We use ultra-fast Magnetic Resonance Imaging (MRI) to characterise hydrodynamics during pulsing flow in trickle-bed reactors. One-dimensional (1-D) liquid holdup profiles along the flow direction were acquired using Fast Low Angle SHot (FLASH) MRI at spatial and temporal resolutions of 352 μm pixel-1 and 3.3 ms, respectively. Liquid pulse properties such as pulse velocity, duration and frequency obtained with MRI are in good agreement with those measured using a well established technique called the conductance method. In addition, MRI gives local measurements and provides additional spatial information to track individual liquid pulses, which cannot be obtained with the conductance method approach.

Nuclear Magnetic Relaxation Dispersion (NMRD) is strongly sensitive to the microscopic wettability of oil and brine bearing carbonate rocks. Exploring a very large range of low frequency enables isolating the typical NMRD dispersion features, 1/T1Surf, associated to the different processes of molecular surface dynamics. This allows a separation of the surface and bulk microdynamics of oil and water even for a biphasic saturation of petroleum rocks. Several surface dynamical parameters were determined and related to the concept of microscopic wettability of oil and water in porous media.

We present a modulated gradient spin-echo method (MGSE), which uses a train of sinusoidally shaped gradient pulses separated by 180-degree RF pulses. The RF pulses efficiently refocus chemical shifts and de-phasing due to susceptibility differences, resulting in undistorted, high-resolution diffusion weighted spectra. This allows for simultaneous spectral characterization of diffusion of several molecular components with different chemical shifts. Feasibility of the technique is demonstrated by following the diffusion of water, oil, and water-soluble salt in a highly concentrated water-in-oil emulsion.

Water molecules near the surface of vesicle bilayers exhibit slow dynamics with respect to that of pure bulk water as they belong to the hydration layer. We present a unique analysis tool for the selective detection of local water of the hydration layer on the surface of unilamellar vesicles and the determination of its diffusion coefficients. We utilized stable nitroxide radicals covalently attached to the hydrophilic head groups of DOPC lipid chains that incorporate along with other lipids into vesicles. Through the use of dynamic nuclear polarization (DNP) the 1H NMR signal of local water interacting with the radical is amplified, and we present here an analysis of the local diffusion coefficients of this hydration layer.

Two-dimension (2D) NMR measurements have been performed to provide more information for qualitative identification and quantitative evaluation of the reservoir-fluids both in numerical simulation and in laboratory experiments. The data acquired with variable echo spacing and waiting time was inverted by multi-exponential inversion method. We use these 2D inversion results to identify fluid types and calculate fluid-saturation. We also detect the distribution of internal field gradients of core samples which contain paramagnetic minerals.

MR imaging of moisture ingression into porous tissue of decayed teeth in vitro with resolution of 30´120´180 μm3 was obtained using a 4.7 T research MRI scanner and a spinecho pulse sequence. High resolution images allowed the visualisation of the 3D structure of tooth pores and the estimation of their size and extent. Using a Single Point Imaging method, images of the mineralized tissue of teeth were obtained.

Pore-pore relaxation exchange experiments are a recent development and hold great promise to spectrally derive length scales and connectivity information relevant for transport in porous media. However, for large pores, NMR diffusion-relaxation techniques reach a limit because bulk relaxation becomes dominant. A combination of NMR and Xray-CT techniques could be beneficial and lead to better models for regions of unresolved porosity in CT images, increasing the accuracy of image based calculations of transport properties. In this study we carry out numerical NMR pore-pore exchange experiments on selected Xray-CT images of sandstones and carbonate rock, while at the same time tracking information about the geometry and topology of the pore space. We use pore partitioning techniques and geometric distance fields to relate T2-T2 relaxation exchange spectra to underlying structural quantities. It is shown that T2-T2 pore-pore exchange measurements at room temperatures for the samples considered likely reflect exchange between pores and throats or pores and roughness.

Transport of micronutrients (iron, cobalt, nickel, etc.) within biofilms matrixes such as methanogenic granules is of high importance, because these are either essential or toxic for the microorganisms living inside the biofilm. The present study demonstrates quantitative measurements of metal transport inside these biofilms using T1 weighted 3D RARE. It is shown that iron(II)-EDTA diffusion within the granule is independent of direction or the inner structure of the granules. Assuming position dependence of the spin-lattice relaxivity, Fick’s law for diffusion in a sphere can be applied to simulate the diffusion within the methanogenic granules under investigation. A relatively low diffusion coefficient of 2.5*10-11 m2·s-1 was obtained for iron diffusion within the methanogenic granule.

129Xe NMR spectra of natural abundant xenon gas trapped in fully dehydrated mesoporous materials with pore sizes smaller than 2 nm in diameter were observed under atmospheric pressure in the temperature range between 168 and 373 K. The average pore diameters of the materials studied in this paper were 0.5, 1 and about 2 nm for molecular sieves 5A and 13X and synthesized mesoporous silica, respectively. The samples were fully dehydrated using an ultra-high vacuum (UHV) system and xenon gas was introduced with the sample pre-cooled to 168 K just above the boiling point of xenon. The 129Xe NMR spectra were observed as a function of increasing temperature and the 129Xe shift were observed at each temperature for the three samples under atmospheric pressure. The behaviors of xenon atoms in small pores observed in equilibrium states can provide important information on relationships between the pore structure and 129Xe chemical shift.

Ensembles of molecules confined to pore spaces with diameters of the order of a couple of molecular diameters reveal features which may notably deviate from their behaviour both in the bulk phase and under dominating host-guest interaction. We are going to demonstrate that under identical external conditions (temperature, pressure), different ensemble \"histories\" may give rise to dramatic differences in the states of these ensembles. PFG NMR diffusion measurements are introduced as a most sensitive tool for probing these differences.