The example in figure 5 is a set of electron images which show a uraninite crystal, partially pseudomorphized by carbonates, and a long microfissure
crosscutting the rock matrix from the source term to a small area where U-silicates have been precipitated.
We still get some microfissure
cracks, but well within the weld area--not way outside the fusion zone."
The 68 cm/yr (27 in/yr) reported using tritium in a Dorset chalk (5) and the 54 cm/yr (21 in/yr) reported in the Cambridgeshire chalk (12) are related to microfissure
flow within the chalk.
Explanations proposed by Wang and Wei  indicated that the effect of drying-wetting cycle on the engineering property of clay was attributed to the irreversible volume shrinkage, the increase of large pore volume, and the development of microfissure
. The effects of the drying-wetting cycle on the Atterberg limits of specimens were tested and analyzed by Rao et al.
To solve the problems on borehole sealing and microfissure
sealing through application of material composite technology, research is conducted for the development of laboratory materials, performance test, and comparisons with traditional borehole sealing material.
The acoustic emission monitoring shows that the prepressed rock samples produce randomly distributed microfissure
damage, which is consistent with the field.
The permeability of coal mainly depends on the fissures, which not only provides gas reservoir space but also connects the matrix pores via a microfissure
Typical coal samples were selected for SEM test (magnify 500 times), and the microfissures
observed under scanning electron microscopy were photographed, as shown in Figure 1.
So, the chemical grouting materials with lower viscosity, better liquidity and grout ability into microfissures
, and adjustable range of curing time have been widely applied to the management of underground coal mine water bursts.
Related laboratory microscopic experiments denote that the evolution of hydraulic fractures (or cracks) is the damage evolution with initiation, extension of many microfissures
due to the impact of external load and hydraulic pressure [3, 4]; additionally, gas drainage in damaged coal-rock mass after fracturing is a process with coal-rock mass deformation and gas flow coupling.
found that thermal shock from microwave irradiation produces small cracks and microfissures
in coke particle by microphotographs .
The pores between soil particles can be seen as a kind of microfissures
, and the visible macroscopic cracks are caused by cracking of these microfissures