Optimal control technique for magnet design in inside-out nuclear magnetic resonance

2001 ◽  
Vol 37 (2) ◽  
pp. 1015-1023 ◽  
Author(s):  
B. Luong ◽  
J.C. Goswami ◽  
A. Sezginer ◽  
D. Davies
Keyword(s):  
Optimal Control ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Control Technique ◽  
Magnet Design ◽  
Inside Out ◽  
Nuclear Magnetic

scholarly journals Mini Inside-Out Nuclear Magnetic Resonance Sensor Design for Soil Moisture Measurements

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1682 ◽  
Author(s):  
Jiamin Wu ◽  
Pan Guo ◽  
Sheng Shen ◽  
Yucheng He ◽  
Xin Huang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Soil Moisture ◽  
Magnetic Resonance ◽  
Sandy Soil ◽  
Particle Diameter ◽  
Silica Sand ◽  
Resonance Sensor ◽  
Small Pore ◽  
Inside Out ◽  
Nuclear Magnetic

The improvement of water management in agriculture by exactly detecting moisture parameters of soil is crucial. To investigate this problem, a mini inside-out nuclear magnetic resonance sensor (NMR) was proposed to measure moisture parameters of model soils. This sensor combines three cylindrical magnets that are magnetized in the axial direction and three arc spiral coils of the same size in series. We calculated and optimized the magnet structure by equivalent magnetization to current density. By adjusting the radius and height between the cylinders, a circumferential symmetric constant gradient field (2.28 T/m) was obtained. The NMR sensor was set at 2.424 MHz to measure the water content of sandy soil with small particle diameter and silica sand with large particle diameter. The complete decaying, an NMR signal was analyzed through inverse Laplace transformation and averaged on a T2 space. According to the results, moisture content of the sample is positively correlated with the integral area of T2 spectrum peak (Apeak); T2 of the water in small pores is shorter than that in large pores, because the movement of water molecules are limited by the inner wall of the pores. In the same volume, water in large pore sample is more than that in small pore sample, so Apeak of silica sand is larger than Apeak of sandy soil. Therefore, the sensor is capable of detecting moisture both content and pore size of the sample. This mini sensor (4.0 cm in diameter and 10 cm in length) is portable, and the lowest measurable humidity is 0.38%. Thus, this sensor will allow easy soil moisture measurements on-field in the future.

On the application of geometric optimal control theory to Nuclear Magnetic Resonance

2013 ◽  
Vol 3 (4) ◽  
pp. 375-396 ◽  
Author(s):  
Elie Assémat ◽  
◽  
Marc Lapert ◽  
Dominique Sugny ◽  
Steffen J. Glaser ◽  
...  
Keyword(s):  
Optimal Control ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Control Theory ◽  
Optimal Control Theory ◽  
Geometric Optimal Control ◽  
Nuclear Magnetic

Optimal control of the inversion of two spins in Nuclear Magnetic Resonance

2012 ◽  
Vol 405 ◽  
pp. 71-75 ◽  
Author(s):  
E. Assémat ◽  
L. Attar ◽  
M.-J. Penouilh ◽  
M. Picquet ◽  
A. Tabard ◽  
...  
Keyword(s):  
Optimal Control ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic

New Magnet Design for Fast-Field-Cycling Nuclear Magnetic Resonance

2013 ◽  
Vol 11 (1) ◽  
pp. 251-256 ◽  
Author(s):  
Stephan Kruber ◽  
German Farrher ◽  
Esteban Anoardo
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnet Design ◽  
Field Cycling ◽  
Fast Field ◽  
Nuclear Magnetic

400-MHz/60-mm All-REBCO Nuclear Magnetic Resonance Magnet: Magnet Design

2016 ◽  
Vol 26 (4) ◽  
pp. 1-4 ◽  
Author(s):  
Kwang Lok Kim ◽  
Sangwon Yoon ◽  
Kyekun Cheon ◽  
Jaemin Kim ◽  
Hunju Lee ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnet Design ◽  
Nuclear Magnetic

scholarly journals Geometric Optimal Control of the Contrast Imaging Problem in Nuclear Magnetic Resonance

2012 ◽  
Vol 57 (8) ◽  
pp. 1957-1969 ◽  
Author(s):  
B. Bonnard ◽  
O. Cots ◽  
S. J. Glaser ◽  
M. Lapert ◽  
D. Sugny ◽  
...  
Keyword(s):  
Optimal Control ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Contrast Imaging ◽  
Geometric Optimal Control ◽  
Nuclear Magnetic
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