Search Results (2,465)

Sewerage systems are a main element of a city’s infrastructure. Roughness coefficients are fundamental parameters for sewage system operation. The intermittent nature of the flow leads to the appearance of deposits that become an integral part of the sewerage systems. Deposited material not only leads to the loss of hydraulic capacity and decreases the concentration of dissolved oxygen (which is found in direct relation to all quality parameters), but it also results in more transported particles being intercepted. In the design calculations, the roughness coefficient is estimated rather than calculated. It has been demonstrated that the estimation of stress within and above roughness elements improves the predictive capability for the concentration of suspended sediment. In this study, we focused on a local evaluation of the roughness coefficient when the flow velocity is below the minimum self-cleansing velocity. Some authors consider the selection of the most reliable method for estimating bed shear stress to be the main challenge. Other authors have suggested that all possible methods should be applied simultaneously to achieve a reliable bed shear stress estimation, knowing that the roughness coefficient can be determined through the shear boundary stress. We calculate the local roughness coefficient in Manning’s equation using a laboratory model, considering clear water flowing over a solid boundary with consolidated deposits, represented by artificial roughness elements (calibrated hemispheres). The European standard EN 752:2017 specifies a minimum average cross-sectional velocity of 0.7 m/s for pipe self-cleansing. This study established the range of possible roughness coefficient values when the minimum velocity design criterion is not met. The second criterion was to consider acceptable a sediment deposit occupying between 1% and 2% of the collector diameter. Velocity distributions around artificial roughness and statistical parameters of the turbulent flow were obtained using a PIV system. Five methods were implemented and the range of roughness coefficient values varied between 0.007 and 0.023. This variation is closely related to sewer performance. We selected the dissipation method as the primary reference for this study, as it is most closely aligned with the underlying physics of flow over roughness elements. This approach allows for robust validation by correlating multiple characteristic mechanisms of the turbulent cascade. Full article

Welding is a critical joining process in civil and transportation infrastructure, enabling the fabrication of complex steel structural systems used in bridges, buildings, and other essential infrastructures. Despite strict adherence to established welding codes and standards, such as AWS D1.1 and AASHTO/AWS D1.5, welding flaws and service-induced defects can occur in welded components. Cause of defects and their structural impact, along with detection, sizing, and localization of these anomalies and flaws, are crucial for adequate maintenance, repair, or replacement planning without compromising the functionality of in-service components. Among available NDT techniques, ultrasonic testing (UT) remains one of the most widely adopted methods of weld inspection due to its depth of penetration, sensitivity to internal defects, and suitability for field deployment. Recent advancements in ultrasonic technologies, particularly Phased Array Ultrasonic Testing (PAUT), along with its emerging approaches such as Full Matrix Capture (FMC) and the Total Focusing Method (TFM), have significantly enhanced inspection accuracy, repeatability, and interpretability. These techniques enable flexile beam steering, multi-angle interrogation, and improved imaging of complex geometries. This paper presents a comprehensive review of PAUT for the inspection of welded steel infrastructure adhering to the recommendations and requirements of the relevant codes and standards, synthesizing the current literature on PAUT principles, wave modes, probe configurations, and data acquisition strategies. Emphasis is placed on the practical implementation of PAUT in civil infrastructure inspection, its advantages over conventional NDT methods, and its potential to support informed decisions related to quality acceptance, repair, and long-term maintenance planning. This paper concludes by identifying current challenges and future research directions for advanced ultrasonic inspection of welded steel structures. Full article

