Stable Created Fracture Growth between Two Parallel Boreholes

Journal of Mining Science - The authors describe numerical modeling of a growing fracture created between two parallel boreholes in an isotropic medium in the nonuniform stress field. The fracture...     

Hydrothermal Synthesis of Zeolite NaX on Porous Ceramic Supports

Data are presented on the hydrothermal crystallization of zeolite NaX on porous aluminosilicate supports. The chemical composition of the starting gel and the crystallization time are shown to have a significant effect on the phase composition and microstructure of the resulting zeolite coating. All of the synthesized materials contain zeolite NaP.     

Study of Structural Modification of Composites with Ge Nanoclusters by Optical and Electron Microscopy Methods

Semiconductors - Composites consisting of Ge nanoclusters embedded in GeO2 matrix were modified by selective removal of the germanium dioxide in deionized water or HF. Thin (up to 200 nm) and thick...     

3D Modeling of Hydraulic Fracturing in an Isotropic Elastic Medium with a Fracture Initiator at the Hole Bottom

Journal of Mining Science - The authors describe the numerical studies into hydraulic fracturing in an isotropic elastic medium with a fracture initiator set at the hole bottom. The influence of...     

Accumulation of structural defects in silicon irradiated with PF<Stack><Subscript><Emphasis Type="Italic">n</Emphasis></Subscript><Superscript>+</Superscript></Stack> cluster ions with medium energies

The method of Rutherford backscattering spectrometry in combination with channeling is used to study the accumulation of structural defects in silicon at room temperature as a result of irradiation with P⁺ and F⁺ atomic ions and also with cluster PF _n ⁺ ions (n = 1, …, 4) with the energy of 2.1 keV/amu and with identical generation rate of primary defects. The conditions for correct comparison of the results of bombardment with atomic and cluster ions composed of atoms of various types are suggested. It is found that the characteristics of accumulation of structural defects in silicon in the case of bombardment with PF _n ⁺ cluster ions differ widely from those under irradiation with both atomic ions that are involved in the cluster ion (P⁺ and F⁺) and with atomic heavy ions that have atomic mass close to that of the mass of a PF _n ⁺ cluster. It is shown that, with irradiation conditions being the same, cluster ions produce much more radiation defects in the surface region than do atomic ions; i.e., a molecular effect is observed. Plausible mechanisms of this phenomenon are considered.     

Effect of additives on the pore structure of ceramics based on crystalline SiO<Subscript>2</Subscript>

We have studied a method of controlling the pore structure of ceramics based on crystalline silica by introducing different burnable additives into the starting mixture. We have developed mathematical models in the form of best fit equations, which adequately represent the relationships between the burnable additive content of the starting mixture, the porosity of the ceramic samples, and their mechanical strength.