Submersion In Sea Water Research Articles

Seawater submersion for cylindrical lithium-ion batteries thermal runaway prevention

Lithium-ion batteries (LIBs) are currently used in various electric vehicles, including electric boats. To assess the risk of fire due to thermal runaway of the LIB during the operation of ferries, seawater can be used as a cooling fluid for the LIB to prevent thermal runaway as it is abundant. However, the seawater could corrode the electrodes of the battery, which would lead to toxic wastewater. Prevention of thermal runaway of lithium-ion batteries by submersion in seawater needs to be investigated to clarify the corrosion that could lead to toxic wastewater. In this study, fully charged, pristine 18650 NMC Li-ion cells were submerged in synthetic seawater (SSW) to investigate the corrosion effect compared to deionized (DI) water. The results showed that SSW induced rapid voltage discharge, leading to corrosion on the electrodes and toxic effluents, while DI water maintained the stability of the cells and did not cause any corrosion effect. In addition, the prevention of thermal runaway was investigated by exposing fully charged LIB to extreme overheating conditions. The liquid submersion system was activated by rapid voltage drop monitoring to evaluate its effectiveness in preventing thermal runaway (TR). The investigation of TR prevention by SSW submersion showed that the TR process can be effectively prevented. In addition, no corrosion effect was observed during submersion in SSW as the battery voltage was not applied. This study shows that seawater can be used to prevent TR in LIB and does not cause environmental problems comparable to water.

Anti-corrosion and flame-retardant properties of environmentally benign smart functionalized WS2/rGO in epoxy coatings for enhanced steel structural protection in natural seawater

The epoxy matrix (EP) was filled with the rGO-APOD/WS2 nanofiller that was generated through mixing the surface-modified WS2 with reduced graphene oxide (rGO) and 2-amino-5-(4-aminophenyl)− 1, 3-oxadiazole (APOD). The effectiveness of epoxy coating on mild steel as a barrier against various concentrations of rGO-APOD/WS2 in naturally occurring seawater was assessed using EIS, SECM, and salt spray tests. In order to achieve the best coating performance, it was found that the optimal weight ratio of rGO-APOD/WS2 in the EP matrix was 0.3. The limiting oxygen index (LOI) test showed that the rGO-APOD/WS2 considerably enhanced the flame retardancy properties of the epoxy coating. In comparison to pure epoxy coating, the EP-rGO/APOD-WS2 demonstrated better flame retardancy with considerable reductions in the values of PHRR and THR, i.e., 81% and 70%, respectively. It was discovered that the coating resistance of EP-rGO/APOD-WS2 was much higher (Rcoat: 9.89E10 kΩ.cm2) than that of pure matrix (1.49E5 kΩ.cm2) after being exposed to natural seawater for one hour. The EIS experiments showed that the EP-rGO/APOD-WS2 nanocomposite had increased coating resilience even after 200 h of submersion in seawater. Because the coated substrate is more resistant to anodic dissipation than the uncoated substrate, SECM investigations showed that the least quantity of Fe2+ ions discharged at the scratch of the EP-rGO/APOD-WS2 coating. WS2 was found in rusted parts, producing an excellent inert layer at the surface, according to FE-SEM/EDX investigation. The newly created EP-rGO/APOD-WS2 composite has higher barrier and hydrophobic characteristics, according to the results (WCA:162°). The epoxy matrix's mechanical properties were enhanced by the addition of rGO/APOD-WS2. It was discussed how graphene-based polymer nanocomposites might prevent corrosion. As a result, an industrial coating made of the EP-rGO/APOD-WS2 nanocomposite may be used.

An Empirical Model to Predict Chloride Penetrations in Concrete Containing Palm Oil Fuel Ash Based on 10-Year Exposure Under Marine Environment

The main objective of this study is to develop an empirical model for predicting the chloride penetration into concrete exposed to the sea water along shorelines. Concrete mixed with 0–50% of palm oil fuel ash, using W/B ratio of 0.40–0.50 were examined. Available database of concrete samples under the sea water submersion at 1, 3, 5, 7 and 10 years was collected. The study found that the developed empirical model could predict total chloride content in palm oil fuel ash concrete at any position below the concrete surface, which had been submerged under sea water for 1 year and over. The W/B ratio is also limited between 0.40 and 0.50. Application of this model is valid in the situation where penetration of chloride is in one direction. It was also shown that the margin of errors in this study is within ± 35% range when compared to the results presented by other researchers.

