Water Accumulation Research Articles

SCIENTIFIC TECHNOLOGIES OF MONITORING THE STATE OF BOTTOM SEDIMENTS, AS AN INDICATOR OF THE LEVEL OF ENVIRONMENTAL DANGER TO HYDROECOSYSTEMS

The work proposes a method of monitoring the condition of surface water bodies on the territory, which was subject to the influence of enterprises of the aviation industry, by studying the contamination of bottom de-posits. Using the example of petroleum hydrocarbons - specific pollutants of aviation enterprises, it is proved that bottom sediments are an integral indicator of the level of man-made pollution, an indicator of the level of ecological safety of hydroecosystems. The calculated coefficients of bottom accumulation indicate progres-sive water pollution and accumulation of the main mass of pollutants in bottom sediments. The results of the research of the small river flowing along the airline show that the bottom sediments belong to the category of "extremely polluted" and on the one hand, they contribute to the process of self-purification of the water envi-ronment by accumulating oil products, but on the other hand, they represent a danger of secondary pollution of the water column, after which, when physical and chemical conditions change, pollutants from bottom sediments are able to move into the water phase.

Applying ensemble machine learning models to predict hydrogen production rates from conventional and novel solar PV/T water collectors

Applying ensemble machine learning models to predict hydrogen production rates from conventional and novel solar PV/T water collectors

A numerical investigation on improving the thermal efficiency of PV panels through integration with solar water collectors

A numerical investigation on improving the thermal efficiency of PV panels through integration with solar water collectors

Detecting evolutionary stages of karst depressions in Central Brazil with deep learning and Planet NICFI time series

AbstractKarst depressions represent significant geomorphological features crucial in environmental monitoring and conservation. This research aims to detect and classify karst depressions according to their evolutionary stages in the Bambuí Group, located between the Cerrado and Caatinga biomes in Central Brazil, using Planet time series provided by Norway's International Climate and Forest Initiative (NICFI) Satellite Data Program and deep learning‐based semantic segmentation models. A new deep learning training dataset was developed containing manually labelled reference data and a time series of monthly images from Planet NICFI data over a year. The research classified three evolutionary stages of karst depressions: (1) temporary lakes, (2) depressions with concentric halos and subsidence and (3) vegetated depressions. These stages represent distinct geomorphological processes, from initial water accumulation to more advanced stages involving subsidence and vegetation development in the depression areas. The study compared six state‐of‐the‐art semantic segmentation architectures (U‐Net, U‐Net++, DeepLabV3+, LinkNet, FPN and PSPNet), each combined with three backbones (EfficientNet‐B7, ResNet‐101 and ResNeXt‐101), resulting in 18 model configurations. The best performing model (U‐Net with EfficientNet‐B7) achieved a mean Intersection over Union (mIoU) of 80 and IoU scores of 97.9 for the background, 80.93 for first stage, 79.89 for second stage and 63.35 for third stage, highlighting the challenges of detecting more advanced stages due to increasing vegetation cover and geomorphological complexity. The sliding window approach was employed to classify the entire image mosaic, testing various stride values (8, 16, 32, 64, 128 and 256), with smaller strides improving segmentation accuracy at the cost of higher computational demands. The results demonstrate the importance of integrating spectro‐spatio‐temporal data to detect multiple evolutionary stages and improve the robustness of semantic segmentation. This research provides a comprehensive dataset and benchmark for future studies on karst depressions, contributing to understanding geomorphological evolution and conservation planning in Central Brazil.

Efficient and continuous water collection on a biomimetic surface with superhydrophobic/hydrophilic patterns

Efficient and continuous water collection on a biomimetic surface with superhydrophobic/hydrophilic patterns

Efficient radiative cooling based on spectral regulation and atmospheric water harvesting with sunflower design.

Inspired by the fog-collecting abilities of the Namib Desert beetle, researchers have developed wettability-engineered surfaces for fog collection. However, these approaches fall short in arid regions where fog is absent. To address these challenges, we developed a dual-sided structure based on radiative cooling. The radiation cooling material on the upper surface can achieve energy free cooling. The lower surface is a pattern with heterogeneous wettability, composed of wedge-shaped and conical structures, which can achieve rapid droplet accumulation and directional transport. The radiation cooling material adjusted by spectrum can achieve a temperature difference of up to 14.2°C, enabling the composite material to achieve a maximum water collection efficiency of 602.5 g·m-2·h-1 under RH of 80% conditions. This study provides an effective solution to alleviate water scarcity in arid regions.

