New experimental evaluation techniques for selectivity of collecting agents for gold and platinum flotation from fine-impregnated noble metal ores

It is proposed to apply nanosize Au and Pt particles to ground mineral particles for the analysis of flotation and adsorptive properties of new reagents. The authors have obtained specimens of pyrite, arsenopyrite and quartz artificially enriched by nanosize gold particles. Reductive adsorption from Na₂[PtCl₆] and Na[AuCl₄] produced pyrrhotine uniformly applied with microsize platinum particles. The article discusses the application range of the proposed techniques and methods of examination of specimens and interaction between reagents and micro- and nanosize gold and platinum particles depending on the conditions of sulfide treatment by the noble metals and on properties of a host mineral. Advanced integrated analysis of interaction between the nitrogen-bearing reagent MTKh and gold confirmed chemically induced selectivity of MTKh towards gold     

Assessing the reliability of switchgear based on censored statistical information

An assessment of the reliability of a switchgear based on the results of normal testing of electrical endurance and the censored statistical information has been carried out, and a more appropriate law has been found.     

Structure of bismuth films obtained using an array of identically oriented single-crystal bismuth islands preliminarily grown on a substrate

An array of identically oriented single-crystal bismuth islands formed on mica plates is used as a substrate to improve the structure of bismuth thin films grown by vacuum thermal evaporation. The array of islands is formed by the chemical etching of a single-crystal bismuth film 1 μm thick grown by floating-zone recrystallization under a coating. The structure of the obtained films is studied by X-ray diffraction, atomicforce microscopy, and electron backscatter diffraction scanning electron microscopy.     

Model for calculating the thermodynamic characteristics of alloyed uranium dioxide

To evaluate the character of the changes in the thermodynamic properties of mixed uranium–plutonium oxide fuel having high reactivity and toxicity, measurements have been performed on uranium–cerium oxides with analogous properties. The electromotive force of a solid-electrolyte galvanic cell and solid-phase coulonometric titration were used to establish the regularities of the variation of the oxygen potential versus the oxygen/metal ratio for the oxide U_0.718Ce_0.282O_2–x . A thermodynamic model of uranium dioxide with elements dissolved in the matrix was developed; the model makes it possible to determine the oxygen potential in a wide interval of temperatures and non-stoichiometry. Translated from Atomnaya énergiya,Vol. 106, No. 4, pp. 195–198, April, 2009.     

Novel platform for direct electron transfer to/from hemoproteins based on a single layer graphite electrode

A novel cheap and easy way of producing carbon electrodes from single layer graphite is proposed. Low production cost allows to generate multiple disposable carbon layer electrodes. The electrodes were tested in a model bioelectrocatalytic process, such as electrochemical regeneration of hemoproteins, and positive results were obtained.     

Software complex for the recognition of diagnostically significant ECG changes

A software complex for the automation of functional electrocardiographic (ECG) studies is presented. The algorithms of ECG signal processing and recognition of diagnostically significant ECG changes are considered. Methods of 3D visualization are proposed to increase the informativeness of electrocardiographic data and improve diagnostic accuracy.     

An experimental investigation of the spectral composition of radiation behind the shock-wave front in a CO2-N2-Ar mixture

Experiments are performed to determine the spectral distribution of radiation in CO₂-N₂ and CO₂-N₂-Ar mixtures in a microwave discharge and behind the front of incident shock wave at velocities up to 7.5 km/s. It is demonstrated experimentally that the spectral region of vacuum ultraviolet makes a significant contribution to radiation.     

Special effects of quartz,calcite and coal on the drying properties of ceramic mixtureS

The method of dispersion analysis and experiments are used to establish the possibility of using coal concentration waste, which contains a clay component close to conventional clay raw materials and quartz, calcite and coal impurities. The results of an experimental study of the physicochemical properties of model mixtures are presented together with some practical recommendations.