Mangrove Growth Monitoring Based on Camera Visible Images—A Case Study on Typical Mangroves in Guangxi

Mangroves are an important coastal wetland ecosystem, and the high-throughput visible light (RGB) images of the canopy obtained by the ecological meteorological station can provide basic data for quantitative and continuous growth monitoring of mangroves. However, as for the mangroves that are subject to periodic seawater submersion, some key technical issues such as image selection, vegetation segmentation, and index applicability remain unsolved. With the typical mangroves in Beihai, Guangxi, as the object in this study, we used canopy RGB images and tidal data to find out the screening methods for high-quality nontidal submerged images, as well as the vegetation segmentation algorithms and RGB vegetation index applicability, so as to provide technical reference for the use of RGB images to monitor mangrove growth. The results showed that: 1) The critical tide levels can be determined according to the periodic changes of submersion in the mangroves, and critical tidal levels and image brightness can be used to quickly screen high-quality images of mangroves that are not submerged by seawater. 2) Machine learning and NLM filtering are effective strategies to obtain high-precision mangrove segmentation results. The machine learning algorithm has superiority in the segmentation of mangrove vegetation with a segmentation accuracy of higher than 80%, and the nonlocal mean filtering can effectively optimize the segmentation results of various algorithms. 3) The seasonal index VEG and antiseasonal index CIVE can be used as the optimal indices for mangrove growth monitoring, and the compound sine function can better simulate the change trend of various RGB vegetation indices, which is convenient for quickly judging mangrove growth changes. 4) Mangrove RGB vegetation indices are sensitive to meteorological factors and can be used to analyze the influence of meteorological conditions on mangrove growth.

Self-healing epoxy coating doped with Elaesis guineensis/silver nanoparticles: A robust corrosion inhibitor

This paper reports the self-healing properties of novel epoxy coating comprised of multi-walled carbon nanotubes (MWCNTs) as nanocontainers loaded with 5% green inhibitor-Elaeis guineensis/silver nanoparticles (EG/AgNPs) that acted as robust corrosion inhibitor for mild steel against adverse seawater environment. The self-healing assisted anti-corrosion effectiveness of the inventive coating for mild steel under seawater exposure for 42 days was evaluated via polarisation resistance, electrochemical impedance spectroscopy, adhesion strength and visual inspections. Further, the coated mild steel surface was characterised using X-ray diffraction, atomic force microscope and scanning electron microscopy analysis. The microstructures of smart powder (MWCNTs-EG/AgNPs) were also screened by a variety of microstructures techniques. Results revealed an excellent self-healing functionality of the produced smart epoxy coating with satisfactory anticorrosion behaviour against seawater exposure. A maximum of 97.87% inhibition efficiency and a minimum of 0.0009 mm/year corrosion rate were recorded after 42 days of exposure. Furthermore, this smart coating disclosed superior corrosion inhibition abilities even after 42 days of submersion in seawater by weakened the lepidocrocite (γ-FeOOH), as a result of the release of Elaeis guineensis /AgNPs, which in turn acted as efficient corrosion inhibitors to repair or self-heal the damaged coatings on mild steel surface.

Complex photobiont diversity in the marine lichen Lichina pygmaea

AbstractLichens are a well-known symbiosis between a host mycobiont and eukaryote algal or cyanobacterial photobiont partner(s). Recent studies have indicated that terrestrial lichens can also contain other cryptic photobionts that increase the lichens’ ecological fitness in response to varying environmental conditions. Marine lichens live in distinct ecosystems compared with their terrestrial counterparts because of regular submersion in seawater and are much less studied. We performed bacteria 16S and eukaryote 18S rRNA gene metabarcoding surveys to assess total photobiont diversity within the marine lichen Lichina pygmaea (Lightf.) C. Agardh, which is widespread throughout the intertidal zone of Atlantic coastlines. We found that in addition to the established cyanobacterial photobiont Rivularia, L. pygmaea is also apparently host to a range of other marine and freshwater cyanobacteria, as well as marine eukaryote algae in the family Ulvophyceae (Chlorophyta). We propose that symbiosis with multiple freshwater and marine cyanobacteria and eukaryote photobionts may contribute to the ability of L. pygmaea to survive the harsh fluctuating environmental conditions of the intertidal zone.