Atmospheric patterns associated with fog water collection in Aparados da Serra National Park, Southern Brazil

Atmospheric patterns associated with fog water collection in Aparados da Serra National Park, Southern Brazil

Active Thermal Field Integration for Marangoni‐Driven Salt Rejection and Water Collection

AbstractUsing solar energy to drive seawater desalination via solar steam generation (SSG) is a sustainable strategy for clean water supply. The weak efficiency and poor durability due to salt deposition severely restrict practical SSG operation. Traditional solar evaporators are difficult to simultaneously guarantee efficient evaporation and long‐term salt rejection due to increased salinity. Herein, to tackle this dilemma, a thermal gradient fabric (TGF) evaporator with an auxiliary active thermal field is constructed. Different from traditional works where additional energy resources with improved evaporation rate exacerbate salt accumulation, the auxiliary active thermal field is well integrated with external solar energy to boost ion circulation through moderate Marangoni flow, leading to a continuous salt rejection and superior energy utilization under high‐salinity desalination. The accelerated evaporation rate (2.42 kg m−2 h−1) and superior salt resistance (30 days of desalination in 10 wt.% brine) are simultaneously achieved through optimized thermal field construction. An outstanding water collection rate (5.84 kg m−2) is observed during high‐salinity outdoor desalination, which proves the practical purification ability. This study provides new insight into the construction of active thermal fields for efficient and sustainable clean water production, is believed.

Unusual and persistent easterlies restrained the 2023/24 El Niño development after a triple-dip La Niña

The 2023/24 El Niño, emerging after a rare triple-dip La Niña, garnered global attention due to its potential to evolve into an extreme event, given the largest accumulation of warm water in the equatorial western Pacific since 1980. Despite initial expectations, its growth rate unexpectedly decelerated in mid-2023, preventing it from reaching the anticipated intensity. Here, we show through observational analyses that unusual easterly anomalies over the tropical western-central Pacific, persisting after the end of the preceding La Niña, significantly contributed to this slowdown. A prominent east‒west sea surface temperature gradient in the region has been identified as the crucial factor associated with these unusual and persistent easterly anomalies. This temperature gradient is directly attributed to a negative North Pacific Meridional Mode and a deepened thermocline over the Philippine Sea. These findings offer a deeper understanding of the atypical transition from a prolonged multi-year La Niña to an El Niño.

Resource redistribution mediated by hydrological connectivity modulates vegetation response to aridification in drylands

Water scarcity poses a significant life constraint in global drylands that determines species adaptations and mosaic of exposed bare areas and vegetation patches. Runoff‐water redistribution resulting from this spatial configuration has been suggested as a key process controlling water availability for vegetation and ecosystem functioning. However, the potential of this process to ameliorate the negative impacts of aridification in drylands remains unclear, and there is no empirical evidence of its relevance on natural ecosystems under different levels of aridity and disturbance regimes. To address this gap, we analysed temporal series of the normalized vegetation index (NDVI, a proxy of vegetation functioning) along a regional aridity–disturbance gradient under current and future climatic conditions. We found that mean NDVI increases in areas of runoff water accumulation (calculated using a water redistribution index) until a certain threshold, above which vegetation patches are not able to retain extra runoff water. Once thresholds were identified, we analysed the role of water redistribution on vegetation dynamics by analysing temporal series of monthly NDVI in a space–for–time substitution approach. The obtained results provided further evidence of the runoff water redistribution on vegetation, triggering a positive feedback between water accumulation and vegetation growth. Results obtained by the combination of the obtained model with climatic data from the 6th IPCC report suggest that this feedback could ameliorate the expected negative effects of aridification in drylands. However, this effect is partially counterbalanced in scenarios of high human disturbance and in areas where vegetation is not able to trap and retain the extra amount of resources given by runoff. Overall, our results provide empirical evidence of the relevance of runoff redistribution as a key process linking vegetation patterns to climate resistance in drylands that underscores its importance in the analysis and modelling of drylands' responses to aridification.

