Integrated modeling to quantify transport and fate of nano-plastics in the hyporheic zone under the influence of hyporheic exchange.

Dynamic interplay between preferential and matrix flows enhances water circulation in rubber agroforestry soil profiles

Optimizing energy efficiency and legionella control in hot water circulation systems: laboratory validation and field assessment in Swedish multifamily buildings

With the rapid development of transportation and aerospace industries, the increasing emphasis on lightweighting has created a demand for advanced metal/polymer joining technologies. Underwater welding is an optimization way to reduce excessive heat effects of joints and improve welding efficiency. To mitigate the overflow of molten polymer matrix during the welding process of carbon fiber reinforced thermoplastic (CFRP) and aluminum alloy, process optimization experiments of water medium-assisted CFRP/aluminum alloy friction stir lap welding (FSLW) are carried out. For this purpose, a welding tool with water circulation function is designed and developed. The influences of water medium on material interface behavior, flow characteristics, and defect control are analyzed. By observing the joint boundary thickness and the interweaving combination of dissimilar materials under different water temperatures, the regulatory effects of water temperature on the microstructure and mechanical properties of the joint are studied. As the water temperature increases, the aluminum alloy is embedded into the CFRP in a plastically deformed state, and the thickness of the aluminum alloy at the joint bottom gradually increases, which enhances the load-bearing capacity of the dissimilar joint. The lap shear strength of the joint reaches 43.3 MPa at the 80°C water temperature.

The Arctic Ocean has been changing rapidly in a warming climate. To monitor these changes, it is useful to classify the Arctic Ocean into water masses-bodies of water with similar origin and physical and biogeochemical properties. However, there are significant barriers to Arctic water mass classification: observations of seawater properties are sparse, and traditional classification relies on extensive knowledge of water mass characteristics and circulation. To address these challenges, we compile existing hydrographic observations of the upper 1000 m of the Arctic Ocean and classify these observations into water masses. We present the classification tool and accompanying dataset, Water Masses of the Arctic (WMA), to support basin-wide investigations of Arctic Ocean circulation, its variability, drivers and impacts on wider Arctic climate. Our dataset reproduces key spatial and temporal features of Arctic water masses, including Atlantic and Pacific Water pathways. The WMA dataset will improve understanding of Arctic Ocean dynamics and provide an accessible framework for assessing the accuracy of the representation of the Arctic Ocean in Earth System Models.

With increasing the circulation time of cooling water, the concentrations of ions (such as Cl − , Ca 2+ , Mg 2+ , SO 4 2 - ) gradually rise, causing the formation of scales and the corrosion of pipelines. They seriously affect the safety and treatment quality of industrial water circulation systems. Therefore, developing protective measures for carbon steel corrosion and scaling in circulating cooling water systems is of great practical significance. In this paper, a high-efficiency corrosion and scale inhibitor composed of zinc gluconate (ZG) and nitrilotri(methylphosphonic acid) (ATMP) was developed in simulated circulating cooling water. Eight groups of experiments were designed through orthogonal array design to screen the optimal compound ratio. The corrosion inhibition mechanism was studied using electrochemical methods and surface characterizations, and the scale inhibition performance was evaluated by static methods, surface analysis and molecular dynamics simulations. The results indicated that ZG200-ATMP10 exhibited the optimal corrosion inhibition efficiency (98.92%), and ZG200-ATMP8 exhibited the best scale inhibition efficiency (97.62%). ZG-ATMP primarily prevented metal corrosion by forming a Zn-ATMP chelate, which co-deposited with Zn(OH) 2 on the metal surface to create a protective film, achieving the corrosion inhibition effect, and mainly inhibited the formation of calcite (110) surface by chelating Ca 2+ , achieving the scale inhibition effect.