This study examines the hydro-sedimentological–radioecological controls governing the distribution of natural (K-40, Ra-226, Th-232) and anthropogenic (Cs-137) radionuclides in surface sediments of the western Black Sea shelf. Activity concentrations were determined by high-resolution gamma spectrometry, and radiological indices—including radium equivalent activity (Ra_eq), external hazard index (H_ex), and annual effective dose (AED)—were calculated to evaluate environmental safety. All indices remained well below internationally accepted thresholds, confirming the absence of radiological hazard in both coastal and offshore settings. Strong correlations between Ra-226 and Th-232 indicate dominant lithogenic control of natural radionuclides, whereas Cs-137 exhibits geochemical decoupling consistent with its behavior. A significant relationship between the fine-grained sediment fraction (<63 µm) and Cs-137 activity highlights the grain size effect, with offshore depositional zones acting as sediment-focusing areas where Cs-137 and excess Pb-210 co-accumulate under low-energy hydrodynamic conditions. Despite localized offshore enrichment, dose contribution analysis shows that natural radionuclides dominate the absorbed-dose budget, while Cs-137 contributes only marginally. Spatial predictive modeling using Artificial Neural Networks, validated under a Spatial Leave-One-Group-Out framework, yielded moderate generalization capacity (R² = 0.61 for Ra-226; R² = 0.41 for Cs-137), reflecting smoother spatial gradients of lithogenic radionuclides than heterogeneous radiocesium deposition. Furthermore, Machine Learning algorithms provided significant analytical value: a Random Forest (RF) model successfully classified environments (nearshore/shelf/depositional basin) based on distinct radionuclide signatures. At the same time, an optimized Artificial Neural Network (ANN-GA) enabled the nonlinear reconstruction of radiometric–granulometric patterns to identify local anomalies. The results show that radionuclide distributions are primarily structured by sediment provenance, grain size sorting, and hydrodynamic energy gradients rather than ongoing anthropogenic inputs. Full article

Parabolic trough collectors (PTCs) are highly sensitive to receiver positioning accuracy; however, most existing studies report optical efficiency degradation without formally defining alignment tolerance limits. This study proposes a tolerance-based thermo-optical risk framework to quantify allowable receiver misalignment envelopes for reliable PTC operation. A Monte Carlo Ray Tracing (MCRT) methodology is employed to evaluate the impact of angular receiver misalignment on optical efficiency and circumferential heat flux redistribution. Beyond conventional efficiency metrics, normalized flux-based thermal non-uniformity indicators are introduced to assess thermo-mechanical risk without requiring full thermo-fluid modeling. The results reveal a nonlinear decoupling between optical acceptability and thermal safety. While optical efficiency remains above 0.80 up to approximately ±6°, pronounced flux localization and rapid growth of thermal stress indicators occur beyond ±4°, marking the onset of thermally critical behavior. The identified ±4° threshold corresponds to approximately twice the collector half-acceptance angle (θ_(crit)/δ ≈ 2), demonstrating geometry-dependent scaling characteristics. The proposed framework formalizes the optical–thermal decoupling phenomenon and transforms conventional efficiency-based evaluation into a reliability-informed alignment tolerance assessment tool applicable to manufacturing precision, installation control, and operational quality management in CSP systems. Full article

Climate change is radically altering the Earth’s natural ecosystems, with temperature/precipitation alterations resulting in mismatches between specific ecosystems and their ‘new’ climatic profiles. Without political action to curb greenhouse gas emissions, most plant/animal species will need to move to higher latitudes to ensure survival. Many are incapable of migrating rapidly and will thus be reliant on human intervention to relocate to new regions (assisted migration). The first hypothetical steps of assisted migration are explored here, using the UK as a model. Urban parks/gardens have a history of hosting non-native plant species and could be used to test the validity of moving non-native plants and animals to regions of higher latitude. In this perspective paper, we added a small experimental component to examine public attitudes to species introductions into urban parks/gardens. Results showed support for using parks and gardens to protect both UK native and non-native wildlife. Indeed, >50% of respondents favoured utilising urban landscapes to conserve small non-native animals (e.g., tortoises and bee-eaters). These results imply there may be some public acceptance of assisted migration. Thus, the paper explores the potential to develop novel, but more sustainable ecosystems in new localities. Full article