Year-round performance evaluation of a solar-powered compact HDH desalination system for remote water scarce regions

ABSTRACT Climate change is intensifying global hydrological stress, increasing evaporation, degrading water quality, raising water temperatures, and altering runoff periods. This study introduces a fully solar-powered humidification-dehumidification (HDH) desalination system designed to address water scarcity in remote and arid regions. The significance of the research lies in its potential to provide a sustainable, off-grid water supply using renewable solar energy, which is particularly relevant in areas with limited infrastructure. The aim of the study is to evaluate the year-round performance of the system by developing a comprehensive mathematical model based on mass, energy, and momentum conservation equations. The model simulates the system’s behavior under varying solar conditions, enabling the optimization of key parameters. The system combines thermal photovoltaic panels and evacuated tube solar water collectors, enhancing energy efficiency through the pre-heating of seawater. The model is implemented in MATLAB, and the performance is evaluated over a full annual cycle. Results show that the system achieves a peak efficiency of 42% during high solar months, with monthly productivities of up to 238.87 L/m2, while the lowest performance occurs in December, with 14% efficiency and 63.02 L/m2 productivity. These findings underscore the system’s capability to provide a sustainable water source year-round.

Brain tissue integrity in neuromyelitis optica spectrum disorder through T1-w/T2-w ratio, MTR and DTI.

The presence of diffuse brain damage in normal-appearing white matter (NAWM) and gray matter (NAGM) in neuromyelitis optica spectrum disorder (NMOSD) remains controversial. We aimed to address this controversy by applying a multiparametric MRI approach. Additionally, the association between MRI metrics and clinical variables was explored. In this cross-sectional study, we prospectively evaluated aquaporin-4-IgG positive NMOSD patients and healthy controls (HC) matched for age and sex. The clinical variables of interest were collected for each participant. The mean values of T1-w/T2-w ratio, magnetization transfer ratio (MTR), fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) were obtained in NAWM, NAGM, as well as in global and hypointense lesion masks. Global lesions refer to those typically associated with aquaporin-4-IgG positive NMOSD. Hypointense lesions were defined as areas of hypointense signal in both T1-w and fluid-attenuated inversion recovery (FLAIR) images. In total, we included 105 participants (59 NMOSD patients and 46 HC). T1-w/T2-w ratio was lower in NAWM of NMOSD patients versus HC (1.83 ± 0.14 vs 1.89 ± 0.14; p = 0.029), while no significant differences were found in NAWM or NAGM across the other metrics: (p range: 0.079 to 0.973). Hypointense lesions showed lower T1-w/T2-w ratio, MTR, and FA, and higher diffusivity metrics as compared to global lesion masks (p < 0.001). T1-w/T2-w ratio in NAWM was inversely correlated with time to start immunosuppressive therapy (r = - 0.278; p = 0.036) and with MD (r = - 0.325; p = 0.014). Microstructural integrity loss seems to be confined to focal tissue damage in NMOSD. Decreased T1-w/T2-w ratio in NAWM may reflect subclinical water accumulation due to astrocyte and blood-brain barrier dysfunction. Hypointense lesions have shown a severe degree of microstructural damage.

Estimating Indoor Tile Friction Coefficient Using Visual Information

Abstract Slip and fall accidents are common both indoors and outdoors, posing and risks from minor to serious injuries. An effective way to prevent these accidents is for pedestrians to know the friction properties of their path beforehand. Developing a network that can discern the frictional properties of surfaces from camera-captured images and convey this information to pedestrians could significantly reduce the incidence of slips. However, predicting the indoor friction coefficient of tiles accurately is challenging due to reflections from multiple fluorescent lights and the tiles themselves. Additionally, water accumulation on tiles due to cleaning or leakage greatly contributes to slip accidents. This paper presents an algorithm that accurately predicts floor friction coefficients in real indoor environments, accounting for image distortions caused by light reflections and water on the floor. Experimental results validate that the proposed system reliably predicts indoor floor friction coefficients despite factors such as lighting angles and water presence. Moreover, to demonstrate its practical applicability, a user-application has been developed to predict the friction coefficient for specific areas as required. This system can be integrated into various devices, including walkers, canes, and smartphones, to assist pedestrians in navigating safely.

Research on the influence of conical micro array chip parameters on fog water collection

Abstract Conducting research on water collection based on the bionic cactus conical spine structure holds significant importance for arid regions, the key parameters of conical micro array chip affecting the contact area between the micro cones and the fog determine the fog water collection. However, the influence of the conical arrays parameters including cone angle and arrangement on water collection is rarely studied. We present research on the influence of conical micro array chip parameters on fog water collection. The conical micro array chips with different parameters including the cone apex angle and arrangement pattern were designed, and the experiments of the fog water collection were conducted. The experiments explored the impact of arrangement patterns, cone apex angle, the distance and orientation of the conical micro array chip (CMAC) relative to the fog flow, and the surface properties (hydrophilic and hydrophobic) of the CMAC on fog water collection efficiency. Through these experiments, the law of influence of key parameters of the conical arrays on fog water collection efficiency was obtained. The experiments indicate the CMAC with large cone apex angle, hexagonal arrangement and hydrophilic surface has a better water collection efficiency . Further, this research can be beneficial to the advancement and application of water collection devices in arid environments.

