Search Results (682)

The issue of formulating scientifically sound standards for mercury (Hg) content in Arctic soils is becoming increasingly pertinent in view of the rising human impact and climate change, which serve to augment the mobility of Hg compounds and their involvement in biogeochemical processes. In the absence of uniform criteria for regulating Hg concentrations, it is particularly important to determine its geochemical baseline values and the factors that determine the spatial and vertical distribution of the element in the soil profile. The study conducted a comprehensive investigation of Hg content and patterns of its distribution in various types of tundra soils in the European North-East of Russia. The mass fraction of total Hg was determined by atomic absorption spectrometry, and the spatial features of accumulation were analysed using geoinformation technologies. The distribution of Hg in the soils of the tundra zone was found to be distinctly mosaic in nature, determined by the combined influence of organic matter, granulometric composition, and hydrothermal conditions. It has been established that the complex influence of the physicochemical properties of soils determines the spatial heterogeneity of Hg distribution in the soils of the tundra zone. The most effective Hg accumulators are peat and gley horizons enriched with organic matter and physical clay fraction, while in Podzols, vertical migration of Hg is observed in the presence of a leaching water regime. In order to standardise geochemical baseline Hg values, a 95% upper confidence limit (UCL_95%) is proposed. This approach enables the consideration of natural background fluctuations and the exclusion of extreme values. The results obtained provide a scientific basis for the establishment of standards for Hg content in background soils of the Arctic. Full article

Rubber particles have been proven to have the advantages of improving the energy absorption effect and enhancing the friction between soil particles when used to modify the soil. The rubber-modified soil technology also provides a new solution for the pollution-free disposal of waste rubber. However, when rubber particles are used to modify collapsible loess, they cannot significantly enhance its strength. Previous studies have not systematically clarified whether combining rubber particles with different cementation mechanisms can overcome this limitation, nor compared their shear mechanical effectiveness under identical conditions. In view of this, a dual synergistic strategy is implemented by combining rubber with lime and rubber with enzyme-induced calcium carbonate precipitation (EICP). Direct shear tests and scanning electron microscopy are used to evaluate four modification approaches: rubber alone, lime alone, rubber with EICP, and rubber with lime. Accordingly, shear strength, cohesion, and internal friction angle are quantified. At a vertical normal stress of 100 kPa and above, samples modified with rubber and lime (7–9% lime and 6–8% rubber) achieve peak shear strength values of 200–203 kPa, representing an 86.4% increase compared to rubber alone. Microscopic analysis reveals that calcium silicate hydrate gel effectively anchored rubber particles, forming a composite structure with a rigid skeleton and elastic buffer. In comparison, the rubber and EICP group (10% rubber) shows a substantial increase in internal friction angle (24.25°) but only a modest improvement in cohesion (16.5%), which is due to limited continuity in the calcium carbonate bonding network. It should be noted that the performance of EICP-based modification is constrained by curing efficiency and reaction continuity, which may affect its scalability in conventional engineering applications. Overall, the combination of rubber and lime provided an optimal balance of strength, ductility, and construction efficiency. Meanwhile, the rubber and EICP method demonstrates notable advantages in environmental compatibility and long-term durability, making it suitable for ecologically sensitive applications. The results offer a framework for loess stabilization based on performance adaptation and resource recycling, supporting sustainable use of waste rubber in geotechnical engineering. Full article

This study presents an integrated, low-cost system for measuring extremely small displacements in Ionic Polymer–Metal Composite (IPMC) actuators operating in aqueous environments. A custom optical setup was developed, combining a glass tank, a tubular microscope with a 10× achromatic objective, a digital USB camera and uniform LED backlighting, enabling side-view imaging of the actuator with high contrast. The microscopy system achieves a spatial sampling of 0.536 μm/pixel on the horizontal axis and 0.518 μm/pixel on the vertical axis, while lens distortion is limited to a maximum edge deviation of +0.015 μm/pixel (≈+2.8%), ensuring consistent geometric magnification across the field of view. On the image-processing side, a predictive grid-based tracking algorithm is introduced to localize the free tip of the IPMC. The method combines edge detection, Harris corners and a constant-length geometric constraint with an adaptive search over selected grid cells. On 1920 × 1080-pixel frames, the proposed algorithm achieves a mean processing time of about 10 ms per frame and a frame-level detection accuracy of approximately 99% (98.3–99.4% depending on the allowed search radius) for actuation frequencies below 2 Hz, enabling real-time monitoring at 30 fps. In parallel, dedicated electronic circuitry for supply and load monitoring provides overvoltage, undervoltage, open-circuit and short-circuit detection in 100 injected fault events, all faults were detected and no spurious triggers over 3 h of nominal operation. The proposed microscopy and tracking framework offer a compact, reproducible and high-resolution alternative to laser-based or Digital Image Correlation techniques for IPMC displacement characterization and can be extended to other micro-displacement sensing applications in submerged or challenging environments. Full article

