Search Results (54,217)

Basalt fiber-reinforced concrete (BFRC) exhibits superior mechanical performance, durability, and environmental benefits, making it a promising material for promoting green and low-carbon construction. This study develops a novel multi-objective mix design optimization method for BFRC under cost and carbon emission constraints, presents a framework that considers tensile strength (f_t) as a core design objective, and establishes high-precision strength prediction models via gene expression programming (GEP). Material cost and carbon emission functions were formulated based on market data, while compressive strength (f_c) and tensile strength (f_t) prediction models were established using using GEP implemented in MATLAB 2018b with seven mix design variables, including cement dosage, aggregate parameters, and basalt fiber (BF) characteristics (diameter, length, and dosage). Multiple constraints covering material quantities, mix ratios, workability, and density were incorporated into the optimization model, which was solved via the non-dominated sorting genetic algorithm II (NSGA-II). The method identifies the optimal cement dosage, aggregate proportions, and BF dosage to maximize tensile strength (f_t) while minimizing cost and carbon emissions. Computational results suggest that within the target strength range of 30–60 MPa, the proposed design yields reductions of 10–20% in carbon emissions and 12–18% in costs compared to conventional methods, offering potential advantages for sustainable construction. Unlike existing multi-objective studies, which focus on compressive strength, this work addresses critical factors of tensile strength (f_t) and prediction inaccuracy, proposing a systematic low-carbon design framework for potential BFRC applications. Full article

Desertification is one of the main threats to high Andean ecosystems, particularly in arid and semi-arid regions subject to increasing climatic and anthropogenic pressures. This study evaluated the spatial-temporal dynamics of desertification in the province of Candarave (Tacna, Peru) by integrating the Remote Sensing-based Desertification Index (RSDI), constructed from a principal component analysis incorporating four biophysical indicators: vegetation greenness, surface moisture, soil grain size, and fraction of solar radiation reflected (albedo), derived from Landsat 5 and 8 satellite images processed in Google Earth Engine. Temporal trends were analyzed using the Mann–Kendall test, while system stability was evaluated using the coefficient of variation, allowing different degrees of stability and environmental degradation to be characterized during the period 2010–2025. The results show that moderate and severe desertification classes predominate in higher altitude areas, covering approximately 92% of the study area, and are characterized by insignificant to weakly significant negative trends associated with high to relatively high temporal volatility. In contrast, stable areas with no significant changes represent 5.3% of the territory, while restoration processes occupy a small proportion, close to 2.7%. The high variability observed in the high Andean sectors is mainly linked to the interaction between reduced water availability, climate variability, and extreme events, as well as anthropogenic pressures, particularly overgrazing and aquifer exploitation. This multitemporal analysis allows us to anticipate the evolution of desertification and highlights the need to strengthen conservation planning in order to reduce the degradation of strategic high Andean ecosystems in the Tacna region. Full article

Under the combined effects of climate change and anthropogenic activities, the dry–wet pattern of the Yellow River Basin is undergoing substantial reconfiguration, yet its long-term evolution and driving mechanisms remain unclear. This study constructs a Terrestrial Water Storage Anomaly-based Drought Severity Index (TWSA-DSI) using 1995–2014 as the historical period to characterize spatiotemporal dry–wet heterogeneity. Future changes during 2026–2100 are projected for the near future (2026–2060) and far future (2061–2100) under the SSP126, SSP245, and SSP585 scenarios. A comprehensive driving factor system incorporating vegetation cover, land use, meteorological conditions, and socio-economic factors is established, and dominance analysis is applied to quantify the controlling mechanisms of terrestrial water storage change (TWSC). Results indicate that the basin experienced a historical transition from aridification to humidification. Future dry–wet conditions differ markedly from the historical period, with the basin shifting toward overall humidification as emissions increase. The driving mechanisms of aridification and humidification are significantly different and precipitation is the decisive driving factor influencing the dry–wet evolution of the Yellow River Basin. Especially in the far future under the SSP585 scenario, the proportion of precipitation is as high as 54.9%. These findings provide scientific support for sustainable water-resource management under climate change. Full article

