flat terrain and economically prosperous downstream regions face significant challenges in achieving a balance between socio-economic development and ecological preservation. The Social–Ecological System (S-ES) serves as a vital framework for quantifying the interactions between human activities and the natural environment, providing insights into the development status of regional social and ecological systems. This study utilizes the Coupling Coordination Degree (CCD) method to construct an S-ES coupling model, integrating correlation analysis, geographic detectors, and grey relational analysis to explore the driving factors influencing Social–Ecological Resilience (S-ER) coordination. The research focuses on 25 counties in Shandong Province, situated in the lower Yellow River Basin, over the period from 2000 to 2022. Key findings include (1) significant spatial clustering, with identifiable hotspots and cold spots in S-ER distribution; (2) substantial changes in S-ER CCD around 2010 and 2020; and (3) persistent mismatches between socio-economic development and ecological improvement, presenting a major challenge for enhancing coordination. These insights provide valuable guidance for sustainable development strategies in the lower Yellow River Basin. Full article

Research on the ecological vulnerability of islands can identify ecologically fragile areas, thereby providing support for the refined management of the ecological and environmental protection of islands and the rational development and utilization of island spaces. Using the ecosystem of Juehua Island (China) in Liaodong Bay and its surrounding marine regions as the study target, this work develops an ecological vulnerability index system for island sea areas based on the VSD model. The analytic hierarchy approach is used to calculate the weights of the indices, and the geographical pattern, zoning, and driving reasons for the ecological vulnerability of Juehua Island and its marine regions in 2019 are investigated. The findings indicate that the regional distribution of ecological vulnerability on Juehua Island varies greatly. In general, the vulnerability of the island land is spatially distributed as “high around and low in the middle”, with the surrounding sea region being non-vulnerable. The regional distribution of ecological vulnerability has considerable spatial agglomeration properties. The ecological vulnerability in the research region is primarily driven by the net primary production of the island land and the environmental quality of the marine water. Furthermore, specific ideas and strategies for the overall administration of Juehua Island have been proposed. Full article

This article proposes event-triggered cruise control in platoons of connected automated vehicles (CAVs) with heterogeneous input limitations. A distributed control protocol is developed to ensure the stability and performance of the platoon, explicitly addressing varying levels of input saturation among vehicles. To further enhance communication efficiency, a centralized event-triggered mechanism is introduced, activating control updates only when necessary, effectively preventing Zeno behaviors through a predefined threshold. The proposed approach not only achieves global asymptotic stability but also significantly reduces communication demands, making it suitable for real-world driving conditions characterized by input constraints. Simulation results validate the effectiveness and robustness of the proposed control strategy, demonstrating its potential for practical implementation in intelligent transportation systems. Full article

To overcome the limitations of traditional Reverse Osmosis (RO) desalination, Membrane Distillation (MD) has gained attention as an effective solution for improving the treatment of seawater and RO brine. Despite its potential, the formation of inorganic scales, particularly calcium sulfate (CaSO₄), continues to pose a major challenge. This research aims to explore the scaling mechanisms in MD systems through a combination of experimental analysis and dynamic modeling. Using real seawater and RO brine as feed sources, the scaling behavior was examined under various operational conditions, such as temperature and feed concentration. Optical Coherence Tomography (OCT) was utilized to monitor the real-time development of fouling layers, offering valuable insights into surface crystal formation processes. A System Dynamics Model (SDM) was created based on the experimental data to predict flux decline trends with precision. The model correlated well with experimental observations, highlighting key factors that drive scaling severity. This integrated approach deepens our understanding of scaling dynamics and provides actionable strategies to mitigate fouling in MD systems, thereby enhancing the efficiency and stability of MD desalination operations. Ultimately, this study underscores the potential of combining OCT with system dynamics modeling as a powerful approach for visualizing and validating scaling processes, offering a practical framework for optimizing MD performance and contributing to more sustainable desalination practices. Full article

