Research computer numerical simulation on heat dissipation model of submarine data centre based on TOPSIS model

Due to the huge energy consumption of land-based data centers, it is necessary to establish undersea data centers as soon as possible in order to alleviate the problem of resource tension. In this paper, the uniformity of containers is assumed. Through force analysis, it is found that the stress of containers is uniformly distributed, so only the external stress should be considered. Hypothesis submarine data center in the 50 m deep seawater, calculate the container need to withstand stress is 76.417403 Mpa, common material in engineering field, then physical parameters of material to deal with the dimensional and normalization, and establishes a comprehensive evaluation model material, the Topsis method is adopted to solve, to solve the optimal evaluation of the results can be divided into: 7-4 PH Stainless Stee 0.7450 points, so choose it as IU server container material.

Moving Seaweed Farms from Shallow to Deep Seawater to Cope with Warming and Diseases in Zanzibar. Current Socio-Economic and Cultural Barriers

This study aimed at identifying the climate and non-climate stressors affecting the seaweed farming practices. It also examines the deep water seaweed farming as a viable adaptation measure to these stressors and barriers that could constrained female seaweed farmers who are the majority. The study was carried out in six selected groups, two groups were from South District, Unguja Main Island (Furahiya Wanawake-Paje and Flower Group-Muungoni). And four groups were selected from Pemba Island (Tuwe Imara and Umoja Kazi- East Msuka and Ipo sababu and Umoja ni Nguvu – East Tumbe) from Micheweni District. These groups were selected because they participated in previous project implemented by Milele Zanzibar Foundation (MZF) and The Panje Project (TPP). Questionnaire interview collected various information related to the study from 111 seaweed farmers who are members of these groups. Information such as baseline seaweed production, climate change and diseases that affect seaweed production, farmer’s awareness on moving seaweed farms to deep water to cope with increasing warming and diseases and their capacity to swim as prerequisite for the adoption of this coping strategy. The focal group discussions were conducted in all six groups to collect various information to triangulate the findings collected from the questionnaire interview. The data obtained from three methods analyzed using descriptive statistics. The findings show that seaweed farming production has declined at least over the last seven years. Climate change and its variability, diseases, over utilization of shallow water space for farming seaweed, COVID 19 and price has contributed a lot in the observed decline. Deep water (0.5 meter during low tide and 3-5 meters during high tide) seaweed farming seen as viable option to cope and adapt to increasing warming and diseases but its adoption especially amongst female seaweed farmers constrained by their limited capacity to swim and their limited ownership of the vessels. The study also identified other barriers such as age, gender and cultural factors that could constrained female seaweed farmers from participation in swimming and sea safety training. To facilitate adoption of the deep-water seaweed farming method amongst the seaweed farmers, concerted effort should be made to overcome the barriers that are likely to limit the massive adoption of this method.

Organic additive release from plastic to seawater is lower under deep-sea conditions

Plastic garbage patches at the ocean surface are symptomatic of a wider pollution affecting the whole marine environment. Sinking of plastic debris increasingly appears to be an important process in the global fate of plastic in the ocean. However, there is insufficient knowledge about the processes affecting plastic distributions and degradation and how this influences the release of additives under varying environmental conditions, especially in deep-sea environments. Here we show that in abiotic conditions increasing hydrostatic pressure inhibits the leaching of the heaviest organic additives such as tris(2-ethylhexyl) phosphate and diisononyl phthalate from polyethylene and polyvinylchloride materials, whereas deep-sea and surface marine prokaryotes promote the release of all targeted additives (phthalates, bisphenols, organophosphate esters). This study provides empirical evidences for more efficient additive release at the ocean surface than in deep seawater, where the major plastic burden is supposed to transit through before reaching the sediment compartment.

