Nitrogenous Compatible Solutes in Native South Australian Plants

1987 ◽  
Vol 14 (3) ◽  
pp. 341
Author(s):  
A Poljakoff-Mayber ◽  
DE Symon ◽  
GP Jones ◽  
BP Naidu ◽  
LG Paleg
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Water Content ◽  
Relative Water Content ◽  
Compatible Solutes ◽  
Native Flora ◽  
Saline Marsh ◽  
Relative Water ◽  
Nuclear Magnetic

Australian native flora was examined with nuclear magnetic resonance (n.m.r.) techniques for its content of nitrogenous compatible solutes. Plants were sampled from four habitats: two arid, one subhumid, and one saline estuarine marsh. Eight and two of the 15 plants in the subhumid area accumulated proline and glycinebetaine, respectively, whereas many of the plants in the two arid habitats accumulated these solutes. With only two exceptions plants in the saline marsh could be described as either proline accumulators (six species) or glycinebetaine accumulators (eight species). Attempts to correlate the glycinebetaine and proline contents with the relative water content (RWC) were not successful. Some plants accumulate compounds other than, or in addition to, proline or glycinebetaine, such as trans- 4-hydroxy-N-methyl-L-proline, which was accumulated in Melaleuca lanceolata. Exocarpos aphyllus accumulated an as yet unidentified compound.

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 Accounting for relaxation during pulse effects for long pulses and fast relaxation times in surface nuclear magnetic resonance

Geophysics ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. JM23-JM36 ◽  
Author(s):  
Denys Grombacher ◽  
Ahmad A. Behroozmand ◽  
Esben Auken
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Water Content ◽  
Relaxation Times ◽  
Initial Amplitude ◽  
Fast Relaxation ◽  
Direct Modeling ◽  
Geophysical Technique ◽  
Insight Into ◽  
Nuclear Magnetic

Surface nuclear magnetic resonance (NMR) is a geophysical technique providing noninvasive insight into aquifer properties. To ensure that reliable water content estimates are produced, accurate modeling of the excitation process is necessary. This requires that relaxation during pulse (RDP) effects be accounted for because they may lead to biased water content estimates if neglected. In surface NMR, RDP is not directly included into the excitation modeling, rather it is accounted for by adjusting the time at which the initial amplitude of the signal is calculated. Previous work has demonstrated that estimating the initial amplitude of the signal as the value obtained by extrapolating the observed signal to the middle of the pulse can greatly improve performance for the on-resonance pulse. To better understand the reliability of these types of approaches (which do not directly include RDP in the modeling), the performance of these approaches is tested using numerical simulations for a broad range of conditions, including for multiple excitation pulse types. Hardware advances that now allow the routine measurement of much faster relaxation times (where these types of approaches may lead to poor water content estimates) and a recent desire to use alternative transmit schemes demand a flexible protocol to account for RDP effects in the presence of fast relaxation times for arbitrary excitation pulses. To facilitate such a protocol, an approach involving direct modeling of RDP effects using estimates of the subsurface relaxation times is presented to provide more robust and accurate water content estimates under conditions representative of surface NMR.

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