Study on how oil type and weathering of crude oils affect interaction with sea ice and polyethylene skimmer material

Understanding the fate of spilled oil in cold environments is essential for oil spill response in Arctic areas. The potential for oils to adhere to sea ice and mechanical skimmers can significantly impact the success of oil spill response and influence the fate of oil in the marine environment. Therefore, the affinity of oil to sea ice and skimmer material was quantified experimentally for three different types of oils at various degrees of weathering. Contact angle measurements of crude oil droplets were performed on the top of and under sea ice and polyethylene-based skimmer material, being submerged in seawater (−2 °C). In addition, “dip- and refloat” tests were performed to quantify the adhesion and study the re-floating process of oil from sea ice at −2 °C (moist ice) and −20 °C (cold dry ice), and from a skimmer material prior to and subsequently to its submersion in seawater (−2 °C). The results indicated limited interaction of oils with sea ice submerged in seawater, but a strong affinity of oils towards polyethylene-based skimmer material.

Effect of Seawater Exposure on Impact Damping Behavior of Viscoelastic Material of Pounding Tuned Mass Damper (PTMD)

The pounding tuned mass damper (PTMD) is a novel vibration control device that can effectively mitigate the undesired vibration of subsea pipeline structures. Previous studies have verified that the PTMD is more effective and robust compared to the traditional tuned mass damper. However, the PTMD relies on a viscoelastic delimiter to dissipate energy through impact. The viscoelastic material can be corroded by the various chemical substances dissolved in the seawater, which means that there can be possible deterioration in its mechanical property and damping ability when it is exposed to seawater. Therefore, we aim to conduct an experimental study on the impact behavior and energy dissipation of the viscoelastic material submerged in seawater in this present paper. An experimental apparatus, which can generate and measure lateral impact, is designed and fabricated. A batch of viscoelastic tapes are submerged in seawater and samples will be taken out for impact tests every month. Pounding stiffness, hysteresis loops and energy dissipated per impact cycle are employed to characterize the impact behavior of the viscoelastic material. The experimental results suggest that the seawater has little influence on the behavior of the viscoelastic tapes. Even after continuous submersion in seawater for 5 years, the pounding stiffness and energy dissipation remains at the same level.

Effect of Sea Water Submersion on GFRP-S Bonding Capacity of Reinforced Concrete Beam

An experimental investigation on laboratory simulation of reinforced concrete beams submerged in sea water was carried out. The research aimed to analyze the beam flexural behavior cause by submersion effect in the marine environment and simulation pool. Flexural testing was conducted by using two point loading up to beams ruptured. Total 18 reinforced concrete beams of 10 cm x 12 cm x 60 cm in dimension with GFRP-S bonded on the bottom side. Nine beams were submerged in the marine environment and 9 beams were submerged in the simulation pool. Exposure period is 1, 3 and 6 months after 28 days cured in fresh water. The result indicate that the ultimate load and bonding capacity of beam specimens submersed in the marine environment were relatively lower than the specimens submersed in simulation pool. Based on this experimental study, submerging of specimens in simulation pool (Pp ) could be used to predict specimens submersed in marine (Ps) by using equation

Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine

Recent advances in the development of high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This paper describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1 to 15metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 800s. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. The 40cm long reactor meets the submersion criticality requirements (a shutdown margin of at least $1 subcritical in all submersion scenarios) with no further modifications. The 80 and 120cm long reactors include small amounts of gadolinium nitride as a spectral shift absorber to keep them subcritical upon submersion in seawater or wet sand following a launch abort.

Tako-Tsubo Syndrome in a 12-Year-Old Girl: Exhausted Heart, Not Broken Heart

We report the case of a 12-year-old girl with Tako-tsubo cardiomyopathy. She was successfully treated in our Pediatric Intensive Care Unit for acute left ventricular failure, which occurred after a brief submersion in sea water. At 2-month follow-up she showed an almost complete recovery of cardiac function. We consider Tako-tsubo syndrome, which is rarely reported in the pediatric population, to be the most likely diagnosis.