Rose-Inspired Adhesive Surface Regulation for Enhanced Fog Water Collection Efficiency and Self-Cleaning.

Inspired by the adhesion differences on the surfaces of fresh and dried rose petals, a rose bionic self-cleaning fog collector (RBSC) was designed and prepared to realize a self-driven fog harvesting function. The droplet detachment iteration rate was revealed by the regulating mechanism of the surface adhesion force of the RBSC and the influence of bionic texture parameters, as demonstrated through the fog harvesting experiment and droplet detachment failure analysis. Through the surface adhesion force regulation, the probability of droplet dissipation with the airflow is reduced by increasing the falling droplets' mass, and the single surface fog capture efficiency is up to 740 mg cm-2 h-1. With the adhesion gradient regulation, the composite hexagonal patterned surface achieves a water collection efficiency of 960 mg cm-2 h-1, which is a 243% improvement compared with that of a slippery surface and is superior to the efficiencies of both circular and 90° square patterns. This is due to the fact that the composite hexagonal patterned surface ensures that the water droplets converge at the center while increasing the distance between the droplets, improving the stability of droplet detachment. Compared to the stainless steel surface, the RBSC exhibits excellent self-cleaning performance, with the impurity deposition rate reduced by 91.2%. The multi-inspired strategy optimizes the entire harvesting process, offering a promising solution to the water crisis in arid regions.

Bioinspired 1D Anisotropic Double-Spiral Metal Wires for Efficient Fog Harvesting.

Innovative design strategies of fog harvesting devices (FHDs) demonstrate promising remedy for water crisis in arid areas. 1D FHDs ensure unimpeded wind circulation and can be manufactured more cost-effectively for extensive regions. Inspired by cactus thorns, desert beetles, and spider silk, two metal organic frameworks (MOFs) functionalized Cu wires with opposite wettability are double-twisted by a mechanical twisting machine, forming 1D double-spiral Cu wires with alternating superhydrophobic/superhydrophilic dual-MOF patterns. The biomimic integration design, namely conical microneedle, stripe-patterned contrasting wettability, and double-spiral geometry, allows for efficient fog water collection due to a collaborative process. Based on such multi-cooperation theory, the optimal fog collection efficiency of dual-MOF functionalized double-spiral Cu wires can reach 0.293 ± 0.013 g cm-2 min-1 by investigating the effect of the composition, the diameter ratio and twisting wavelength λ of the two constituent wires. The double-spiral metal wires with discrepant wettability not only propose a facile and cost-effective method for fog harvesting, but also share new physical insight to inspire novel design concepts for efficient fog collection devices, benefitting the fight against the global water crisis.

Health Inspections of Restaurant Establishments in the Attica Region, Greece. Non-compliance Data Within the Food Hygiene Sector.

Ensuring food safety is a fundamental priority for public health. The catering sector has become prominent as a convenient and cost-effective method of food supply worldwide. Adherence to proper food hygiene practices is crucial for preventing foodborne diseases. The inspection of food items is a key component of internal controls that enables the identification of non-compliance with food hygiene standards. The present study aims to assess Attica restaurant businesses' compliance with international food hygiene standards (FAO/WHO Codex Alimentarius) and European legislation on unsafe food. From January to July 2023, 74 randomly selected restaurants of small, medium, and large capacity in Attica were examined through inspections in terms of compliance for food hygiene standards. The inspections were based on (a) the completion of forms and (b) the collection of water and food samples for laboratory microbiological analysis. Data were collected using a predefined form, referencing the manual of Codex Alimentarius regarding food hygiene standards (CAC/RCP 1-1969/CAC/RCP 39-1993). Additionally, the assessment included the identification of unsafe food placement in accordance with Regulation EC/178/2002 on food safety, as well as Greek national legislation (European Commission, 2002; Hellenic Republic, 2006, 2014). The highest non-compliance rates are in "adequacy of facilities" (14.12%), "equipment maintenance and sanitization" (12.30%), "pest control" (12.45%), "personal hygiene" (7.58%), and "efficient separation of raw materials" (9.76%). Non-compliance rates for other food hygiene parameters (cooking practices, meal apportionment, storage, transport, reheating, etc.) were considerably lower. The inspection results showed that medium-sized restaurant businesses present the highest rate (56.41%) of total non-compliance compared to large-sized businesses (29.68%) and small-sized businesses (13.91%). This study demonstrates that restaurant businesses generally adhere to food hygiene and safety standards at a satisfactory level. There is a need for restaurant operators to prioritize enhancing compliance, particularly in addressing critical issues that could potentially result in outbreaks of foodborne diseases.

