Efficiency of selective crushing with pneumatic separation for the third unit in the OAO NTMK coal-preparation shop 2. Equipment and operating conditions

The efficiency of selective crushing with pneumomechanical separation is investigated as a function of the quality of the coal batch and the operating conditions of the fluidized-bed separator.     

Concomitant Crystallization of Copper(II) Sachharinato Complexes with 2-methylpyrazine as a Monomer and an One-dimensional Polymer: Syntheses,Crystal Structures,Spectroscopic and Thermal Properties

The reaction of [Cu(sac)₂(H₂O)₄] · 2H₂O with 2-methylpyrazine (mpyz) leads two complexes, concomitant crystallization of a mononuclear complex [Cu(sac)₂(mpyz)(H₂O)₂] (1) and a polymeric complex [Cu(sac)₂(μ-mpyz)]_n (2). Both complexes have been characterized by elemental analyses, magnetic measurements, FT-IR and ESR, TG-DTA and single-crystal X-ray diffraction analyses. Single-crystal X-ray analyses show that complex 1 consists of discrete molecules in which the copper(II) ions exhibits a square-pyramidal coordination geometry. The individual molecules of 1 are connected into a hydrogen-bonded chain structure, which is further assembled to form a three-dimensional network by π–π stacking interactions. Complex 2 is an 1D coordination polymer in which copper(II) centers are bridged by the mpyz ligand. The chains are further assembled to form two-dimensional frameworks by π–π and C–H···π stacking interactions.     

Application of the Herring model to explain the impurity content dependence of the viscosity of quartz glasses

It is shown that the structural characteristics of quartz glasses make it possible to use the Herring model to describe their viscous flow, while the nonuniform distribution of impurities explains the known regularities in the dependence of the coefficient of viscosity on their content.     

High density technical ceramics: Technology and preparation of green articles for sintering

It is shown that the degree of aggregation of powders and the properties of aggregates (size, strength, porosity) affect the degree of sintering and the microstructure characteristics of the ceramic fabricated. The conditions for obtaining low-aggregation powder and methods for de-aggregating powder are examined. The requirements which powders must satisfy in order to obtain compacts with a uniform pore size and uniform sintering over the volume of the articles are formulated.     

Grinding high-quality and art glass with diamond grinding wheels with organic binders

It has been found that using the new organic binder MV1 with grinding powder with grain size 45/38 µm instead of the binder M2-01 with micropowder grain size 30/40 µm increases the productivity of the final diamond grinding of high-quality and art glass by a factor of 2–2.5 without any subsequent chemical polishing and decreases the roughness of the worked surface by 20% with 14–28% higher specific consumption.