The ability to autonomously navigate and explore complex 3D environments in a purposeful manner, while integrating visual perception with natural language interaction in a human-like way, represents a longstanding research objective in Artificial Intelligence (AI) and embodied cognition. Vision-Language Navigation (VLN) has evolved from geometry-driven to semantics-driven and, more recently, knowledge-driven approaches. With the introduction of Large Language Models (LLMs) and Vision-Language Models (VLMs), recent methods have achieved substantial improvements in instruction interpretation, cross-modal alignment, and reasoning-based planning. However, existing surveys primarily focus on traditional VLN settings and offer limited coverage of LLM-based VLN, particularly in relation to Sim2Real transfer and edge-oriented deployment. This paper presents a structured review of LLM-enabled VLN, covering four core components: instruction understanding, environment perception, high-level planning, and low-level control. Edge deployment and implementation requirements, datasets, and evaluation protocols are summarized, along with an analysis of task evolution from path-following to goal-oriented and demand-driven navigation. Key challenges, including reasoning complexity, spatial cognition, real-time efficiency, robustness, and Sim2Real adaptation, are examined. Future research directions, such as knowledge-enhanced navigation, multimodal integration, and world-model-based frameworks, are discussed. Overall, LLM-driven VLN is progressing toward deeper cognitive integration, supporting the development of more explainable, generalizable, and deployable embodied navigation systems. Full article

The electrification of mobility increases the need for efficient local distribution and charging infrastructures. In this context, direct current (DC) architectures may reduce conversion stages, transmission losses, and material demand compared with alternating current (AC) systems. This study aims to quantify the environmental implications of AC- and DC-based grid and charging infrastructures for large-scale rollout in Germany. For this purpose, a dynamic life-cycle assessment (DLCA) is conducted for parking garages, parcel centers, and delivery bases over the period 2023–2045, covering the production and use phases with respect to global warming potential (GWP) and material demand. The results show that DC configurations achieve lower total GWP across all application contexts investigated. For parking garages, DC reduces total GWP by 9.3% compared with AC, while for parcel logistics facilities the reduction amounts to 5.7%. Copper is identified as the dominant material driver, and DC reduces copper demand by 17.1–58.7% depending on the application. A screening-based supply-risk assessment further indicates the elevated relevance of copper due to rising demand and Germany’s import dependence. Overall, the findings provide quantitative evidence that DC-based infrastructures can reduce both environmental impacts and copper demand in large-scale charging infrastructure deployment. Full article

Respiratory Syncytial Virus infection is a significant cause of morbidity and mortality in infants. Maternal vaccination with the bivalent vaccine Abrysvo^® in the third trimester (24–36 weeks) is an effective strategy to prevent severe respiratory illnesses in newborns. However, the introduction of this new technology faces structural obstacles that amplify inequalities. This rapid literature review sought to map and synthesize evidence on inequalities and inequities in adherence and accessibility to maternal vaccination among Black pregnant women. A rapid literature review was conducted using a mixed-methods approach (narrative synthesis and thematic analysis), following guidelines adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook. The research question was structured using the acronym Population/Problem, Exposure, Comparison, and Outcome, focusing on Black pregnant women, maternal vaccination, comparison with other groups, and barriers/determinants. The search was conducted in databases such as PubMed (via Medical Literature Analysis and Retrieval System Online), Scopus and Literatura Latino-Americana e do Caribe em Ciências da Saúde, covering studies published between 2022 and 2025 that presented disaggregated analysis by race. The analysis and interpretation of the findings were guided by Critical Race Theory. The analysis of the twelve included studies (mainly from the United States, the United Kingdom, and Brazil) revealed systematic and robust disparities. Black pregnant women had lower vaccination coverage and were less likely to receive timely recommendations compared to White pregnant women. The barriers identified include: institutional distrust (resulting from structural racism), poor access to prenatal care, inadequate communication, and socioeconomic factors. Inequities are structural and multifactorial phenomena. To ensure that the benefits of the vaccine are distributed equitably, strategies such as anti-racist training for healthcare teams, active vaccination outreach, and continuous monitoring of data disaggregated by race are essential. Full article

