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The assessment of the explosion hazard of a combustible gas mixture is not a trivial task if the type of combustible gases is not known precisely. In this paper, a methodology for assessing the degree of the explosiveness of hydrocarbon gases combined with hydrogen is proposed. The methodology does not require the identification of the type of hydrocarbons, their quantity and concentration. The methodology proposed in this work is based on the measurement of heat released during mixture burning in the catalytic sensor chamber. A multi-stage heating profile with different duration and voltage amplitude was developed to heat the sensor and conduct measurements. This allowed for dividing the catalytic sensor response into hydrogen and hydrocarbons mixture. The measurements were carried out for three-component mixtures of explosive gases (propane, butane and hydrogen) in air. The obtained results demonstrate a good agreement between the experimental results and the theoretical values.

A multi-analytical investigation was carried out to study lacquer objects from Noin-Ula burial complex (Mongolia, the first century AD). This complex is a unique source of information about Xiongnu - one of the most ancient nomadic empires, due to the variety of findings of different origin. This study was undertaken to characterize the materials used for manufacturing and decoration of lacquer everyday life objects and works of art from the 22nd and 31st Noin-Ula barrows. Scanning electron microscopy coupled with X-ray microanalysis (SEM-EDS), FT-IR spectroscopy and pyrolysis coupled with gas chromatography/mass spectrometry (Py-GS/MS) and derivatisation in situ with tetramethylammonium hydroxide were used to study both organic and inorganic components of ancient lacquer wares. The components of the drying oil and urushiol were identified in the lacquer coating compositions. Diterpenoid resin and polycyclic aromatic hydrocarbons (charcoal components) were found in some samples. Inorganic pigments of the lacquer wares were umber, iron oxides, cinnabar, orpiment and charcoal.

The collection of textiles from Xiongnu burial was obtained in the recent years as a result of research of the Russian-Mongolian expedition led by N. Polosmak. This collection is a unique source of the different types of information. Xiongnu throughout their long history controlled the Central Asia regions of the Silk Road, by which many and varied products, including textiles and wool, were brought to China from the west. The woolen fabrics and textiles of high quality were found in the Xiongnu noble burials located in the mountains of Mongolia. An analysis of their dyes composition by high performance liquid chromatography (HPLC) showed that the woolen fabrics were dyed with plant and insect dyestuffs. Each sample analyzed was dyed with a set of dyestuffs that indicates that dyers had not only the necessary and various dyes, but possessed highly developed craftsmanship of dyeing. Based on the results of this research it can be proposed that the dyeing of the woolen textiles found in the graves of the Xiongnu nobility was carried out in the manufactories of the Mediterranean, known for their fabrics dyeing culture. Numerous Chinese-made silk fabrics were dyed with traditional Han epoch plant dyes - indigo and Indian madder. Dyes composition of the silk textile fundamentally differs from dyes of the woolen fabrics by the absence of dyestuffs of insect origin.

The most of gas associated industries face with the risks of explosion and fire which may lead to dire consequences. We present an approach for assessing the explosion risks in the presence of hydrocarbon mixtures when the chemical composition and concentration of gases in the mixture are unknown. The core idea is the measurement of warm dissipated during the combustion of hydrocarbons in the reaction chamber of the sensor. To evaluate this approach we use a catalytic planar sensor with limited gas diaphragm in the reaction chamber. We demonstrate the feasibility of our approach experimentally.

A huge number of combustible gas leaks occur every year at industrial and home facilities. These leaks may have grave consequences for health, environment and property. In this work we demonstrate the approach for improving the interoperability of catalytic sensors which are widely used in industrial monitoring applications for combustible gas leaks. To ensure methane detection within the broad concentration range (100 ppm–100% vol.), we propose using of two sensors with catalysts in the modified Wheatstone sensing circuit and to cover them with sealed caps with different holes to enable gas diffusion control.

The design and main technical characteristics of a typical catalytic sensor are described. The main drawbacks related to the lack of stability due to natural ageing and poisoning of sensing elements by catalytic poisons are defined. It is suggested to provide a restricted access of the analyzed gas mixture into the reaction chamber by diffusion through a calibrated hole to increase the stability of sensor.