scholarly journals Bottom interacting sound at 50 km range in a deep ocean environment

2012 ◽  
Vol 132 (4) ◽  
pp. 2224-2231 ◽  
Author(s):  
Ilya A. Udovydchenkov ◽  
Ralph A. Stephen ◽  
Timothy F. Duda ◽  
S. Thompson Bolmer ◽  
Peter F. Worcester ◽  
...  
Keyword(s):  
Deep Ocean ◽  
Ocean Environment

scholarly journals Characterization and Transcriptome Analysis of a Long-Chain n-Alkane-Degrading Strain Acinetobacter Pittii SW-1

2021 ◽  
Vol 18 (12) ◽  
pp. 6365
Author(s):  
Weina Kong ◽  
Cheng Zhao ◽  
Xingwang Gao ◽  
Liping Wang ◽  
Qianqian Tian ◽  
...  
Keyword(s):  
Unsaturated Fatty Acids ◽  
Sulfur Metabolism ◽  
Quantitative Polymerase Chain Reaction ◽  
Deep Ocean ◽  
Rrna Gene ◽  
Alkane Hydroxylase ◽  
Degradation Rates ◽  
Acinetobacter Pittii ◽  
Ocean Environment ◽  
Long Chain

Strain sw-1, isolated from 7619-m seawater of the Mariana Trench, was identified as Acinetobacter pittii by 16S rRNA gene and whole-genome sequencing. A. pittii sw-1 was able to efficiently utilize long-chain n-alkanes (C18–C36), but not short- and medium-chain n-alkanes (C8–C16). The degradation rate of C20 was 91.25%, followed by C18, C22, C24, C32, and C36 with the degradation rates of 89.30%, 84.03%, 80.29%, 30.29%, and 13.37%, respectively. To investigate the degradation mechanisms of n-alkanes for this strain, the genome and the transcriptome analyses were performed. Four key alkane hydroxylase genes (alkB, almA, ladA1, and ladA2) were identified in the genome. Transcriptomes of strain sw-1 grown in C20 or CH3COONa (NaAc) as the sole carbon source were compared. The transcriptional levels of alkB and almA, respectively, increased 78.28- and 3.51-fold in C20 compared with NaAc, while ladA1 and ladA2 did not show obvious change. The expression levels of other genes involved in the synthesis of unsaturated fatty acids, permeases, membrane proteins, and sulfur metabolism were also upregulated, and they might be involved in n-alkane uptake. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) confirmed that alkB expression was significantly induced by C20, C24, and C32, and almA induction extent by C24 and C32 was higher than that with C20. Furthermore, ladA2 expression was only induced by C32, and ladA1 expression was not induced by any of n-alkanes. In addition, A. pittii sw-1 could grow with 0%–3% NaCl or 8 out of 10 kinds of the tested heavy metals and degrade n-alkanes at 15 °C. Taken together, these results provide comprehensive insights into the degradation of long-chain n-alkanes by Acinetobacter isolated from the deep ocean environment.

Development and Subsea Testing of Polymetallic Nodule Crusher for Underwater Mining Machine

2021 ◽  
Vol 55 (6) ◽  
pp. 65-72
Author(s):  
Narayanmurthy Renganayahi Ramesh ◽  
Karuppiah Thirumurugan ◽  
Deepak Chullickal Raphael ◽  
Gidugu Ananda Ramadass ◽  
Malayath Aravindakshan Atmanand
Keyword(s):  
Minimum Weight ◽  
Deep Ocean ◽  
Maximum Size ◽  
Mining Machine ◽  
Design Synthesis ◽  
Polymetallic Nodule ◽  
Polymetallic Nodules ◽  
Underwater Mining ◽  
Nodule Mining ◽  
Ocean Environment

Abstract Polymetallic nodules found in the deep oceans are viewed as potential resources for meeting the world's demand of many metals in the near future. Polymetallic nodule mining systems require subsea crushing systems for reducing the size of nodules to facilitate energy-efficient and safe pumping through risers of optimum size. Polymetallic nodules are friable, and deep-sea crushing has to be done with care to minimize the formation of fines, while obtaining the required size reduction. The crusher could also encounter objects with greater hardness during operation like small rocks, splinters, long fish bones, and shark teeth. All components in the crusher should be capable of operating in the deep ocean environment, which is hyperbaric and sediment laden. The equipment should be compact with minimum weight. Reversal of direction and dumping arrangements in the event of stalling are other essential design requirements. An underwater crusher capable of crushing mined nodules from a maximum size of 100 mm to a crushed size of 30 mm was developed using principles of design synthesis. The crusher was tested in land and integrated into a remotely operated crawler-based underwater mining machine that could mine and pump nodules through a flexible riser. The system was tested using artificial nodules at 512-m water depth off the Malvan coast in the Arabian Sea. This paper describes developmental methodology, land-based performance tests, and sea trials conducted on the developed crusher.

