Metrological Support and Standards in the Design,Production, and Use of High-Load Weighing Machines in Russia

An analysis is presented on development, production, and use of high-capacity weighing machines in Russia in the last ten years. Aspects arising in type approval testing are considered for high-capacity weighing machines working over wide temperature ranges.     

Synthesis and structural studies of a new potassium uranyl selenate K(H5O2)[(UO2)2(SeO4)3(H2O)] with strongly deformed layers

Single crystals of a new uranyl selenate, K(H₅O₂)[(UO₂)₂(SeO₄)₃(H₂O)] (I), were prepared by isothermal evaporation at room temperature. The crystal structure of I was solved by the direct method (space group P2₁/c; a = 11.456(2), b = 10.231(1), c = 14.809(2) ?; β = 101.901(4)°, V = 1698.4(4) ?³; Z = 4) and refined to R ₁ = 0.0547 (wR ₂ = 0.0825) for 3375 reflections with |F _o| ≥ 4σ _F . The structure of I is based on layers of the composition [(UO₂)₂(SeO₄)₃(H₂O)]²⁻. The charge of the inorganic layer is compensated by potassium and oxonium ions located in the interlayer space. Each potassium ion is coordinated by seven oxygen atoms belonging to uranyl selenate layers, including uranyl oxygen atoms, which leads to bending of uranyl selenate structural elements.     

Combustion of Quartz-Containing Oxide Systems Modified by Organic Compounds under Mechanochemical Treatment

The paper deals with the combustion of a SiO₂–Al stoichiometric mixture after mechanochemical treatment in activator mills of two types: mills using predominantly shear loading and those using shear–dynamic compression. It is shown that treatment in different loading regimes, leading to different energy states of the material, and the use of modifying organic additives change significantly the ignition and combustion temperature of the mixture. Modification of the surface of the quartz particle by mechanochemical treatment in the presence of butanol or polystyrene and aluminum activates the combustion process, thus ensuring greater completeness of the oxidation-reduction reaction.     

Complex Investigation into the Abrasion-Reaction Modification of Quartz Particle Surface by Amorphous Iron Compounds

The results are presented for investigating the mechanism and kinetics of chemical interaction between the steel milling bodies and natural quartz particles processed. It is demonstrated that grinding and surface amorphization of quartz particles is accompanied by mechanochemical synthesis of iron silicates from silicon and iron oxides. The thickness of iron silicate layer formed on the surface of quartz particles is estimated. A new method is proposed for processing the geological and technogenic substances by mechanochemical reactions with the material of milling bodies. The method is approved by production of nanocomposite metal-oxide-sulfide powders.     

Synthesis and structural study of new potassium uranyl selenates K2(H5O2)(H3O)[(UO2)2(SeO4)4(H2O)2](H2O)4 and K3(H3O)[(UO2)2(SeO4)4(H2O)2](H2O)5

Single crystals of new uranyl selenates K₂(H₅O₂)(H₃O)[(UO₂)₂(SeO₄)₄(H₂O)₂](H₂O)₄ (1) and K₃(H₃O)[(UO₂)₂(SeO₄)₄(H₂O)₂](H₂O)₅ (2) were prepared by isothermal evaporation at room temperature. The crystal structure of 1 was solved by the direct method [C2/c, a = 17.879(5), b = 8.152(5), c = 17.872(5) Å, β = 96.943(5)°, V = 2585.7(19) ų, Z = 4] and refined to R ₁ = 0.0449 (wR ₂ = 0.0952) for 2600 reflections with |F _o| ≥ 4σ _F . The structure of 2 was solved by the direct method [P2₁/c, a = 17.8377(5), b = 8.1478(5), c = 23.696(1) Å, β = 131.622(2)°, V = 2574.5(2) ų, Z = 4] and refined to R ₁ = 0.0516 (wR ₂ = 0.1233) for 4075 reflections with |F _o| ≥ 4σ _F . The structures of 1 and 2 are based on [(UO₂)₂(SeO₄)₄(H₂O)₂]^4? layers. The charge of the inorganic layer is compensated by potassium and oxonium ions arranged in the interlayer space. Each K ion is surrounded by seven O atoms belonging to uranyl selenate layers and water molecules, so that it binds with each other the adjacent uranyl selenate structural elements.     

General specifications for determining the metrological characteristics of weighbridges for moving vehicles

General specifications are drawn up for methods of checking weighing machines for vehicles: automobiles,railroad wagons, and compound vehicles in motion, from which standards have been derived for methods of checking such weighing machines.Translated from Izmeritelnaya Tekhnika, No. 9, pp. 13–16, September, 2004.