Protistan grazing impacts microbial communities and carbon cycling at deep-sea hydrothermal vents

Microbial eukaryotes (or protists) in marine ecosystems are a link between primary producers and all higher trophic levels, and the rate at which heterotrophic protistan grazers consume microbial prey is a key mechanism for carbon transport and recycling in microbial food webs. At deep-sea hydrothermal vents, chemosynthetic bacteria and archaea form the base of a food web that functions in the absence of sunlight, but the role of protistan grazers in these highly productive ecosystems is largely unexplored. Here, we pair grazing experiments with a molecular survey to quantify protistan grazing and to characterize the composition of vent-associated protists in low-temperature diffuse venting fluids from Gorda Ridge in the northeast Pacific Ocean. Results reveal protists exert higher predation pressure at vents compared to the surrounding deep seawater environment and may account for consuming 28 to 62% of the daily stock of prokaryotic biomass within discharging hydrothermal vent fluids. The vent-associated protistan community was more species rich relative to the background deep sea, and patterns in the distribution and co-occurrence of vent microbes provide additional insights into potential predator–prey interactions. Ciliates, followed by dinoflagellates, Syndiniales, rhizaria, and stramenopiles, dominated the vent protistan community and included bacterivorous species, species known to host symbionts, and parasites. Our findings provide an estimate of protistan grazing pressure within hydrothermal vent food webs, highlighting the important role that diverse protistan communities play in deep-sea carbon cycling.

Complete Genome Sequence of Polycladomyces abyssicola JIR-001 T , Isolated from Hemipelagic Sediment in Deep Seawater

Here, we report the complete genome sequence of Polycladomyces abyssicola strain JIR-001, which we isolated from hemipelagic sediment in deep seawater. The genome, generated by combining long (Flongle) and short (NovaSeq) read sequencing data, is 3,197,230 bp, with a mean G+C content of 52.0%.

Wave Height Distributions and Rogue Waves in the Eastern Mediterranean

There is a lack of scientific knowledge about the physical sea characteristics of the eastern part of the Mediterranean Sea. The current work offers a comprehensive view of wave fields in southern Israel waters covering a period between January 2017 and June 2018. The analyzed data were collected by a meteorological buoy providing wind and waves parameters. As expected for this area, the strongest storm events occurred throughout October–April. In this paper, we analyze the buoy data following two main objectives—identifying the most appropriate statistical distribution model and examining wave data in search of rogue wave presence. The objectives were accomplished by comparing a number of models suitable for deep seawater waves. The Tayfun—Fedele 3rd order model showed the best agreement with the tail of the empirical wave heights distribution. Examination of different statistical thresholds for the identification of rogue waves resulted in the detection of 99 unique waves, all of relatively low height, except for one wave that reached 12.2 m in height which was detected during a powerful January 2018 storm. Characteristics of the detected rogue waves were examined, revealing the majority of them presenting crest to trough symmetry. This finding calls for a reevaluation of the crest amplitude being equal to or above 1.25 the significant wave height threshold which assumes rogue waves carry most of their energy in the crest.

Isotopically Light Cd in Sediments Underlying Oxygen Deficient Zones

Cadmium is a trace metal of interest in the ocean partly because its concentration mimics that of phosphate. However, deviations from the global mean dissolved Cd/PO4 relationship are present in oxygen deficient zones, where Cd is depleted relative to phosphate. This decoupling has been suggested to result from cadmium sulphide (CdS) precipitation in reducing microenvironments within sinking organic matter. We present Cd concentrations and Cd isotope compositions in organic-rich sediments deposited at several upwelling sites along the northeast Pacific continental margin. These sediments all have enriched Cd concentrations relative to crustal material. We calculate a net accumulation rate of Cd in margin settings of between 2.6 to 12.0 × 107 mol/yr, higher than previous estimates, but at the low end of a recently published estimate for the magnitude of the marine sink due to water column CdS precipitation. Cadmium in organic-rich sediments is isotopically light (δ114/110CdNIST-3108 = +0.02 ± 0.14‰, n = 26; 2 SD) compared to deep seawater (+0.3 ± 0.1‰). However, isotope fractionation during diagenesis in continental margin settings appears to be small. Therefore, the light Cd isotope composition of organic-rich sediments is likely to reflect an isotopically light source of Cd. Non-quantitative biological uptake of light Cd by phytoplankton is one possible means of supplying light Cd to the sediment, which would imply that Cd isotopes could be used as a tracer of past ocean productivity. However, water column CdS precipitation is also predicted to preferentially sequester light Cd isotopes from the water column, which could obfuscate Cd as a tracer. We also observe notably light Cd isotope compositions associated with elevated solid phase Fe concentrations, suggesting that scavenging of Cd by Fe oxide phases may contribute to the light Cd isotope composition of sediments. These multiple possible sources of isotopically light Cd to sediments, along with evidence for complex particle cycling of Cd in the water column, bring into question the straightforward application of Cd isotopes as a paleoproductivity proxy.