[U. of Ottawa NMR Facility Blog] Resolution During a Liquid Nitrogen Refill
Resolution During a Liquid Nitrogen Refill
Just as it is not advisable to collect high resolution NMR data during (and shortly after) a liquid helium refill, it is similarly not advisable to collect data during a liquid nitrogen fill. The figure below illustrates this point. A 300 MHz NMR spectrometer was set up to collect an NMR spectrum every minute before, during and after a liquid nitrogen refill. The resolution deteriorates as soon as the one-way valves are removed from the nitrogen cryostat. One can see that the resolution during the fill is much worse than before the fill. Even 60...
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09-28-2011 07:25 PM
[U. of Ottawa NMR Facility Blog] Nitrogen Pressure and Spectral Resolution
Nitrogen Pressure and Spectral Resolution
Super-conducting NMR magnets are cooled with liquid helium. The boil off rate of the liquid helium is minimized by surrounding it with a high vacuum and a liquid nitrogen cryostat. The liquid nitrogen cryostat may either be vented directly to the atmosphere or it may be maintained at a pressure slightly above atmospheric pressure with the use of pressure relief valves. NMR users should be aware that the homogeneity of an NMR magnet is affected drastically by the pressure in the liquid nitrogen cryostat. The left-hand panel of the figure below shows...
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08-25-2011 06:00 AM
Direct Detection of Nitrogen-14 in Solid-State NMR Spectroscopy
Direct Detection of Nitrogen-14 in Solid-State NMR Spectroscopy
Publication year: 2011
Source: Progress in Nuclear Magnetic Resonance Spectroscopy, In Press, Accepted Manuscript, Available online 20 April 2011</br>
Luke A., O’Dell</br>
*Highlights:*? Experimental methods for the direct detection of 14N are surveyed ? Advantages, disadvantages and practicalities of each technique are discussed ? Includes single-crystal, ultra-wideline, MAS and overtone spectroscopy</br></br>
More...
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04-21-2011 03:00 PM
[NMR paper] Nitrogen-15 NMR studies of nitrogen metabolism in Picea glauca buds.
Nitrogen-15 NMR studies of nitrogen metabolism in Picea glauca buds.
Related Articles Nitrogen-15 NMR studies of nitrogen metabolism in Picea glauca buds.
Plant Physiol Biochem. 2004 Dec;42(10):803-9
Authors: Bagh K, Hiraoki T, Thorpe TA, Vogel HJ
In vivo (15)N nuclear magnetic resonance (NMR) as well as (15)N solid-state magic angle spinning (MAS) NMR spectroscopy were used to investigate nitrogen metabolism in cultured white spruce (Picea glauca) buds. Long-term as well as short-term experiments were carried out involving the use of...
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11-24-2010 10:03 PM
Nitrogen-14 NMR Spectroscopy Using Residual Dipolar Splittings in Solids
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Nitrogen-14 NMR Spectroscopy Using Residual Dipolar Splittings in Solids
Simone Cavadini, Adonis Lupulescu, Sasa Antonijevic,* and Geoffrey Bodenhausen
Laboratoire de Résonance Magnétique Biomoléculaire, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland, and Département de Chimie, associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond 75231, Paris Cedex 05, France
J. Am. Chem. Soc., 128 (24), 7706 -7707, 2006.
A mist of evaporating liquid nitrogen
Linear Mode