Introduction: Motorized components on power wheelchairs (PWC) enable repositioning to pre-programmed positions (e.g., tilt, leg support, verticalization) to prevent prolonged static positions. Smart technologies can track positioning information and give feedback according to clinical recommendations and personal goals. This study aimed to explore users’ and clinicians’ perceptions of an intelligent dynamic seating (IDS) system prototype comprising a PWC with motorized multi-components connected to a web interface. Methods: A purposive sample of six PWC users and eight clinicians were recruited in this exploratory descriptive qualitative study. Semi-structured interviews included viewing a video of the IDS and images of the web interface. Interviews were transcribed, deductively coded, and thematically analyzed using a conceptual model for evaluating eHealth interventions. Results: Clinicians found the IDS system intuitive to use, customizable, relevant in terms of positioning and clinical recommendations, and timesaving. Powered wheelchair users perceived benefits that could motivate behavioural change, autonomy, health, and inclusion. Concerns related to familiarity with complex technology, funding, cognitive requirements, and technical and health risks were raised. Conclusion: The results inform improvements for the integration of the IDS in clinical practice to respond to the positioning needs of PWC users. Full article

This research focusses on three satellite-derived bathymetry methods and optical satellite instruments: (1) a stereo photogrammetry bathymetry module (SaTSeaD) developed for the NASA Ames stereo pipeline open-source software (version 3.6.0) using stereo WorldView data; (2) physics-based radiative transfer equations (PBSDB) using Landsat data; and (3) a modified composite band-ratio method for Sentinel-2 (SatBathy) with an initial simplified calibration, followed by a more rigorous linear regression against in situ bathymetry data. All methods were tested in three different areas with different geological and environmental conditions, Cabo Rojo, Puerto Rico; Key West, Florida; and Cocos Lagoon and Achang Flat Reef Preserve, Guam. It is demonstrated that all satellite derived bathymetry (SDB) methods have increased accuracy when the results are aligned with higher-accuracy ICESat-2 ATL24 track bathymetry data using the iterative closest point (ICP). SDB vertical accuracy depends more on location characteristics than the method or optical satellite instrument used. All error metrics considered (mean absolute error, median absolute deviation, and root mean square error) can be less than 5% of the maximum bathymetry depth penetration for at least one method, although not necessarily for the same method for all sites. The SDB error distribution tends to be bimodal irrespective of method, satellite instrument, alignment, site, or maximum bathymetry depth, leading to the potential ineffectiveness of traditional error metrics, such as the root mean square error. However, our analysis demonstrates that performing detrending where possible can achieve an error distribution as close to normality as possible for which error metrics are more diagnostic. Full article

The Daylight Glare Probability (DGP) includes the luminance of a glare source quadratically, but the solid angle only linearly. While this is in line with formulae of other glare metrics, it must be questioned for small glare sources, if the glare stimulus can no longer be distinguished from larger stimuli causing equal vertical illuminance at the eye, especially in the peripheral visual field. To account for this, the modified version Daylight Glare Metric (DGM) was previously developed. We conducted two studies to evaluate the effect of the modified DGM. First, in a laboratory study under an artificial sky with an LED sun, 35 test subjects evaluated different glare situations. Second, we performed a comprehensive simulation study for an office space, including three locations, three view directions, and 17 window systems (electrochromic glazing, fabric shades). The results from the perception study under the artificial sky provide evidence that the adapted DGM is better suited to predict glare from small, bright sources. The results from the simulation study for a realistic office setting show that, compared to the DGP, the DGM reduces glare ratings for many hours of the year, thus underscoring the practical relevance of improving the DGP formula. Full article

