Background: Hemorrhage is a leading cause of death in trauma. Hemorrhage control includes surgical and endovascular techniques, with use of topical hemostatics playing an increasing role. The ...defensive slime produced by hagfish (a deep-sea animal) forms within milliseconds and entraps up to 26 000 times its weight in water within a fine mesh-like network. Our project aims to determine if hagfish slime can be applied as a novel innovative hemostatic "clot." Methods: Research ethics approval were obtained and a standardized protocol for extraction was developed. Hagfish were anesthetized and electrical stimulation was used to extract slime exudate. The exudate was placed in a buffer solution and tested with normal saline, seawater, blood and varying concentrations of calcium chloride. Initial "clot" samples were evaluated with direct observation to determine viability. Additional viscosity testing using thromboelastography and rheometry was attempted. Results: Thromboelastography and rheometry testing was unsuccessful because of the speed of reaction and the volume limitations of the testing devices. One hundred milligrams of slime exudate in combination with either normal saline or seawater created a total volume of 100 mL of "clot." An experimental set-up was used to mix the slime exudate, solution and calcium and to suspend the formed "clot" above a beaker on a scale. The weight of the solution returning to the beaker over time was used as a proxy for "clot" formation and deterioration. Increasing the amount of calcium added did not increase the amount of slime formed. Tests conducted with blood demonstrated successful creation of a "clot" that was observed to be cohesive and stable for approximately 30 minutes. The "clot" appeared more viscous than the slime created with normal saline or seawater. Conclusion: Initial results show that slime can be formed with solutions isotonic to human plasma. The durability of the slime "clot" created with blood may be due to the clotting cascade interacting with the slime exudate, but further exploration is needed.
The sun and sea are inexhaustible sources of energy and water that could be used to transform drylands into more viable ecosystems. A sustainable and cost-effective approach is proposed for greening ...drylands and restoring wildlife and biodiversity in deserts using seawater desert-houses (or movable seawater ponds) that could offer important environmental advantages.
Metal anode instability, including dendrite growth, metal corrosion, and hetero-ions interference, occurring at the electrolyte/electrode interface of aqueous batteries, are among the most critical ...issues hindering their widespread use in energy storage. Herein, a universal strategy is proposed to overcome the anode instability issues by rationally designing alloyed materials, using Zn-M alloys as model systems (M = Mn and other transition metals). An in-situ optical visualization coupled with finite element analysis is utilized to mimic actual electrochemical environments analogous to the actual aqueous batteries and analyze the complex electrochemical behaviors. The Zn-Mn alloy anodes achieved stability over thousands of cycles even under harsh electrochemical conditions, including testing in seawater-based aqueous electrolytes and using a high current density of 80 mA cm
. The proposed design strategy and the in-situ visualization protocol for the observation of dendrite growth set up a new milestone in developing durable electrodes for aqueous batteries and beyond.
•Effects of sea-sand and/or seawater on the properties of concrete are summarised.•Admixtures can enhance the performance of concrete with sea-sand and/or seawater.•Combination of sea-sand seawater ...concrete with FRP leads to sustainable structures.•Sea-sand seawater concrete incorporating recycled coarse aggregate is attractive.•Research needs and application opportunities are discussed and recommended.
This paper presents a critical review of existing studies on the effects of using sea-sand and/or seawater as raw materials of concrete on the properties of the resulting concrete, including its workability, short- and long-term strength as well as durability. It has been shown by existing research that concrete made with sea-sand and seawater develops its early strength faster than that of ordinary concrete, but the former achieves a similar long-term strength to the latter. Existing studies have also shown that the use of sea-sand and seawater may have a significant effect on chloride-induced steel corrosion but has only a negligible effect on the carbonation process of concrete. Strong evidence exists that a combination of mineral admixtures for the concrete and reinforcement with fiber reinforced polymer (FRP) can effectively solve the durability problem associated with the abundance of chloride ions in sea-sand seawater concrete (SSC). Such use of SSC also offers a good opportunity for the incorporation of recycled coarse aggregate (RCA) in concrete, particularly those that have been chloride-contaminated, as has been demonstrated by some preliminary research. The current understanding of the behavior of SSC, as summarized in the present paper, provides a solid basis for further research in the area to enable the wide use of SSC in concrete construction worldwide, particularly when combined with FRP as the reinforcing material.
Firms aim to capture carbon in the oceans Service, Robert F
Science (American Association for the Advancement of Science),
2024-Mar-29, 20240329, Volume:
383, Issue:
6690
Journal Article
Peer reviewed
Schemes to process seawater may be cheaper than snagging carbon dioxide from the air.
The Ti6Al4V alloy is extensively utilized in critical marine equipment components due to its low density, high specific strength, and exceptional corrosion resistance in marine environments. However, ...its low hardness and inadequate wear resistance pose challenges in meeting the urgent demand for prolonged service life of relative motion friction pairs under complex wear and corrosion conditions. As a newly developed lightweight friction pair material, hardened 60NiTi is considered highly desirable owing to its combination of high hardness, high compressive strength, and excellent corrosion resistance. Nevertheless, the tribocorrosion properties of 60NiTi compared to those of Ti6Al4V are not yet fully comprehended. The present study conducted a series of sliding wear tests using a ball-on-plate configuration in artificial seawater environment to compare the response of 60NiTi with Ti6Al4V. In order to gain a comprehensive understanding of the factors contributing to the divergence in tribocorrosion response between both materials, further analysis was performed on the wear track subsurface and transfer film using focused ion beam-scanning electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy respectively. The 60NiTi demonstrates significantly enhanced wear resistance in artificial seawater compared to Ti6Al4V, attributed to its combination of high hardness and excellent corrosion resistance. However, Ti6Al4V exhibits a lower friction coefficient (∼0.30) than 60NiTi (∼0.45) due to the formation of a stable transfer film primarily composed of SiO2, Al(OH)3, and Al2O3.