Blue Economy of India and Technology Initiatives II

2018 ◽  
Vol 52 (5) ◽  
pp. 19-26
Author(s):  
Malayath Aravindakshan Atmanand ◽  
Ramasamy Venkatesan ◽  
Mallavarapu Venkata Ramanamurthy ◽  
Gidugu Ananda Ramadass ◽  
Ramalingam Kirubagaran ◽  
...  
Keyword(s):  
Deep Ocean ◽  
Early Warning Systems ◽  
Social Needs ◽  
Coastal Protection ◽  
Economic Policies ◽  
Tsunami Early Warning ◽  
Ocean Environment ◽  
Technology Initiatives ◽  
Tsunami Early Warning Systems ◽  
Gas Leaks

AbstractWith land-based resources depleting fast, sustained harvesting of ocean resources with an appropriate trade-off between economic growth, social needs, and the health of the ocean environment is essential. India, with an over 7600-km-long coastline, an exclusive economic zone of 2.3 million km2, and seeking extension for additional 560 km, has initiated blue economic policies for leveraging the growth of the national economy. The first part of the paper presented in the OCEANS '18 conference in Kobe discussed the technology initiatives to harness the vast living and nonliving blue economic resources in India, including deep-ocean minerals, hydrocarbons, renewable energy, ocean desalination, and bioprospecting. This paper describes the activities carried out related to the activities undertaken by the National Institute of Ocean Technology (NIOT) in the areas of coastal protection, cyclone and tsunami early warning systems, coral habitat observations, sustainable fishing, and numerical studies carried out to understand the influence of natural gas leaks on deep-ocean ecology.

scholarly journals Performing ‘blue degrowth’: critiquing seabed mining in Papua New Guinea through creative practice

2019 ◽  
Vol 15 (1) ◽  
pp. 117-129 ◽  
Author(s):  
John Childs
Keyword(s):  
Papua New Guinea ◽  
Deep Sea ◽  
Deep Ocean ◽  
New Guinea ◽  
Distinct Form ◽  
Economic Uncertainty ◽  
Counter Narrative ◽  
Blue Growth ◽  
Ocean Environment ◽  
Seabed Mining

AbstractScripted as a sustainable alternative to terrestrial mining, the licence for the world’s first commercial deep-sea mining (DSM) site was issued in Papua New Guinea in 2011 to extract copper and gold from a deposit situated 1600 m below the surface of the Bismarck Sea. Whilst DSM’s proponents locate it as emergent part of a blue economy narrative, its critics point to the ecological and economic uncertainty that characterises the proposed practice. Yet, due its extreme geography, DSM is also profoundly elusive to direct human experience and thus presents a challenge to forms of resistance against an industry extolled as having ‘no human impact’. Against this background, this paper analyses the ways in which ‘blue degrowth’—as a distinct form of counter-narrative—might be ‘performed’, and which imagined (and alternative) geographies are invoked accordingly. To do this it critically reflects upon 2 years of participatory research in the Duke of York Islands focusing on three, community-developed methods of resisting DSM. Practices of counter mapping, sculpture and participatory drama all sought to ‘perform’ the deep-ocean environment imagined as relational whilst simultaneously questioning the very notion of ‘economy’ central to the discourse of ‘blue growth’.

CORROSION BEHAVIOR OF 5052 AND 6061 ALUMINUM ALLOYS IN DEEP OCEAN ENVIRONMENT OF SOUTH CHINA SEA

2013 ◽  
Vol 49 (10) ◽  
pp. 1219 ◽  
Author(s):  
Feilong SUN ◽  
Xiaogang LI ◽  
Lin LU ◽  
Xuequn CHENG ◽  
Chaofang DONG ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
South China Sea ◽  
Corrosion Behavior ◽  
South China ◽  
Deep Ocean ◽  
China Sea ◽  
Ocean Environment
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