Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505098
Title: NMR relaxation and imaging for the characterisation of wood and trees
Author: Cox, Julia
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 2008
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Abstract:
In this thesis, the application of NMR to the characterization and imaging of wood, and to wood in living trees, is investigated in two parts. The fIrst part characterises wood using advanced two dimensional (2-D) NMR measurements. The second part presents a novel portable magnet, purpose built for the imaging ofliving trees in-situ. The NMR relaxation parameters (T1 and T2) of the wood water components are established using standard one dimensional (I-D) procedures. Generally, three T2 components are found in wood with values of 10-100's ~s (small cell wall pores), 1-8 ms (larger cell wall pores) and lO's ms (lumen cavities). There are also three T1 components: a few ms (cell wall pores), lO's ms (latewood lumen) and -lOOms (earlywood lumen). Information on these components is furthered by application of the 2-D T1-T2 correlation experiment. T1-T2 spectra show that at T2 times of a few ms (cell wall pores), there are two components which have different T1 relaxation times: 12ms (peak C) and 85ms (peak B). Peak B is suggested to arise from exchange between peak C and lumen water. Another exchange peak (peak D) is identified at 0.05ms T2 and 58ms T1 (data from spruce at 45% MC). Peaks B and D are further investigated by 2-D T2-T2 correlation experiments, allowing fIrst estimates of the exchange times to be made. The time for exchange ofwaterl magnetisation between lumen and cell wall water was found to be 4.6ms and between smaller and larger cell wall pores to be 21ms.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.505098  DOI: Not available
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