•The wear-accelerated corrosion resistance of 60NiTi surpasses that of Ti6Al4V.•The tribocorrosion loss of 60NiTi is lower than that of Ti6Al4V by an order of magnitude.•The wear form of Ti6Al4V and 60NiTi exhibit distinct differences during the tribocorrosion.•The lubricating film can be generated when Si3N4 ball slides against Ti6Al4V disc in seawater.
The effect of Ocean Acidification (OA) on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO(2), reveal sensitivities and responses ...of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species' natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO(2), often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100. Our data provide a first step toward crystallizing the biophysical link between environmental history of pH exposure and physiological resilience of marine organisms to fluctuations in seawater CO(2). Knowledge of this spatial and temporal variation in seawater chemistry allows us to improve the design of OA experiments: we can test organisms with a priori expectations of their tolerance guardrails, based on their natural range of exposure. Such hypothesis-testing will provide a deeper understanding of the effects of OA. Both intuitively simple to understand and powerfully informative, these and similar comparative time series can help guide management efforts to identify areas of marine habitat that can serve as refugia to acidification as well as areas that are particularly vulnerable to future ocean change.
^sup 210^Pb was measured during the 3rd Chinese National Arctic Research Expedition cruise to investigate its spatial pattern in the western Arctic Ocean, as well as its relation with the thermocline ...in the Canadian Basin. The specific activities varied from 0.04 to 2.72, <0.013 to 4.37, and 0.1 to 4.85 Bq/m^sup 3^ for dissolved, particulate, and bulk ^sup 210^Pb, respectively, corresponding to respective averages of 0.65, 0.43, and 1.08 Bq/m^sup 3^. In the Canadian Basin, the minimum ^sup 210^Pb activities occurred in the thermocline, which was characterized by low temperature of -1.52°C and salinity of 33.1. Combining the spatial distribution of ^sup 210^Pb and hydrographical characteristics in the western Arctic Ocean, this scenario was ascribed to the effective scavenging of ^sup 210^Pb when the Pacific water flowed across the Chukchi Shelf. Quantitatively, this interpretation was supported by both the shorter residence times and higher scavenging efficiencies (SE) of dissolved ^sup 210^Pb over the Chukchi Shelf. The highest SE values were observed in the Herald Shoal and bottom waters over the slope.PUBLICATION ABSTRACT
Although the early coral reef-bleaching warning system (NOAA/USA) is established, there is no feasible treatment that can minimize temperature bleaching and/or disease impacts on corals in the field. ...Here, we present the first attempts to extrapolate the widespread and well-established use of bacterial consortia to protect or improve health in other organisms (e.g., humans and plants) to corals. Manipulation of the coral-associated microbiome was facilitated through addition of a consortium of native (isolated from Pocillopora damicornis and surrounding seawater) putatively beneficial microorganisms for corals (pBMCs), including five Pseudoalteromonas sp., a Halomonas taeanensis and a Cobetia marina-related species strains. The results from a controlled aquarium experiment in two temperature regimes (26 °C and 30 °C) and four treatments (pBMC; pBMC with pathogen challenge - Vibrio coralliilyticus, VC; pathogen challenge, VC; and control) revealed the ability of the pBMC consortium to partially mitigate coral bleaching. Significantly reduced coral-bleaching metrics were observed in pBMC-inoculated corals, in contrast to controls without pBMC addition, especially challenged corals, which displayed strong bleaching signs as indicated by significantly lower photopigment contents and F
/F
ratios. The structure of the coral microbiome community also differed between treatments and specific bioindicators were correlated with corals inoculated with pBMC (e.g., Cobetia sp.) or VC (e.g., Ruegeria sp.). Our results indicate that the microbiome in corals can be manipulated to lessen the effect of bleaching, thus helping to alleviate pathogen and temperature stresses, with the addition of BMCs representing a promising novel approach for minimizing coral mortality in the face of increasing environmental impacts.
Development of efficient non-precious catalysts for seawater electrolysis is of great significance but challenging due to the sluggish kinetics of oxygen evolution reaction (OER) and the impairment ...of chlorine electrochemistry at anode. Herein, we report a heterostructure of Ni
3
S
2
nanoarray with secondary Fe-Ni(OH)
2
lamellar edges that exposes abundant active sites towards seawater oxidation. The resultant Fe-Ni(OH)
2
/Ni
3
S
2
nanoarray works directly as a free-standing anodic electrode in alkaline artificial seawater. It only requires an overpotential of 269 mV to afford a current density of 10 mA·cm
−2
and the Tafel slope is as low as 46 mV·dec
−1
. The 27-hour chronopotentiometry operated at high current density of 100 mA·cm
−2
shows negligible deterioration, suggesting good stability of the Fe·Ni(OH)
2
/Ni
3
S
2
@NF electrode. Faraday efficiency for oxygen evolution is up to ∼ 95%, revealing decent selectivity of the catalyst in saline water. Such desirable catalytic performance could be benefitted from the introduction of Fe activator and the heterostructure that offers massive active and selective sites. The density functional theory (DFT) calculations indicate that the OER has lower theoretical overpotential than Cl
2
evolution reaction in Fe sites, which is contrary to that of Ni sites. The experimental and theoretical study provides a strong support for the rational design of high-performance Fe-based electrodes for industrial seawater electrolysis.
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