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We report the first record of a species of Pareiorhaphis in the Manhuaçu River basin, an affluent to the right bank of the middle Doce River drainage in eastern Brazil. The description is based on a series of specimens recently collected and also on historical samples. All specimens were obtained from habitats with very strong water current running over flat bedrock. The new species is readily diagnosed from congeners by features related to the distinct morphology of lower lip papillae, unique pattern of plates covering the pectoral girdle between insertions of pectoral fins, and the lack of a maxillary barbel. In addition, the combination of longer snout, smaller orbital diameter, shape of the pectoral-fin spine, low number of dentary teeth, and lack of a dorsal-fin spinelet also distinguishes the new species from all species of Pareiorhaphis. The new species is further compared to Pareiorhaphis nasuta, P. scutula, P. proskynita, and P. vetula, congeners from the Doce River basin, and hypothesized to have traits that represent important adaptations for living in torrential habitats. [ABSTRACT FROM AUTHOR]

Parental investment is any expenditure of time or energy by parents that increases their offspring survival at the cost of future reproduction. The costs associated with parental investment can be reflected in a deterioration of their physiological condition. In insects, juvenile hormone has been identified as having a role in the control of parental care. However, its effects on parental investment remain unclear for many taxa, especially in species with exclusive paternal care. We evaluated whether juvenile hormone influences postzygotic parental investment in Abedus ovatus, a waterbug with exclusive paternal care. Males provide parental care by carrying eggs on their backs and ventilating them by generating water currents through push‐ups called brood pumping. In an experiment, we applied methoprene (an analog of juvenile hormone) to males at early and late parental care stages and quantified the frequency of brood pumping and the contents of energy reserves (lipids, carbohydrates, and glycogen) at the end of parental care as a measure of physiological condition. We found that methoprene increases the frequency of brood pumping only when the water temperature increases. However, there was no correlation between the parent's energy reserves and methoprene treatments. We found that males who cared for large egg pads had lower amounts of lipids and carbohydrates at the end of parental care, and both effects are greater as the water temperature increases. These results suggest that energy expenditure during parental care is high due to intense muscular activity during brood pumping, which depletes male energy reserves and could affect future reproduction. [ABSTRACT FROM AUTHOR]

The northern Chilean coast is characterized by its high productivity and diversity due to the presence of the cold, nutrient-rich water of the Humboldt Current. The coasts in the area are mainly bordered by rocky shores that provide many microhabitats for invertebrates. The aim of the present study was to analyse the spatial distribution of three sympatric intertidal decapods, Leptograpsus variegatus , Cyclograpsus cinereus and Petrolisthes granulosus , using probabilistic models. The studied locality was situated on the rocky shores of Taltal Bay, in the north of Chile. The counting of individuals could reveal the presence of the reported species, and if they did or did not coexist. The results revealed that L. variegatus and C. cinereus had a uniform pattern with Binomial distribition, whereas P. granulosus showed a random occurrence with Poisson distribution. These results would not coincide with classical observations of intertidal decapods on the rocky shores of continental Chile, as those denoted a gregarious pattern, but the distributions found would rather explain potential territorial behaviour. [ABSTRACT FROM AUTHOR]

In order to clarify the hydrodynamic effect and seismic response of a continuous beam with 4-column pile column frame pier, the bridge-water coupling numerical model is established. The effects of wave, current and water depth on the seismic response are analyzed. Analysis of flow around pier shows that the velocity field and pressure field of each column are asymmetric. Compared with the seismic response under condition of no-water, the seismic response under still water condition is greater. The seismic responses under wave and current environment are not the superposition of dynamic response under the action of earthquake, wave and current. [ABSTRACT FROM AUTHOR]

To anticipate disasters (drought, floods, etc.) caused by environmental forcing and reduce their impacts on its fragile economy, sub-Saharan Africa needs a good knowledge of the availability of current water resources and reliable hydroclimatic forecasts. This study has an objective to quantify the availability of water resources in the Nyong basin and predict its future evolution (2024–2050). For this, the SWAT (Soil and Water Assessment Tool) model was used. The performance of this model is satisfactory in calibration (2001–2005) and validation (2006–2010), with R2, NSE, and KGE greater than 0.64. Biases of − 11.8% and − 13.9% in calibration and validation also attest to this good performance. In the investigated basin, infiltration (GW_RCH), evapotranspiration (ETP), surface runoff (SURQ), and water yield (WYLD) are greater in the East, probably due to more abundant rainfall in this part. The flows and sediment load (SED) are greater in the middle zone and in the Southwest of the basin, certainly because of the flat topography of this part, which corresponds to the valley floor. Two climate models (CCCma and REMO) predict a decline in water resources in this basin, and two others (HIRHAM5 and RCA4) are the opposite. However, based on a statistical study carried out over the historical period (2001–2005), the CCCma model seems the most reliable. It forecasts a drop in precipitation and runoff, which do not exceed − 19% and − 18%, respectively, whatever the emission scenario (RCP4.5 or RCP8.5). Climate variability (CV) is the only forcing whose impact is visible in the dynamics of current and future flows, due to the modest current (increase of + 102 km2 in builds and roads) and future (increase of + 114 km2 in builds and roads) changes observed in the evolution of land use and land cover (LULC). The results of this study could contribute to improving water resource management in the basin studied and the region. [ABSTRACT FROM AUTHOR]

The half‐life of 228Ra (5.7 years) aligns well with near‐surface and near‐bottom ocean mixing timescales. Because 228Ra is sourced from sediments, regions of enhanced activity represent water that has recently interacted with sediments on the continental margin or seabed. The GP15 meridional transect from Alaska to Tahiti along152°W encountered several regions in the upper ocean where 228Ra was enriched. These enrichments follow surface and subsurface ocean current patterns and pair with earlier measurements of 228Ra and transient radionuclides to reveal the origins of these enriched regions. An enriched region at Alaska margin stations 1–3 was sourced locally but did not extend to the Alaskan trench at station 4. A large shallow region between 47° and 32°N. was sourced from the west by the North Pacific Current; another shallow enriched region between 11° and 5° N was also sourced from the west by the North Equatorial Countercurrent. Subsurface enrichments (100–400 m) between 18 and 47°N were associated with Central Mode Water and North Pacific Intermediate Water. The 228Ra activities in the upper Pacific were six times lower than activities in the Atlantic. In deep waters the primary enrichment was 27°–47°N. Two stations (32° and 37°N) were especially enriched, having near‐bottom inventories several times greater than other stations. With these two exceptions the remaining Pacific stations exhibited averaged inventories lower than those in the Atlantic. There was one region of enriched 223Ra (half‐life = 11 days) above the Puna Ridge near Hawaii. Plain Language Summary: The international GEOTRACES program aims to identify processes and quantify fluxes that control the distribution of trace elements and isotopes (TEIs) in the ocean. Some TEIs are important micronutrients, which may control biological productivity. Others may become concentrated as they pass up the food web and reach potentially harmful levels in some seafood. But measurements of these TEIs are not adequate to determine controlling processes or quantify their fluxes in the marine environment. Radionuclide tracers provide a means to link TEI measurements with fluxes and processes. Here we employ measurements of 228Radium (half‐life = 5.75 years) to trace water movements and current speeds in the upper Pacific and to determine regions near the seabed where sediment‐water interactions are most intense. The upper ocean measurements confirmed a broad circulation pattern that brought water from the Asian margin to the northeast Pacific at speeds of 2–8 cm/sec, in agreement with other estimates of these current speeds. Near the seabed we discovered a region of enhanced 228Ra activity indicating intense sediment‐water interactions. Such regions may control the release of TEIs from the seabed to the water column. We anticipate others will utilize these data to elucidate aspects of other TEI distributions. Key Points: Several open‐ocean regions of enriched 228Ra were documented in the North and Equatorial Pacific at 152°WThe upper ocean 228Ra‐enriched regions correspond to major surface and subsurface currents transporting water from the Asian marginOne seabed region near 32°N was especially enriched in 228Ra [ABSTRACT FROM AUTHOR]