Highly Selective Construction of Unique Cyclic [4]Catenanes Induced by Multiple Noncovalent Interactions

AbstractThe synthesis of high‐ordered mechanically interlocked supramolecular structures is an extremely challenging topic. Only two linear [4]catenanes have been reported so far and there is no defined strategy to obtain cyclic [4]catenane. Herein, two unprecedented cyclic [4]catenanes, 1 and 2, were prepared in high yields. The syntheses rely on the strategic selection of naphthalenediimide (NDI) based Cp*Rh/Ir building blocks E1/E2 (Cp*=pentamethyl‐cyclopentadienyl) and nonlinear diimidazole ligand precursor L1, exhibiting large conjugate plane, appropriate coordination angles, and freely rotating imidazole units, thereby enabling multiple π⋅⋅⋅π stacking interactions to maintain the supramolecular structures. The use of other Cp*Rh building blocks E3, E4 or E5 featuring slightly shorter metal‐to‐metal distances than E1/E2 and different chemical properties led to the formation of a complex 3 and two metallamacrocycles 4 or 5, respectively. The structures of these assemblies were confirmed by X‐ray crystallographic analysis, ESI‐TOF‐MS and NMR spectroscopy. Complex 1, exhibiting a broad‐band absorption in the UV/Vis to NIR regions and a remarkable photothermal conversion was thereafter used to build the new 1 membrane. The solar power‐induced water steam generation performance of 1 membrane was investigated, reaching a value of 2.37 kg ⋅ m−2 ⋅ h−1, making it suitable for collection of fresh water via desalination and wastewater.

Burden of leptospirosis in Brazil in the last decade.

OBJECTIVES: To correlate the incidence of leptospirosis with sociodemographic data in the Brazilian Unified Health System from 2011 to 2022.METHODS: This ecological study used national health and economic secondary data sources. Secondary analyses summarized the scenario of disease-related hospitalizations among federative units. In total, two analyses were conducted: variable description for relationship analysis and a secondary analysis with population health and sanitation indicators and economic indicators from the Instituto Brasileiro de Geografia e Estatística (IBGE - Brazilian Institute of Geography and Statistics). The statistical analysis following this framework summarized raw data by year-monthfederative unit. A time series regression was conducted, comparing the time variable with other national-level variables. Then, several simple linear regressions were performed.RESULTS: Linear regressions show the relationship between the reduction in cases and improved access to treated water and sewage collection, whereas an increase in per capita income seems to be inversely related to leptospirosis incidence. Geospatial distribution shows higher incidence in the Brazilian South and Southeast. Disease lethality varied over time but without significant change during the period. The average treatment cost remained constant over the years, despite its complexity. CONCLUSION: Leptospirosis incidence in Brazil from 2011 to 2021 decreased and wasassociated with improvements in socioeconomic conditions despite no changes in lethality.

A dual-biomimetic surface with leaf-skeleton-based hierarchical structures for efficient atmospheric water harvesting

Atmospheric water harvesting (AWH) has been extensively researched as a sustainable solution to current freshwater scarcity. Various bioinspired AWH surfaces have been developed to enhance water-harvesting performance, yet challenges remain in optimizing their structures. In this work, we report a dual-biomimetic AWH surface that combines beetle-inspired heterogeneous wettability with leaf-skeleton-based hierarchical microstructures on a rigid substrate. An authentic leaf skeleton innovatively serves as the mask during photolithography complemented by O2-plasma treatment, enabling precise design of superhydrophilic SiO2 structures with a hierarchy of vein orders forming reticulate meshes on a hydrophobic Si substrate. This design facilitates enhanced water collection through intricate reticulate meshes and directional droplet transport along the abundant multi-order veins. Such AWH surface shows a water-harvesting efficiency of 172 mg cm−2 h−1, increasing up to 62% and 58% over the pristine SiO2/Si wafer and Si wafer, respectively. Additionally, the role of structure orientation in the open-surface droplet transport is explored while the AWH surface is vertically placed during the water-harvesting process. This work highlights the potential of using meticulous natural designs, like leaf skeletons, to improve AWH surfaces, with broad applications in compact devices, such as on-chip evaporative cooling and planar microfluidics manipulation.