Reviewing hook degradation to promote ejection after ingestion by marine fish

A widely recommended strategy for releasing fish that have ingested hooks is to simply cut the line. The utility of this approach is based on the premise that the individual will eventually eject the hook following sufficient oxidation. However, few quantitative data are available describing the mechanisms affecting hook decay. We addressed this issue by testing the independence of various technical factors on the degradation of 828 hooks comprising 23 designs (absolute sizes 227–611 mm2) after protracted submersion in seawater. Twelve replicates of each hook were destructively assessed for compression and tensile strengths (using a force gauge) and 24 replicates were weighed, photographed and submersed in seawater. After submersion for 8 and 28 days, 12 replicate hooks were removed, re-photographed, re-weighed and tested for compression and tensile strengths to provide indices of decay. Hook degradation was mainly affected by the wire material and diameter and could be significantly promoted by choosing carbon steel designs, either with a wire diameter of ≤0.9 mm for the examined sizes or, alternatively, bait-holder barbs (or similar modifications) along the shaft. By rapidly oxidising and weakening after ingestion, such designs could ultimately help to reduce negative impacts of hooks on released fish.

Potential Use of Uniola paniculata Rhizome Fragments for Dune Restoration

Abstract Uniola paniculata (sea oats) rhizomes uprooted by hurricanes and deposited as wrack could be salvaged and replanted in dune restoration. To test this unexplored technique, percent tiller emergence was observed for 4 years from U. paniculata rhizomes replanted after submersion in seawater; air exposure of 0, 1, 3, 5, 7, and 11 days; freshwater rinse; and reburial in pots (watered) or on the beach (with or without supplemental water). In addition, U. paniculata rhizomes uprooted by Hurricane Georges were experimentally planted, and effects of soil salinity and moisture on emergence were tested in the greenhouse. Tiller emergence declined with increasing length of air exposure and decreasing size of rhizome. Tiller survival was enhanced by rainfall, rinsing with salt or fresh water during exposure and immediately after planting or supplemental beach watering. Although emergence was not reduced by soil salinity of 1,800 μS/cm, emergence was reduced by soil salinity of 5,800 μS/cm. Across the 4 years of the study tiller emergence from treated rhizomes varied considerably. U. paniculata rhizomes lost bud viability after 3–5 days of beach exposure, unless fresh water from rainfall, wet burlap storage, or watering was applied within 3 days. Bud viability was extended through 11 days when supplied with water. Thus, reburial within 3–11 days after a storm is a viable restoration technique.

Survival of terrestrial soil‐dwelling arthropods on and in seawater: implications for trans‐oceanic dispersal

Summary 1. The ability of six species of high Arctic soil arthropod to survive oceanic transport in or on sea water was tested experimentally. 2. Five species of Collembola, Hypogastrura tullbergi (Schäffer), Onychiurus groenlandicus (Tullberg), Onychiurus arcticus (Tullberg), Folsomia quadrioculata (Tullberg) and Tetracanthella arctica Schött were exposed on the surface film of seawater in chambers agitated within a shaking water bath. 3. All five species survived for over 14 days, at the end of which survival among species varied between 27 and 100%. 4. In a separate experiment the cryptostigmatic mite Camisia anomia Colloff and the ‘wettable’ collembolan T. arctica survived submersion in sea water for longer than 2 weeks. Survival of C. anomia exceeded 75% but that of T. arctica, when submerged, fell to 12%. 5. Survival times are sufficient to permit ocean current transport from northern Norway to Svalbard in the high Arctic, a distance of around 700 km. The implications of the experiments for long‐distance trans‐oceanic dispersal of non‐specialized soil arthropods are discussed.

