Deep Ocean Engineering (United States)

Located in the subtropics, the record-breaking extreme rainfall (ER) that struck Dubai on April 16, 2024, provides a high-impact case for diagnosing subtropical jet–moist-convection coupling from an energetics perspective. This study applies the perturbation potential energy (PPE) framework to diagnose the energetics of this event. We develop an energetically closed, self-reinforcing energy-pump feedback mechanism, identify extreme conditions using the Rank Attribution Method relative to the 1979–2024 baseline, and quantify moisture source contributions using the Water Accounting Model (WAM). The energetics exhibit clear precursors, with stratospheric PPE and upper-tropospheric perturbation kinetic energy (PKE) becoming significantly anomalous 24–48 h before rainfall onset. Critically, as the bridge between PPE and PKE, the perturbation conversion from PPE to PKE term (PCK) leads to rainfall by about 2 h and effectively anchors both subsequent intensity and the primary rainband. When PCK intensifies, PKE increases in both the upper and lower troposphere, enhancing upper-tropospheric divergence and lower-tropospheric convergence; ascent then accelerates and rainfall amplifies. Latent heating (LH) further warms the column, increases PPE, and strengthens conversion, closing the positive energy-pump feedback loop (LH–PPE–PCK–PKE–LH) that sustains deep convection. Two distinct episodes in this event share this mechanism but differ dynamically: Process I is upper-level dominated and primarily jet-divergence forced, whereas Process II is lower-tropospheric dominated with stronger moisture transport, producing a more rapid rise to peak intensity. Moisture sourcing is dominated by the northwestern Arabian Sea (50.4%), with secondary contributions from the Red Sea (8.2%), the Gulf of Aden (6.7%), and the eastern Mediterranean (4.5%). These results deepen understanding of the energetics of ER over the Arabian Peninsula and highlight PCK as a physically based early-warning indicator for forecasting and risk assessment.

Hydrothermal vent fields harbour a heterogeneous seascape owing to complex topography and vent fluid emissions, including in peripheral areas beyond active venting. At the Lucky Strike hydrothermal vent field, a remotely operated vehicle was used to acquire two hectares of seabed imagery to evaluate the role of environmental conditions on the structure and distribution of benthic communities. Our analyses revealed that large and mature edifices are potential keystone structures supporting hotspots of vent specialists (e.g., Bathymodiolus azoricus)and associated fauna (e.g., Zoanthidae). Higher densities of mobile bathyal shrimps were found in slabs adjacent to active venting areas. Communities occupying areas with lower hydrothermal exposure displayed significantly higher diversity than areas located closer (≤ 40m) to vent emissions. Between 40 and 120m from active sites, community diversity was greatest on hard substrata dominated by sessile organisms-such as octocorals, Cladorhizid and Hexactinellid sponges-in greater densities when these substrates were composed of basalt with complex topography. While the gradient in hydrothermal exposure creates a spatial zonation of benthic communities, abundance and diversity patterns remain locally conditioned by seabed topography and substratum hardness. This interplay fosters a patchwork of faunal communities at the decametre scale. These results underscore the complexity of designing surveys encompassing the diversity of habitat conditions within the deep hydrothermal seascape. Although historically overlooked, the diversity of distinct benthic communities beyond venting zones emphasises the ecological significance and vulnerability of areas that could be targeted by mining.

Manganese nodules in the Clarion-Clipperton Fracture Zone (CCZ) of the eastern Pacific Ocean have been considered a target for the development of useful metal resources for more than half a century, due to the depletion of onshore resources and advances in mining technology, and are currently the closest to development. Because sediment surface disturbances and suspended plumes are expected to occur due to manganese nodule mining, characterizing sediments in exploitable areas as an environmental baseline is important to minimizing impacts on the marine environment. Here, we report on sediment properties in the Japanese exploration areas, DORD West Area and APEI-10, an area of particular environmental interest, in the western CCZ, where data are scarce compared with the eastern CCZ. We analyzed grain-size composition, chemical composition, and metals, including mercury, to a depth of 20 cm in the sediment. Based on the distribution patterns, metals were divided into group 1 (Mn, Ni, Cu, Zn, Cd, and rare earth elements), group 2 (Fe, Cr, As, and Pb), and group 3 (Hg), with each group observed to be affiliated with manganese oxides, silicate minerals, and organic materials, respectively. Mercury concentrations (<10 ng g−1 to 102 ng g−1) were comparable to those of deep basins; nevertheless, their fluxes were very low, reflecting the limited sedimentation of organic matter. The bulk compositions of the sediments from the western CCZ in this study were similar to those in the eastern-to-central CCZ, although the strong manganese concentrations in the topmost 10 cm of the eastern CCZ were not observed here. We suggest that during the last glacial period, when bottom-water dissolved oxygen concentrations were lower, the east–west gradient of surface primary production and organic matter flux was stronger than today, resulting in less extensive manganese reduction in surface sediments in the western CCZ.

The growing global energy sector demands battery systems with enhanced stability and operational safety. Aqueous zinc-ion energy-storage-integrated batteries have emerged as potential candidates due to their high theoretical capacity and environmentally benign aqueous electrolytes. Despite continuous advances in battery-related technologies, current systems still face challenges in balancing mechanical robustness with energy density for structural energy-storage applications. To address these limitations, we developed a triangular stabilized ether–water–epoxy hybrid structural membrane system by incorporating a tetraglyme additive into zinc trifluoromethanesulfonate solution, which was infused into a porous epoxy resin membrane. This ether–water–epoxy hybrid structural membrane system effectively inhibits zinc dendrite formation while exploiting its antiswelling characteristics to preserve mechanical integrity (swelling ratio <2% after 48 h immersion and maintained a tensile strength of 6.8 MPa). The optimized battery demonstrated exceptional cycling stability (>880 h at 1.0 mA cm–2 and 1.0 mAh cm–2) while achieving 83.2% capacity retention over 400 cycles at 1 C. Furthermore, the structural energy device retained >80% capacity after 100 cycles under 0.5 C while withstanding bending stresses exceeding 400 MPa. Remarkably, the structural energy device achieved complete in situ full mechanical and electrochemical recyclability under 300 MPa bending stress, demonstrating a great potential for application in the field of both sustainable materials and structural energy-storage devices.