In the tropical Pacific, weak ventilation and intense microbial respiration at depth give rise to a low dissolved oxygen (O2) environment that is thought to be ventilated primarily by the equatorial current system (ECS). The role of mesoscale eddies and vertical mixing as potential pathways of O2 supply in this region, however, remains poorly known due to sparse observations and coarse model resolution. Using an eddy resolving simulation of ocean circulation and biogeochemistry, we assess the contribution of these processes to the O2 budget balance and find that vertical mixing of O2, which is modulated by the surface wind speed and the vertical shear of the eddying currents, contributes substantially to the replenishment of O2 in the upper equatorial Pacific thermocline, complementing the advective supply of O2 by the ECS and meridional circulation at depth. These transport processes vary seasonally in conjunction with the wind: mixing of O2 into the upper thermocline is strongest during boreal summer and fall when the vertical shear and eddy kinetic energy are intensified. The relationship between eddy activity and the downward mixing of O2 arises from the modulation of equatorial turbulence by Tropical Instability Waves via their impacts on the vertical shear. This interaction of processes across scales sustains a local pathway of O2 delivery into the equatorial Pacific interior and highlights the need for adequate observations and models of turbulent mixing and mesoscale processes for understanding and predicting the fate of the tropical Pacific O2 content in a warmer and more stratified ocean. Plain Language Summary: The eastern tropical Pacific interior is an O2 deficient environment, due to intense O2 consumption by microbial communities that is not vigorously replenished by ocean circulation at depth. In this study, we use a high resolution simulation of ocean circulation and biogeochemistry to understand the role of finer scale processes such as turbulence and eddies in injecting O2 locally. We find that mixing due to turbulence along the equator supplies a key portion of O2 into the ocean by exchanging waters between the well‐aerated mixed layer near the surface and the ocean's interior where O2 falls precipitously with depth. We also find that this mixing varies considerably with the seasons. This annual cycle in mixing arises from the seasonal variability in wind stress and the passage of eddies, which amplify turbulence through their influence on the subsurface currents along the equator, and represents a previously unexplored but potentially important route of O2 delivery into the ocean's interior. As the upper ocean warms and becomes less dense, the ocean's O2 content is expected to decrease, and thus observing and accurately modeling these O2 pathways will be crucial to monitoring how marine ecosystem habitats will shift in a warmer climate. Key Points: Mesoscale‐resolving ocean biogeochemistry simulations show vertical mixing is a key source of oxygen to the equatorial Pacific thermoclineThe supply of oxygen by advection and vertical mixing is strongly seasonal and is driven by seasonal variability in the windThe vertical mixing of oxygen is modulated by the wind stress and mesoscale eddy impacts on equatorial shear‐driven turbulence [ABSTRACT FROM AUTHOR]

Indigenous Peoples in Canada have shown great strength and resilience in maintaining their cultures and ways of life to date in the face of settler colonialism. Centering the Water crises within Indigenous sovereignty and self-determination, we explore the impacts these crises have on community members. Particularly, the continuous failure of the Canadian government to end the Water crises in remote Indigenous communities, Star Blanket Cree Nation, is investigated in this paper. What implications have these Water governance gaps had on Indigenous Peoples' sovereignty and self-determination? We adopted an Indigenist theoretical framework to guide the study. Additionally, a community-based participatory research approach was adopted. To achieve our research goals of investigating the implications of the current Water crises for Indigenous sovereignty and self-determination, specific methods of sharing circles were used to gather knowledge from community members, Elders, and knowledge keepers. The research findings strongly highlight the strength and resilience shown by remote Indigenous communities in the face of the current Water crises and continuous government failure. Solving the current Water crises will involve remote Indigenous communities taking charge of their own Water governance through Indigenous-led Water governance systems. Additionally, taking steps to rebuild trust through genuine reconciliation will be key. Therefore, listening to remote Indigenous communities and taking collaborative action are fundamental. [ABSTRACT FROM AUTHOR]

Current irrigation water use (IWU) estimation methods confront uncertainties warranting further attention, primarily stemming from constraints within model structure and data quality. This study proposes a hybrid framework that integrates multiple machine learning (ML) methods with theory‐guided strategies to calculate IWU for three principal cereal crops within the Chinese agricultural landscape. We generated high resolution time series data sets of evapotranspiration and surface soil moisture (SM) using remote sensing resources. ML techniques, along with the Bayesian three‐cornered hat ensemble, were employed to drive multiple remote sensing‐derived data sets in IWU calculation. We applied two theory‐guided mechanisms to quantify irrigation signals: first, converting original SM values into logarithmic terms, and second, extracting process‐based SM residuals. Proposed framework has been validated at 12 field stations across China, yielding coefficient of determination (R2) ranging from 0.54 to 0.70, and root mean square error (RMSE) spanning 278–335 mm/yr. Our framework demonstrates considerable strength in IWU estimation when compared to reported IWU values form 341 cities across China. Specifically, for rice, wheat, and maize, the R2 values range from 0.78 to 0.83, 0.68 to 0.76, and 0.53 to 0.64, respectively, with corresponding RMSE measuring 0.22–0.25, 0.10–0.12, and 0.11–0.13 km3/yr, respectively. These findings highlight the effectiveness of theory‐guided strategies in discerning irrigation‐related information, thereby improving overall model performance. Attention should be directed toward the uncertainties in evapotranspiration and precipitation products on model performance, which remained modest, with a relative change of less than 5%. Key Points: Hybrid framework is developed to estimate irrigation water use (IWU) for three staple cereal crops in ChinaMachine learning is employed to drive multiple remote sensing‐derived products for precise IWU estimationProposed framework accurately estimates IWU and incorporates theory‐guided module to reveal implicit irrigation signal [ABSTRACT FROM AUTHOR]

Given the importance of water in human life, most communities have developed specific systems to exploit water resources in various aspects of life. From region to region, settlement to settlement, a set of determinant factors have contributed to these systems' creation and development. In this research, we have tried to highlight the particularities of the traditional water management system in the case of the village of Menades. We also tried to identify the transformations (technical, economic and social, etc.) and the development process that have influenced this system over the last forty years to become what it is today. By addressing these aspects, we attempted to identify the current difficulties of water management in the village and their possible solutions. The methodological tools used were observation, interviews, Google Earth Pro software, and microbiological analysis of the water. The results of the research indicate that the system has evolved as a result of a number of exogenous and endogenous factors. This evolution presents some positive aspects, but also a number of challenges and problems to which the various stakeholders need to work together to find appropriate solutions. [ABSTRACT FROM AUTHOR]

Community assembly is influenced by disturbance intensity, sequential colonization (arrival order) of species, and interactions between species arriving early and species arriving later. We documented both intra- and interspecific patterns of colonization following hydrological disturbance using a 20-year time series of marsh-fish density at 21 study sites located in the Everglades, Florida, USA, as a case study of sequential colonization. The critical swimming speed (UCRIT) of 20 juveniles and 20 adults for six species was estimated using UCRIT tests to evaluate if UCRIT predicted timing of re-colonization. We observed a consistent pattern of species colonization over 500 disturbance events. On average, juveniles of early arriving species were collected prior to adults, while adults consistently appeared prior to juveniles for late-arriving species. Density at first collection was inversely correlated with arrival order; early arriving species tended to have higher density when first collected following marsh re-flooding than later arriving ones. Females consistently arrived before males for all species where sex could be identified. Neither absolute nor size-adjusted UCRIT was correlated with arrival order. Although interspecific colonization was highly repeatable, intraspecific differences among demographic groups were species-specific and possibly tied to reproductive biology and juvenile life history. Juvenile early arrival may indicate rapid colonization of pregnant females (Poeciliidae), diapausing eggs laid before marsh drying, or early development of robust swimming capacity (Cyprinodontidae and Fundulidae); in the Everglades, water currents are absent or too weak to support larval drift as an important mechanism. Stage- and sex-specific UCRIT and reproductive traits such as embryo diapause in oviparous species need more attention to understand successional dynamics following disturbance in aquatic communities. [ABSTRACT FROM AUTHOR]

Due to the nature of nitrogen cycling, policies designed to address water quality concerns have the potential to provide benefits beyond the targeted water quality improvements. For example, actions to protect water quality by reducing nitrate leaching from agriculture also reduce emissions of nitrous oxide, a potent greenhouse gas. These positive effects, which are incidental to the regulation's intended target, are termed "co‐benefits." To quantify the co‐benefits associated with reduced nitrate leaching, we integrate an economic model of farmer decision making with a model of terrestrial nitrogen cycling for the watershed surrounding Lake Mendota, Wisconsin, USA. Our modeling approach provides a framework that links air and water pollutants in an agri‐environmental system and offers a direction for future studies. Our model results highlight the finding that the co‐benefits from nitrous oxide abatement are substantial, and their inclusion increases the benefit–cost ratio of water quality policies. Consideration of these co‐benefits has the potential to reverse the conclusions of benefit–cost analysis in the assessment of current water quality policies. [ABSTRACT FROM AUTHOR]

Vacancy‐ordered halide double perovskites (VOPs) are reported to be suitable for photoelectrochemical (PEC) water splitting, due to their panchromatic visible absorption and stability in electrolyte. In this work, ruthenium‐based VOP, Cs2RuX6 (X = Cl−, Br−), is reported for PEC water splitting, and the material is found to be extremely stable in harsh pH media, between pH1 and pH11. The PEC devices made with these materials show good photogenerated hole transport to electrolyte; however, the photovoltage remains low due to high recombination. To enhance the performance, Ru4+ is partially substituted with Pt4+ tetravalent cation, where the latter is shown to possess better photovoltage. The mixed‐tetravalent compound, Cs2RumPt1−mX6, leads to high PEC water oxidation current at m = 0.5, compared to their end members. The mixed‐tetravalent compounds show a synergic effect of reduced charge‐transfer resistance from the material to the electrolyte and increased photovoltage leading to increased PEC performance. [ABSTRACT FROM AUTHOR]

