scholarly journals Design Overview of a Toroidal Fast-Field Cycling electromagnet

2021 ◽  
Vol 19 ◽  
pp. 368-372
Author(s):  
Joao T. Cunha ◽  
◽  
Pedro J. Sebastiao ◽  
António Roque ◽  
Vitor Vaz da Silva ◽  
...  
Keyword(s):  
Simulation Software ◽  
Comsol Multiphysics ◽  
Iron Core ◽  
Induced Magnetic Field ◽  
Field Range ◽  
Field Homogeneity ◽  
Innovative Solution ◽  
Field Cycling ◽  
Cooling Effects ◽  
Fast Field

In this paper, the design and development of a novel Fast-Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometer’s electromagnet is described. This magnet is tailored to increase the relaxometers’s usability, by increasing its portability capacities. It presents a compact toroidal shaped iron core, allowing to operate in a field range of 0 to 0.21 T, with high field homogeneity (less than 800 ppm in a volume of ≈ 0.57 cm3 ), low power consumption and reduced losses (about 40W). The simulation software COMSOL Multiphysics® is used to characterize the induced magnetic field, the heating and the cooling effects. The proposed optimized layout constitutes an innovative solution for FFC magnets.

Field-cycling NMR experiments in an ultra-wide magnetic field range: relaxation and coherent polarization transfer

2018 ◽  
Vol 20 (18) ◽  
pp. 12396-12405 ◽  
Author(s):  
Ivan V. Zhukov ◽  
Alexey S. Kiryutin ◽  
Alexandra V. Yurkovskaya ◽  
Yuri A. Grishin ◽  
Hans-Martin Vieth ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Experimental Method ◽  
Field Range ◽  
Magnetic Field Range ◽  
Wide Range ◽  
Field Cycling ◽  
Fast Field

An experimental method is described allowing fast field-cycling Nuclear Magnetic Resonance (NMR) experiments over a wide range of magnetic fields from 5 nT to 10 T.

scholarly journals Fast-field-cycling ultralow-field nuclear magnetic relaxation dispersion

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sven Bodenstedt ◽  
Morgan W. Mitchell ◽  
Michael C. D. Tayler
Keyword(s):  
High Resolution ◽  
Magnetic Relaxation ◽  
Magnetic Measurements ◽  
Nuclear Magnetic Relaxation ◽  
Relaxation Dispersion ◽  
Relaxation Rates ◽  
Field Range ◽  
Field Cycling ◽  
Fast Field ◽  
Nuclear Magnetic

AbstractOptically pumped magnetometers (OPMs) based on alkali-atom vapors are ultra-sensitive devices for dc and low-frequency ac magnetic measurements. Here, in combination with fast-field-cycling hardware and high-resolution spectroscopic detection, we demonstrate applicability of OPMs in quantifying nuclear magnetic relaxation phenomena. Relaxation rate dispersion across the nT to mT field range enables quantitative investigation of extremely slow molecular motion correlations in the liquid state, with time constants > 1 ms, and insight into the corresponding relaxation mechanisms. The 10-20 fT/$$\sqrt{{\rm{H}}}{\rm{z}}$$ H z sensitivity of an OPM between 10 Hz and 5.5 kHz 1H Larmor frequency suffices to detect magnetic resonance signals from ~ 0.1 mL liquid volumes imbibed in simple mesoporous materials, or inside metal tubing, following nuclear spin prepolarization adjacent to the OPM. High-resolution spectroscopic detection can resolve inter-nucleus spin-spin couplings, further widening the scope of application to chemical systems. Expected limits of the technique regarding measurement of relaxation rates above 100 s−1 are discussed.

A compact X-Band resonator for DNP-enhanced Fast-Field-Cycling NMR

2016 ◽  
Vol 271 ◽  
pp. 7-14 ◽  
Author(s):  
Oliver Neudert ◽  
Carlos Mattea ◽  
Siegfried Stapf
Keyword(s):  
X Band ◽  
Field Cycling ◽  
Fast Field

scholarly journals Effect of magnetic field on nanofluid free convection in Conical Partially Annular Space

2020 ◽  
Vol 330 ◽  
pp. 01005
Author(s):  
Abderrahmane AISSA ◽  
Mohamed Amine MEDEBBER ◽  
Khaled Al-Farhany ◽  
Mohammed SAHNOUN ◽  
Ali Khaleel Kareem ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hartmann Number ◽  
Volume Fraction ◽  
Boussinesq Approximation ◽  
Simulation Software ◽  
Comsol Multiphysics ◽  
Governing Equations ◽  
Element Analysis ◽  
Vertical Side ◽  
Side Walls

Natural convection of a magneto hydrodynamic nanofluid in a porous cavity in the presence of a magnetic field is investigated. The two vertical side walls are held isothermally at temperatures Th and Tc, while the horizontal walls of the outer cone are adiabatic. The governing equations obtained with the Boussinesq approximation are solved using Comsol Multiphysics finite element analysis and simulation software. Impact of Rayleigh number (Ra), Hartmann number (Ha) and nanofluid volume fraction (ϕ) are depicted. Results indicated that temperature gradient increases considerably with enhance of Ra and ϕ but it reduces with increases of Ha.

Insights into the translational and rotational dynamics of cations and anions in protic ionic liquids by means of NMR fast-field-cycling relaxometry

2021 ◽  
Vol 23 (4) ◽  
pp. 2663-2675
Author(s):  
Viviane Overbeck ◽  
Henning Schröder ◽  
Anne-Marie Bonsa ◽  
Klaus Neymeyr ◽  
Ralf Ludwig
Keyword(s):  
Ionic Liquids ◽  
Rotational Dynamics ◽  
Protic Ionic Liquids ◽  
Field Cycling ◽  
Fast Field ◽  
Hydrogen Bonded

NMR Fast-Field-Cycling (FFC) relaxometry provides important information about translational and rotational dynamics of hydrogen bonded protic ionic liquids (PILs). 

A Method for Harvesting Energy Using Piezoelectric Transducers

2015 ◽  
Vol 727-728 ◽  
pp. 607-611 ◽  
Author(s):  
Kshitij Chopra ◽  
Kritika Nigam ◽  
Sujata Pandey
Keyword(s):  
Zinc Oxide ◽  
Simulation Software ◽  
Piezoelectric Transducers ◽  
Comsol Multiphysics ◽  
Ambient Vibrations ◽  
Multiphysics Simulation

This paper analyses the behaviour ofpiezoelectric transducer for harvesting energy. The transducer was designedusing different materials for harnessing energy that include Zinc Oxide, LeadZirconate Titanate (PZT-2) and Quartz. The transducer was simulated using thesematerials and the voltage generated from ambient vibrations was analysed. MEMsmodule of COMSOL Multiphysics Simulation software was used to perform thesimulations. Behaviour of different materials towards various frequencies madeknown in this study gives an opportunity to estimate the fabricated device and alsosheds light on prospective applications it fits.

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