The development of vaccines against RNA viruses has undergone a rapid evolution in recent years, particularly driven by the COVID-19 pandemic. This review examines the key roles that RNA viruses, with their high mutation rates and zoonotic potential, play in fostering vaccine innovation. We also discuss both traditional and modern vaccine platforms and the impact of new technologies, such as artificial intelligence, on optimizing immunization strategies. This review evaluates various vaccine platforms, ranging from traditional approaches (inactivated and live-attenuated vaccines) to modern technologies (subunit vaccines, viral and bacterial vectors, nucleic acid vaccines such as mRNA and DNA, and phage-like particle vaccines). To illustrate these platforms’ practical applications, we present case studies of vaccines developed for RNA viruses such as SARS-CoV-2, influenza, Zika, and dengue. Additionally, we assess the role of artificial intelligence in predicting viral mutations and enhancing vaccine design. The case studies underscore the successful application of RNA-based vaccines, particularly in the fight against COVID-19, which has saved millions of lives. Current clinical trials for influenza, Zika, and dengue vaccines continue to show promise, highlighting the growing efficacy and adaptability of these platforms. Furthermore, artificial intelligence is driving improvements in vaccine candidate optimization and providing predictive models for viral evolution, enhancing our ability to respond to future outbreaks. Advances in vaccine technology, such as the success of mRNA vaccines against SARS-CoV-2, highlight the potential of nucleic acid platforms in combating RNA viruses. Ongoing trials for influenza, Zika, and dengue demonstrate platform adaptability, while artificial intelligence enhances vaccine design by predicting viral mutations. Integrating these innovations with the One Health approach, which unites human, animal, and environmental health, is essential for strengthening global preparedness against future RNA virus threats. Full article

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by both motor symptoms and non-motor features. A hallmark of PD is the misfolding and accumulation of alpha-synuclein (α-syn), which triggers neuroinflammation and drives neurodegeneration. Microglia, brain cells that play a central role in neuroinflammatory responses and help clear various unnecessary molecules within the brain, thus maintaining the brain’s internal environment, respond to α-syn through mechanisms involving inflammation, propagation, and clearance. This review delves into the complex interplay between α-syn and microglia, elucidating how these interactions drive PD pathogenesis. Furthermore, we discuss emerging therapeutic strategies targeting the α-syn–microglia axis, with a focus on modulating microglial functions to mitigate neuroinflammation, enhance clearance, and prevent α-syn propagation, emphasizing their potential to slow PD progression. Full article

Background: The persistence of chemotherapy-resistant and dormant cancer cells remains a critical challenge in the treatment of lung cancer. Objectives: This review focuses on non-small cell lung cancer and small cell lung cancer, examining the complex mechanisms that drive treatment resistance. Methods: This review analyzed current studies on chemotherapy resistance in NSCLC and SCLC, focusing on tumor microenvironment, genetic mutations, cancer cell heterogeneity, and emerging therapies. Results: Conventional chemotherapy and targeted therapies, such as tyrosine kinase inhibitors, often fail due to factors including the tumor microenvironment, genetic mutations, and cancer cell heterogeneity. Dormant cancer cells, which can remain undetected in a quiescent state for extended periods, pose a significant risk of recurrence upon reactivation. These cells, along with intrinsic resistance mechanisms, greatly complicate treatment efforts. Understanding these pathways is crucial for the development of more effective therapies. Emerging strategies, including combination therapies that target multiple pathways, are under investigation to improve treatment outcomes. Innovative approaches, such as antibody–drug conjugates and targeted protein degradation, offer promising solutions by directly delivering cytotoxic agents to cancer cells or degrading proteins that are essential for cancer survival. The lung cancer organoid model shows substantial promise to advance both research and clinical applications in this field, enhancing the ability to study resistance mechanisms and develop personalized treatments. The integration of current research underscores the need for continuous innovation in treatment modalities. Conclusions: Personalized strategies that combine novel therapies with an in-depth understanding of tumor biology are essential to overcome the challenges posed by treatment-resistant and dormant cancer cells in lung cancer. A multifaceted approach has the potential to significantly improve patient outcomes. Full article

The education policy of the Macao Special Administrative Region is a driving factor in the investment of educational resources and the construction of a comprehensive education system. At the same time, the Macao Special Administrative Region Government closely integrates its education policy with the overall national development strategy, focuses on the training of teachers with a strong sense of national responsibility, and attaches importance to the needs of young people in national education, information technology education, and vocational education. Taking the policy addresses of the Macau Special Administrative Region over the past 25 years as the research sample, this study pioneered the use of policy modeling consistency index modeling combined with text mining to construct an evaluation system featuring the development of education policies. This approach provides a more in-depth quantitative analysis of the evolution and effectiveness of specific education policies. The results show that the MSAR has made significant progress in strengthening educational resources and aligning educational goals with national priorities. However, there is still room for improvement in areas such as information technology and vocational training. Based on this, the study recommends that these areas be targeted for strengthening, providing a reference basis for the future formulation or adjustment of existing education policies. Full article