ABSTRACT Water resources development and the intensification of water uses have profoundly altered water circulation in the arid river basins of southeast Morocco, leading to water reallocation and scarcity. Four case studies show how the State and farmers are adapting, often unsustainably, to the created water scarcity, including by promoting local water circularity. This paper argues that incorporating the principles of the circular economy ‘Reduce’ and ‘Replenish’ might be helpful to reconnect surface and groundwater at the explicit condition to reduce anthropogenic pressure on water resources and consider water circulation at the basin level.

ABSTRACT As one of the most important river basins in China, the Haihe River is confronted with significant water quality challenges, which indicates the need for effective methods to assess the water quality. This study evaluates the water quality of the southern Haihe River network in 2020 using data from 18 monitoring sites across 9 rivers. Water Quality Index (WQI), cluster analysis, and principal component analysis (PCA) were employed to assess spatial and temporal pollution patterns. WQI values ranged from 60 to 90, indicating moderate to good water quality. Organic matter, nitrogen, and phosphorus were identified as key pollutants, with seasonal fluctuations influenced by water supplement. Spatial clustering highlighted areas with poor water circulation and high non-point source pollution. PCA supported these findings, revealing consistent pollutant profiles across time and space. The results underscore the spatiotemporal variability of water quality and provide valuable guidance for water management in urban river ecosystems.

Experimental investigation on hydrate dissociation enhanced by deep gas geothermal energy transport via water circulation: Effects of depressurization strategies on thermal transport characteristics

Water circulation, redox, and productivity dynamics shaped late Ediacaran ecosystems: Insights from trace elements and combined Sr–Cr–Cd isotopes in the Corumbá Group, Brazil

Seasonal, spatial, and high-frequency monitoring of dissolved oxygen and net ecosystem metabolism in a shallow coastal lagoon, Ria Formosa - Portugal.

Multi-channel flow phantom for MRI-guided focused ultrasound.

Occurrence, spatial distribution, and risk assessment of mercury in bivalves from a human-impacted Tropical Atlantic Bay.

Abstract. This work addresses the limitations of traditional air conditioners (AC) by incorporating an innovative design for DC air conditioners, optimizing energy resources, developing an adaptive feedforward incremental conductance (FFINC) algorithm, and validating the approach through experiments and a cost-benefit analysis. The proposed AC is designed to effectively regulate moisture levels within a room, utilizing an innovative structure that circulates comfortable air throughout the room. This design serves as a promising alternative to traditional air conditioning systems. The authors have developed a solar air cooler suitable for the modern era that can either replace AC units under specific conditions or reduce their number when operating in hybrid mode. Proposed design maintains a distance of 3 cm between the water circulation area and the DC fan to optimize air cooling efficiency. The system includes a 60 W DC fan that draws cool air containing water, which passes through a water absorber filter. Moreover, a 50 W dehumidifier inside the air cooler effectively controls room humidity, ensuring that the air remains dry and comfortable. By absorbing excess moisture, the dehumidifier enhances the overall cooling performance of the system, contributing to improved air quality and comfort for occupants. A 20 W DC water pump and the DC fan use energy from various electrical sources. Under sunny conditions, a solar panel, connected via a DC to DC zeta converter, provides power to the DC air cooler. During cloudy weather or nighttime, an AC to DC converter is used to optimize operation in emergency situations; a battery is available to ensure uninterrupted operation.

