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The paper is focused on turning of structural steels C45. Cutting tools were represented by carbide cutting inserts without coatings, with reference coating TiAlN, as well as with multilayered composite nano-structured coatings Ti-TiN-(TiCrAl)N and Zr-ZrN-(ZrCrNbAl)N (of different thickness of 3-7 μm). The following studies of the properties of coated tools were carried out: measurement of microhardness and strength of adhesion bonds in the "tool-coating" system and investigation of elemental and phase compositions of coatings. The cutting tests were carried out at the following cutting modes: f = 0.2 mm/rev; аp = 1.0 mm; vc = 200, 250, 300, 350 and 400 m/min. [ABSTRACT FROM AUTHOR]

Enhanced photocatalytic activity of WO3 was attempted by carbon nanodots (C-dots) loading. C-dots were prepared using citric acid and urea for enhancing photocatalytic activity of WO3. Physicochemical character of C-dots was studied by fluorescence spectrophotometry and for the modified WO3, evaluation was studied by using x-ray diffraction (XRD) and scanning electron microscope (SEM). Effect of varied citric acid: urea ratio to photocatalytic activity was evaluated in methylene blue photodegradation. Increasing photocatalytic activity was achived by higher intensity in blue color range that obtained by higher urea molar ratio. Kinetics of reaction obey pseudo-first order and pseudo-second order reaction. Reaction reached 80% MB degradation for an hour treatment for 50mM of methylene blue solution. [ABSTRACT FROM AUTHOR]

This work describes an analytical procedure for determination of petroleum hydrocarbons in petroleum-contaminated water. The method involves a solid-phase extraction method with stationary phase sorbent from natural raw material shungite. Method development was performed on model samples of water samples contaminated by petroleum from Tengiz deposit. The use of natural raw nanomaterial shungite as stationary phase solves the problems concerned with industry wastes, since this nanomaterial is waste of gold mining plant in Eastern Kazakhstan from dumps of the polymetallic Bakyrchik deposit. The proposed method provides a rapid, environmentally friendly and accurate method for identification and quantification of the petroleum hydrocarbons contaminating water resources of Western Kazakhstan. This work describes application of the developed methodology for analysis of petroleum hydrocarbons in the water resources of Western Kazakhstan. It was investigated that 5 g of sorbent was the optimal mass for solid-phase extraction of petroleum with concentration to 3000 mg/L. In addition, it was established that 5% hexane solution extracted petroleum more effectively from water samples. The most advanced stage of sorption of a sorbent occurs at 0.8 mm of a sorbent particles size. The optimum solvent for elution was chloroform, that allows to elute the greatest amount of petroleum hydrocarbons. Also, it was proved that an activated shungite has the highest sorption ability comparing to non activated (extraction recovery at concentration of 100 mg/L is equal about 90 and 40% for activated and non activated sorbents, respectively). [ABSTRACT FROM AUTHOR]

Structure, electrical properties and interaction with electromagnetic radiation of polymer with carbon nanomaterials were observed to study loading influence. Properties of produced samples were measured and compared with same measurement results for the initial PU. [ABSTRACT FROM AUTHOR]

NbN and Nb-Si-N films were deposited by magnetron sputtering the Nb and Si targets on silicon wafers at various powers supplied to the Nb target, PNb. The films were investigated by an atomic force microscope (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The deposited films were annealed to establish their thermal stability. The NbN films were nanostructured, and the Nb-Si-N films had a nanocomposite structure, and represented an aggregation of δ-NbNx nanocrystallites embedded into the amorphous Si3N4 tissue (nc-δ-NbNx/a-Si3N4). [ABSTRACT FROM AUTHOR]

The possibility of As containing various group 13 elements, viz., B, Al and Ga, in the form of hexagonal units and their higher order derivatives, as the building blocks for novel semiconductor materials is investigated in detail under the density functional framework. A series of fifteen clusters, formed by a linear combination of hydrogen saturated hexagonal motifs up to five units, (MAs)2n+1H2n+4 (M=B, Al, Ga; n=1-5) are considered to look into their different physicochemical properties and possible applications. It is come out that a combination of arsenic and group 13 elements provides promising building blocks for designing novel semiconductor materials, in the planar hexagonal form. [ABSTRACT FROM AUTHOR]