how do we decide on power levels and lengths of purge gradients in a new experiment?...As for coherence selection, relative lengths of two gradients are based on a ratio..again, I am lost on what power level to use!
Also, how do one correlate power level with strength in G/cm? ..what are the safe limits? (I use agilent(varian) spectrometer)
Check if somebody has answered this question on NMRWiki QA forum
Did you find this post helpful? |
Similar Threads
Thread
Thread Starter
Forum
Replies
Last Post
[Question from NMRWiki Q&A forum] Gradient strength recalculation
Gradient strength recalculation
Iam bit stuck with % z gradient calculation used in Bruker pulse programs. In some instruments (Varian) they use as short as 200us for some gradient pulses, but in Bruker, they fix the length of all the gradient pulses as constant (say 500 us) and vary the gradient strength accordingly.
Hence, is there any easy way to convert a gradient pulse of say 17 G/cm applied for 0.5 ms to 'x' G/cm for 1ms.(where 'x' is the new gradient strength for 1ms).
Once this conversion is completed,the next step would be to calculate the gradient % which i think is the...
nmrlearner
News from other NMR forums
0
06-12-2012 11:25 PM
[KPWU blog] [PyMOL] gradient background color
gradient background color
Starting at *PyMOL 1.4, *single color for the background is no longer the only choice. By using 3 PyMOL commands, the gradient background color can be easily shown. The only thing users have to know is that command “ray” doesn’t support this gradient color yet. So if you type “ray” in the pymol terminal , http://stats.wordpress.com/b.gif?host=kpwu.wordpress.com&blog=76132&post=619&subd=kpwu&ref=&feed=1
Go to KPWU blog to read complete post.
nmrlearner
News from NMR blogs
0
11-15-2011 11:36 PM
[Question from NMRWiki Q&A forum] relation of T2 relaxation time to gradient strengths
relation of T2 relaxation time to gradient strengths
to detect short T2 NMR relaxation time, we use high gradient strengths. but how? what is the relation? what is the mechanism behind it? I am interested more in physical picture rather than mathematical description.
Check if somebody has answered this question on NMRWiki QA forum
nmrlearner
News from other NMR forums
0
10-21-2011 09:52 AM
[Question from NMRWiki Q&A forum] Problem with the gradient shimming
Problem with the gradient shimming
Dear Friends,
I've recently encountered a problem with gradient shimming that has never happened to me before. I can't clearly determine what caused it but it certainly didn't involve anybody manipulating with the probe. Here's the symptom: when running the gmapz experiment, the Z-profiles (before and after gradient) look like this:
http://img833.imageshack.us/img833/2213/zprofilef.png
As you can see the second profile (after the gradient) is distorted at the left edge (more or less severely, depending on a sample - here it's just a tiny "step")....
nmrlearner
News from other NMR forums
0
10-11-2011 06:35 PM
[Question from NMRWiki Q&A forum] gradient shim map question
gradient shim map question
Does anyone know for sure if a shim map is off center slightly left in a negative direction...and I assume it is a centering issue do you whether it would be probe up/down?
Check if somebody has answered this question on NMRWiki QA forum
nmrlearner
News from other NMR forums
0
10-19-2010 06:35 PM
[U. of Ottawa NMR Facility Blog] Gradient Spin Echoes for Selective Excitation
Gradient Spin Echoes for Selective Excitation
Shaped excitation pulses can replace the non-selective hard pulses typically used in a one-pulse measurement to achieve selective excitation. Another method of achieving selective excitation is the gradient spin echo using a selective 180° pulse. This technique is demonstrated in the figure below. http://4.bp.blogspot.com/_5wBTR2kKTqA/S_UxeG5oXdI/AAAAAAAAAzc/BHWef-Tse7s/s400/grad_spin_echo.jpgA non-selective hard 90°x pulse is first given followed by a pair of identical pulsed field gradients sandwiching a soft selective 180° pulse about the y...
Gradient settings in an experiment
Linear Mode