Orientation behaviour and heterozygosity of sandhopper populations in relation to stability of beach environments

Felicita Scapini,’ Marcello Buiatti,’ Elvira De Matthaeis’ and Marco Mattoccia3 ‘Dipartimento di Biologia animale e Genetica, Universitri, via Romana 17, 50125 Firenze, Italy *Dipartimento di Biologia animale e dell’Uomo, Universitti “La Sapienza”, viale dell’Universitci 32, 00185 Roma, Italy 3Dipartimento di Biologia, Tor Vergata, II Universitd di Roma, via 0. Raimondo, 00173 Roma, Italy Key words: Amphipoda; behaviour; orientation; heterozygosity. Introduction The talitrid amphipod Talitrus saltator (Montagu) is a common inhabitant of sandy beaches, where it lives its whole life cycle, avoiding both the arid environment inland and submersion in sea water. Orientation towards the sea is critical for fitness, because good orientation is needed to avoid death by dehydration. During the night sandhoppers from Mediterranean populations migrate inland to feed, during the day they remain burrowed in moist sand at the water’s edge (Scapini et al., 1992). Orientation for zonal recovery occurs mainly by following a sun compass (see Pardi and Ercolini, 1986 for a review). This is of high survival value since these amphipods are not protected against dehydration by morphological structure and the narrow strip of moist sand at water’s edge is subjected to periodic and aperiodic shifting due to tides and storms. It has been shown that the sun compass is genetically determined. Differences among natural populations along the Italian Tyrrhenian and Adriatic shores are related to the orientation of the seashores where they live (Pardi, 1960; Pardi and Scapini, 1983; Scapini et al., 1985; Scapini and Buitatti, 1985; Scapini and Fasinella, 1990). However, the orientation tendency seems to be the result of a non-additive continuous interplay between individual learning and plasticity on one hand, and genetic variation on the population level on the other. It is through both processes that populations adapt to rapid environmental changes (Scapini et al., 1988; Ugolini and Scapini, 1988). Orientation, therefore, being a genetically determined character connected to fitness, for which the relative contributions of genetic and learning components 43

Long-term diffusion of elements from municipal solid waste combustor ash blocks in the marine environment

Municipal solid waste (MSW) combustor ash was combined with Portland cement to form blocks which were placed in Conscience Bay, Long Island Sound, New York. During a 4·5-year period, ash blocks were returned to the laboratory to examine changes in the total elemental content of the ash blocks following placement. A continuous loss of calcium, potassium and zinc from the ash blocks was measured following submersion. Calculated effective diffusion coefficients ranged from 4·75 × 10 −8 cm 2 s −1 for potassium to 5·56 × 10 −8 cm 2 s −1 for calcium. In contrast, lead an cadmium were effectively retained within the cementitious matrix of the submerged ash blocks. Following seawater submersion, the substitution of magnesium for calcium in the ash block pore spaces, the alkaline ash block porewaters and the encapsulation of ash particles within the Portland cement matrix contribute to reduce the leaching of contaminants from ash blocks in the marine environment.

Implications of a Pliocene stand of Nothofagus (southern beech) within 500 kilometres of the South Pole

Branches, stems and roots of Nothofagus (southern beech) were reported from the Beardmore Glacier area (Sirius Formation) some 500 km from the South Pole. The Sirius Formation is a glacially derived unit which is considered Pliocene in age. We considered two scenarios by which a Nothofagus forest could flourish so close to the South Pole during the Pliocene. One scenario calls for the disappearance of this genus from Antarctica during the early Tertiary (Oligocene) and its re-introduction during a warm Pliocene interval. Seeds from modern Nothofagus, however, are not viable after submersion in sea water, are not carried by migrating birds and are not designed for long-distance wind transport. The second scenario involves survival of Nothofagus in Antarctic refugia through middle Tertiary glacial advances and its flourishing during a Pliocene warming. Excluding its occurrence in the Beardmore Glacier area, the known range of this genus in Antarctica is Cretaceous to Oligocene with some questionable occurrences in the early Miocene. The existing data do not support the refugia scenario. We also considered published speculations in which the closest modern analogue to the Beardmore Glacier Region, during the time that the Nothofagus represented by these specimens lived, was the coastal region of southern Chile where average annual temperatures are approximately 5°C and summer temperatures are of the order of 8–10°C. We incorporated these observations and speculations into a palaeoenvironmental model, assuming them to be valid; the results require Pliocene temperatures as warm as, or warmer than, the Cretaceous, a scenario which is not supported by the literature. We conclude, therefore, that the occurrence of Nothofagus in the Beardmore Glacier area is older than Pliocene. Instead, we suggest that it represents a relict assemblage which is probably no younger than Oligocene but which may have persisted into the early Miocene.