This research examines the potential of Battlefield Tourism as a strategic tool for rural development, focusing on the cultural heritage of Extremadura, Spain. Given the specific nature of the regional tourism offer, this paper is presented as a case study to analyze how military historical resources can be integrated into sustainable tourism models. The study employs a mixed-methodology approach, combining a quantitative cross-sectional survey with complementary qualitative analysis of open-ended responses. A sample of 149 municipal managers was analyzed to evaluate their institutional perceptions of military cultural tourism and its potential integration into regional strategic initiatives. Results, supported by χ² tests and Cronbach’s α reliability analysis, suggest that the use of specific terminology associated with cultural heritage, rather than ‘war’ or ‘dark’ tourism, is perceived by local stakeholders as more socially and politically acceptable for rural development plans. Given the sample size and self-selection bias, these perception-based findings highlight the importance of terminological sensitivity for local leaders exploring new tourism offerings. The study concludes that, from an institutional standpoint, framing Battlefield Tourism through professional heritage protocols may facilitate its acceptance as a potential tool for economic diversification in inland destinations facing challenges of depopulation. Full article

Conservation easements (CEs) represent a complex policy instrument designed to mediate the feedback loops within coupled human and natural systems in protected areas. However, their efficacy is often constrained by a lack of systemic understanding of the localized drivers of community support. Building upon the successful implementation of Forest Land Easements (FLEs) within China’s Qianjiangyuan National Park Pilot, this study investigates the potential to expand this policy model to other land types. This study investigates the multilevel factors influencing residents’ willingness to adopt three types of CEs, including forest land (FLE), agricultural land (ALE) and homestead land (HLE) easements in China’s Qianjiangyuan National Park Pilot, the country’s primary CE reform site. We conceptualize a hierarchical support model wherein community participation (CP) and human well-being (HW) interact with support for park management (SM), forming a subsystem that drives decisions within the broader land-use. Utilizing structural equation modelling (SEM) and stepwise regression analysis on survey data from 336 households, we tested this model. The results reveal that SM acts as a critical direct mediator and positive driver of CE acceptance, while CP and HW exert significant indirect effects through SM, demonstrating a key feedback pathway. Regression analyses further elucidate that support for different CE types is driven by distinct configurations of factors, highlighting the heterogeneous nature of subsystems. Notably, livelihood benefits and prior participation experiences emerged as consistent, cross-cutting systemic leverages. It demonstrates that leveraging the implementation experience and community support gained from existing forest land easements is crucial. This study concludes that effective CE design must move beyond one-size-fits-all approaches. It necessitates differentiated, adaptive policies that are coherently aligned with local livelihood subsystems and strategically strengthen participatory feedback mechanisms initiated by successful FLEs. Our findings provide an evidence-based framework for designing resilient, socially sustainable conservation policies in complex protected area systems, grounded in proven practice. Full article

Autonomous vehicle technology has rapidly advanced in recent years. Such technology is increasingly viewed not merely as a technical innovation but also as a social and behavioural transformation shaped by how these systems are interpreted, trusted, and integrated into everyday life. There are mounting expectations regarding its potential to improve traffic safety, enhance energy efficiency, reduce congestion, and support sustainable mobility; however, key questions remain about how different groups and communities experience autonomous mobility. This review synthesizes equity, governance, and sustainability dimensions as they appear within the existing corpus of AV user acceptance research. A structured review of research on autonomous vehicles (AVs) and user acceptance was conducted using an initial database search followed by iterative literature refinement and structured thematic coding. Using this approach, the review identifies key thematic patterns, highlights structural research gaps, and explores regional differences, offering a framework that supports subsequent comparative analysis. AVs have the potential to shape accessibility, social relations, and sustainable lifestyles. By integrating technological advancement with local governance, community practices, and social equity considerations, automated public transit may serve as a catalyst for sustainable and inclusive urban transformation. Full article