Thermo-mechanically stabilized nanocrystalline (NC) alloys are increasingly valued for their enhanced mechanical strength and high-temperature stability, achieved through thermodynamic and kinetic stabilization methods. However, their fine-grained structure also increases susceptibility to internal oxidation due to higher atomic diffusivity associated with a greater volume fraction of grain boundaries (GBs). By incorporating solutes that form protective oxides, or the so-called thermally growing oxides (TGO), this vulnerability can be mitigated. The TGO scale acts as a diffusion barrier for oxygen that slows down the oxidation kinetics and prevents internal oxidation that impairs the structural integrity of the metal. This review examines advancements in oxidation-resistant NC alloys, focusing on the interplay between grain size and alloy chemistry. We explore how grain refinement influences diffusion coefficients, particularly the enhanced GB diffusion of Ni and Cr in Ni-Cr-based alloys, which improves oxidation resistance in NC variants like Ni-Cr and Cu-Cr compared to coarse-grained counterparts. We also analyze the role of third elements as oxygen scavengers and the impact of reactive elements such as Hf, Zr, and Y in NiAl alloys, which can slow down diffusion through early establishment of protective TGO layers and enhance oxidation resistance. The concomitant effect of grain size refinement, modifications in alloy stoichiometry, and enhanced atomic diffusion is shown to manifest via drastic reductions in oxidative mass gain, and visualization of the stable, protective oxide scales is delivered through characterization techniques such as TEM, SEM, and EDS. A brief overview is provided regarding stress effects and the role of induced stress in driving oxide scale spallation, which can negatively impact oxidation kinetics. Lastly, we propose future research directions aimed at developing micro-structurally stable NC alloys through multi-solute strategies and surface modification techniques, targeting robust materials for high-stress applications with improved oxidation resistance. Full article

Unveiling the scale effects on the interactions and driving factors of ecosystem services (ESs) contributes to the differentiated conservation of ESs across multiple scales. Utilizing models such as Integrated Valuation of Ecosystem Services and Trade-offs (InVEST), Self-organizing map (SOM), and Geographic Detector, we analyzed the spatiotemporal changes, interactions, and dominant driving factors of water yield (WY), soil conservation (SC), carbon storage (CS), and habitat quality (HQ) in the Three River Source Basin (TRSB) from 2000 to 2020 at both grid and sub-watershed scales; explored the impact of scale effects; and proposed ecological conservation strategies. The results indicated the following: (1) Over the 20 years, the average values of WY, SC, CS, and HQ in the TRSB were 146.12 mm, 10.95 t, 224.77 gC m⁻², and 0.6942, respectively, which exhibited a distribution with lower values in the northwest and higher values in the southeast. Over the study period, WY and SC experienced declines at rates of −7.26 mm per 5 years and −0.08 t per 5 years, while CS and HQ showed increases at rates of 6.97 gC m⁻² per 5 years and 0.007 per 5 years. (2) The relationships among WY, SC, and CS were primarily synergistic, whereas HQ exhibited more trade-offs with other ESs, and as the scale increased, the trade-off effects diminished, and synergistic effects were enhanced. (3) ESs were influenced by a combination of factors, and the interactions among these factors strengthened the explanatory power regarding ESs. Increasing vegetation cover and reducing irrational human activities were effective approaches to enhance the ESs in the TRSB. This study helps to expand the understanding of the relationships among ESs and the effects of scale, providing support for the protection and sustainable development of the TRSB ecosystem. Full article

Heritage language (HL) research has investigated adults and children, while adolescents have garnered far less attention, despite adolescence being a crucial time in the development of idiolects and identities, and, hence, also for language maintenance. This study describes HL usage among Estonian-Swedish bilingual teenagers. Data were collected from 21 first- and second-generation Estonian heritage speakers (aged 12–17). Non-standard usage occurred in our corpus at low rates but was found across most speakers in certain areas of morphosyntax. We describe which factors drive such non-standard usage based on the example of two structures with more frequent non-standard occurrence: (1) object marking and (2) experiencer constructions with the verb meeldima ‘to like/please’. Around 6% of objects were marked in divergent ways. Speakers employed two strategies for marking non-standard objects: case omission (i.e., using nominative and/or unmarked forms) and substitution (i.e., using non-target-like marking). Non-standard forms occurred in 11% of experiencer constructions. Speakers diverged more with marking the nominative Stimulus than the dative-like Experiencer, although both occurred in standard and non-standard forms. The reported usage patterns can be explained through the combined effect of cross-linguistic influence, simplification, and input frequency. We also tested the relation between non-standard usage and the speaker’s sociolinguistic background, with mixed results. Considering the limited size and scope of the corpus, overall, the reported divergent usage patterns evidence the role of linguistic input and cross-linguistic effects. Full article

