Search results for "micro-tomography"
showing 5 items of 5 documents
In situ analysis of garnet inclusion in diamond using single-crystal X-ray diffraction and X-ray micro-tomography
2012
A single crystal of garnet enclosed in a diamond from the Jericho kimberlite (Slave Craton, Canada) has been investigated using X-ray diffraction and X-ray micro-tomography. The novel experimental approach allowed us to determine the crystal structure of the garnet. The unit-cell edge a and fractional atomic coordinates of oxygen were used to determine the composition via an updated Margules model for garnets. The composition is Pyr(0.41(5))Alm(0.36(7))Gro(0.22(1))Uva(0.01(1)), which is indistinguishable from the eclogitic garnets found in other Jericho diamonds. We also demonstrated that residual pressures on the inclusion of up to 1 GPa do not affect significantly the determination of the…
Water dynamics in different biochar fractions.
2014
Biochar is a carbonaceous porous material deliberately applied to soil to improve its fertility. The mechanisms through which biochar acts on fertility are still poorly understood. The effect of biochar texture size on water dynamics was investigated here in order to provide information to address future research on nutrient mobility towards plant roots as biochar is applied as soil amendment. A poplar biochar has been stainless steel fractionated in three different textured fractions (1.0-2.0 mm, 0.3-1.0 mm and0.3 mm, respectively). Water-saturated fractions were analyzed by fast field cycling (FFC) NMR relaxometry. Results proved that 3D exchange between bound and bulk water predominantly…
Use of micro-tomography for validation of method to identify interfacial shear strength from tensile tests of short regenerated cellulose fibre compo…
2016
The interfacial shear strength of short regenerated cellulose fibre/polylactide composites was characterized by means of an industry-friendly adhesion test method. The interfacial shear strength was back-calculated from the experimental tensile stress-strain curves of composites by using a micro-mechanical model. The parameters characterizing the microstructure of the composites, e.g. fibre length and orientation distributions, used as input in the model were obtained by micro-tomography. The investigation was carried out on composites with untreated and surface treated fibres with various fibre weight contents (5wt%, 10wt%, and 15wt% for untreated fibres, and 15wt% for treated fibres). The…
X-ray micro-tomography based FEM modelling of hygroexpansion in PLA composites reinforced with birch pulp fibres
2017
This article presents a microscale modelling approach coupled with X-ray computed micro-tomography for the evaluation of material properties of polylactic acid (PLA) reinforced by birch pulp fibers under the effect of moisture. The results in terms of elastic moduli and hygroexpansion deformation were found in good agreement with the measurements taken at different levels of water uptake.
Analysis of fluid flow through porous media based on x-ray micro-tomographic reconstructions
2010
This thesis deals with creeping fluid flow through fibrous porous materials. Permeability through a porous medium is a measure of the ability of the material to transmit fluids. For testing and demonstration purposes the permeability values of a few fibrous heterogeneous materials, namely synthetic non-woven felt, wet pressing felt, cardboard, newsprint and hardwood paper, were measured experimentally. Reconstructions of the same materials under similar compression states were captured by x-ray micro-tomography. The actual microscopic pore structure thus obtained was utilised in the numerical lattice-Boltzmann analysis for solving the fluid flow permeability of the materials. Agreement betw…