New graphene technologies of manipulation with molecular objects

A new technique of manipulating with fullerene C₆₀ over graphene on a SiO₂ substrate is proposed. To stop the chaotic motion of molecules and limit its range, it is suggested to use a corrugated substrate. The study has shown that, at the corrugation wavelength of 3.4 nm and depth of 1.6 nm, the fullerene motion becomes directed with a deviation within 0.5 nm. The fullerene motion becomes even more definite, with a deviation from a straight line within tenths of an angstrom by the action of an external electric field, which allows one to manipulate the motion along the bottom of a groove. The method proposed can serve as a basis for the controlled assembly of molecules to supermolecular structures of given configurations, which can be applied in bio- and nanoelectronics.     

Tribochemical transformations of glycerol

The friction process is considered in this work from the viewpoint of chemical transformations, which occur in liquid lubricating medium and on the friction surface during the friction interactions. The results of tribotechnical tests of a conventional latten brass–glycerol–steel tribosystem are given and an attempt has been made to rationalize the evolution of tribotechnical characteristics of the tribosystem in the context of tribochemistry. The results of tunneling and IR spectroscopies indicate the formation of complex organic and organometallic films on the friction surface, which differ in chemical composition from the initial lubricating medium, which proves its deep triboconversion upon friction engagement. Chromato-massspectrometry studies of the products of tribotransformations of the lubricating medium enabled its identification. Based on this identification, chemical reactions, and a general scheme according to which tribochemical transformations take place in the lubricating medium have been suggested.     

Solid-Fuel Combustion in the Sintering of Siderite Ore

Two technologies are considered for the preparation of solid fuel used in sintering: crushing with portions of roasted siderite ore whose strength is less than that of the fuel; or crushing of the fuel alone and subsequent mixing with the ore portions. On the basis of derivatographic data, kinetic equations are written for the high-temperature combustion of coke fines in a fuel–ore mixture obtained by the two methods. The most flammable fuel fraction in sintering is established. The results indicate that crushing of the fuel mixed with weaker additives is more effective in terms of decreasing the content of fines in the fuel and hence intensifying the combustion of large pieces.     

Influence of the type of calcium salt on the cation absorption and firmness of black ripe olives

The preservation of olives intended for processing as black ripe olives must be done in a salt-free environment although it involves the use of calcium addition to retard olive softening. Calcium chloride and calcium lactate were added by up to 1600 mg Ca L⁻¹ (i) in the preservation liquid of olives before darkening and (ii) in the cover packing brine. The highest texture and calcium absorption were found in the latter case. In addition, the sensory characteristics of the final product were not affected by the use of any of the calcium salts studied at concentrations of up to 1600 mg Ca L⁻¹. Calcium chloride and calcium lactate can be employed to obtain higher texture and calcium content in black ripe olives, although it is advisable to add the cation to the cover packing brine of pitted olives rather than to the preservation liquid.     

X-ray diffraction,calorimetric, and spectroscopic studies of lithium borate glass activated with various oxide admixtures based on europium

Lithium borate glass activated with europium oxide, europium borate, and europium molybdate has been obtained by melt quenching. It has been found that by excitation with UV light of λ_ex = 365 nm, the highest luminescence intensity is observed in the samples activated with europium molybdate. The extreme europium molybdate concentration at which a sharp drop in the glass optical quality starts is measured. The thermal regions of stability are determined and the thermophysical characteristics (jumps of the thermal capacity in the glass-transition point and thermal effects of crystallization) for lithium borate glass doped with various oxides based on europium are calculated.     

Optimal materials for the manufacture of metal-cutting machines

With the goal of improving machine-tool design, attention focuses on the possibility of manufacturing the components of metal-cutting machines from effective new nonmetallic materials that not only meet all the current requirements on such machines but also in most cases improve their performance. The best results are obtained with metal–concrete structures in which the nonmetallic binder consists of modified cement with chemically active additives. Results from materials science are compared with multiyear production tests of metal-cutting machines based on metal–concrete components, which are characterized by stable performance over time. On that basis, an effective new approach is proposed for the modernization of machine tools at the end of their effective working life, without replacing the fundamental structures. The design of the basic structures is analyzed. The production of metal–concrete components in a specialized department of the manufacturing plant is recommended.     

Modelling Acoustic–Electric Nondestructive Testing for Defects in Dielectric Materials

Russian Journal of Nondestructive Testing - The influence of defectiveness of solid-state dielectric samples on the parameters of the electromagnetic response under deterministic acoustic action on...