Against the backdrop of urban renewal and population ageing in China, elevator retrofitting in older residential compounds has emerged as a critical yet contentious issue, primarily due to uneven cost-sharing and perceived inequities in the distribution of benefits. This study employs a combined empirical framework integrating Difference-in-Differences (DID) and cost–benefit analysis to systematically evaluate the economic impacts of elevator installation in older neighbourhoods of Hangzhou. Using transaction data from 879 housing units across 18 residential compounds between 2018 and 2020, along with actual project cost records, we quantify the premium effects and assess economic feasibility. The results show that elevator retrofitting leads to an overall 5.53% increase in housing prices, with significant vertical differentiation: upper-floor units appreciate by 8.10%, middle-floor units by 4.58%, and lower-floor units by 1.59%. Further analysis confirms that the aggregate increase in property value fully covers installation costs, long-term maintenance, and reasonable compensation for lower-floor residents, thereby achieving a Pareto improvement. The study establishes a floor-gradient linkage mechanism between value uplift and cost-sharing, providing a quantifiable basis for policy design and community negotiation. These findings challenge the prevailing zero-sum view of elevator retrofitting while offering a replicable model for urban renewal that equitably balances stakeholder benefits. Full article

This study investigates why Generation Z in Surabaya remains reluctant to live in vertical housing despite strong urbanization pressures and policy promotion. Using an explanatory sequential mixed-methods approach with 340 respondents aged 18–27, the research identifies five key factors influencing preferences: physical environment, psychological-social concerns, social status and stress, economic considerations, and cultural accommodation. Factor analysis explains 45.1% of total variance, while structural equation modeling reveals that physical environment preferences play a central mediating role. Economic factors affect psychological-social concerns both directly and indirectly, and cultural accommodation strongly shapes social status perceptions but does not directly influence physical preferences. Qualitative analysis of 411 statements shows consistently negative psychological themes, predominantly negative economic sentiments, and more balanced views of physical attributes. Subgroup analysis reveals stronger economic effects among early-career professionals than students. The findings challenge purely rational housing choice models, demonstrating that cultural and economic factors shape psychological acceptance through indirect pathways. Recommendations include culturally sensitive designs (flexible guest rooms, communal gathering spaces), innovative ownership schemes (rent-to-own, cooperative models), and reframed marketing emphasizing lifestyle enablement rather than amenity features. Full article

FY-4B/GIIRS (Geostationary Interferometric Infrared Sounder) is a new-generation infrared hyperspectral atmospheric vertical sounder onboard a Chinese geostationary meteorological satellite. Its observations with high spatial and temporal resolution play an important role in high-impact weather forecasts. The GIIRS data assimilation module is developed in the GSI (Gridpoint Statistical Interpolation) assimilation system. Super Typhoon Doksuri in 2023 (No. 5) is taken as an example based on this module in this paper. Firstly, the sensitivity of analysis fields to five data thinning schemes at four daily assimilation times from 22 to 28 July 2023 is analyzed: the wavelet transform modulus maxima (WTMM) scheme, the grid-distance schemes of 30 km, 60 km, and 120 km in the GSI assimilation system, and a center field of view (FOV) scheme. Taking the ERA5 reanalysis fields as true, it is found that the mean error of temperature and humidity analysis for the WTMM scheme is the smallest, followed by the 120 km thinning scheme. Subsequently, a 72 h cycling assimilation and forecast experiments are conducted for the WTMM and 120 km thinning schemes. It is found that the root mean square error (RMSE) profiles of temperature and humidity forecast fields with no thinning scheme are the largest at all pressure levels and forecast times. The temperature forecast error decreases after data thinning at altitudes below 300 hPa. Since the WTMM scheme has assimilated more observations than the 120 km scheme, the accuracy of its temperature and humidity forecast fields gradually increases with the forecast time. In terms of typhoon track and intensity forecast, the typhoon intensities are underestimated before landfall and overestimated after landfall for all thinning schemes. As the forecast time increases, the advantage of the WTMM is increasingly evident, with both the forecast intensity and track being closest to the actual observations. Similarly, the forecasted 24 h accumulated precipitation over land is overestimated after typhoon landfall compared with the IMERG Final precipitation products. The location of precipitation simulated by no thinning scheme is more westward overall. The forecast accuracy of the locations and intensities of severe precipitation cores and the typhoon’s outer spiral rain bands over the South China Sea has been improved after thinning. The Equitable Threat Scores (ETSs) of the WTMM thinning scheme are the highest for most precipitation intensity thresholds. Full article