Path planning is crucial for unmanned surface vehicles (USVs) to navigate and avoid obstacles efficiently. This study evaluates and contrasts various USV path-planning algorithms, focusing on their effectiveness in dynamic obstacle avoidance, resistance to water currents, and path smoothness. Meanwhile, this research introduces a novel collective intelligence algorithm tailored for two-dimensional environments, integrating dynamic obstacle avoidance and smooth path optimization. The approach tackles the global-path-planning challenge, specifically accounting for moving obstacles and current influences. The algorithm adeptly combines strategies for dynamic obstacle circumvention with an eight-directional current resistance approach, ensuring locally optimal paths that minimize the impact of currents on navigation. Additionally, advanced artificial bee colony algorithms were used during the research process to enhance the method and improve the smoothness of the generated path. Simulation results have verified the superiority of the algorithm in improving the quality of USV path planning. Compared with traditional bee colony algorithms, the improved algorithm increased the length of the optimization path by 8%, shortened the optimization time by 50%, and achieved almost 100% avoidance of dynamic obstacles. [ABSTRACT FROM AUTHOR]

The inflow of warm and salty Circumpolar Deep Water affects the melting of the ice shelf on the Amundsen Sea, a significant contributor to global sea level rise. Multi‐year mooring data (2014–2016 and 2018–2020) from the front of the Dotson Ice Shelf show the modified Circumpolar Deep Water layer was thicker during 2018–2020 than during 2014–2016. During 2014–2016, Ocean surface stress curl influenced the barotropic process and strengthened southward velocity, while during 2018–2020, it caused lift and downwelling of thermocline depth, increasing the impact of the baroclinic process in ocean circulation. The heat transport to the ice shelf during 2018–2020 (57.42 MW m−1) was half as much as it was during 2014–2016 (111.06 MW m−1) due to a weaker lower layer current. The difference in ocean circulation between two periods, caused by a difference in warm layer thickness, ultimately impacts the heat transport entering the ice shelf cavity. Plain Language Summary: Warm and salty water from the deep ocean flows into the ice shelf cavities in the West Antarctic, causing the ice to melt and contribute to global sea level rise. We measured the current and water properties in front of the Dotson Ice Shelf during 2014–2016 and 2018–2020 and found that the warm layer was thicker during the latter period. Unlike during 2014–2016 when ocean surface stress curl created a spatial imbalance in sea level and affected the southward current due to pressure gradients, during 2018–2020, ocean surface stress curl changed the density by causing upwelling and downwelling. This density change influenced the velocity variation toward the ice shelf. Although the mCDW layer was ticker, the heat influx to the ice shelf during 2018–2020 was half as much as it was during 2014–2016. The difference in ocean current during these two periods, due to differences in the warm layer thickness, ultimately affects how much heat is transported into the ice shelf cavity. Key Points: The modified circumpolar deep water layer was thicker in 2018–2020 than that during 2014–2016The baroclinic effect plays a more important role in the variability of the current entering the ice shelf during 2018–2020Differences in the seasonal cycle of the ocean surface stress curl can affect ocean circulation by changing ocean conditions [ABSTRACT FROM AUTHOR]

In this study, we aim to investigate how the functional properties of microalgae help to delineate the major groups of aquatic habitats. Using functional trait-based and Reynolds' functional group-based approaches similarities of the microalgal flora of all aquatic habitats occurring in Hungary were compared. The habitats covered the whole size spectrum of standing waters (10-2–108 m2) and water currents (watershed: 102–1011 m2), , limnological and chemical properties. Both functional trait-based and functional group-based habitat classifications overrode the hydromorphology-based typology, however, functional group-based clusters showed closer resemblance to limnological-hydromorphological types than clusters created by trait-based approaches both for qualitative and quantitative data. Most of the aquatic habitats that have similar limnological characteristics showed resemblance in the functional properties of their microflora. Rivers and river-related habitats were the most diverse functionally. These were followed by standing waters with extended macrophyte coverage. The small, unique habitats displayed the lowest functional richness. The occurrence of several functional groups in some extreme habitats implies two alternative explanations: first, the habitat template of the groups is wider than defined in the original description; second, detailed information on the autecology of species assigned to a functional group necessitates the creation of new groups specific for the unique habitats. [ABSTRACT FROM AUTHOR]

The processes of ocean dynamics are complex near the Pearl River Estuary and are not clear due to a lack of abundant observations. The spatial characteristics of the spring sea surface currents in the adjacent waters of the Pearl River Estuary were analyzed using the current data observed by a three-station high-frequency surface wave radar system (HFSWRS). Compared with the two-station HFSWRS, the deviation of current velocity and direction observed by the three-station HFSWRS from the underway measurements decreased by 42.86% and 38.30%, respectively. The analyzed results show that the M2 tidal current is the dominant current among all the tidal constituents, followed by K1, with angles of inclination ranging from 130° to 150°. The tidal flow is dominated by northwest–southeast back-and-forth flow. In the southern part of the observed area, which is far from the coastline, the tidal current ellipses exhibit a circular pattern. The prevalent tidal current type in this region is irregularly semi-diurnal, and the shallow water constituents also have a significant effect. The tidal energy in the adjacent waters of the Pearl River Estuary is affected by potential energy flux and kinetic energy flux. As the water depth and currents velocity increase in the southeast direction, the tidal energy flux increases. In the nearshore zone, the direction of tidal energy flux varies along the coastline. The changes in the residual current within the observed area are correlated with the sea surface wind field. Based on the high-precision sea surface current observed by the three-station HFSWRS, the characteristics of the ocean dynamic processes near the Pearl River Estuary are analyzed comprehensively, which provides important reference and confidence for the application of the developing new radar observing network with about 10 radar stations near the Pearl River Estuary. [ABSTRACT FROM AUTHOR]

Water, an unwelcome guest in current battery industry, has been strictly prohibited in almost all the battery production procedures. In particular, the requirement for an extremely low water content (below 20 ppm) in electrolyte has necessitated the use of water‐free raw materials and ultradry conditions, which resulting in significantly higher material cost, energy consumption, and production complexity. Here, it is shown that lithium nitrate (LiNO3) can efficiently restore water‐containing electrolyte for Li metal full batteries through a simple and scalable approach. The dual‐functional NO3− anion not only exhibits strong interaction with water molecules which suppresses the hydrolysis of hexafluorophosphate anion, but also contributes to a robust solid‐electrolyte interphase (SEI) that improves the electrochemical reversibility of Li metal plating and stripping process. These enable the first practical Li metal/LiNi0.8Co0.1Mn0.1O2 full cell with a negative/positive electrode capacity (N/P) ratio of 3.8 using a water‐containing electrolyte, which delivers a high energy density of 511 Wh kg−1 and impressive cycling stability of 240 cycles. Remarkably, the introduction of LiNO3 can tolerate moist raw materials for electrolyte preparation, and revitalize moist electrolytes after 5‐day storage, which provides a new paradigm to overcome the water hazard in the current battery industry. [ABSTRACT FROM AUTHOR]

The rational design of the current anion exchange polyelectrolytes (AEPs) is challenging to meet the requirements of both high performance and durability in anion exchange membrane water electrolyzers (AEMWEs). Herein, highly‐rigid‐twisted spirobisindane monomer is incorporated in poly(aryl‐co‐aryl piperidinium) backbone to construct continuous ionic channels and to maintain dimensional stability as promising materials for AEPs. The morphologies, physical, and electrochemical properties of the AEPs are investigated based on experimental data and molecular dynamics simulations. The present AEPs possess high free volumes, excellent dimensional stability, hydroxide conductivity (208.1 mS cm−1 at 80 °C), and mechanical properties. The AEMWE of the present AEPs achieves a new current density record of 13.39 and 10.7 A cm−2 at 80 °C by applying IrO2 and nonprecious anode catalyst, respectively, along with outstanding in situ durability under 1 A cm−2 for 1000 h with a low voltage decay rate of 53 µV h−1. Moreover, the AEPs can be applied in fuel cells and reach a power density of 2.02 W cm−2 at 80 °C under fully humidified conditions, and 1.65 W cm−2 at 100 °C, 30% relative humidity. This study provides insights into the design of high‐performance AEPs for energy conversion devices. [ABSTRACT FROM AUTHOR]