Maize–tropical grass intercropping has been adopted during the dry season as a strategy for soil cover; however, a knowledge gap remains regarding adequate nitrogen (N) supply and the efficiency of this system in degraded pasture areas. The objective of this study was to evaluate dry biomass, grain yield, and macronutrient concentrations in maize–tropical grass intercropping as a function of N rates applied as side-dressing in the dry season. The experimental design consisted of a randomized complete block design in a split-plot arrangement with four replications. Main plots comprised maize monoculture, maize intercropped with Urochloa ruziziensis (Congo grass), and maize intercropped with Megathyrsus maximus cv. Aruana (Aruana Guinea grass). Subplots consisted of N rates (0, 50, 100, and 150 kg ha⁻¹). Maize–Aruana intercropping showed a positive linear response to N rates for grain yield; specifically, the nitrogen rate of 150 kg ha⁻¹ resulted in a 71.71% increase in grain yield compared to the lack of nitrogen supply. Conversely, maize monoculture showed a negative linear response, where the highest N rate (150 kg ha⁻¹) resulted in a 68.83% reduction in grain yield compared to the lack of nitrogen supply. Despite yield potential being capped by seasonal water deficits and frost events, the intercropping systems maintained essential growth dynamics. Aruana grass provided a protective effect for maize development under stress. The findings demonstrate that N side-dressing in the maize–Aruana intercropping system in a minimum of 71.83 kg ha⁻¹ is an adequate strategy to enhance grain yield and biomass production. Full article

This paper focuses on the modeling and design of an adaptive vortex generator (AVG). The device is actuated through shape memory alloy (SMA) elements. The interest of the research community in these devices is due to their ability to improve the performance of the aircraft, directly altering and controlling the boundary layer. Their action consists of energizing the flow, thereby hindering separation. The peculiarity of the presented AVG architecture lies in its compactness and adaptability, which allows for its activation just for some specific phases that are not adequately covered by the conventional. This system can enable load alleviation in the cruise phase when a gust occurs (spoiler modality) and stall prevention in high-lift conditions (vane modality). These two working capabilities can be obtained by mounting the AVGs at different angles of incidence, with respect to the direction of the flow. The present paper is structured as follows. First, the project of RADAR, hosting the activities, is presented with specific focus on the main objectives and on the strategy of maturation of the technologies. Then, attention is paid to the simulations of the aerodynamic field produced by the AVG. These outcomes have driven the next part of the work, focusing on the identification of the architecture of the AVG. A dedicated finite element modeling approach was implemented to address the design task, even in the presence of SMA non-linear elements. Three main operational phases were simulated: (1) the stretching of the springs up to their connection to the architecture (pre-load phase); (2) the elastic recovery of the springs and the achievement of equilibrium with the hosting structure; and (3) the activation of the springs through heating to deflect the AVG. The simulations proved the capability of the system to produce the required deflection/deployment, even under the most severe load conditions. In particular, the simulations highlighted the capability of the system to produce a deflection of the vortex generator of 83.5 deg under the most severe load conditions, against the required value of 80 deg. This result was obtained by also keeping the structural safety factor at a value of four, in line with the wind tunnel facility requirement. Another key outcome of the dynamic analysis was the absence of coupling with vortex shedding, since the system resonance frequencies (135 and 415 Hz) are well outside the vortex-shedding frequency range (500–1400 Hz). Full article

To overcome the intrinsic trade-off among miniaturization, ultrawideband (UWB) performance, and structural simplicity in conventional frequency-selective rasorber (FSR) design, this paper proposes a miniaturized UWB absorption–transmission–absorption (A-T-A) FSR based on an inter-cell current-interaction mechanism. The structure comprises a dielectric matching layer (DML), a lossy frequency-selective surface (FSS), a lossless FSS layer, and air/dielectric spacers. Both FSS layers are fabricated on Rogers 4350B substrates without any metallized via or multiple lossy/lossless FSS stacking. The proposed FSR achieves a miniaturized structure with dimensions of 0.085 λ_L × 0.085 λ_L × 0.118 λ_L (where λ_L corresponds to the wavelength at the lowest absorption frequency). A fractional operational bandwidth around 144% is obtained, covering 2.88–12.87 GHz and 14.98–17.61 GHz with absorptivity over 80%, together with a low-loss transmission band of 13.57–14.56 GHz exhibiting a minimum insertion loss of 0.41 dB. As the incident angle increases up to 40°, the FSR retains more than 134% bandwidth for both TE and TM polarizations. A prototype was fabricated and measured, and the results agree well with the simulations. Full article