The external spatial form and skyline of high-density waterfront iconic building clusters in super-large cities are the most distinctive features of urban image. However, traditional static research methods (such as fixed-point photography) cannot capture the continuous visual experience of people in motion, thereby imposing obvious limitations. This study proposes a dynamic visual quantification method that constructs a linear observation path using the parametric platform Grasshopper. The method calculates two core parameters in real-time: the vertical perspective angle (θ, reflecting the building’s “sense of height”) and the horizontal perspective angle (β, reflecting the “sense of density” of the building cluster), so as to realize the dynamic and continuous quantification of the building cluster’s form. Using Shanghai Lujiazui as a case study, this paper validates the method’s effectiveness. The results show that the visual perception of buildings is not only determined by their absolute height but also influenced by the distance from the observation point and spatial relationships. Furthermore, through variance analysis and an annealing algorithm, this study can identify “visually stable points” (suitable for arranging core landmarks) and “optimal viewing points” (suitable for setting up urban viewing platforms). This method provides a reproducible quantitative tool and specific guidance for the optimization of waterfront building layouts and the planning of urban viewing platforms. Full article

Introduction: Malocclusion and dysfunctional or atypical swallowing are two conditions that significantly affect the health and well-being of the stomatognathic system, so much so that they often interact, influencing each other, and the presence of one can cause the onset or aggravation of the other. In this regard, over the years studies have been carried out that tried to discover the correlation between atypical swallowing and malocclusion. The aim is to evaluate the prevalence of dysfunctional swallowing in patients with malocclusion, to examine the pathophysiological mechanisms linking malocclusion and dysfunctional swallowing, and above all to investigate what potential risk factors may be. Materials and Methods: A sample of 60 patients aged between 6 and 16 years was analyzed at the Department of Dentistry of the University of L’Aquila. Some characteristics of the subjects’ face and posture were analyzed both from a frontal and lateral point of view. An orthodontic, temporomandibular joint, and masticatory muscle diagnosis was made. In addition, an examination of oral structures and functions was performed that allowed breathing, swallowing, chewing, and phono-articulation to be assessed. Results: It was observed that all the children had atypical swallowing, with significant postural abnormalities of the tongue; in fact, only 5% had a correct posture of the tongue at rest. In the analysis of occlusal characteristics, it emerged that with regard to the transverse plane, 21.67% of subjects have a condition of No Cross, while 10% show a Unilateral Cross. Finally, 68.33% show a Bilateral Cross. As far as the anterior–posterior plane is concerned, most of the subjects, equal to 76.67%, are placed in Class I, while 23.33% are in Class II. Finally, in relation to the vertical plane, 63.33% of subjects have normal occlusion, while 25% suffer from deep bite and 11.67% from open bite. The sample, stratified by presence or absence of alerts, shows significant differences for atypical swallowing (p = 0.031), for the presence of Class II malocclusion (p = 0.002), for low lingual posture, (p < 0.001), and for labial incompetence (p = 0.001). The multivariate logistic regression model showed that the presence of atypical swallowing (OR 1.04, 95% CI 1.04–1.07, p = 0.029), open bite malocclusion (OR 1.09, 95% CI 1.01–1.18, p = 0.013), low lingual posture (OR 1.11, 95% CI 1.04–1.18, p = 0.002), and the presence of labial incompetence (OR 1.06, 95% CI 1.02–1.10, p = 0.029) were significant clinical risk factors independently associated with the presence of alerts. Conclusions: The data collected confirm that atypical swallowing is a key element in the development of malocclusions, with a strong impact on posterior crossbite, anterior overjet, and other occlusal discrepancies. Among the data collected in the diagnostic phase, patients who presented at least one significant alert were also considered and atypical swallowing, low lingual posture, open bite malocclusion, and the presence of labial incompetence were statistically significant. Full article

For the purpose of Fitness-For-Service analysis, the effect of a semi-elliptical surface crack on a parallel quarter-circle corner crack in a semi-infinite solid subjected to pure bending is studied using 3D finite element analyses. While keeping the geometry of the quarter-circle corner crack constant, the SIF distributions along its front are studied for various geometrical configurations of the semi-elliptical surface crack and several crack layouts. The problem is solved for a wide range of parameters, e.g., the ellipticity of the semi-elliptical b₁/a₁ = 0.1~1; the relative crack size of the two parallel cracks a₁/a₂ = 1/3~2; the normalized vertical and horizontal gaps between the two cracks, H/a₂ = 0.4 and 1.2, and S/a₂ = −0.5 and 1, respectively. The results indicate that the semi-elliptical surface crack might have a considerable effect on the SIF distribution along the quarter-circle corner crack both in amplifying and reducing the SIF. These effects are highly dependent on the semi-elliptical surface crack geometry and the cracks’ configuration. It is further concluded that it is necessary to perform a full 3D analysis, similar to the present one, in order to quantify the “real” effect of neighbouring cracks, in view of the existing inadequate fitness for service criteria. Full article