Hydrokinetic turbines use different rotors for technological and economic reasons. Even though it performs poorly, vertical-axis hydrokinetic turbines use the Savonius rotor. The object of research is a Savonius rotor model with additional grooves. The study addresses the need to improve the efficiency and overall performance of Savonius rotor models in hydrokinetic turbines, which are widely used for harnessing energy from flowing water currents. The problem involves understanding how different groove configurations affect the aerodynamic behavior and energy extraction efficiency of the Savonius rotor in hydrokinetic turbine applications. The test results revealed that incorporating grooves led to notable improvements in efficiency ( ) and coefficient of drag (CD). Grooved blades exhibited a maximum efficiency of 30.97 % and a maximum drag coefficient of 2.71. Notably, blades with a groove width of 12.5 mm emerged as the optimal model, demonstrating an efficiency peak of 35.66 % and a drag coefficient 3.08. This indicates a substantial increase in efficiency by 4.69 % and a corresponding rise in the drag coefficient by 0.37 for grooved blades. The grooves on grooved blades increase friction, improving performance. Grooved rotor blades improve turbine performance significantly. Savonius rotor models in hydrokinetic turbines extract more energy by optimizing groove width and arrangement to maximize drag coefficient and efficiency. This research affects hydrokinetic turbine design and optimization for renewable energy generation. Engineers and designers can improve the performance and efficiency of the Savonius rotor model in hydrokinetic turbine applications by applying this study’s findings. [ABSTRACT FROM AUTHOR]

In the eastern off-equatorial Indian Ocean, deep current intraseasonal variability within a typical period of 10–20 days was revealed by a mooring at 5°N, 90.5°E, accounting for over 50% of the total bottom subtidal velocity variability. The 10–20-day oscillations were more energetic in the cross-isobathic direction (STD = 3.02 cm s−1) than those in the along-isobathic direction (STD = 1.50 cm s−1). The oscillations were interpreted as topographic Rossby waves (TRWs) because they satisfied the TRWs dispersion relation that considered the smaller Coriolis parameter and stronger β effect at low latitude. Further analysis indicated significant vertical coupling between the deep cross-slope oscillations and cross-isobathic 10–20-day perturbations at the depth of 300–950 m. The 10–20-day TRWs were generated by cross-isobathic motions under the potential vorticity conservation adjustment. The Mercator Ocean output reproduced the generation of kinetic energy (KE) of deep current variability. The associated diagnostic analysis of multiscale energetics showed that the KE of TRWs was mainly supplied by vertical pressure work. In the seamount region (2°–10°N, 89°–92°E), vertical and horizontal pressure works were identified to be the dominant energy source (contributing to 94% of the total KE source) and sink (contributing to 98% of the total KE sink) of the deep current variability, transporting energy downward and redistributing energy horizontally, respectively. [ABSTRACT FROM AUTHOR]

Underwater bionic-legged robots encounter significant challenges in attitude, velocity, and positional control due to lift and drag in water current environments, making it difficult to balance operational efficiency with motion stability. This study delves into the hydrodynamic properties of a bionic crab robot's shell, drawing inspiration from the sea crab's motion postures. It further refines the robot's underwater locomotion strategy based on these insights. Initially, the research involved collecting attitude data from crabs during underwater movement through biological observation. Subsequently, hydrodynamic simulations and experimental validations of the bionic shell were conducted, examining the impact of attitude parameters on hydrodynamic performance. The findings reveal that the transverse angle predominantly influences lift and drag. Experiments in a test pool with a crab-like robot, altering transverse angles, demonstrated that increased transverse angles enhance the robot's underwater walking efficiency, stability, and overall performance. [ABSTRACT FROM AUTHOR]

Archaeocyaths are a group of extinct filter feeders that flourished in the early Cambrian period and occupied an important position in the evolution of basal fauna and the early marine ecosystem. However, the detailed morphological and anatomical information of this group are still unclear due to insufficient fossil material and limited experimental analyses. Here, we report exquisitely preserved phosphatized archaeocyathan fossil cups, ca. 515 million years old, from the top of the Shuijingtuo Formation (Series 2, Stage 3) and the Xiannüdong Formation (Series 2, Stage 3) of the Yangtze Platform, South China. Detailed observation of their external morphology via scanning electron microscopy (SEM) and micro-computed tomography (Micro-CT) analysis revealed detailed information of their internal structure. They have a typical double-walled cup, with the perforated inner and outer walls concentrically distributed, but the structure between the two walls differs. The inverted cone-shaped cups have radially distributed septa between the walls. Perforated septa connect the two walls. The low and columnar cups have canals between the two walls, forming the network. These pores and cavities constitute an important component of the water current system (pumping and filtering water with a network of canals and chambers) and influence the process of filtration in the cup. In comparison to traditional thin-section analysis, the combination of SEM and Micro-CT analysis on phosphatized archaeocyaths presented in this study further explored the detailed internal structure and finely reconstructed the microscopic overall morphology and anatomy, which provide important information to help us understand the systematic taxonomy, anatomy, and morphology of archaeocyaths during the Cambrian period. [ABSTRACT FROM AUTHOR]

The current conventional water resources management planning method realizes the optimal allocation of water resources by constructing a function aiming at economic benefits; it causes poor model planning repercussions as a result of the disregard of comprehensive benefits. In this regard, a hydrological model-based water resource management planning method for climate change is proposed. By combining geological conditions, hydrological conditions and other climate change factors, a hydrological model is constructed to calculate watershed flows, and the hydrological model is used to divide the watershed scale and hydrological response units. A multi-objective function planning model is constructed with economic and ecological benefits as the objective functions. The proposed approach is tested in trials and shown to provide advantages for thorough planning. The results of the study demonstrate that the algorithm has a high value of extensive benefit when the recommended strategy is utilized for the optimum allocation of water resources, and has a more preferable optimal allocation consequence. [ABSTRACT FROM AUTHOR]

Access to safe drinking water, sanitation, and hygiene in Chad's cities, especially N'Djamena, is a persistent and significant challenge. This study aimed to assess current practices in water, sanitation, and hygiene in N'Djamena's third and ninth districts. We surveyed 395 households, conducted water source identification, and analyzed seven water samples at the National Water Laboratory. Temperature, ammonium, total coliforms, and aerobic flora values exceeded World Health Organization (WHO) guidelines. Ammonium and temperature averaged 0.7 mg/L and 30.1-31.93 °C, respectively. Bacterial contamination (>100 MPN/100 mL) exceeded the WHO's 0 MPN/100 mL guidelines, rendering the water unfit for consumption. Survey results indicate that 78.7% use hand pumps, 21.1% have tap water access, and 0.2% rely on rivers for water. Regarding toilets, 92.8% have traditional models, 2.9% have modern facilities, and 4.3% practice open defecation. 95% dispose of untreated wastewater into nature, with only 5% using septic tanks. For solid waste, 72% use illegal dumpsites, 18% rely on public services, and 10% burn waste. Finally, 95.5% of households wash their hands with clean water and soap after using the toilet. It is crucial to treat drinking water and implement proper hygiene and sanitation measures to safeguard the population's health in the studied area. [ABSTRACT FROM AUTHOR]

Hummocky cross‐stratification is commonly observed in the marine offshore transition to lower shoreface environments. However, to date, the origins of hummocky cross‐stratification and its associated hummocky bedforms and hydrodynamic processes remain controversial and enigmatic. In the present study, a large‐scale flume experiment was conducted to study the formation of hummocky bedforms. In the central test area of the flume, combined flow with water waves, with period of 2 s and velocity of 0.34 m s−1, progressed at a right angle to a current with velocity of 0.17 m s−1, whereas a wave‐alone condition pertained upstream and downstream of the test area. The combined‐flow ripples in the test area had smaller dimensions than wave ripples, but their cross‐section geometries were very similar. Most importantly, the experimental results, for the first time, revealed that humps occur with lengths up to approximately 40 mm beneath combined flow ripples. The formation of these structures appears to relate to the enhanced turbulence for the combined flow, because the turbulence kinetic energy for combined flow was ca 50% higher than that under the wave‐only condition. Moreover, the observed small‐scale humps in the present experiment had comparable cross‐section geometries with hummock‐like bedforms previously reported in laboratories and fields under storm conditions. Additionally, these humps could scale up to large‐size hummocks under waves with longer period and faster velocity than the present conditions. The present experiment indicates that waves perpendicular to a current do generate hummock‐like structures in association with ripples and therefore provide a new perspective for future study of the origins of hummocky cross‐stratification. [ABSTRACT FROM AUTHOR]

