Reliability Assessment of the Water Distributing Valve of a Hydrostatic Sediment Corer

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Huawei Qin ◽  
Hangmin Hu ◽  
Wei Ye ◽  
Jianjun Wang ◽  
Zhen Cai ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Atmospheric Pressure ◽  
Failure Modes ◽  
Reliability Assessment ◽  
Ambient Water ◽  
Ambient Seawater ◽  
Future Improvement ◽  
Potential Pressure ◽  
Sediment Corer

The hydrostatic corer is designed for sampling sediment from the seafloor. Its operation relies on a water distributing valve which converts the potential pressure difference between ambient seawater and a built-in chamber with atmospheric pressure to the dynamic energy as the driving power. As the valve is exposed to the ambient water, the deformation of its components may exceed their fitting tolerance under the high pressure and low temperature on seafloor, and thus cause the failure of the valve. Three possible failure modes have been taken into account, representing the positions where interference of fitting tolerance is likely to occur. Corresponding models are then created considering the coupled effects of pressure and temperature on the valve. Based on the model results and the reliability requirement of the corer, one failure mode is selected to calculate the reliability of the valve and is used as guidance for the future improvement of the design.

The Effect of Ge Segregation on Oxidation of Si

1987 ◽  
Vol 105 ◽  
Author(s):  
E. C. Frey ◽  
N. R. Parikh ◽  
M. L. Swanson ◽  
M. Z. Numan ◽  
W. K. Chu
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Epitaxial Layer ◽  
Atmospheric Pressure ◽  
Oxidation Rate ◽  
Oxidation Temperature ◽  
Pressure Oxidation ◽  
Enhanced Oxidation ◽  
High Pressure Oxidation

AbstractWe have studied oxidation of various Si samples including: Ge implanted Si, CVD and MBE grown Si(0.4–4% Ge) alloys, and MBE grown Si-Si(Ge) superlattices. The samples were oxidized in pyrogenic steam (800–1000°C, atmospheric pressure) and at low temperature and high pressure (740°C, 205 atm of dry O2). The oxidized samples were analyzed with RBS/channeling and ellipsometry.An enhanced oxidation rate was seen for all Ge doped samples, compared with rates for pure Si. The magnitude of the enhancement increased with decreasing oxidation temperature. For steam oxidations the Ge was segregated from the oxide and formed an epitaxial layer at the Si-SiO2 interface; the quality of the epitaxy was highest for the highest oxidation temperatures. For high pressure oxidation the Ge was trapped in the oxide and the greatest enhancement in oxidation rate (>100%) was observed.

Cyclone Bomb hits Southern Brazil in 2020

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Ricardo Gobato ◽  
Alireza Heidari
Keyword(s):  
High Pressure ◽  
Atmospheric Pressure ◽  
High Speed ◽  
Satellite Images ◽  
The State ◽  
Southern Brazil ◽  
Santa Catarina ◽  
High Area ◽  
South Of Brazil ◽  
Rapid Drop

An “explosive extratropical cyclone” is an atmospheric phenomenon that occurs when there is a very rapid drop in central atmospheric pressure. This phenomenon, with its characteristic of rapidly lowering the pressure in its interior, generates very intense winds and for this reason it is called explosive cyclone, bomb cyclone. With gusts recorded of 116 km/h, atmospheric phenomenon – “cyclone bomb” (CB) hit southern Brazil on June 30, the beginning of winter 2020, causing destruction in its influence over. One of the cities most affected was Chapecó, west of the state of Santa Catarina. The satellite images show that the CB generated a low pressure (976 mbar) inside it, generating two atmospheric currents that moved at high speed. In a northwest-southeast direction, Bolivia and Paraguay, crossing the states of Parana and Santa Catarina, and this draft that hit the south of Brazil, which caused the destruction of the affected states.  Another moving to Argentina, southwest-northeast direction, due to high area of high pressure (1022 mbar). Both enhanced the phenomenon.

Low-Temperature Hydrogenation of Mg-Ni-Nb2O5 Alloy Processed by High-Pressure Torsion

2021 ◽  
pp. 160309
Author(s):  
M. Osorio-García ◽  
K. Suárez-Alcántara ◽  
Y. Todaka ◽  
A. Tejeda-Ochoa ◽  
M. Herrera Ramírez ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
High Pressure Torsion

Study of high-pressure air jet controlled compression ignition with compound thermodynamic cycle for combustion and emission formation process

2020 ◽  
pp. 146808742096933
Author(s):  
Xiangyu Meng ◽  
Sicheng Liu ◽  
Jingchen Cui ◽  
Jiangping Tian ◽  
Wuqiang Long ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Low Temperature ◽  
Formation Process ◽  
Combustion Process ◽  
Thermodynamic Cycle ◽  
Compression Ignition ◽  
Temperature Reaction ◽  
Air Jet ◽  
High Temperature Reaction

A novel method called high-pressure air (HPA) jet controlled compression ignition (JCCI) based on the compound thermodynamic cycle was investigated in this work. The combustion process of premixed mixture can be controlled flexibly by the high-pressure air jet compression, and it characterizes the intensified low-temperature reaction and two-stage high-temperature reaction. The three-dimensional (3D) computational fluid dynamics (CFD) numerical simulation was employed to study the emission formation process and mechanism, and the effects of high-pressure air jet temperature and duration on emissions were also investigated. The simulation results showed that the NOx formation is mainly affected by the first-stage high-temperature reaction due to the higher reaction temperature. Overall, this combustion mode can obtain ultra-low NOx emission. The second-stage high-temperature reaction plays an important role in the CO and THC formation caused by the mixing effect of the high-pressure air and original in-cylinder mixture. The increasing air jet temperature leads to a larger high-temperature in-cylinder region and more fuel in the first-stage reaction, and therefore resulting in higher NOx emission. However, the increasing air jet temperature can significantly reduce the CO and THC emissions. For the air jet duration comparisons, both too short and too long air jet durations could induce higher NOx emission. A higher air jet duration would result in higher CO emission due to the more high-pressure air jet with relatively low temperature.

scholarly journals Dynamics of flow in albumin solution treated by low-temperature atmospheric pressure helium plasma jet

AIP Advances ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 125216
Author(s):  
Tetsuji Shimizu ◽  
Hiromasa Yamada ◽  
Masanori Fujiwara ◽  
Susumu Kato ◽  
Yuzuru Ikehara ◽  
...  
Keyword(s):  
Low Temperature ◽  
Atmospheric Pressure ◽  
Plasma Jet ◽  
Helium Plasma ◽  
Albumin Solution ◽  
Solution Treated
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