High-resolution X-ray photoelectron spectroscopy and characteristic electron-energy loss spectroscopy of the electronic structure of phosphorus-implanted silicon and quantum dots of silicon dioxide with silicon impurities

The effect of phosphorus impurities on the electronic structure of silicon single crystals and SiO₂: Si nanocomposites is studied. The SiO₂: Si structures with phosphorus impurities that are annealed over 2 h at a temperature of 1000°C exhibit an increase in the photoluminescence peak related to Si nanocrystals. The experimentally determined densities of states in the valence and conduction bands of SiO₂: Si composites are in good agreement with the local electronic structure in the vicinity of silicon impurities that is calculated within the approximation of linear muffin-tin orbitals.     

Photocatalytic properties of screen-printed titania

Nanocrystalline thin films of important surface roughness and complexity were prepared by screen-printing of commercial TiO₂ powder. The screen-printed titania films were tested in the photocatalytic decomposition reaction of methyl orange under UV light (350 nm). The photocatalytic activity strongly depends on the titania paste components and especially on the presence of a surface modifier (acetyl acetone) combined with a rheology controlling agent (ethyl cellulose). This results in improvement of the paste viscosity and optimization of the films morphology. Experiments under direct full sunlight illumination prove the importance of the screen-printed films for practical applications.     

Volatile N-nitrosamines in sausage products

The authors studied the content of volatile N-nitrosamines (NA) in the most common sausage products. It was established that the total content of NA in sausage products is not high and ranges from trace amounts up to 10 micrograms/kg product. The allowable doses of nitrite in the sausage manufacture being low, no relationship was discovered between the content of NA and residual nitrite in meat products.     

Determination of the characteristic length of thickness fluctuations for a tunneling-thin insulator in MIS structures from electrical data

New methods for determining the “correlation length” for thickness fluctuations of a thin insulator film from data obtained in measurements of the electrical characteristics of MIS tunnel structures, i.e., without the use of microscopy, have been suggested and tested. One of these methods relies on statistical processing of electric current data for a random sample of structures. The other technique analyzes abrupt downward changes in current, observed in tests of devices under a sufficiently high bias. The methods have been tested on Al/SiO₂/Si tunnel structures. The resulting estimates of the characteristic scale of thickness fluctuations are compared with the data obtained in direct measurements of this scale for the same oxide layers.     

Effect of yttrium and chromium on the recrystallization of Al-Sc alloys

The effect of small chromium and yttrium additions (0.14–1.0 wt%) on the recrystallization of Al-Sc alloys having 0.1–0.4% Sc is studied with polarized light. The microstructure of cold-rolled samples annealed at 100–630°C for 1 h is examined. The chromium and yttrium additions are found to slightly affect the recrystallization temperature of the Al-Sc alloys: they increase or decrease it slightly depending on the scandium content.     

Aqua-Biomant: integrated biological and electrochemical oxidation for industrial wastewater treatment.

An innovative technology for industrial wastewater treatment has been developed. The main focus of the new system is a transformation of persistent organic compounds (biorecalcitrant COD) into a biodegradable fraction, followed by high efficient biological elimination using specialised bacteria's. To fulfill these targets the Aqua-Biomant process integrates two treatment steps: an aerated biological upflow filter and a electrochemical oxidation technique using boron doped-diamond electrodes. The advantages of the process are high efficient COD removal with reduced energy consumption combined with low total residence time.