Water current interaction with arrays of plates is studied by use of the computational fluid dynamics focusing on hydrokinetic energy production applications. Various configurations of arrays of equidistant rectangular plates are considered. The velocity and the pressure fields around an array of plates are determined, and the forces on individual plates are computed and compared with the empirical relations. It is found that the current-induced force on the leading plate in the array is substantially different from those on the downstream plates, which may experience negative forces, due to the change of the flow field. In three parametric studies, the effect of plate spacing, the number of plates, and the relative water depth on the current-induced forces is investigated. It is shown that the relative size of the plates and the number of plates in an array play a significant role on the current-induced loads. Finally, the relative direction of the plates and the incoming flow is changed, and its effect on the hydrodynamic forces on the plates is studied in a three-dimensional computational tank. The current loads on an oriented set of plates is shown to be remarkably different, when compared with those perpendicular to the current direction. It is concluded that the current-induced loads on an array of plates cannot be estimated by empirical relations, and specific computations, similar to those shown here, or laboratory experiments are required to investigate the current loads. [ABSTRACT FROM AUTHOR]

Inland waters are significant emitters of greenhouse gases for the atmosphere and play an important role in the global carbon cycle. With a vast land area in East Asia spanning a broad range of climatic conditions, China has a large number of natural and human‐made water bodies. These inland water systems are of global importance because of their high carbon emission fluxes. Over the past decades, China has experienced unprecedented environmental changes driven by rapid economic development, which have profoundly modified its inland water carbon biogeochemistry and associated emissions. This review focuses on carbon dioxide (CO2) and methane (CH4) emission dynamics from China's inland waters in response to global change. Major drivers of CO2 and CH4 emissions, including aquatic metabolism, hydrological and climatic factors, and prevailing human impacts, are examined. To advance our understanding of carbon emissions from China's inland waters, we further identify several critical knowledge gaps, such as inadequate research in headwater streams and the climate‐sensitive Tibetan Plateau aquatic ecosystems. Furthermore, insufficient understanding of carbon emissions from inland waters undergoing extensive human interventions (e.g., damming, flow regulation, pollution, and farming practices in aquaculture ponds) is highlighted. We suggest that future efforts should be made to better capture the spatiotemporal heterogeneity in dissolved CO2 and CH4 concentrations and fluxes across China as well as their long‐term trends. To overcome uncertainties in carbon sources and current flux estimates, future research to mechanistically understand carbon transport and transformation in Chinese inland waters and their underlying processes is particularly needed. Plain Language Summary: Inland waters (e.g., streams, rivers, lakes, reservoirs, and ponds) are important sources of greenhouse gases (i.e., CO2 and CH4) for the atmosphere, affecting the earth's carbon balance. With a vast land area (∼9.6 million km2) and diverse climate regions, China contains numerous natural and man‐made water bodies. Dissolved carbon dioxide (CO2) and methane (CH4) emissions from these inland water systems have been significantly disturbed by global climate change and human activities. This review focuses on the current research progress of CO2 and CH4 emissions from China's inland waters. Major factors controlling dissolved CO2 and CH4 emission dynamics are examined. Furthermore, we discuss the shortcomings of current research on inland water carbon emissions in climate‐sensitive regions and anthropogenically disturbed regions of China. There is a pressing need to strengthen the monitoring of aquatic CO2 and CH4 emissions over space and time and to gain a deeper understanding of the underlying mechanisms. Key Points: Chinese inland waters have significantly higher water‐to‐air carbon emission fluxes than lateral transport of carbon to the coastal oceanAquatic metabolism, hydrological and climatic factors, and human disturbance are main drivers regulating the aquatic carbon emissionsDynamics of CO2 and CH4 evasion from inland waters in China's climate‐sensitive and anthropogenically disturbed regions are understudied [ABSTRACT FROM AUTHOR]

Turbulence structures across the Antarctic circumpolar current (ACC) in the Indian Ocean at around 50°E were revealed using microstructure measurements. Depth‐averaged turbulent energy dissipation rates (ε) in 320 m segments estimated using a conductivity‐temperature‐depth (CTD)‐attached micro‐temperature fast‐response thermistor (FP07) were well reproduced using existing finescale parameterizations excluding near‐surface and near‐bottom 160 m. The spatial variations of ε are explained by density stratification N2, bottom topographic roughness, and depth‐averaged current speed U. Diapycnal diffusivity Kρ(=0.2εN−2) is found proportional to the squared internal wave energy (EIW2 ${E}_{IW}^{2}$) and increases toward the bottom, especially over rough bottom topography. The decay scale height is >1000m and the turbulence remains large even in the upper pycnocline. Existing shear‐based finescale parameterizations were generally consistent with the FP07 measurements but tended to overestimate in the areas with large shear‐strain ratio Rω and low ε in the Continental Zone (CZ) south of the ACC fronts (58–65°S). This overestimation is improved by using the strain‐based finescale parameterization with a constant Rω = 3. Plain Language Summary: Turbulent vertical mixing in the Southern Ocean is an important contributor to the meridional overturning circulation and material distribution, which are essential for understanding the climate and ecosystems of the Earth. It is therefore imperative to quantitatively estimate the vertical mixing in the Southern Ocean; however, direct measurements are scarce owing to the harsh weather conditions and the requirements of expensive instruments and specialist techniques. The present study demonstrated the full‐depth turbulent structures across the Antarctic Circumpolar Current (ACC) in the Indian Ocean using a recently developed technique for microstructure measurement based on fast‐response thermistor attached to a conductivity‐temperature depth (CTD) frame. This unprecedented turbulence data set implicated that internal waves generated by the effects of rough bottom topography propagate upward even near the surface with dissipating mainly with large density stratification, and confirmed the long (>1000 m) exponential decay scale of bottom roughness impact. The existing parameterizations formulated by wave‐wave interactions among internal waves generally agreed well with the micro‐temperature method measurements. In particular, the parameterization available only from CTD density profiles were reasonably consistent with micro‐temperature data. Key Points: Turbulence structures across the Antarctic Circumpolar Current in the Indian Ocean were revealed through micro‐temperature measurementsTopographic roughness enhances turbulence even in the upper layer (surface to 2000 m depth) with a large exponential decay scale >1000 mStrain‐based finescale parameterization with a fixed shear‐strain ratio (=3) works well in this region [ABSTRACT FROM AUTHOR]

Observations indicate that symmetric instability is active in the East Greenland Current during strong northerly wind events. Theoretical considerations suggest that mesoscale baroclinic instability may also be enhanced during these events. An ensemble of idealized numerical ocean models forced with northerly winds shows that the short time‐scale response (from 10 days to 3 weeks) to the increased baroclinicity of the flow is the excitation of symmetric instability, which sets the potential vorticity of the flow to zero. The high latitude of the current means that the zero potential vorticity state has low stratification, and symmetric instability destratifies the water column. On longer time scales (greater than 4 weeks), baroclinic instability is excited and the associated slumping of isopycnals restratifies the water column. Eddy‐resolving models that fail to resolve the submesoscale should consider using submesoscale parameterizations to prevent the formation of overly stratified frontal systems following down‐front wind events. The mixed layer in the current deepens at a rate proportional to the square root of the time‐integrated wind stress. Peak water mass transformation rates vary linearly with the time‐integrated wind stress. Mixing rates saturate at high wind stresses during wind events of a fixed duration which means increasing the peak wind stress in an event leads to no extra mixing. Using ERA5 reanalysis data we estimate that between 0.9 Sv and 1.0 Sv of East Greenland Coastal Current Waters are produced by mixing with lighter surface waters during wintertime due to down‐front wind events. Similar amounts of East Greenland‐Irminger Current water are produced. Plain Language Summary: Symmetric instability is a process that leads to the mixing of waters with different densities. Observations show that in winter, when winds blow from the north, along the coast of Greenland, symmetric instability occurs; however, observations are limited which makes it difficult to understand the effect of the instability on the ocean currents in the region. We test the hypothesis that symmetric instability leads to the production of dense waters which are known to form in the region and contribute to the Atlantic Meridional Overturning Circulation (or "ocean conveyor" (Broecker, 1991, https://doi.org/10.5670/oceanog.1991.07)). We find that symmetric instability makes waters at the ocean surface denser, so that subsequent cooling can make them dense enough to sink to the deep ocean. A second type of instability, called baroclinic instability leads to the development of a fresh water "lid" which sits on top of the newly formed water masses, isolating them from the atmosphere. State of the art climate models don't resolve symmetric instability which means they may not get the density structure in the sub‐polar North Atlantic correct, which could lead to errors in ocean heat transports which are important in determining the Earth's climate. Key Points: Gravitational and symmetric instabilities deepen the mixed layer proportional to the square root of time‐integrated down‐front wind stressTime‐mean water mass transformation rates are linearly proportional to the time‐integrated down‐front wind stressDown‐front winds transform 0.9–1.0 Sv of buoyant surface water into East Greenland Coastal Current water between November and April [ABSTRACT FROM AUTHOR]