Hourly concentrations of PM_2.5-bound elements were continuously monitored in Windsor, Canada, from April 2021 to April 2023. Health risk assessment methods of the USEPA were utilized to quantify lifetime cumulative cancer risks (CRs) using six PM_2.5-bound elements, and chronic non-cancer hazard quotients (HQs) using 11 elements, for each season, each source factor, and each hour of day. The two-year average PM_2.5 mass concentration was 9.2 μg/m³, slightly exceeding Ontario’s Ambient Air Quality Criteria of 8.8 μg/m³. A discernible diurnal concentration pattern was noted for most elements, peaking during morning rush hours and tapering during the daytime, largely attributed to local human activities and changes in atmospheric mixing heights. Despite this, both the total lifetime cumulative CR (4.1 × 10⁻⁵) and non-cancer total HQ (0.82) from exposure to ambient elements remained below the corresponding USEPA-acceptable levels. The seasonal variation in CRs and HQs was minimal. However, the diurnal variation was strong, with higher risks during morning rush hours (6:00–8:00) when traffic volume peaks, and lower risks during the daytime (12:00–20:00) when atmospheric mixing height is enhanced. Metal processing emerged as the most significant contributor to the total CR (52%) and HQ (60%), followed by coal/heavy oil burning (19% and 16%, respectively), and vehicular exhaust (19% and 12%, respectively). The remaining two source factors accounted for 10% of CR and 12% of HQ. Cd (62%) was the largest contributor to CRs, followed by Cr(VI) (25%), Co (6%), As (5%), Ni (2%), and Pb (<0.1%). Similarly, Cd dominated HQs (73%), followed by Mn (11%), Ni (6.3%), with the remaining eight elements collectively contributing 9.7%. Although levels of CRs and HQs are low, efforts to mitigate ambient Cd emissions from metal processing sources will help reduce exposure and protect the environment and human health, given Cd is the primary contributor to the total CR and HQ during the study period. Full article

Moving beyond traditional sociodemographic models, this study investigates the psychometric drivers of lexical change. Using Swiss German as a case study, we compare historical data from the Sprachatlas der deutschen Schweiz (1939–1958) with a recent large-scale app-based survey (N = 1013) to quantify trajectories over the past century. We identify four distinct mechanisms: exogenous convergence (Schmetterling), endo-normative leveling (Rande), endogenous innovation and divergence (schlittschuhlaufen), and diachronic persistence (Stäge). For the locally rooted speakers in our dataset, structural analysis indicates that traditional variables carry less weight than expected. While age remains the primary vertical predictor, psychological factors outperform traditional variables (e.g., gender, social networks) in this environment of ubiquitous exposure. Multivariate models demonstrate that lexical choices are strongly influenced by individual disposition: traits such as agreeableness accelerate the adoption of supraregional forms, whereas a strong local identity functions as a “brake” against standardization. Ultimately, while macro-factors create the pressure for change, individual micro-factors determine whether it takes hold. A speaker’s attitude acts as a “filter” and their personality as a “gate,” deciding whether they accept or resist new forms. These findings challenge purely structural accounts, suggesting that for these locally rooter speakers, even without high physical mobility, lexical change is shaped by a psychometric architecture. Full article

Indigenous cultures in Taiwan embody rich ecological knowledge and strong environmental conservation values. However, elementary and secondary education often provides limited exposure to these cultures due to geographic constraints and insufficient instructional resources, relying primarily on textbooks and teacher-centered teaching methods. Such approaches restrict experiential learning, which may diminish students’ motivation and depth of understanding. However, 360-degree virtual reality (VR360) enables immersive simulations of authentic environments, increasing the accessibility of cultural and ecological education through smartphones and low-cost Google Cardboard. In addition, drone technology enhances learning by offering multiple perspectives for environmental exploration and data collection. This study examines the effectiveness of integrating a VR360 and virtual drone system into instruction focused on the ecological context of Sun Moon Lake and Thao Indigenous culture. Learning outcomes for Indigenous and non-Indigenous students were compared in terms of learning effectiveness, motivation, cognitive load, and technology acceptance. Ecological and cultural materials were collected through field investigations and drone photography, enabling students to explore landscapes from a first-person perspective and engage with Thao cultural practices and their relationship with local ecology. The findings indicate that the proposed VR-based system significantly enhances learning experiences and demonstrates strong potential for cultural and ecological education, offering valuable guidance for the design of future immersive instructional strategies and learning materials related to Indigenous cultures. Full article