Conservation and management of built cultural heritage require multidisciplinary approaches and reliable information to support decision-making. In this context, digital transformation strategies that combine Building Information Modeling (BIM) with monitoring technologies offer significant potential to improve heritage management. This paper presents a monitoring solution based on a wireless network of low-cost Internet of Things (IoT) sensors integrated within a Heritage Building Information Model (HBIM), applied to Monserrate Palace in Sintra, Portugal. The proposed approach covers all implementation stages, including HBIM development from as-built data collection, deployment of a wireless monitoring network for acceleration and environmental parameters, and integration of monitoring data into a BIM-based platform. The system aims to create a Digital Shadow of the building as a step towards a Digital Twin framework, enabling centralized visualization and management of structural and environmental information through the HBIM model and dedicated dashboards. Given the lower accuracy of low-cost sensors, in situ calibration with reference equipment was conducted to validate the recorded data. Implementing monitoring systems in heritage contexts presents challenges, such as limited historical documentation and the need for minimally invasive interventions. Despite these constraints, the proposed solution demonstrates the advantages of integrating monitoring data within HBIM, enabling centralized data management and improved understanding of building performance and conservation needs. Full article

Malignant biliary obstruction is commonly treated with biliary stenting either endoscopically or percutaneously; however, tumor ingrowth might occlude the stent, often leading to recurrent jaundice and repeat interventions. Endobiliary microwave ablation (MWA) is an emerging adjunct intended to devitalize intraductal tumors and potentially prolong stent patency. This review assesses the state of the art of endobiliary ablation for malignant biliary obstruction, focusing on the technique and safety of percutaneous procedures, as well as patient outcomes. It also discusses the use of flexible endobiliary MWA for hilar cholangiocarcinoma. The review covers ablation methods such as radiofrequency and MWA, which can be performed endoscopically or percutaneously. Research indicates that endobiliary thermal ablation is technically feasible and can be safely combined with stenting. Some studies suggest it may prolong stent patency and decrease the necessity for repeat procedures compared with stenting alone. Percutaneous techniques may be particularly helpful in complex hilar cases, allowing accurate energy delivery, protection of secondary bile ducts, and tailored stent placement. New microwave systems can heat tissue more deeply and evenly than radiofrequency ablation, which may improve local tumor control. Endobiliary thermal ablation appears to be a useful supplement to stenting, especially for patients with unresectable hilar cholangiocarcinoma. Flexible percutaneous MWA probes could make this treatment more widely available. Still, more high-quality studies are needed to find optimal ablation settings, identify which patients benefit most, and compare this method with standard stenting. Full article

The research conducted in this paper is a practical example of the Design of Experiments methodology. In accordance with the assumptions of the experimental design, the authors drew attention to the problem: how should the spark plasma sintering process be planned to obtain the maximum amount of information needed to optimise the consolidation of the WC-6Co composite at the lowest possible cost? The DOE methodology—a powerful technique for investigating new processes and gaining knowledge about existing ones in order to optimise them for high performance—was employed in the study. The aim of the research was to optimise the consolidation of the spark-plasma sintering process of the WC-6Co composite using the DoE (Design of Experiments) methodology. Four sintering factors were selected for the study: sintering temperature (factor A, 1300–1400 °C); heating rate (factor B, 100–300 °C/min); sintering time (factor C, 150–600 s); and pressure (factor D, 40–50 MPa). Each consolidation factor was designed to cover three levels. The L9 orthogonal array was used. It was found that sintering temperature and heating rate had the greatest impact on apparent density. To validate the statistical model, sintering tests were performed at a temperature of 1380 °C, a heating rate of 100 °C/min, a sintering time of 150 s and a pressing pressure of 45 MPa. Validation analysis of the statistical model demonstrated consistency with the experimental results. The WC-6Co composite achieved an apparent density of 14.85 g/cm³, corresponding to 97.42% of the theoretical density, with a hardness of 1809 HV30 and total porosity of 2.583%. X-ray diffraction studies revealed the presence of tungsten carbide and cobalt in the structure. Full article