Mesoscale eddies play an important role in transporting water properties, enhancing air‐sea interactions, and promoting large‐scale mixing of the ocean. They are generally referred to as "coherent" structures because they are organized, rotating fluid elements that propagate within the ocean and have long lifetimes (months or even years). Eddies have been sampled by sparse in‐situ vertical profiles, but because in‐situ ocean observations are limited, they have been characterized primarily from satellite observations, numerical simulations, or relatively idealized geophysical fluid dynamics methods. However, each of these approaches has its limitations. Many questions about the general structure and "coherence" of ocean eddies remain unanswered. In this study, we investigate the properties of seven mesoscale eddies sampled with relative accuracy during four different field experiments in the Atlantic. Our results suggest that the Ertel Potential Vorticity (EPV) is a suitable parameter to isolate and characterize the eddy cores and their boundaries. The latter appear as regions of finite horizontal extent, characterized by a local extremum of the vertical and horizontal components of the EPV. These are found to be closely related to the presence of a different water mass in the core (relative to the background) and the steepening of the isopycnals due to eddy occurrence and dynamics. Based on these results, we propose a new criterion for defining eddies at the mesoscale. We test our approach using a theoretical framework and explore the possible magnitude of this new criterion, including its upper bound. Plain Language Summary: Mesoscale eddies are ubiquitous rotating currents in the ocean. They are considered as one of the most important sources of ocean variability because they can live for months and transport and mix heat, salt, and other properties within and between ocean basins. They have been studied extensively from satellite observations because they are often at or near the ocean surface. However, observations of their 3D structure are rare, and calculations of eddy transport are often approximated without precise knowledge of their true vertical extent. In addition, recent studies suggest the existence of subsurface eddies that are not detectable from satellite observations. Here, we characterize and attempt to generalize 3D eddy properties by analyzing observations collected during specific high‐resolution field experiments in the Atlantic Ocean. We also propose a criterion, based on geophysical fluid dynamics theory, that defines the lateral and vertical eddy boundaries. This criterion can be applied broadly to assess eddy structure, volume, transport, and evolution more quantitatively than in previous studies. We also provide insight into why these boundaries are substantial, which may explain why oceanic eddies are coherent structures that can span long distances and have long lifetimes. Key Points: A new criterion that compare the horizontal and vertical components of Ertel PV is introduced to characterize eddies boundariesEddy boundaries behave like a frontThe Rossby number and the vertical stratification anomaly drive eddies boundaries intensity [ABSTRACT FROM AUTHOR]

The dynamics of sediments entering lakes in river plumes is virtually unknown. This field study provides unprecedented evidence of the initiation and evolution of suspended sediment flocculation in the nearfield of the negatively‐buoyant Rhône River plume, flowing as interflow in the thermocline of stratified Lake Geneva. Sediment floc property changes (formation, size, composition, shape) with depth and distance from the mouth, were determined by combining digital holographic camera LISST‐HOLO data with full‐depth in situ profiles of particle size (LISST‐100X), density, turbidity, currents and water samples taken along the plume path. The total suspended matter volume of inflowing Rhône River waters (∼155 mg l−1) mostly consisted of clays (<4 μm), very fine silts (4–8 μm) and small contributions of microflocs (20–100 μm). This composition was also found in the interflow plume core. Above the plume, in the epilimnion, fine silts, microflocs and numerous phytoplanktonic organisms (∼200 μm) were observed, representative of the lake background. High levels of shear (15–27 s−1) and turbulence occurred in the shear layer that formed between the interflow bottom and the hypolimnion below. It was found that macroflocs only formed in this shear layer. In the hypolimnion, sediment load was the lowest and macroflocs (up to ∼300 μm) composed of inorganic particles were dominant. The size of the largest flocs was limited by the size of the smallest turbulent eddies determined by the Kolmogorov microscale. Floc 3D fractal dimensions of ∼2.1–2.5 suggest an intermediate shape complexity between marine snow and sludge flocs. Plain Language Summary: Suspended sediments with potentially hazardous substances adsorbed to them can enter lakes via river inflow, and thus can significantly impact lake water quality. It is therefore essential to understand their dynamics and fate in order to optimize water management policies. Suspended sediment aggregation (flocculation) is a process that allows aggregated particles to settle faster than primary particles, thereby affecting transport, dispersion and flux of suspended particles. Flocculation of suspended sediments is well documented in fluvial, estuarine and marine environments, but has rarely been investigated in lakes. In a new approach based on holographic camera images and water samples, this study, carried out in Lake Geneva, describes for the first time, the formation and evolution of large aggregates of sediments (flocs) along a river plume pathway in a large lake. Turbulence measurement revealed that a sufficient level of shear enhances floc formation in the shear layer at the bottom boundary of the plume, while the smallest turbulent eddies limit floc size. This knowledge is crucial, since it determines how sediment particles will spread or be deposited. Furthermore, our findings demonstrate that results from marine systems and estuaries cannot be directly applied to river plume interflows in lakes. Key Points: Unprecedented evidence of initiation/evolution of suspended sediment flocculation in a river plume interflow nearfield in a lake is providedIn the nearfield, all along the interflow path, macroflocs only formed in the shear layer between the interflow and the hypolimnion belowKolmogorov microscale limits macrofloc size, floc 3D fractal dimensions suggest a shape complexity between marine snow and sludge flocs [ABSTRACT FROM AUTHOR]

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Whole lake residence time has been associated with various water quality parameters, including harmful algal blooms. Despite observations of spatial variability in commonly measured lake water quality parameters, little attention is given to the spatial variability of residence time in lakes. In this paper we use water age as a surrogate for residence time and we examine its spatial and temporal distribution in 10 bays of varying size in Lake George, New York (USA). Using a validated hydrodynamic model against observations of water temperature and water currents, and using simulated water age, we show that the average residence time in most of the bays is less than 3 days. Timeseries of bay‐average water age shows that it can sharply decrease within 1 day due to a strong wind event. The average spatial distribution is shown to be non‐uniform, with only a small section of the bottom layer of the bays having a substantially greater age, which may be more than 1 week in certain bays. Snapshots of water age transects indicate that strong wind events substantially change the vertical distribution of water age in some bays, even to the extent of inverting the distribution. The substantial decreases of water age in the bays were associated with the shallowing and deepening of the thermocline. Our results highlight how variations in water residence times within lakes could introduce substantial variation in water quality attributes. Whole lake residence times may serve as a poor proxy to understand the dynamics of water masses, especially in large and morphologically complex waterbodies. Key Points: Simulation of water age with a validated hydrodynamic model against temperature and currentsAverage water age (surrogate to residence time) in bays is smaller than 6 daysSpatial distribution of water age within bays is not uniform and strong wind events lead to lower water age within 1 day [ABSTRACT FROM AUTHOR]

We examined the relationship between water risk and the information environment of financial analysts using data from Chinese listed companies from 2010 to 2020. We theorized that corporate water risk deteriorates analysts' information environment by affecting operational and financial uncertainty and corporate legitimacy. Specifically, we found that corporate water risk is associated with higher analyst forecast errors and analyst forecast dispersion and lower analyst following. This relationship weakens with corporate water information disclosure and strengthens with the environmental attention of local governments. Furthermore, we explored the impact of corporate water risk on financial risk and future financial performance and discovered that water risk increases corporate financial risk and reduces future earnings. This suggests that corporate nonfinancial risk may also include subtle financial risk, and current water risk has a certain predictive effect on future earnings, which is an interesting finding. Our results are robust to a range of tests, including instrumental variable, generalized method of moments estimates, propensity score matching, and alternative measures of analysts' information environment. Generally, our study provides insights into the complementary role of nonfinancial risks represented by water risk in understanding financial risk and has important implications for academia and practitioners in understanding the economic consequences of corporate water risk. [ABSTRACT FROM AUTHOR]

In this paper, the ditching performance of a seaplane model on calm water and a uniform water current coupled with wind was numerically investigated. The overset grid technique was applied to treat the large amplitude of the body motions of the seaplane without leading to mesh distortion. The effects of the initial velocity and the initial pitch angle on the slamming loads and motion responses were investigated for the seaplane's ditching on calm water. A good agreement with the experimental data on the velocity and angle was obtained. Besides ditching on calm water without the water current and wind, three more-complicated conditions were adopted, including the seaplane's ditching on calm water with wind, a water current without wind, and a water current coupled with wind. The accelerations and impact pressures of the seaplane can be influenced by the wind or current. Water splashing and overwashing could be observed during the water entry process, with water overtopping the seaplane head or nose and flowing over the body surface. It can be concluded that the relative motion between the water and the seaplane model should be carefully controlled to avoid possible damages caused by the occurrence of overwashing. [ABSTRACT FROM AUTHOR]