Background: The global rise in antimicrobial resistance (AMR) has created an urgent need for innovative antibacterial strategies and localized delivery systems. This study aimed to develop and characterize electrospun poly (vinyl alcohol) (PVA) nanofibers co-loaded with atorvastatin (ATR) and zinc oxide (ZnO) nanoparticles for use as a multifunctional topical platform for wound healing and infection control. Methods: ZnO nanoparticles were prepared via ball milling and characterized for size and zeta potential. Four PVA-based nanofiber formulations were fabricated using electrospinning: blank (F1), ZnO-loaded (F2), ATR-loaded (F3), and ATR/ZnO co-loaded (F4). The nanofibers were evaluated for morphology, thermal properties, crystallinity, and drug release. Antibacterial efficacy was tested against S. aureus, S. epidermidis, MRSA, and P. aeruginosa using broth microdilution and checkerboard assays. Biocompatibility and wound healing potential were assessed via MTT and fibroblast scratch assays on human foreskin fibroblasts (hFFs). Results: SEM imaging confirmed the production of uniform, bead-free nanofibers. ATR and ZnO nanoparticles were successfully incorporated in the nanofiber. The co-loaded formulation (F4) demonstrated a sustained release profile, releasing approximately 78.7% of ATR over 24 h. While all treatments showed limited activity against P. aeruginosa, the ATR/ZnO co-loaded nanofibers exhibited significantly enhanced antibacterial activity against Gram-positive strains, achieving the lowest MIC values (1.5–2.0 mg/mL). Synergy analysis confirmed an enhanced effect with ATR and ZnO against MRSA. Furthermore, F4 achieved the highest wound closure rate of 92.41% in 24 h while maintaining acceptable cytocompatibility. Conclusions: The integration of ATR and ZnO into PVA nanofibers provides an enhanced antibacterial effect consistent with the synergistic potential observed between free agents targeting Gram-positive wound pathogens. The platform’s ability to simultaneously inhibit bacterial growth and promote rapid fibroblast migration positions it as a promising localized therapeutic for managing infected wounds. Full article

Objectives: This study aimed to evaluate the setup accuracy and intrafractional geometric stability of surface-guided radiation therapy (SGRT) under frameless immobilization in lung cancer radiotherapy and to assess its clinical utility in a relatively large patient cohort. Materials and Methods: A total of 678 treatment fractions from 52 patients with primary non-small cell lung cancer (NSCLC), treated between October 2024 and November 2025, were retrospectively analyzed. Patient setup was performed using SGRT with the Identify system, and cone-beam computed tomography (CBCT) served as the reference for internal target localization Intrafractional setup displacements, center-of-mass (COM) shifts, residual setup errors, and intrafractional clinical target volume (CTV) variations were evaluated. Spatial agreement between planned and intrafractional tumor volumes was quantified using the Dice Similarity Coefficient (DSC). Results: The mean CBCT-based intrafractional shifts were −0.01 mm (vertical), 0.03 mm (longitudinal), and 0.01 mm (lateral), indicating negligible systematic errors. The greatest variability was observed in the longitudinal direction (standard deviation, 1.32 mm), with a maximum displacement of 4.58 mm. COM-based analysis demonstrated near-zero mean displacements in all directions, with standard deviations ranging from 0.01 to 0.02 mm. DSC values ranged from 0.91 to 0.98, with a mean of 0.96, indicating excellent spatial agreement between planned and intrafractional tumor volumes. Residual setup errors were predominantly within ±1 mm, and the mean intrafractional CTV volume change was minimal (0.27 cm³). Conclusions: SGRT-based frameless lung cancer radiotherapy demonstrated high setup accuracy and robust intrafractional geometric stability. Although slightly greater variability was observed in the longitudinal direction, overall positional deviations and volumetric changes remained within clinically acceptable limits. These findings support the feasibility of integrating SGRT with CBCT-guided radiotherapy and suggest potential benefits for workflow efficiency and planning target volume margin optimization. Full article

