scholarly journals Static penetration test on deep-sea shark skins - reports on needle types and penetration forces for developing an autonomous in situ biopsy equipment

2019 ◽  
Vol 28 (0) ◽  
pp. 35-42
Author(s):  
Shinji Tsuchida ◽  
Masaru Kawato ◽  
Shinpei Gotoh ◽  
Yoshimi Takahashi ◽  
Ayaka Kasai ◽  
...  
Keyword(s):  
Deep Sea ◽  
Penetration Test ◽  
Static Penetration

Development of a deep-sea mercury sensor using in situ anodic stripping voltammetry

2015 ◽  
Vol 49 (6) ◽  
pp. 613-620 ◽  
Author(s):  
Masahiro Yamamoto ◽  
Hitoshi Kodamatani ◽  
Yuriko Kono ◽  
Akinori Takeuchi ◽  
Ken Takai ◽  
...  
Keyword(s):  
Deep Sea ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Anodic Stripping ◽  
Mercury Sensor

scholarly journals Development of an Easy-to-Operate Underwater Raman System for Deep-Sea Cold Seep and Hydrothermal Vent In Situ Detection

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5090
Author(s):  
Qingsheng Liu ◽  
Jinjia Guo ◽  
Wangquan Ye ◽  
Kai Cheng ◽  
Fujun Qi ◽  
...  
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Methane Hydrate ◽  
Sulfur Cycle ◽  
Cold Seep ◽  
Remotely Operated Vehicle ◽  
Bacterial Mats ◽  
Optical Module ◽  
In Situ Detection

As a powerful in situ detection technique, Raman spectroscopy is becoming a popular underwater investigation method, especially in deep-sea research. In this paper, an easy-to-operate underwater Raman system with a compact design and competitive sensitivity is introduced. All the components, including the optical module and the electronic module, were packaged in an L362 × Φ172 mm titanium capsule with a weight of 20 kg in the air (about 12 kg in water). By optimising the laser coupling mode and focusing lens parameters, a competitive sensitivity was achieved with the detection limit of SO42− being 0.7 mmol/L. The first sea trial was carried out with the aid of a 3000 m grade remotely operated vehicle (ROV) “FCV3000” in October 2018. Over 20,000 spectra were captured from the targets interested, including methane hydrate, clamshell in the area of cold seep, and bacterial mats around a hydrothermal vent, with a maximum depth of 1038 m. A Raman peak at 2592 cm−1 was found in the methane hydrate spectra, which revealed the presence of hydrogen sulfide in the seeping gas. In addition, we also found sulfur in the bacterial mats, confirming the involvement of micro-organisms in the sulfur cycle in the hydrothermal field. It is expected that the system can be developed as a universal deep-sea survey and detection equipment in the near future.

Assessment of the range of variation of Nγ from 60 estimation methods for footings on sand

2013 ◽  
Vol 50 (7) ◽  
pp. 793-800 ◽  
Author(s):  
Edgar Giovanny Diaz-Segura
Keyword(s):  
Friction Angle ◽  
Standard Penetration Test ◽  
Estimation Methods ◽  
Penetration Test ◽  
In Situ Tests ◽  
Vertical Loading ◽  
Simplified Method ◽  
Bearing Capacity Factor ◽  
Range Of Variation

The range of variation of the bearing capacity factor, Nγ, was assessed using 60 estimation methods for rough footings on sand subjected to static vertical loading. The influence on the Nγ values of the use of correlations for the estimation of the friction angle, [Formula: see text], derived from in situ tests was also assessed. The analysis shows a marked dependency on the methods used to determine Nγ, showing differences for the same [Formula: see text] values of up to 267% between estimated values. Uncertainty in the estimation of [Formula: see text], due to the use of correlations with in situ tests, leads to a range of variation for Nγ higher than that seen using the 60 estimation methods. Finally, given the regular use of the in situ standard penetration test (SPT) on sands, and based on a series of analyses using finite elements, a simplified method in terms of the SPT N-values is proposed for estimation of Nγ in footings on sands.