As direct geomorphic evidence and records of earthquakes on the surface, coseismic surface ruptures have long been a key focus in earthquake research. However, compared with strike-slip and normal faults, studies on reverse-fault surface ruptures remain relatively scarce. In this study, surface rupture characteristics of the most recent earthquake on the Kumysh thrust fault in eastern Tianshan were investigated using high-resolution topographic data, including 0.5 m- and 5 cm-resolution Digital Elevation Models (DEMs) generated from the WorldView-2 satellite stereo image pairs and Unmanned Aerial Vehicle (UAV) images, respectively. We carefully mapped the spatial geometry of the surface rupture and measured 120 vertical displacements along the rupture strike. Using the moving-window method and statistical analysis, both moving-mean and moving-maximum coseismic displacement curves were obtained for the entire rupture zone. Results show that the most recent rupture on the Kumysh Fault extends ~25 km with an overall NWW strike, exhibits complex spatial geometry, and can be subdivided into five secondary segments, which are discontinuously distributed in arcuate shapes across both piedmont alluvial fans and mountain fronts. Reverse fault scarps dominate the rupture pattern. The along-strike coseismic displacements generally form three asymmetric triangles, with an average displacement of 0.9–1.1 m and a maximum displacement of 2.8–3.2 m, yielding an estimated earthquake magnitude of M_w 6.6–6.7. This study not only highlights the strong potential of high-resolution remote sensing data for investigating surface earthquake ruptures, but also provides an additional example to the relatively underexplored reverse-fault surface ruptures. Full article

Multiple ocular diseases frequently coexist in fundus images, while image quality is highly susceptible to imaging conditions and patient cooperation, often manifesting as blurring, underexposure, and indistinct lesion regions. These challenges significantly hinder robust multi-disease joint classification. To address this, we propose a novel framework, BiNeXt-SMSMVL (Bilateral ConvNeXt-based Structure-aware Multi-scale Multi-view Learning Network), that integrates structural medical biomarkers with deep semantic image features for robust multi-class fundus disease recognition. Specifically, we first employ automatic segmentation to extract the optic disc/cup and vascular structures, calculating medical biomarkers such as vertical/horizontal cup-to-disc ratio (CDR), vessel density, and fractal dimension as structural priors for classification. Simultaneously, a ConvNeXt-Tiny backbone extracts multi-scale visual features from raw fundus images, enhanced by SENet channel attention mechanisms to improve feature representation. Architecturally, the model performs independent predictions on left-eye, right-eye, and fused binocular images, leveraging multi-view ensembling to enhance decision stability. Structural priors and image features are then fused for joint classification modeling. Experiments on public datasets demonstrate that our model maintains stable performance under variable image quality and significant lesion heterogeneity, outperforming existing multi-label classification methods in key metrics including F1-score and AUC. Also, our approach exhibits strong robustness, interpretability, and clinical applicability. Full article

Precision spraying is a crucial goal for modern agriculture to achieve water and fertilizer conservation, reduced pesticide use, high yield, and green and sustainable development. This relies on the accurate identification of crop positions, high-precision path planning, and the positioning and control of intelligent agricultural machinery. For the precision production of corn, this paper proposes a new row detection method based on histogram peak detection and sliding window search, avoiding the issues of deep learning methods that are not conducive to lightweight deployment and large-scale promotion. Firstly, green channel segmentation and morphological operations are performed on high-resolution drone images to extract regions of interest (ROIs). Then, the ROIs are converted to a top-view image using perspective transformation, and a histogram analysis is performed using the find_peaks function to detect multiple peaks corresponding to row positions. Furthermore, a sliding window centered around the peak is constructed to search for complete single-row crop pixels in the vertical direction. Finally, the least squares method is used to fit the row curve, estimating the average row spacing (RowGap) and plant spacing (PlantGap) separately. The experimental results show that the accuracy of row detection reaches 93.8% ± 2.1% (n = 60), with a recall rate of 91.5% ± 1.8% and an F1 score of 0.925 ± 0.018. Under different growth stages, row numbers (6–8 rows), and weed interference conditions, the average row spacing measurement error is better than ±2.5 cm, and the plant spacing error is less than ±3.0 cm. Through field verification, this method reduces pesticide use by 23.6% and water consumption by 21.4% compared to traditional uniform spraying, providing important parameter support for field precision planting quality assessment and the dynamic monitoring of planting density, achieving variable irrigation and fertilization and water resource conservation. Full article