The high-resolution analysis of radiolarians and silicoflagellates in sediments from Holes U1545A and U1549A drilled during IODP Expedition 385 in the Guaymas Basin, in the Gulf of California provides detailed insights into the evolution of ocean circulation and water masses, and its relation to Eastern Tropical Pacific Ocean climate conditions, over the past 31,000 cal years BP (based on AMS radiocarbon dates). In the pre-Last Glacial Maximum, the Guaymas Basin experienced alternating circulation patterns of California Current Water (CCW) and Gulf of California Water (GCW), with an extended presence of the Pacific Intermediate Water (PIW) owing to: amplified jet streams; southern movement of the California Current System (CCS) and the incursion of CCW into the gulf; and increased North Pacific Intermediate Water (NPIW) formation. The Last Glacial Maximum witnessed the incursion of CCW due to the stronger CCS. The dominance of the PIW indicates the expansion and formation of NPIW. The Heinrich-I event as manifested in the core record, displays two distinct patterns, one suggesting GCW-like dominance and the other, the occurrence of CCW. The Bølling-Ållerød interstadial featured the entry of Tropical Surface Water (TSW), GCW, and CCW, linked with the northward migration of the Intertropical Convergence Zone. In the Younger Dryas, CCW dominated, transitioning to GCW as colder climatic conditions and more intense CCS. The Holocene displayed alternating periods of TSW and GCW, with a modern monsoon regime from 7,600 to 1,000 cal years BP. From 1,000 cal years BP to the present the ITCZ shifted to the south. [ABSTRACT FROM AUTHOR]

This paper discusses the technical and economic feasibility of a renewable energy-based system, aimed to replace the traditional diesel engines implemented on a pushed and pusher bulk carrier barge. This barge has a challenging navigational route in the Nile River from Alexandria to Aswan and vice versa. It is scheduled to complete 30 trips annually while carrying 850 tons/trip. The system is based on photovoltaic panels, and was selected with its excess energy to be stored primarily in the form of H 2 gas through electrolysis, and batteries (i.e. Power to Gas technology) to be later converted back to electrical energy through fuel cells. Hence, an operation algorithm was formulated to optimize the performance of the system by defining operating modes that use solar energy, hydrogen energy, batteries, or hybrid energy coming from multiple sources that result in an internal rate of return (IRR) of 15.1% and overall efficiency of 57.9%. This high efficiency is due to the nature of water current that flows from south to north of Egypt, therefore, causing a significant reduction in power demand in the trip from Aswan to Alexandria that requires 11,980 kW h, compared to the trip from Alexandria to Aswan that requires 21,064 kW h. • Zero emission solution combining solar energy, hydrogen generation and fuel cell propulsion for a barge in Nile River. • Preparation to achieve the 7th goal of sustainable development ensuring green propulsion in Nile River cargo transport. • Efficient use of natural resources, solar energy and water current from south to north of Egypt. • Integrating electrolizer, fuel cell, solar energy pv, batteries, and hydrogen storage to form an autonomous barge. [ABSTRACT FROM AUTHOR]

Water reuse, the beneficial use of highly treated municipal wastewater (reclaimed water), is expanding throughout the United States (U.S.); however, there are currently no federal reclaimed water use regulations, only guidelines. As a result, state policies on reclaimed water vary widely, emphasizing the need for a comprehensive understanding to facilitate coordinated national planning. Our systematic literature review, utilizing an online legal research database, presents an updated overview of U.S. reclaimed water policies from 2004 to 2023. A novel categorization scheme tracks policy changes, highlighting a 38% increase in states regulating reclaimed water between 2004 and 2023. We also created maps of current reclaimed water use regulations across the U.S. including: (1) a national overview of the reclaimed water policy landscape; and (2) documentation of non-food crop and food crop irrigation policies. As of November 2023, 74% of states (37/50) intentionally regulated reclaimed water use. Regions with historically low water scarcity, such as the Midwest, exhibited lower participation rates in reclaimed water regulation than water-scarce regions in the West. Of the 37 states regulating direct reclaimed water use in 2023, all allowed for at least some agricultural uses; 23 permitted non-food and food crop production use, while 14 states have statutory allowances for direct reclaimed water use on non-food crop production. As climate change stresses freshwater resources, our work provides up-to-date information for policymakers to navigate existing reclaimed water use policies. [ABSTRACT FROM AUTHOR]

Very complex aquatic ecosystem, the mangrove forest colonizes coastal lagoons, estuaries and deltas in tropical and subtropical zones. This study investigates the impact of mangrove vegetation on tidal propagation in the Somone Coastal Lagoon, located on the Senegalese small coast. The analysis of new field data is complemented with the application of a 3D circulation model accounting for vegetation. The analysis of well-reproduced water levels and currents over the whole lagoon make it possible to spatially study the amplitudes of the main tidal harmonics, semi-diurnal (M2), diurnal (K1) and the major overtide (M4). The comparison between our baseline model accounting for vegetation and a configuration without vegetation reveals firstly that the mangrove strongly attenuates tidal propagation in the lagoon, whit a stronger impact on semi-diurnal waves than diurnal waves. Tidal currents are also strongly reduced when the mangrove is accounted for, even close to the inlet mouth, far away from vegetation areas. The mangrove also enhances tidal asymmetry and promotes ebb dominance, both in terms of duration (ebbs last from 0.5 up to 3 h more than floods) and current magnitude (ebb currents are about 50% stronger). Spring tides accentuate ebb-dominance compared to neap tides, where tidal asymmetry is weaker. [ABSTRACT FROM AUTHOR]

The Barents Sea, an important component of the Arctic Ocean, is experiencing shifts in ocean currents, stratification, sea-ice variability, and marine ecosystems. Inflowing Atlantic Water (AW) is known to be a key driver of change. Although AW predominantly enters the Barents Sea via the Barents Sea Opening, other pathways exist but remain relatively unexplored. Summer climatology fields of temperature in the last century compared to 2000–2019 indicate warming in the trench Storfjordrenna and the shallow banks Hopenbanken and Storfjordbanken in the Svalbard Archipelago, and shoaling of AW, extending further into the 'channel' between Edgeøya and Hopen islands. This region emerges as a pathway of AW into the northwestern Barents Sea. One year-long records from a mooring deployed between September 2018 and November 2019 at a saddle in this channel, show the flow of Atlantic-origin waters into the Arctic domain of the northwestern Barents Sea. The average current is directed eastward, into the Barents Sea, but is dominated by large variability throughout the year. Here, we investigate this variability on time scales from hours to months. Wind forcing mediates the currents and the water and heat exchange through the channel through geostrophic adjustment to Ekman transport. The main drivers for the AW inflow and the cross-saddle transport of positive temperature anomalies are persistent strong semidiurnal tidal currents, intermittent wind-forced events, and wintertime warm water intrusions forced by upstream conditions. We propose that similar topographic constraints where the Polar Front acts like a barrier may become more important for AW inflow and heat exchange in the future. The ongoing warming and possible shoaling of AW together with changes in the large-scale weather patterns would likely increase inflow and heat transport through the processes identified in this study. [ABSTRACT FROM AUTHOR]

The current research aimed to study the effect of monthly changes on the density and distribution of the two most common snails, Melanopsis nodosa and Melanopsis costata, in five stations in the middle part of the Shatt alArab River. It provides us with knowledge of the intertidal area on banks of the Shatt Al-Arab coast that the environment is suitable for the life of these species of snails in the lowest tidal region; these species were found in high densities during months of Spring and Autumn seasons compared with Summer and Winter at all stations, which indicates the effect of the moderation of temperature on the density and distribution of these species. The statistical analysis showed an inverse correlation between the density of snails, salinity, and current waters of the Shatt al-Arab River and a positive correlation between the density with water temperature and pH. However, the excessive rise in water temperatures of the Shatt al-Arab, which was associated with the rise in the concentration of salinity during most of the Summer months as a result of the decrease in water releases, which was originally caused by climate changes and problems with the upstream countries neighboring Iraq, which caused sharp decreases in the densities of individuals of these species. [ABSTRACT FROM AUTHOR]

As a part of the hydrofoil optimisation project for windsurfing, a system for measuring vessel motions, weather elements and water conditions was developed. By measuring the speed, acceleration, angular velocity, inclination and direction of the vessel movement and weather elements in real time, the hydrodynamic optimisation process of hydrofoils was accelerated. Measurements were performed with a measuring device attached to the observed vessel, while measurements of weather elements and sea conditions were performed with another device on the accompanying vessel. Wind speed, direction and temperature, environmental temperature, atmospheric pressure, surface water current and wave properties were measured. By combining data from both devices, a database was created on the state of the environment and the vessel motions. Analysis of the database provided the necessary data for the hydrodynamic optimisation of the hydrofoil. The polar diagram of the vessel speed in relation to the speed and direction of the wind, together with the data on the inclinations of the hydrofoil and the angle between the direction of movement and the pointing direction at the moments of reaching the maximum speed, accelerate the hydrofoil hydrodynamic optimisation process. [ABSTRACT FROM AUTHOR]

