Water migration in poplar wood during microwave drying studied by time domain nuclear magnetic resonance (TD-NMR)

Holzforschung ◽  
2017 ◽  
Vol 71 (11) ◽  
pp. 881-887 ◽  
Author(s):  
Xinyu Li ◽  
Yulei Gao ◽  
Minghui Zhang ◽  
Ximing Wang ◽  
Xinyue Wei
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Time Domain ◽  
Bound Water ◽  
Free Water ◽  
Microwave Drying ◽  
Drying Rate ◽  
Drying Time ◽  
The Time Domain ◽  
Nuclear Magnetic

AbstractThe migration of bound water and free water has been investigated during microwave drying of wood by the time domain nuclear magnetic resonance (TD-NMR) technique. Both the heartwood (hW) and sapwood (sW) of Beijing poplar (Populus beijingensisW. Y. Hsu) and Qingpi poplar (Populus platyphyllaT. Y. Sun) were studied. The microwave drying is characterized by a fast drying rate, and there is a linear relation between moisture content (MC) and microwave drying time (t). The drying rate of free water is about 2.7 times more rapid than that of bound water. The spin-spin relaxation time (T2) revealed that most of the water was free water situated in smaller pores. The irregular T2 signal amplitudes of free water in hWs indicated that fractional water in smaller pores was transferred into bigger pores during drying.

Measurement of bound water in an aqueous DNA solution using nuclear magnetic resonance and time domain reflectometry

1992 ◽  
Vol 96 (25) ◽  
pp. 10087-10089 ◽  
Author(s):  
Minoru Fukuzaki ◽  
Toshihiro Umehara ◽  
Daisaku Kurita ◽  
Sumie Shioya ◽  
Munetaka Haida ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Time Domain ◽  
Bound Water ◽  
Time Domain Reflectometry ◽  
Nuclear Magnetic

scholarly journals Mechanisms of liquid imbibition in Douglas-fir inferred from 1H nuclear magnetic resonance methods

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dang Mao Nguyen ◽  
Sabine Care ◽  
Denis Courtier-Murias ◽  
Meng Zhou ◽  
Philippe Coussot
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cell Walls ◽  
Bound Water ◽  
Free Water ◽  
Douglas Fir ◽  
Water Control ◽  
Water Imbibition ◽  
Hydraulic Network ◽  
Nuclear Magnetic

AbstractThis study aims at identifying the mechanisms of oil and water imbibition in heartwood and sapwood of Douglas-fir through a combination of original experiments with magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) relaxation measurements for oil and free water, and deformation measurements for bound water. Experiments by weighing are performed to verify whether the imbibition process is also consistent with Washburn law. All the results are discussed taking into account the structure of wood (tubular tracheids closed at their tips, but possibly connected to each other via open pits on the side faces) and the preparation of samples. The observation of relatively fast oil flow imbibition confirms that sapwood exhibits a connected hydraulic network through which a liquid can a priori flow and climb along the structure. However, the spontaneous water imbibition is strongly damped by its very poor wetting when in contact with cell-walls only partially saturated with bound water, so that the diffusion of bound water control the uptake dynamics. However, due to preferentially closed pits, the heartwood does not exhibit a continuous hydraulic network and water essentially penetrates into wood by diffusion through the cell walls.

Probing water partitioning in unsaturated weather rock using nuclear magnetic resonance

Geophysics ◽  
2021 ◽  
pp. 1-70
Author(s):  
Fan Zhang ◽  
Chi Zhang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Structure ◽  
Gaussian Function ◽  
Decomposition Analysis ◽  
Bound Water ◽  
Free Water ◽  
Critical Zone ◽  
Pore Sizes ◽  
Nuclear Magnetic

The “Rock moisture” (exchangeable water stored in weathered bedrock beneath the soil) is a key and yet overlooked component in hydrologic cycles. It can be partitioned to free water and capillary-bound water. Determining dynamic partitioning of rock moisture is crucial for conceptualizing critical zone functions and climate and hydrologic modeling. However, the quantification of rock moisture partitioning is challenging, especially in rocks with complex pore structure and weathering patterns. To quantify the dynamics of rock moisture partitioning during the drying process, laboratory nuclear magnetic resonance (NMR) measurements are performed on heterogeneous bedrock samples from a merokarst aquifer. By fitting a multi-Gaussian function, NMR T2 relaxation time spectra are auto-decomposed into multiple T2 peaks representing different pore sizes and environments. This spectral analysis enables us to track the change of position, width, and area of peaks at any given saturation stage, shedding light on water depletion rates and patterns, water residence time, and partitioning and redistribution of the water in drying rocks. Combining with mineralogic information and T2- T2 measurements, it is shown that rock moisture depletion and redistribution are closely related to the pore structures. Limestone with well-connected macropores shows a sequential water loss from large to small pores, while limestone with poorly-connected macropores simultaneously loses water from all pore sizes. The T2 peak decomposition analysis is rigorous and can be extended to field-scale to discern nuanced rock moisture partitioning in complex pore structure and to harness the rich information provided by NMR during critical zone hydrogeological investigations. Valuable insights are gained from our work towards groundwater recharge and discharge, weathering, and dry season evapotranspiration.

Measuring the solubility product constant of paramagnetic cations using time-domain nuclear magnetic resonance relaxometry

2015 ◽  
Vol 121 ◽  
pp. 14-17 ◽  
Author(s):  
Paulo Falco Cobra ◽  
Bruna Ferreira Gomes ◽  
Cirlei Igreja Nascimento Mitre ◽  
Lucio Leonel Barbosa ◽  
Lucinéia Vizzotto Marconcini ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Time Domain ◽  
Solubility Product ◽  
Nuclear Magnetic Resonance Relaxometry ◽  
Solubility Product Constant ◽  
Nuclear Magnetic

scholarly journals Rapid Determination ofMoisture/Solids and Fat in Dairy Products by Microwave and Nuclear Magnetic Resonance Analysis: PVM 1:2004

2005 ◽  
Vol 88 (1) ◽  
pp. 107-120 ◽  
Author(s):  
Gary Cartwright ◽  
Bobbie H McManus ◽  
Timothy P Leffler ◽  
Cindy R Moser
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Dairy Products ◽  
Rapid Determination ◽  
Microwave Drying ◽  
Nuclear Magnetic Resonance Analysis ◽  
Nmr Analysis ◽  
Plant Operations ◽  
Solids Content ◽  
Nuclear Magnetic

Abstract A peer-verified method is presented for the determination of percent moisture/solids and fat in dairy products by microwave drying and nuclear magnetic resonance (NMR) analysis. The method involves determining the moisture/solids content of dairy samples bymicrowave drying and using the dried sample to determine the fat content by NMR analysis. Both the submitting and peer laboratories analyzed various dairy products by using a CEM SMART system (moisture) and the SMART Trac (fat). The samples included milks, creams, ice cream mix, sour cream, yogurt, cream cheese, and mozzarella, Swiss, and cheddar cheeses. These samples represented a range of products that processors deal with in daily plant operations. The results were compared with moisture/solids and fat values derived from AOAC-approved methods.

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