Microplastics (MPs) have emerged as contaminants of growing concern due to their widespread distribution, high mobility, and ability to act as vectors for pollutants in marine ecosystems. This review examines MP contamination in the Arabian Gulf, one of the world’s most environmentally vulnerable semi-enclosed seas. The Gulf’s extreme conditions, including high salinity, elevated temperatures, restricted water circulation, and intensive coastal development, promote MP accumulation and biological exposure, increasing potential risks to marine organisms, aquaculture, and human health. Conventional detection and quantification techniques, including Fourier-transform infrared (FTIR) and Raman spectroscopy, as well as pyrolysis–gas chromatography/mass spectrometry, are critically assessed with emphasis on limitations related to size detection thresholds, analytical throughput, and processing efficiency. The review highlights artificial intelligence (AI) as a transformative approach for MP analysis. Machine-learning algorithms applied to FTIR and Raman spectral data improve polymer classification accuracy, whereas computer-vision models such as U-Net and Mask R-convolutional neural network enable automated particle segmentation and sizing. These tools reduce manual bias, enhance reproducibility, and facilitate high-throughput analysis across laboratories. Meanwhile, eco-friendly bioremediation strategies are reviewed. Microorganisms, algae, and aquatic plants have demonstrated the ability to adsorb, colonize, or partially degrade MPs, offering sustainable alternatives to conventional remediation methods. However, the effectiveness of these biological approaches under the harsh environmental conditions of the Arabian Gulf remains limited. Finally, this review proposes a Gulf-specific roadmap that includes standardized monitoring protocols and shared spectral and image databases to support AI-based detection, interlaboratory proficiency testing, and pilot-scale bioremediation studies tailored to regional conditions.

Abstract. The Ain Leuh watershed occupies a strategic hydrogeographic position that favors surface water circulation and accumulation. Considering the persistent water stress affecting Morocco, a detailed characterization of this watershed is essential to support sustainable water resource management and to mitigate geohazards such as flooding and soil erosion. This study aims to characterize the Ain Leuh watershed using morphometric analysis based on the FABDEM (Forest and Buildings removed Copernicus DEM). Covering an area of 143.58 km², the watershed is geomorphologically young, well-drained, and characterized by significant surface runoff. Surface and linear morphometric include drainage density (2.96 km/km²), stream frequency (7.41 km⁻²), drainage texture (13.45 km⁻¹), elongation ratio (0.40), circularity ratio (0.29), and form factor (0.10). The values reflect a long, narrow basin with high runoff potential and limited infiltration capacity. Hypsometric contour mapping at 200-meter intervals highlighted a dominant NE–SW alignment, indicative of the region’s terraced geomorphology. Elevation data pointed to higher altitudes in the southeastern part of the basin and lower elevations in the northwest, while slope analysis indicated that low to moderate gradients are more dominant. These results were complemented by the relief parameters: the relief ratio (Rh), dissection index (Dis), and roughness number (Rn). The relief ratio (0.03) underscores the predominance of broad, low-relief areas such as floodplains and wide valleys. The dissection index (0.58) confirms considerable valley incision, implying a heightened risk of both fluvial and slope-driven erosion, while the roughness number (3.43) combines indicators of steep terrain and dense drainage to describe a rugged watershed with a significant susceptibility to surface water dynamics and erosion. The morphometric analysis identifies the Ain Leuh watershed as a young, elongated basin with efficient drainage, high surface runoff, and moderate to steep slopes. While its flood potential appears limited due to its geomorphological structure, the basin exhibits significant vulnerability to erosion. These findings provide valuable insights for regional water management strategies and underscore the need for erosion control measures to enhance the watershed’s resilience.

As a potential strategic resource of critical metals, deep-sea cobalt-rich crusts represent one of the most promising metal reservoirs within oceanic seamount systems, and their metallogenic mechanism constitutes a frontier topic in deep-sea geoscience research. This review focuses on the cobalt-rich crusts from the Magellan Seamount region in the northwestern Pacific and synthesizes existing geological, mineralogical, and geochemical studies to systematically elucidate their mineralization processes and metal enrichment mechanisms from a microstructural perspective, with particular emphasis on cobalt enrichment and its controlling factors. Based on published observations and experimental evidence, the formation of cobalt-rich crusts is divided into three stages: (1) Mn/Fe colloid formation—At the chemical interface between oxygen-rich bottom water and the oxygen minimum zone (OMZ), Mn2+ and Fe2+ are oxidized to form hydrated oxide colloids such as δ-MnO2 and Fe(OH)3. (2) Key metal adsorption—Colloidal particles adsorb metal ions such as Co2+, Ni2+, and Cu2+ through surface complexation and oxidation–substitution reactions, among which Co2+ is further oxidized to Co3+ and stably incorporated into MnO6 octahedral vacancies. (3) Colloid deposition and mineralization—Mn–Fe colloids aggregate, dehydrate, and cement on the exposed seamount bedrock surface to form layered cobalt-rich crusts. This process is dominated by the Fe/Mn redox cycle, representing a continuous evolution from colloidal reactions to solid-phase mineral formation. Biological processes play a crucial catalytic role in the microstructural evolution of the crusts. Mn-oxidizing bacteria and extracellular polymeric substances (EPS) accelerate Mn oxidation, regulate mineral-oriented growth, and enhance particle cementation, thereby significantly improving the oxidation and adsorption efficiency of metal ions. Tectonic and paleoceanographic evolution, seamount topography, and the circulation of Antarctic Bottom Water jointly control the metallogenic environment and metal sources, while crystal defects, redox gradients, and biological activity collectively drive metal enrichment. This review establishes a conceptual framework of a multi-level metallogenic model linking macroscopic oceanic circulation and geological evolution with microscopic chemical and biological processes, providing a theoretical basis for the exploration, prediction, and sustainable development of potential cobalt-rich crust deposits.