Abstract Barrier islands are especially vulnerable to hurricanes and other large storms, owing to their mobile composition, low elevations, and detachment from the mainland. Conceptual models of barrier‐island evolution emphasize ocean‐side processes that drive landward migration through overwash, inlet migration, and aeolian transport. In contrast, we found that the impact of Hurricane Dorian (2019) on North Core Banks, a 36‐km barrier island on the Outer Banks of North Carolina, was primarily driven by inundation of the island from Pamlico Sound, as evidenced by storm‐surge model results and observations of high‐water marks and wrack lines. Analysis of photogrammetry products from aerial imagery collected before and after the storm indicate the loss of about 18% of the subaerial volume of the island through the formation of over 80 erosional washout channels extending from the marsh and washover platform, through gaps in the foredunes, to the shoreline. The washout channels were largely co‐located with washover fans deposited by earlier events. Net seaward export of sediment resulted in the formation of deltaic bars offshore of the channels, which became part of the post‐storm berm recovery by onshore bar migration and partial filling of the washouts with washover deposits within 2 months. This event represents a volumetric setback in the overwash/rollover behavior required for barrier transgression, but the new ponds and lowland habitats may provide beneficial habit for endangered species and will likely persist for years.

Mapping of short metagenomic (or metatranscriptomic) read data to reference isolate or single-cell genomes or metagenome-assembled genomes (MAGs) to assess microbial population relative abundance and/or structure represents an essential task of many studies across environmental and clinical settings. The filtering for the quality of the read match and assessment of read mapping results are frequently performed without visual aids or with the assistance of visualizations produced through ad-hoc, in-house approaches. Here, we introduce RecruitPlotEasy, a fully automated, user-friendly pipeline for these purposes that integrates statistical approaches to quantify intra-population sequence and gene-content diversity and identify co-occurring relative populations in the sample. Hence, RecruitPlotEasy should also greatly facilitate population genetics studies.RecruitPlotEasy is implemented in Python and R languages and is freely available open source software under the Artistic License 2.0 from https://github.com/KGerhardt/RecruitPlotEasy.

Working in the virtual world is different to real experiment in field. Nowadays, with remote sensing and new analysis programs we can assure a quick response and with less costs. The problem is efficiency of these methods and formulation of an exact response with low errors to manage an environmental risk. The objective of this article is to ask question about performance of some tools in this decision making in Morocco. The study uses (Test 1: TaylorFit Multivariate Polynomial Regressions (MPR); Test 2: SAS Neural Network (NN) to modeling relationship between European Center for Medium-Range Weather Forecasts dataset and NDVI eMODIS-TERRA at arid Eastern Morocco. The results revealed that the both test could accurately predict future scenario of water stress and livstock production decrease. The experience shows that virtual work with Artificial Intelligence is the future of ecological modeling and rapid decision-making in case of natural disasters.

Direct catalytic coupling of nitrobenzene hydrogenation and cyclohexanol dehydrogenation was studied in the gas phase over mesoporous MgO-SBA15 supported Cu nanoparticles. This approach avoids an external supply of H2 and utilizes the in situ liberated H2 from the dehydrogenation step of the first reactant for the hydrogenation reaction of the second reactant. A catalyst series consisting of four Cu/MgO-SBA15 mesoporous solids with varying Cu loadings (5–20 wt%) were prepared and systematically characterized by BET, ICP, XRD, TPR, TPD, FT-IR, SEM, XPS, and TEM. Among the series, the 15 wt% Cu catalyst exhibited the best performance with ≥82% conversion of nitrobenzene along with ≥89% cyclohexanol conversion. In addition, significantly higher yields of cyclohexanone (83%) and aniline (75%) could be achieved successfully over the same catalyst. Furthermore, the catalyst exhibited almost stable activity during 30 h time-on-stream with slow deactivation. The highly ordered mesoporous silica increases the metal–support interaction with smaller particles of Cu on the surface, and the synergism between acid–base sites is responsible for the improved catalytic activity.

Two new flow regimes named unstable dripping and unstable jetting are identified in aqueous droplet generation within high inertial air flow inside a T-Junction microchannel.

Background and Objective: A Setiu Wetland located in Terengganu, Malaysia is well modelled using a commercial software so called the MIKE 3 DHI which the two-dimensional model of flow model was used in this study to simulate the hydrodynamic causes by the event of flood and ebb cycles at the inlet of estuary.Methodology: The area of the study was model as according to actual situation and with appropriate initial and boundary condition were used in order to run the simulation.In ensuring the computational model is successful, the results obtained from computational model are compared with actual data.It observes that the model performed well with the actual data of the surface elevation where root mean square error ranges between 0.1716-0.3797m and the bias ranges between -0.2979 to 0.097.Results: The simulation results show that the highest current velocities found on June, 2014 due to interchanges of Southwest monsoon into Northeast monsoon but on November, 2014 the current velocities were very low and during February, 2015 the current velocities getting stronger back at the end of Northeast monsoon season.Conclusion: The modelling outcome from this study could be further explore for investigating such as the sediment transport and water quality since the models are intergrated in the MIKE 3 HD model.The set-up model could be useful for the planning purposes to enhance the ecosystem of the Setiu Wetland.