Automatically Tuned Probe Head System for Pulsed NQR Spectroscopy in Extreme Thermodynamic Conditions

1994 ◽  
Vol 49 (1-2) ◽  
pp. 42-46 ◽  
Author(s):  
Michał Ostafin ◽  
Mariusz Maćkowiak ◽  
Marek Bojarski
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Operating Frequency ◽  
High Pressure Chamber ◽  
Serial Port ◽  
Remote Location ◽  
Thermodynamic Conditions ◽  
Automated Tuning ◽  
System Operating ◽  
Probe Head

Abstract A complete N Q R probe-head system operating in the frequency ranges 0.5 -150 and 150- 300 MHz is described. The head is particularly suited for NQR experiments carried out at a remote location, for example in a low-temperature cryostat or high-pressure chamber. Moreover, the head system includes a microprocessor-controller for automated tuning of the probe to the operating frequency of the associated NQR spectrometer. The controller can be easily interfaced to a PC via standard serial port.

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.

Low Temperature (4K) and High Pressure (6.5 Kbars) Crystal Structures of (TMTSF)2PF6

1985 ◽  
Vol 119 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Bernard Galiois ◽  
Jacques Gaultier ◽  
Christian Hauw ◽  
Daniel Chasseau ◽  
Alain Meresse ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Crystal Structures
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