Adaptations of Coleoptera to the marine environment. I. Observations on rove beetles (Staphylinidae) from sandy beaches

The sandy beaches of British Columbia are inhabited by a small number (11 species) of indigenous Staphylinidae which live near the drift line in the mid to upper littoral zone. They prefer fine-grained sandy beaches and most species feed on other intertidal invertebrates. All species investigated survived submersion in seawater by becoming quiescent, thereby reducing their metabolic rate. Oxygen consumption in seawater was greatly reduced. On re-exposure to air, a large overshoot in oxygen consumption occurred (in Thinopinus pictus), signifying a prior oxygen debt. In Cafius canescens, Cafius seminitens, and Hadrotes crassus the time required to reach full recovery was directly related to the duration of submersion, with 50% mortality in the population when recovery time exceeded 25 min. At a seawater temperature of 10 °C, LT50 was reached at 12–16 h submersion and at 20 °C, after 6.5 h. In Thinopinus pictus, however, recovery time was independent of duration of submersion, although the mortality curves were almost the same as for the three previously mentioned species, with LT50 occurring at 13 h at 10 °C and 7–8.5 h at 20 °C. Bledius monstratus showed symptoms of oxygen depletion only after a considerable time lag. Experimental submersion of this beetle resulted in an LT50 of 18 h at 20 °C.

Effects of submersion on the oxygen consumption of the estuarine sandhopper Transorchestia Chiliensis (Milne Edwards, 1840)

Oxygen consumption of Transorchestia chiliensis (Milne Edwards) was measured in air and following submersion in sea water of salinity 34%.. In all experimental conditions oxygen consumption increased with dry body weight; the weight exponent in air was 0.76 ( sd ± 0.16) and 0.63 ( sd ± 0.08) in aquatic conditions. At exposure temperatures > 10°C, aquatic rates were consistently below the aerial rate of oxygen consumption, which increased with temperature up to 20°C in winter amphipods and up to 25°C in summer samples. Following submergence, winter-collected amphipods showed maximal oxygen consumption at 10° C and lower oxygen uptake at15°C than at 5°C. For summer amphipods seasonal adjustment in the slope of the R-T curve for aquatic respiration resulted in a plateau of temperature-independent metabolism at temperatures between 5 and 20°C. Oxygen consumption of winter- and summer-collected Transorchestia stored at a constant temperature of 15°C showed a similar relationship between size and oxygen uptake to seasonally collected amphipods. In all acclimated amphipods the oxygen consumption in water remained markedly temperature-dependent up to an exposure temperature of 25°C. Although aerial oxygen consumption of winter-acclimated amphipods approximated the summer values, storage at constant temperatures could not effect completely the changes observed in the aquatic oxygen consumption of seasonally collected amphipods. The ability of Transorchestia to maintain its oxygen uptake at various temperatures following submergence is discussed in relation to the submersion tolerance and its position as a semi-terrestrial member of the supralittoral fringe of New Zealand shores.

Aquatic respiration in the land crab, Gecarcinus lateralis (Fréminville)

1. 1. Respiration of the land crab, Gecarcinus lateralis was studied during submersion in sea water. 2. 2. In inactive animals, the rate of oxygen consumption fell to about 50% of the rate in air. Ventilation volume increased as a result of the increase in the rate of beating of the scaphognathites, but the oxygen tension of the post-branchial blood nevertheless fell from 80 torr to 17 torr. 3. 3. A bradycardia of approximately 50%, coupled with a fall in postbranchial blood oxygen content, was compensated for, to some extent, by a doubling of the percentage extraction of oxygen from the blood at the tissues. 4. 4. Lactic acid accumulation in the blood indicated an increase in anaerobic metabolism when submerged and it is suggested that the failure of the respiratory system to meet the oxygen demand is associated primarily with the reduction of oxygen diffusion at the respiratory surfaces.