Medical care in the gastrointestinal (GI) tract is a major global issue. Soft actuators are expected to solve associated issues such as poor accessibility and difficult operability within the GI tract. The actuators will be inserted into the body through the mouth or anus with a small diameter, perform various tasks in the GI tract with a large diameter, and finally be removed again. Therefore, deployability and retractivity are common requirements. Variable stiffness is also required to adjust or maintain forces on weak tissues. We proposed the new deployable and stiffness-variable miniature actuator consisting of a shape memory polymer bar and flexible channel part with water circulation, which is useful for medical applications in the GI tract. We established the design method of the actuator based on derived physical models and the fabrication method of prototypes. We evaluated the performances of thermal response, retractive deformation, and variable stiffness and confirmed the validity of the concept through the demonstration of continuous actuation, including deploying, retracting, and stiffness-varying. Furthermore, as a case study, we verified the feasibility of endoscopic submucosal dissection traction using prototypes and artificial materials. In the future, the actuator mechanism and design method may also contribute to the development of other medical tools interacting with delicate tissues in the GI tract.

Integrating water quality assessment and circulation models for a sustainable management of a strategic carbonate system: Clues from the Mt. Nerone-Mt. Catria Ridge (Central Italy).

Abstract Minerals in the epidote group, such as zoisite, clinozoisite, and epidote, are important water carriers to the Earth’s deep interior through subducting slabs. In this study, we have performed synchrotron X-ray diffraction (XRD) measurements on four epidote-group minerals up to 60 GPa at 300 K in diamond-anvil cells (DACs) to investigate the influence of structure and Fe content on the equation of state and density of these minerals. The obtained volume-pressure data were fitted using a third-order Birch-Murnaghan equation of state, giving V0 = 902.6(1) Å3, KT0 = 112(2) GPa, and KT0′=7.1(3) for zoisite with XFe = 0 [XFe = Fe3+/(Fe3++Al-2)], V0 = 455.0(2) Å3, KT0 = 160(6) GPa, and KT0′=3.4(6) for clinozoisite with XFe = 0.24, V0 = 457.53(5) Å3, KT0 = 142(4) GPa, and KT0′=4.5(3) for clinozoisite with XFe = 0.47, and V0 = 458.5(7) Å3, KT0 = 157(5) GPa, and KT0′=2.9(2) for epidote with XFe = 0.84. Together with literature results, we found that elevating the Fe content will increase the density of epidote-group minerals but decrease the bulk modulus. Compared to monoclinic clinozoisite with the same iron content, the orthorhombic zoisite has a higher density but a lower bulk modulus. The axial-compression behavior of epidote-group minerals is also discussed. Combining the elastic properties and density of other minerals in the CaO-Al2O3-SiO2-H2O (CASH) system, we discuss the effect of water and Fe on this system and further elucidate the role of epidote minerals in water circulation inside the Earth.