Advanced Materials Research Vol. 1040

Abstract: It is found out that activation of the sintering process for refractory clay-containing raw materials (rusk kaolin and wocheinite) is provided using additives of 3d-transition elements oxides (Fe₂O₃ and MnO₂) in the amount of 2 - 5 wt. % due to formation of defective solid solutions of mullite by isovalent substitution mechanism as well as fluxing additives of alkaline and alkaline-earth oxides (Na₂O, MgO) in the amount of 2 wt. % by regulating rheological properties of silicate melts.

Abstract: The possibility of ceramic pigments synthesis using industrial waste is studied. These raw materials will lower production costs of ceramic pigments. The synthesized pigments can be recommended for obtaining on-glaze ceramic paints and volume coloring of ceramic pastes in the manufacture of construction materials.

Abstract: Nowadays the actual problem of geochemistry is a deep and complex processing of mineral raw materials. Data on the quantitative content of precious and rare metals in various types of ores and rocks are necessary. It stimulates the development and improvement of chemical analytical methods for determination of these elements. Such methods are not applicable without sample preparation stage. Preparation of samples for analysis is the decomposition and preconcentration of rare and precious metals from matrix of mineral raw materials. The sample preparation schemes of platinum, palladium and rhenium are described in this paper.

Abstract: A method for determination of gold, lead, nickel, cobalt in a range of concentrations from mg/g to ng/g was developed. Method can be applied for determination of corresponding metals in ores, rocks and waste mining industry. Method consists of annealing, treatment with hydrofluoric acid and aqua regia followed by extraction (in the case of gold) di-n-octyl sulphide (DOS). Method was tested by certified reference material (8773-2006 РВ 3-8) and various rock samples Altai-Sayan folded area.

Abstract: In this article, both the composition and composite properties of radioactive sources for medical applications are worked out and studied. The bases of these sources are bioinert ceramic solids and radionuclides. The active source is constituted from dispersed radioactive yttriа oxide or strontium oxide monolithically encapsulated with bioinert glass flux. The thermal expansion properties of the analyzed composites are highly similar to the ones of both titanium metal and titanum alloys. Therefore, the developed radioactive sources can be mounted on titanium holder. Importantly, all utilized elements and alloys are already applied in medicine. In this article we demonstrate the use of a radioactive β-source placed on a titanium holder. The device is finally applied in a oncological model disease treatment.

Abstract: In this paper for determination of heparin in pharmaceuticals by constant-current sweep voltammetry on the mercury-film electrode (MFE) we used cationic malachite green (MG) dye which is capable to form a complex with heparin. In the 0.05 M potassium tetraoxalate (KH₃C₄O₈ ∙ 2H₂O) buffer solution with pH 1.65 MG had a well-defined peak of electroreduction at -0.46 V (vs. CSE). During the study of electrochemical properties of heparin in complex with MG in cathodic potential range from 0.0 V to -1.3 V on MFE besides the signal from the dye at E = - 0.46 V the second signal at E = –0.87 V was found. Increasing the concentration of heparin in the solution led to decrease of signal intensity at E = -0.87 V. Optimum conditions for the electrochemical determination of heparin in dosage form with using MG were picked up. Influence of auxiliary components of heparin pharmacological solution on electroreduction of the complex MG-Hep was investigated. Under optimal conditions the decrease of reduction peak currents at E = -0.87 V was proportional to heparin concentration in the range from 3.9 ∙ 10^-4 mg/ml to 3.9 ∙ 10^-3 mg/ml.

Abstract: The electrochemical activity of gold nanoparticles at graphite electrodes by the method of cyclic voltammetry is studied. In this article the nature of the supporting electrolyte, modification time of graphite electrode by gold nanoparticles and the potential range on the value of the “inverse” cathodic peak are investigated. The “inverse” cathodic peak of gold nanoparticles formed in the reaction mixture HAuCl₄:Na₃C₆H₅O₇:NaBH₄=1:1:4 is observed on the cathodic branch of cyclic voltamperegram at E_c = 0.05 V at graphite electrode. The mechanism of stepwise electrochemical oxidation and reduction of the phase structure of gold on the surface of the graphite electrode in 0.1 M NaOH is offered. The “inverse” cathodic peak of gold nanoparticles on the cathodic branch of cyclic voltammogram at graphite electrode is caused by oxidation of Au₂O to Au₂O₃.

Abstract: The issues of structural changes produced in ceramic materials on the basis of Al₂O₃ and ZrO₂(Y₂O₃) during thermomagnetic processing (B=0.02–1 T) are considered. The contribution of the electromagnetic field to the linear shrinkage of processed ceramic samples has been estimated to be 1–6%. The possibility of using the thermomagnetic processing method for obtaining the disperse and homogeneous structure has been shown. The technological modes of processing under the electromagnetic field are suggested, facilitating self-cleaning and perfecting the crystalline structures of Al₂O₃ and ZrO₂(Y₂O₃), including annealing in the temperature range of 800–1200 °C within 8–12 hours.

Abstract: The nanoscale materials and their application have received considerable attention for the last few years owing to its potential use in biomedical fields of science and technology. Recent studies have demonstrated the ability of arenediazoniumtosylates (ADTs) to modify nanoscale materials. An efficient method of modifying zero-valent iron nanoparticles using ADT with different functional organic groups in a water suspension at the room temperature has been developed. Particle composition, size, stability and possible functionalization with ADT have been characterised by using the FT-IR and X-ray diffraction methods, the low-temperature nitrogen adsorption analysis (BET), TGA/DSC/DTA analyses in the air and the elemental analysis. The obtained methods and results are to foster better understanding of nanoparticles modification process and contribute to its further research and development due to the ability of changing functional groups in the ADT molecule for medical and other applications. Variation of the functional groups in the ADT molecule can change the properties of Fe-NPs and predetermine the field of their use.

Abstract: It is established that the eliminations of construction sand with the content of SiO₂ about 70 wt. % and particle size less than 60 mk are suitable for the production of a foamglass-crystal material on the basis of the low-temperature frit, which was synthesized at the temperature 900 °C. The obtained foamglass-crystal material exceeds foamglass (by 3.0 times) and clayite (by 1.5 times) by strength and is characterized by low value of water absorption (0.1 %).