Phosphate-hydroxyquinoline method for separation and volumetric determination of zirconium

The proposed method consists of a combination of the well-known phosphate method for separation of zirconium, and determination of zirconium as the hydroxyquinolate. The separation of zirconium hydroxyquinolate from an oxalate medium after solution of the phosphate preccipitate in oxalic acid has been used for the first time. The conditions of separation of zirconium from titanium and thorium in the phosphate precipitation, and from niobium and tantalum in precipitation of the hydroxyquinolate, have been studied. By this method it is possible to separate zirconium in practice from all accompanying elements (except hafnium), and to determine small amounts of zirconium (2–5 mg) by a volumetric method to an accuracy of ± 2–4%.     

A method for comparison of 3D surfaces using pyramidal height maps and fussy masks

A method for comparison of 3D surfaces mutually displaced in space is developed. This method is based on the measure of distinction expressed by the volume between two optimally superimposed surfaces. The volume is determined from the height map calculated with respect to a specified plane. Pyramidal representation of height maps is used to reduce the amount of examination. In addition, the maps are calculated using graphic processors. This method can be used in the problem of superposition (and identification) of identically oriented, mutually displaced surfaces.     

Sintering of nanostructured powders

Results are provided for a study of the internal structure of submicron spherical particles in ZrO₂–Y₂O₃ aerosol powders synthesized by ultrasonic atomization pyrolysis. It is shown the sintering potential for these powders is determined mainly by their internal nanostructural parameters, and not the degree of starting powder fineness. It is detected that the activity of submicron nanostructured powders is commensurate with the activity of ultrafine powders. In contrast to the latter, these powders consist of individual particles not joined in stable multiparticle formations, i.e., agglomerates. This simplifies considerably their practical application without loss of quality for the material obtained.     

CuBr2‐induced charge screening on photoactive nanocolloidal polypyrrole:poly(styrene sulfonate) composite multilayer thin‐film counter electrodes for high‐efficiency dye‐sensitized solar cells

Nanocolloidal polypyrrole (PPy):poly(styrene sulfonate) (PSS) particles were synthesized by chemical oxidative polymerization using 15 wt% of PSS. The highly processable polymer composite (PPy:PSS) was spin‐coated at 4000 rpm on fluorine‐doped tin oxide glass and subsequently employed as a counter electrode (CE) for dye‐sensitized solar cells (DSCs). PPy:PSS multilayer (one, three, five) CEs were treated with CuBr₂ salt, which enhances the efficiency of the DSCs. Optical studies reveal that a bulkier counterion hinders interchain interactions of PPy which on salt treatment shows a moderate redshift in absorption maxima. Salt‐treated PPy:PSS films exhibit lower charge transfer resistance, higher surface roughness and better catalytic performance for the reduction of I₃^?, when compared with untreated films. The improved catalytic performance of salt‐treated PPy:PSS multilayer films is attributed to charge screening and conformational change of PPy, along with the removal of excess PSS. Under standard AM 1.5 sunlight illumination, salt treatment is shown to boost the efficiency of multilayer PPy:PSS composite film‐based DSCs, leading to enhanced power conversion efficiency of 6.18, 6.33 and 6.37% for one, three and five layers, respectively. These values are significantly higher (ca 50%) than those for corresponding devices without CuBr₂ salt treatment (3.48, 2.90 and 2.01%, respectively). © 2016 Society of Chemical Industry     

Calculating the size and operating parameters of a slotted filter

The calculation method that yields rational ratios of the thickness of the filter layer and the rate and time of filtration of a slotted filter that provide the target cleaning efficiency of dusted gases in processes at a constant filtration rate has been proposed. The method is based on the concepts of stationary factor and residence time of dusted gas in the filter layer; it considers the efficiency decrease caused by the secondary dust entrainment. It helps to determine the necessary data for the design of a slotted filter that has any target capacity and cleaning efficiency.     

The microstructure of composite cermet coatings produced by carbo-vibroarc surfacing

The results of investigation of the microstructure of composite coatings produced by carbo-vibroarc surfacing using cermet pastes are presented. It is shown that the composite cermet coating consists of two zones – the main and transition. The main zone of the coating contains the Fe₂B hardening phase with nickel and chromium atoms implanted in the crystal lattice of the phase. The zone is situated in the matrix of the solid solution of iron and nickel Ni₃Fe. The transition zone of the coating is formed by the mutual diffusion of the coating and the substrate and consists of the (Fe, Ni)₂B hardening phase and the Ni₃Fe matrix. It is also shown that the hardening phases form plate-shaped grains with thicknesses of 1–4 μm and more than 100 μm long, distributed in the form of colonies throughout the entire volume of the coating zone. In the direction to the transition zone, the shape of the structural components changes to circular with the diameter of up to 5 μm.     

Study of Deformation Phenomena in TRIP/TWIP Steels by Acoustic Emission and Scanning Electron Microscopy

Modern metastable steels with TRIP/TWIP effects have a unique set of physical-mechanical properties. They combine both high-strength and high-plasticity characteristics, which is governed by processes activated during deformation, namely, twinning, the formation of stacking faults, and martensitic transformations. To study the behavior of these phenomena in CrMnNi TRIP/TWIP steels and stainless CrNiMo steel, which does not have these effects in the temperature range under study, we used the method of acoustic emission and modern methods of signal processing, including the cluster analysis of spectral-density functions. The results of this study have been compared with a detailed microstructural analysis performed with a scanning electron microscope using electron backscatter diffraction (EBSD).