The surface of cancer cells is covered in abnormal carbohydrate antigens that facilitate tumor growth, immune evasion and metastasis. Overexpressed and often specific to cancer cells, these tumor-associated carbohydrate antigens (TACAs) offer a valuable handle for targeted immunotherapy and were soon targeted by TACA–protein conjugate vaccines. Despite good initial results, sTn-KLH conjugate Theratope^® failed in clinical trials fifteen years ago for failure to improve life expectancy. This has been attributed to poor immunogenicity, inhomogeneous expression of TACAs within tumors, and vaccine carrier interference. This review covers the two decades of subsequent effort to overcome these limitations and the now large toolbox available to vaccine researchers to improve the outcome of anticancer vaccines: analogues and conformation-locked mimics of TACAs, monomolecular multivalent vaccines, more biologically relevant presentation of TACAs through clusters and glycopeptides, and a new generation of vaccine carriers to reduce carrier interference, immune reaction, or provide simple modular vaccine delivery platforms. Full article

Background and Objectives: Dental caries remains one of the most prevalent chronic conditions among children worldwide, with considerable variation in burden shaped by differences in health-system organization and preventive program implementation. Some countries have reported notable progress through coordinated school-based programs and supportive policy environments, while others continue to face challenges despite extensive public health efforts. This study aims to explore how selected structural and programmatic elements within national health systems may be associated with childhood caries outcomes, using Germany and Saudi Arabia as illustrative contexts. Materials and Methods: A descriptive comparative secondary-data analysis combined with legal and policy mapping was conducted using published national oral health surveys, systematic reviews, and governmental reports. Caries indicators (dmft/DMFT) for children aged 6–7 and 12 years were extracted following WHO criteria. Health system organization, preventive program coverage, and policy enforcement mechanisms were mapped and critically reviewed. No new primary data were collected, and no inferential modeling was performed. Results: Germany has achieved substantial reductions in childhood caries prevalence through a legally mandated school-based prevention program, supported by individual prophylaxis covered by health insurance. This framework corresponds with low mean dmft (1.73) among 6–7-year-olds and mean DMFT (0.5) among 12-year-olds. By contrast, Saudi Arabia continues to report elevated caries rates despite substantial public-health investments, with mean dmft (5.0) and mean DMFT (3.5), with over 90% of children affected. Preventive initiatives in Saudi Arabia remain fragmented across sectors and lack a unified legal mandate. Conclusions: The findings suggest that structured governance, coordinated prevention strategies, and reliable monitoring systems may be associated with more favorable oral health outcomes. In the context of Saudi Arabia, the persistently high caries burden suggests that strengthening national legislation, implementing an interoperable digital surveillance system, and improving the consistency of school-based preventive programs could support more equitable and effective oral health delivery. Full article

This study investigates the impact of political risk on inbound tourism in the context of Mauritius. Political risk can be measured in several ways; the present study uses a comprehensive measure encompassing various political sub-components. In the first instance, the principal component analysis is used to design a political risk index, composed of various political sub-components. The political risk and tourism nexus is then explored using a dynamic time series approach with annual data covering the period 1990 to 2021, both in the short run equilibrium and in the long run. The findings reveal that in the long run, political risk negatively impacts inbound tourism. The study also attempts to assess the asymmetry in the political risk and tourism linkage. The results from the non-linear system imply that increase in political risk presents a higher impact on inbound tourism as compared to a negative change in political risk in the long run. The results from this study are expected to have pivotal implications for the targeted stakeholders and for future researchers in the field. This can help better monitor the level of risk and develop appropriate strategies to mitigate the effects of risk and attract visitors. Full article