Calcite dissolution driven by benthic mineralization in the deep-sea: in situ measurements of Ca 2+ , pH, pCO 2 and O 2

2001 ◽  
Vol 65 (16) ◽  
pp. 2677-2690 ◽  
Author(s):  
F Wenzhöfer ◽  
M Adler ◽  
O Kohls ◽  
C Hensen ◽  
B Strotmann ◽  
...  
Keyword(s):  
Deep Sea ◽  
In Situ Measurements ◽  
Calcite Dissolution

Pressure and Temperature Adaptation of Cytosolic Malate Dehydrogenases of Shallowand Deep-Living Marine Invertebrates: Evidence for High Body Temperatures in Hydrothermal Vent Animals

1991 ◽  
Vol 159 (1) ◽  
pp. 473-487 ◽  
Author(s):  
ELIZABETH DAHLHOFF ◽  
GEORGE N. SOMERO
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vents ◽  
Elevated Temperatures ◽  
Marine Invertebrates ◽  
Distribution Patterns ◽  
Pressure Effects ◽  
Temperature Adaptation ◽  
Body Temperatures ◽  
Elevated Pressures

Effects of temperature and hydrostatic pressure were measured on cytosolic malate dehydrogenases (cMDHs) from muscle tissue of a variety of shallow- and deep-living benthic marine invertebrates, including seven species endemic to the deep-sea hydrothermal vents. The apparent Michaelis-Menten constant (Km) of coenzyme (nicotinamide adenine dinucleotide, NADH), used to index temperature and pressure effects, was conserved within a narrow range (approximately 15–25 μmoll−1) at physiological temperatures and pressures for all species. However, at elevated pressures, the Km of NADH rose sharply for cMDHs of shallow species (depths of occurrence >Approximately 500 m), but not for the cMDHs of deep-sea species. Cytosolic MDHs of invertebrates from the deep-sea hydrothermal vents generally were not perturbed by elevated temperatures (15–25°C) at in situ pressures, but cMDHs of cold-adapted deep-sea species were. At a single measurement temperature, the Km of NADH for cMDHs from invertebrates from habitats with well-characterized temperatures was inversely related to maximal sustained body temperature. This correlation was used to predict the maximal sustained body temperatures of vent invertebrates for which maximal habitat and body temperatures are difficult to estimate. Species occurring on the ‘smoker chimneys’, which emit waters with temperatures up to 380°C, are predicted to have sustained body temperatures that are approximately 20–25°C higher than vent species living in cooler vent microhabitats. We conclude that, just as adaptation of enzymes to elevated pressures is important in establishing species’ depth distribution patterns, adaptation of pressure-adapted enzymes to temperature is critical in enabling certain vent species to exploit warm-water microhabitats in the vent environment.

scholarly journals Adenosine Triphosphate Measurement in Deep Sea Using a Microfluidic Device

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 370 ◽  
Author(s):  
Tatsuhiro Fukuba ◽  
Takuroh Noguchi ◽  
Kei Okamura ◽  
Teruo Fujii
Keyword(s):  
Adenosine Triphosphate ◽  
Microfluidic Device ◽  
Deep Sea ◽  
Temperature Sensor ◽  
Biochemical Parameter ◽  
Underwater Vehicle ◽  
Luciferase Assay ◽  
Bioluminescence Intensity

Total ATP (adenosine triphosphate) concentration is a useful biochemical parameter for detecting microbial biomass or biogeochemical activity anomalies in the natural environment. In this study, we describe the development and evaluation of a new version of in situ ATP analyzer improved for the continuous and quantitative determination of ATP in submarine environments. We integrated a transparent microfluidic device containing a microchannel for cell lysis and a channel for the bioluminescence L–L (luciferin–luciferase) assay with a miniature pumping unit and a photometry module for the measurement of the bioluminescence intensity. A heater and a temperature sensor were also included in the system to maintain an optimal temperature for the L–L reaction. In this study, the analyzer was evaluated in deep sea environments, reaching a depth of 200 m using a remotely operated underwater vehicle. We show that the ATP analyzer successfully operated in the deep-sea environment and accurately quantified total ATP within the concentration lower than 5 × 10−11 M.

In situ Enclosure Experiment Using a Benthic Chamber System to Assess the Effect of High Concentration of CO2 on Deep-Sea Benthic Communities

2005 ◽  
Vol 61 (5) ◽  
pp. 835-843 ◽  
Author(s):  
Hiroshi Ishida ◽  
Yuji Watanabe ◽  
Tatsuo Fukuhara ◽  
Sho Kaneko ◽  
Kazushi Furusawa ◽  
...  
Keyword(s):  
Deep Sea ◽  
Benthic Communities ◽  
Chamber System ◽  
High Concentration ◽  
Enclosure Experiment ◽  
Benthic Chamber
Sign in / Sign up

Export Citation Format

Share Document