Background/Objectives: Management of bipolar disorder is marked by variability in lithium response, with responders constituting a distinct clinical subgroup. Although pharmacogenetic studies implicate polymorphisms in neuroplasticity-related genes (BDNF) and hypothalamic–pituitary–adrenal (HPA) axis regulators (NR3C1), the underlying biophysical mechanisms remain poorly characterized. This study aims to bridge this structural–mechanistic gap by quantifying the atomic-level effects of key lithium-response polymorphisms on protein–protein interaction stability and conformational dynamics. Methods: Variant sequences for BDNF rs6265 and NR3C1 rs56149945 were generated and structurally modeled with SWISS-MODEL. Protein–protein interaction analyses focused on the BDNF–TrkB and NR3C1–FKBP5 systems. Structural alignment and conformational comparisons were performed with ChimeraX and US-align, while interaction energetics were evaluated with PRODIGY and HawkDock. Conformational flexibility was assessed using CABS-flex through RMSF analysis. Results: Structural validation showed acceptable model quality. Binding analyses indicated stronger interactions in the variant complexes. In the BDNF–TrkB complex, binding affinity shifted from −13.8 to −15.1 kcal/mol with an ~8.5-fold lower dissociation constant, while the NR3C1–FKBP5 variant complex shifted from −16.3 to −18.8 kcal/mol with an ~65-fold lower dissociation constant. MM/GBSA calculations supported increased stability, with binding energies changing from −61.98 to −83.91 kcal/mol (BDNF–TrkB) and from −18.88 to −31.25 kcal/mol (NR3C1–FKBP5). Structural superposition showed high conservation of global folds (pruned RMSD 0.779 Å and 0.310 Å; TM-scores 0.753 and 0.967). RMSF profiles were largely overlapping, indicating localized interface adjustments rather than global conformational changes. Conclusions: These findings suggest that lithium-response polymorphisms may modulate protein–protein interaction stability while preserving overall structure, providing a structural framework for exploring genetic influences on lithium treatment response. Full article

Shot-peening treatments improve the fatigue performance of mechanical components thanks to the surface modifications introduced and mainly due to the residual compressive stresses present in the layer of material near the shot-peened surface. There is no unanimous agreement in scientific literature regarding the kinetics of the damage process. However, it is generally accepted that, due to morphological and microstructural changes in the shot-peened layer, the material is more prone to early crack initiation, the propagation of which is then significantly slowed down or even stopped by the local stress field. This work focuses on applying the acoustic emission (AE) technique to detect fatigue crack initiation and propagation in shot-peened Al-alloy components. The analysis is conducted on Al-7075-T6 alloy, subjected to different shot-peening conditions and fatigue tested under alternating four-point bending. The results from the AE analyses are then correlated with a fractographic analysis. For all shot-peening conditions investigated, acoustic emission consistently indicated probable crack nucleation at approximately two-thirds of the total fatigue life, followed by a significant damage accumulation phase prior to dominant crack propagation. The final increase in acoustic activity coincided with the measurable loss of stiffness, confirming the onset of accelerated crack growth leading to fracture. The results demonstrate that, despite some experimental challenges, AE monitoring has the potential for the early detection of damage initiation. Full article