Zero bias terahertz and subterahertz detector operating at room temperature

In this paper, the experimental study of the terahertz and subterahertz hot electron bolometer based on narrow-gap semiconductor compound Hg₁₋xCdxTe is presented. The measurements were performed in the temperature range from 77 to 300 K at various operating mode and frequency. The estimated value of the noise equivalent power at room temperature for detector proposed was 1.3·10⁻⁸ W/Hz¹/² and 5.4·10⁻⁹ W/Hz¹/² at bias current I = 1 mA and I = 0, respectively

Peculiarities of the use of siliceous raw materials of the Russian Far East in the integrated pipeline protection

Modern trends in the development of Russian oil and gas infrastructure are examined. The important role of the Far East in the transportation and export of oil is revealed. The main threats in the operation of pipelines are described. The integrated protection technology of pipeline surfaces is proposed. The structure and properties of local silicate raw material – diatomite – are studied. The technology of obtaining glass enamel coating is designed to protect the internal surface of the pipe. The phase composition, microstructure and properties of the coating are compared with analogues. The technology of foam glass production is designed to protect the external surface of the pipe. The foaming processes are studied; the properties and structure of the material are examined. The optimum ratio of raw materials is revealed. Recommendations on the application of the developed technology for integrated pipeline protection are given

Peculiarities of the use of siliceous raw materials of the Russian Far East in the integrated pipeline protection

Modern trends in the development of Russian oil and gas infrastructure are examined. The important role of the Far East in the transportation and export of oil is revealed. The main threats in the operation of pipelines are described. The integrated protection technology of pipeline surfaces is proposed. The structure and properties of local silicate raw material – diatomite – are studied. The technology of obtaining glass enamel coating is designed to protect the internal surface of the pipe. The phase composition, microstructure and properties of the coating are compared with analogues. The technology of foam glass production is designed to protect the external surface of the pipe. The foaming processes are studied; the properties and structure of the material are examined. The optimum ratio of raw materials is revealed. Recommendations on the application of the developed technology for integrated pipeline protection are given

Recycling Ash and Slag Waste from Thermal Power Plants to Produce Foamed Geopolymers

Ash and slag waste (ASW) from coal combustion creates significant environmental and economic challenges. A promising method of ASW recycling is alkali activation with geopolymer material formation. This study investigates the influence of activating solution components (sodium hydroxide and sodium silicate) on the formation of porous geopolymers using ASW of different origins. The sodium hydroxide content of 0–4 wt.% and the sodium silicate content of 17–25 wt.% were studied. An increase in sodium hydroxide resulted in decreased density, but it adversely affected the strength. An increase in sodium silicate led to a compromised porous structure with relatively high density and compressive strength. An optimal composition, S19N3, comprising 3 wt.% of sodium hydroxide and 19 wt.% of sodium silicate obtained porous geopolymers with uniformly distributed 1.4–2 mm pores and a corresponding density of 335 kg/m3, a compressive strength of 0.55 MPa, a porosity value of 85.6%, and a thermal conductivity value of 0.075 W/(m·K). A mechanism for porous geopolymer formation was developed, including the interaction of alkaline components with ASW and a foaming agent, foaming, curing, and densification. The mechanism was examined using ASW from the Severodvinsk CHPP-1. This study allows for the optimization of geopolymer mixtures with various waste sources and the utilization of waste materials in the construction industry

Improving the Properties of Porous Geopolymers Based on TPP Ash and Slag Waste by Adjusting Their Chemical Composition

The possibility of improving the properties of porous geopolymer materials based on ash and slag waste from thermal power plants by adjusting their chemical composition is considered. An X-ray phase analysis of ash and slag wastes was carried out, the geopolymers’ precursor compositions were calculated, and additives to correct their chemical composition were selected. The samples were synthesized and their physical and mechanical properties (density, porosity, compressive strength, thermal conductivity) were analyzed. The micro- and macro-structure of the samples and the pore distribution of the obtained geopolymers were studied and pore-distribution histograms were obtained. The influence of Si:Al ratio on structural changes was described. The geopolymers’ phase composition was studied, consisting of an amorphous phase and high quartz and mullite. A conclusion about the applicability of this method for obtaining high-quality porous geopolymers was made

Thermal imager based on the array light sensor device of 128×128 CdHgTe-photodiodes

The results of investigation of developed thermal imager for middle (3—5 µm) infrared region are presented and its applications features are discussed. The thermal imager consists of cooled to 80 K 128×128 diodes focal plane array on the base of cadmium–mercury–telluride compound and cryostat with temperature checking system. The photodiode array is bonded with readout device (silicon focal processor) via indium microcontacts. The measured average value of noise equivalent temperature difference was NETD= 20±4 mK (background radiation temperature T = 300 K, field of view 2θ = 180°, the cooled diaphragm was not used)