A simple device for T1 measurements on a nuclear magnetic resonance spectrometer by adiabatic rapid passage

1968 ◽  
Vol 1 (9) ◽  
pp. 963-964 ◽  
Author(s):  
J A Glasel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Simple Device ◽  
Nuclear Magnetic Resonance Spectrometer ◽  
Adiabatic Rapid Passage ◽  
Rapid Passage ◽  
Nuclear Magnetic

scholarly journals The Brine Content of Sea Ice Measured with a Nuclear Magnetic Resonance Spectrometer

1966 ◽  
Vol 6 (43) ◽  
pp. 89-100 ◽  
Author(s):  
Charles Richardson ◽  
E. E. Keller
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Sea Ice ◽  
Water Content ◽  
Field Studies ◽  
Analysis Data ◽  
Nuclear Magnetic Resonance Spectrometer ◽  
Magnetic Resonance Data ◽  
Weight Content ◽  
Nuclear Magnetic

Abstract Nuclear magnetic properties of hydrogen are used for the quantitative analysis of the water content of sea ice from 0° C. to −40° C. The data on water content are utilized to calculate the brine volume and brine weight content of the samples. Over a range of water contents of 2% to 96% the standard deviation of the nuclear magnetic resonance data from chemical analysis data is ±0.6%, An estimate of water content in a sample of sea ice at −70° C. is given, and the value of nuclear magnetic resonance measurements for field studies is discussed.

scholarly journals Synthesis, Characterization, and Antifungal Property of Hydroxypropyltrimethyl Ammonium Chitosan Halogenated Acetates

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 315 ◽  
Author(s):  
Yingqi Mi ◽  
Wenqiang Tan ◽  
Jingjing Zhang ◽  
Lijie Wei ◽  
Yuan Chen ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ammonium Chloride ◽  
Antifungal Drugs ◽  
Chitosan Derivatives ◽  
Antifungal Activities ◽  
Nuclear Magnetic Resonance Spectrometer ◽  
13C Nuclear Magnetic Resonance ◽  
Substitution Degree ◽  
Nuclear Magnetic

Hydroxypropyltrimethyl ammonium chitosan halogenated acetates were successfully synthesized from six different haloacetic acids and hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with high substitution degree, which are hydroxypropyltrimethyl ammonium chitosan bromacetate (HACBA), hydroxypropyltrimethyl ammonium chitosan chloroacetate (HACCA), hydroxypropyltrimethyl ammonium chitosan dichloroacetate (HACDCA), hydroxypropyltrimethyl ammonium chitosan trichloroacetate (HACTCA), hydroxypropyltrimethyl ammonium chitosan difluoroacetate (HACDFA), and hydroxypropyltrimethyl ammonium chitosan trifluoroacetate (HACTFA). These chitosan derivatives were synthesized by two steps: first, the hydroxypropyltrimethyl ammonium chloride chitosan was synthesized by chitosan and 3-chloro-2-hydroxypropyltrimethyl ammonium chloride. Then, hydroxypropyltrimethyl ammonium chitosan halogenated acetates were synthesized via ion exchange. The structures of chitosan derivatives were characterized by Fourier transform infrared spectroscopy (FTIR), 1H Nuclear magnetic resonance spectrometer (1H NMR), 13C Nuclear magnetic resonance spectrometer (13C NMR), and elemental analysis. Their antifungal activities against Colletotrichum lagenarium, Fusarium graminearum, Botrytis cinerea, and Phomopsis asparagi were investigated by hypha measurement in vitro. The results revealed that hydroxypropyltrimethyl ammonium chitosan halogenated acetates had better antifungal activities than chitosan and HACC. In particular, the inhibitory activity decreased in the order: HACTFA > HACDFA > HACTCA > HACDCA > HACCA > HACBA > HACC > chitosan, which was consistent with the electron-withdrawing property of different halogenated acetates. This experiment provides a potential idea for the preparation of new antifungal drugs by chitosan.

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