Research Gallery

My ongoing studies are reviewed here.

W.L. Bragg (Nobelist) humourously used to give a piece of advice to the young scientists entering his lab.

'Never hesitate do an experiment that the theoreticians have declared stupid.'

Click the photo below for the enlargement. Commentary The articles
We performed nondestructive determinationof the atomic number and molar concentration of a heavy element in a sample using polychrimatic single-voltage medical X-ray CT. Analytical Sciences (2012)
Extensive pore-scale computer simulations were performed for the steady-state local diffusive fluxes in fluid-filled porous geomaterials to obtain some statistical finding.. Transport in Porous Media (2012)
The renormalization technique was applied to the fast estimation of the electric resistivity of porous rocks saturated with conductive fluid, and the factors controlling the estimation accuracy were discussed quantitatively. J. Appl. Geophys. 75, 31-41(2011)
We applied low-filed NMR relaxometry (photo) to the oil-contaminated soil core samples to detect the contaminated portions non-destructively. X-ray CT measurements were also carried out to visualize the pore water distribution within the core. Water Air & Soil Pollution (2011)
We calculated the diffusion ellipsoids of anisotropic porous rocks by the X-ray CT-based random walk simulations. The principal axes and eigen values of the diffusion tensor were determined. Water Resour. Res. (2008)


NMR relaxometry/diffusometry under a ultra low magnetic field (earth’s magnetic field).

 

 

An original NMR surface scanner was developed to detect hidden water-filled cracks and pores in tunnels.

1.AIST HP(Japanese)

2.AIST HP(Japanese)

Three-dimensional trajectory of a single random walk trial through a percolated pore cluster in a 3-D X-ray CT image set of a porous Niijima lava sample. J. Nucl. Sci .Tecnol. 44
NMR logging was performed at a Sumikawa geothermal test well to estimate the fracture apertures in andesite lava.

Geophysical Prospecting, 55

Errata

Pulsed-field-gradient NMR was applied to bentonite-water mixture samples to construct a diffusion model of H2O molecules in water-rich smectite gels.

Clay Minerals, 41

Errata

Micro-focus X-ray CT image of a porous andesite sample from Sumikawa, Akita, Japan. The image dimension is 2563 voxels = 3.93 mm3.


Arrhenius plot of T2 relaxation time (0.47 T) of water protons in Kunigel-V1 bentonite gels for various clay weight fractions. J. Nucl. Sci. Tecnol., 41
X-ray microtomography of a porous sandstone was performed at a synchrotron facility (SPring-8) to analyze the pore tortuosity. J. Contam. Hydrol., 74
Diffusion of heavy ions in Wyoming bentonite gels was monitored by X-ray CT to measure the dependence of the diffusivity on the clay weight fraction and ion species. The 2-D image is the strontium diffusion in gels and bulk water obtained by a medical X-ray CT scanner. The image dimension is 5122 voxels = 1602 mm2. J. Contam. Hydrol., 61
Review on the self-diffusivity measurement of H2O in clay gels by pulsed-field-gradient NMR spectroscopy. The photo is the NMR spectrometer used (Bruker, Minispec, 0.47T)


Transport properties (permeability and tortuosity) of porous media were estimated by random walk simulation using a three-dimensional X-ray CT image set. The image is a monodisperse bead pack (diameter, 2.11 mm) obtained by micro-focus X-ray CT. The image dimension is 2563voxels=13.63mm3.

Water Resources Research, 38

Errata

X-ray CT was applied to the diffusion test of iodine diffusion in water-rich montmorillonite gels. The image dimension is 5122 voxels = 1602 mm2. Clays and Clay Minerals, 50
H2O self-diffusivities in water-rich montmorillonite gels were measured using pulsed-gradient nuclear magnetic resonance spectroscopy to discuss the dependence of the diffusivities on the temperature and clay fraction.

American Mineralogist, 86

Errata

The X-ray CT system was successfully applied for the first time to the nondestructive and in-situ measurement of the diffusion of heavy ions in water-saturated porous media. The photo is the medical X-ray CT system used. Engineering Geology, 56