The advantages of asphalt pavement in terms of driving comfort, construction efficiency, and ease of maintenance have established it as the predominant choice for high-grade pavements at present. However, being highly sensitive to temperature and stress, asphalt performance is significantly influenced by external environmental conditions and loading, making it susceptible to various distress phenomena. Particularly in high-latitude regions, asphalt pavement cracking severely limits asphalt pavement’s functional performance and service lifespan under cold climatic conditions. To enhance the low-temperature cracking resistance of asphalt pavement in cold regions, tools such as VOS viewer 1.6.20 and Connected Papers were utilized to systematically organize, analyze, and summarize relevant research from the past 40 years. The results reveal that temperature shrinkage cracks and thermal fatigue cracks represent the primary forms of asphalt pavement distress in these regions. Cracking in asphalt pavement in cold regions is primarily influenced by structural design, pavement materials, construction technology, and climatic conditions. Among these factors, surface layer stiffness, base layer type, and the rate of temperature decrease exert the most significant impact on cracking resistance, collectively accounting for approximately 45.4% of all cracking-related factors. The low-temperature performance of asphalt pavement can be effectively improved through several strategies, including adopting full-thickness asphalt pavement with a skeleton-dense structure or reduced average particle size, incorporating functional layers, appropriately increasing the thickness of the upper layer and the compaction temperature of the lower layer, utilizing continuous surface layer construction techniques, and applying advanced materials. High-performance modifiers such as SBR and SBS, nanomaterials with good low-temperature performance, and warm mixing processes designed for cold regions have proven particularly effective. Among various improvement methods, asphalt modification has demonstrated superior effectiveness in enhancing the deformation capacity of asphalt and its mixtures, significantly boosting the low-temperature performance of asphalt pavements. Asphalt modification accounts for approximately 50% of the improvement methods evaluated in this study, with an average improvement in low-temperature performance reaching up to 143%. This paper provides valuable insights into the underlying causes of cracking distress in asphalt pavements in cold regions and offers essential guidance for improving the service quality of such pavements in these challenging environments. Full article

The Belt and Road Initiative (BRI) proposed by China in in 2013 prioritizes environmental sustainability and regional economic development from a global perspective. Although the BRI has achieved considerable economic progress in many cities and regions, research on its environmental impacts is still insufficient, with limited attention paid to domestic urban areas in particular. Existing studies have focused primarily on carbon emissions, ignoring the broader environmental impacts of industrial emissions, such as those from smart transportation. To address this gap, this study adopts four major pollutant emissions—carbon dioxide (CO₂), industrial particulate matter, industrial sulfur dioxide (SO₂), and industrial wastewater emissions—as indicators to assess pollution levels in urban environments. Adopting panel data from 281 Chinese cities from 2003 to 2021, this study employs the difference-in-differences (DID) method to estimate the effect of the BRI on urban environmental pollution. This study is based on the following hypotheses: Hypothesis 1. BRI implementation has reduced urban pollution emissions. Hypothesis 2. Advancements in science and technology will drive the implementation of the BRI. Hypothesis 3. A proactive government response can significantly reduce urban environmental pollution. The main findings of this study are as follows. First, BRI implementation significantly reduces urban environmental pollution by 1.05%. Second, the policy effects of the BRI are more pronounced in the eastern and western regions and in larger cities, implying that geopolitical- and market-oriented strategies are important for regional performance. Third, scientific and technological progress positively affects pollution reduction in urban environments. Fourth, the BRI contributes to strengthening government intervention, which subsequently improves sustainable governance, reduces urban environmental pollution, and promotes regional economic cooperation. Our findings will serve as a crucial reference for future policymaking endeavors toward eco-friendly logistics cooperation in the region. Full article

This paper suggests an adaptive car-following strategy for autonomous connected vehicles (ACVs) that integrates a robust controller with an extended disturbance estimator (EDE) and reinforcement learning (RL) to improve performance in dynamic traffic environments. Traditional car-following methods struggle to handle external disturbances and uncertainties in vehicle dynamics. The suggested method addresses this by dynamically adjusting the EDE gain using RL, enabling the system to optimize its control strategy in real time continuously. Simulations were conducted in two scenarios, a single following vehicle and two following vehicles, each tracking a leading vehicle. Results showed significant improvements in velocity tracking, with the RL-based control method reducing velocity error by over 50% compared to conventional approaches. The technique also led to smoother acceleration control, enhancing stability and driving comfort. Quantitative metrics, such as total reward, velocity error, and acceleration magnitude, indicate that the suggested EDE-RL-based strategy provides a robust and adaptable solution for autonomous vehicle control. These findings indicate that RL, combined with robust control, can improve the performance and safety of ACV systems, making it suitable for broader applications in autonomous vehicle platooning and complex traffic scenarios, including vehicle-to-vehicle (V2V) communication. Full article