The Weddell Gyre is one of the dominant features of the Southern Ocean circulation and its dynamics have been linked to processes of climatic relevance. Variability in the strength of the gyre's horizontal transport has been linked to heat transport toward the Antarctic margins and changes in the properties and rates of export of bottom waters from the Weddell Sea region to the abyssal global ocean. However, the precise physical mechanisms that force variability in the Weddell's lateral circulation across different time scales remain unknown. In this study, we use a barotropic vorticity budget from a mesoscale eddy active model simulation to attribute changes in gyre strength to variability in possible driving processes. We find that the Weddell Gyre's circulation is sensitive to bottom friction associated with the overflowing dense waters at its western boundary. In particular, an increase in the production of dense waters at the southwestern continental shelf strengthens the bottom flow at the gyre's western boundary, yet this drives a weakening of the depth-integrated barotropic circulation via increased bottom friction. Strengthening surface winds initially accelerate the gyre, but within a few years the response reverses once dense water production and export increases. These results reveal that the gyre can weaken in response to stronger surface winds, putting into question the traditional assumption of a direct relationship between surface stress and gyre strength in regions where overflowing dense water forms part of the depth-integrated flow. [ABSTRACT FROM AUTHOR]

The article discusses the importance of water resources and the challenges they face. It describes the history of humanity's relationship with water, from the early manipulation of water resources to the current age of scientific advancements and infrastructure development. However, the article also highlights the negative consequences of these developments, such as threats to ecosystems, water pollution, and lack of access to safe water and sanitation. The author argues for a transition to a more sustainable future, where everyone has access to safe water, ecosystems are protected, and climate change is addressed. The article emphasizes the possibility of achieving this positive future through technological innovations and international cooperation. [Extracted from the article]

Hip implants have a modular structure which enables patient-specific adaptation but also revision of worn or damaged friction partners without compromising the implant-bone connection. To reduce complications during the extraction of ceramic inlays, this work presents a new approach of a shape-memory-alloy-actuator which enables the loosening of ceramic inlays from acetabular hip cups without ceramic chipping or damaging the metal cup. This technical in vitro study exam-ines two principles of heating currents and hot water for thermal activation of the shape-memory-alloy-actuator to generate a force between the metal cup and the ceramic inlay. Mechanical tests concerning push-in and push-out forces, deformation of the acetabular cup according to international test standards, and force generated by the actuator were generated to prove the feasibility of this new approach to ceramic inlay revision. The required disassembly force for a modular acetabular device achieved an average value of 602 N after static and 713 N after cyclic loading. The actuator can provide a push-out force up to 1951 N. In addition, it is shown that the necessary modifications to the implant modules for the implementation of the shape-memory-actuator-system do not result in any change in the mechanical properties compared to conventional systems. [ABSTRACT FROM AUTHOR]

Objective: Estimate preferences and Willingness to Pay (WTP) for improvements in the attributes of the recreation ecosystem service, based on changes in Crowding, Species Abundance, and Water Visibility of the APFF-Balandra. Methodology: An analysis of stated preferences consisting of a choice experiment was carried out to estimate the WTP. Results: The presence of heterogeneity of preferences for the valued attributes was confirmed, highlighting that most visitors registered an improvement in their well-being due to the 25% increase in the abundance of species recorded in the area. Limitations: The study only considered main effects in the design of the choice experiment. Conclusions: From the analysis of latent classes, it was concluded the presence of two subgroups that register improvements in their welfare derived from an incremental change in the abundance of species, as well as a marked disutility due to increases in the level of crowding and visibility of the water with respect to the current state. [ABSTRACT FROM AUTHOR]

The freshwater phase of the first seaward migration of juvenile Atlantic salmon (Salmo salar) is relatively well understood when compared with our understanding of the marine phase of their migration. In 2021, 1008 wild and 60 ranched Atlantic salmon smolts were tagged with acoustic transmitters in 12 rivers in England, Scotland, Northern Ireland and Ireland. Large marine receiver arrays were deployed in the Irish Sea at two locations: at the transition of the Irish Sea into the North Atlantic between Ireland and Scotland, and between southern Scotland and Northern Ireland, to examine the early phase of the marine migration of Atlantic salmon smolts. After leaving their natal rivers' post‐smolt migration through the Irish Sea was rapid with minimum speeds ranging from 14.03 to 38.56 km.day−1 for Atlantic salmon smolts that entered the Irish Sea directly from their natal river, to 9.69–39.94 km.day−1 for Atlantic salmon smolts that entered the Irish Sea directly from their natal estuary. Population minimum migration success through the study area was strongly correlated with the distance of travel, populations further away from the point of entry to the open North Atlantic exhibited lower migration success. Post‐smolts from different populations experienced different water temperatures on entering the North Atlantic. This was largely driven by the timing of their migration and may have significant consequences for feeding and ultimately survivorship. The influence of water currents on post‐smolt movement was investigated using data from previously constructed numerical hydrodynamic models. Modeled water current data in the northern Irish Sea showed that post‐smolts had a strong preference for migrating when the current direction was at around 283° (west‐north‐west) but did not migrate when exposed to strong currents in other directions. This is the most favorable direction for onward passage from the Irish Sea to the continental shelf edge current, a known accumulation point for migrating post‐smolts. These results strongly indicate that post‐smolts migrating through the coastal marine environment are: (1) not simply migrating by current following (2) engage in active directional swimming (3) have an intrinsic sense of their migration direction and (4) can use cues other than water current direction to orientate during this part of their migration. [ABSTRACT FROM AUTHOR]

Indonesian Marine Energy Association 2014 provided the results of ratifying the potential of ocean current energy in Indonesia of 17,989 MW. The amount is quite large for the results of several potential points in the territory of Indonesia. However, the potential of ocean currents in Indonesia has not been utilized optimally, even though the current turbine technology is developing rapidly in the world. The existing turbine technology that is already available worldwide cannot be applied directly in Indonesia. This is because the water condition in Indonesia is classified as low-speed current, unlike some countries in the world which are classified as high-speed current. Therefore, a turbine that can work in the condition of the territorial waters in Indonesia, in general, with a low current speed is needed. The turbine technology used in this study consists of turbine A (without a flow disturber) and turbine B (with a single flow disturber). The purpose of this study was to determine the increase in turbine performance at low current speeds. The method used in this study was an in-situ experiment because it was closer to the actual conditions. The results obtained from this study indicated that the addition of a single flow disturber could increase turbine performance at all variations of current speed, namely 0.4, 0.88, and 1 m/s. The most exciting result was that under the low current speed of 0.4 m/s, adding a single flow disturber could increase the ability to self-start from 0 rpm to 7.180 rpm and efficiency from 0 to 4%. In addition, at a current speed of 0.88 m/s with the addition of a single flow disturber, it could increase efficiency from 10.8% to 11.1%. At a current speed of 1 m/s with the addition of a single flow disturber, it could increase efficiency from 16.6% to 18%. That is, turbine B (with a single flow disturber) is very suitable to be applied in the territorial waters of Indonesia, which tend to have low current velocity [ABSTRACT FROM AUTHOR]

Simple Summary: Cetaceans, which include dolphins, porpoises, and whales, show astounding and distinctly specialised adaptations of their senses that allow them to thrive in the aquatic environment. They possess the abilities to echolocate, are likely to discern bioelectric fields, sense water currents, and perform various other sensory tasks, amidst shifting and challenging environmental circumstances. For many of their senses, we still lack a basic understanding of their underlying physiology. In this review, we provide a summary of the neuroanatomical knowledge of cetacean sensory systems to date. We describe the peripheral sensory cells in organs like the eye, ear, and skin, and trace the nervous pathways up to the brain where the signals are processed in dedicated areas. We highlight recent advances and knowledge gaps that exist at the various anatomical levels, accentuating the pressing need for further research to bridge these knowledge gaps. Cetaceans have undergone profound sensory adaptations in response to their aquatic environment during evolution. These adaptations are characterised by anatomo-functional changes in the classically defined sensory systems, shaping their neuroanatomy accordingly. This review offers a concise and up-to-date overview of our current understanding of the neuroanatomy associated with cetacean sensory systems. It encompasses a wide spectrum, ranging from the peripheral sensory cells responsible for detecting environmental cues, to the intricate structures within the central nervous system that process and interpret sensory information. Despite considerable progress in this field, numerous knowledge gaps persist, impeding a comprehensive and integrated understanding of their sensory adaptations, and through them, of their sensory perspective. By synthesising recent advances in neuroanatomical research, this review aims to shed light on the intricate sensory alterations that differentiate cetaceans from other mammals and allow them to thrive in the marine environment. Furthermore, it highlights pertinent knowledge gaps and invites future investigations to deepen our understanding of the complex processes in cetacean sensory ecology and anatomy, physiology and pathology in the scope of conservation biology. [ABSTRACT FROM AUTHOR]