NMR - magnetic field vs. frequency; Hz vs. T

Can you recalculate Hz to Tesla?

Not really. They are connected, but both have different dimensions, so can't equate them.

1Hz = 1 cycle/second - it is frequency, not magnetic field
Magnetic field strength (B) is measured in Tesla (T).

The larger the magnetic field, the faster the frequency.
1 GHz corresponds to 23.5 T
800 MHz corresponds to 18.8 T

The Earth magnetic field is around 30-60 µT.

Frequencies can be represented also in radians per second (rad/s).

2π rad/s = 1 Hz = 1 s^-1

^{Nucleus frequency depends on the electromagnetic environment: when nearby atoms strip away electrons (like electronegative O or N), then nucleus has higher frequency; so less electrons nearby, stronger the nucleus magnetic field, higher frequency.}
^{frequency of the atom = type of atom x magnetic field strength around the atom}

^{Larmor frequency- precession}

^{The frequency of the precession (Larmor frequency) depends on the gyromagnetic ratio and gyromagnetic ratio units are Hz/T, as:}

^ω=γB

^Where
^{ω is the frequency of the precession}
^{γ is the gyromagnetic ratio}
^{B is the strength of the magnetic field}

^{The precession of the magnetization vector is what we detect in NMR, but because of interference from B0 , the precession can't be measured while the net magnetization is along z-axis. That's why we use radiofrequency pulses to rotate the net magnetization.}

Komentarze

Popularne posty z tego bloga

Thesis stuff - PyMOL - how to remove alternative conformation; renumbering, measuring distances with 2 decimals

Sometimes I'm googling stuff. How to do something.. And I'm forgetting then. Or writing on paper. But better to keep it on-line, so other googlers can find it, too ;) Thanks for http://randomthesisstuff.blogspot.co.uk/ useful! Another great one - http://www.keepcalmandpublishpapers.com/ So PyMOL, alternative conformation . It makes messy some of my calculations to keep alternative conformations, so to remove it, simply type: PyMOL>remove not (alt ''+A) PyMOL>alter all, alt='' But it's choosing conformation A, not that with higher occupancy! See here - https://pymolwiki.org/index.php/Property_Selectors#Alternate_Locations Alternatively in Phenix - Model tools - pdb tools - options - remove alternate conformers, but it gave me the same output as PyMOL, conformation A, not higher occupancy. You can do it in Coot , but then (probably?) have to go from residue to residue (with double occupancy), I didn't find how to do it for whole

Czytaj więcej

How to make gif from PyMOL - easily!

Firstly, save your movie as png images. You can set_view/get_view to have the right orientation. To save scenes go to > scene > store > F 1/2/3... then > Movie > Program > Scene Loop I use usually: Nutate > 30 deg. over 4 sec. > file > save movie as png images then for 300 images you can easily use http://gifmaker.me/ (quite slow even with highest speed) or https://ezgif.com/maker up to 2000 files (delay time 1 makes a nice speed) or it's easy to find some png to gif conventer online

Czytaj więcej

phasing (pseudo) 3D spectrum in TopSpin

1. Open your 3D processed spectrum. 2. Click on "show F2-F3 plane" (button "23" in TopSpin 3.2) xfb 3. Select plane orientation: "23" 4. Select plane number: "1" 5. Enter new PROCNO: can be "231" 6. Interactive phase correction 7. Add 3 points, then "R" - start the phase correction on rows 8. Phase and save. 7. Save for 3D spectrum (second button after "R") 8. Return to 3D spectrum. 9. process: tf3 and tf2 check you F2-F3 plane and enjoy! ;-)

Czytaj więcej

thesisandpapers

Szukaj na tym blogu