Forward simulation and characteristic analysis on the low field NMR transverse relaxation response of fractured shale reservoir

Roots are at the core of plant water dynamics. Nonetheless, root morphology and functioning are not easily assessable without destructive approaches. Nuclear Magnetic Resonance (NMR), and particularly low-field NMR (LF-NMR), is an interesting noninvasive method to study water in plants, as measurements can be performed outdoors and independent of sample size. However, as far as we know, there are no reported studies dealing with the water dynamics in plant roots using LF-NMR. Thus, the aim of this study is to assess the feasibility of using LF-NMR to characterize root water status and water dynamics non-invasively. To achieve this goal, a proof-of-concept study was designed using well-controlled environmental conditions. NMR and ecophysiological measurements were performed continuously over one week on three herbaceous species grown in rhizotrons. The NMR parameters measured were either the total signal or the transverse relaxation time T2. We observed circadian variations of the total NMR signal in roots and in soil and of the root slow relaxing T2 value. These results were consistent with ecophysiological measurements, especially with the variation of fluxes between daytime and nighttime. This study assessed the feasibility of using LF-NMR to evaluate root water status in herbaceous species.

Download Full-text

Hydration Dynamics of Portland Cement Studied by Magnetic Resonance

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.193-194.509 ◽

2012 ◽

Vol 193-194 ◽

pp. 509-512 ◽

Cited By ~ 1

Author(s):

An Ming She ◽

Wu Yao ◽

Wan Cheng Yuan

Keyword(s):

Portland Cement ◽

Initial Period ◽

Bound Water ◽

Transverse Relaxation Time ◽

Rate Of Change ◽

Individual Stage ◽

Transverse Relaxation ◽

Low Field ◽

Low Field Nmr ◽

Hydration Dynamics

Hydration dynamics of Portland cement was investigated by low field NMR, a technique with advantage of continuous and nondestructure monitor. The transverse relaxation time, T2, and signals intensity arising from the physically bound water in paste were measured. Their evolution with the hydration time could be used well to describe the hydration dynamics. Three successive periods, comprising of initial period, accelerated period and steady period, were defined according the different rate of change. The reactions and mechanism for individual stage were disscussed based on the cement chemistry theory.

Download Full-text

Low Field-NMR in Measuring Water Mobility and Distribution in Beef Granules during Drying Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.3406 ◽

2012 ◽

Vol 550-553 ◽

pp. 3406-3410 ◽

Cited By ~ 12

Author(s):

Xin Li ◽

Li Zhen Ma ◽

Yuan Tao ◽

Bao Hua Kong ◽

Pei Jun Li

Keyword(s):

Bound Water ◽

Free Water ◽

Transverse Relaxation Time ◽

Water Mobility ◽

Drying Process ◽

Transverse Relaxation ◽

Low Field ◽

Different Temperatures ◽

Low Field Nmr ◽

Lf Nmr

Low field-nuclear magnetic resonance (LF-NMR) was employed in this study to evaluate water mobility and distribution in beef granules during drying process due to its fast and nondestructive detection. Beef granules were dried in a blast drying oven at different temperatures (40, 50 and 60 °C) to a final moisture content around 21% after cooking. Results showed that it took about 150, 90 and 60 min for the samples dried at 40, 50 and 60 °C to get to the drying destination, respectively. The immobilized water was transformed into bound water with lower association degree and free water during drying at different conditions. Drying also resulted in a proportion increase of bound water; what’s more, the proportion of bound water is the largest when drying at 50 °C compared to 40 and 60 °C. After the drying destination was reached, the transverse relaxation time for bound water and immobilized water appeared significant change. It revealed that LF-NMR was an effective tool to assess water mobility and distribution during food drying process.

Download Full-text