МЕТОДИЧЕСКИЕ ПОДХОДЫ К УПРАВЛЕНИЮ ЭНЕРГЕТИЧЕСКИМИ РЕСУРСАМИ ПРОМЫШЛЕННЫХ ПРЕДПРИЯТИЙ, С УЧЕТОМ МОНИТОРИНГА

Objective: statement of the research results of the modern methodical approaches to the management of energy resources of the industrial enterprises. Work performance methodology: the research is execu-ted from the perspective of actual power management concepts of the industrial enterprises. Results: the tool base basic elements on the management of enterprise energy resources are revealed; the organizational aspects of formation of power management, power audit and monitoring at the industrial enterprises are opened; the organizational and functional structure of an analytical laboratory on the energy saving is offered. Application field of the results: can be used when car-rying out the complex researches in the field of power management of the industrial enterprises.Цель: изложение результатов исследования современных методических подходов к управлению энергетическими ресурсами промышленных предприятий. Методология проведения работы: исследование выполнено с позиций актуальных концепций энергетического менеджмента промышленных предприятий. Результаты: выявлены основные элементы инструментальной базы по управлению энергоресурсами предприятия; раскрыты организационные аспекты формирования на промышленных предприятиях энергетического менеджмента, энергетического аудита и мониторинга; предложены организационно-функциональная структура аналитической лаборатории по энергосбережению. Область применения результатов: могут быть использованы при проведении комплексных исследований в области энергетического менеджмента промышленных предприятий

Economic rationale for the option of connecting reinforcing bars in the construction

The article proposes methodology for economic feasibility of choosing the option of joining reinforcing steel when installing supporting structures based on a comparative approach. To confirm the practical applicability of the proposed recommendations, a study was conducted at a large construction company operating in the Tyumen region in Russia. The obtained results confirmed the applied nature of the proposed recommendations at the design stage of the analyzed construction object and preparation of local estimates

Nanocomposites SnO2/SiO2:SiO2 Impact on the Active Centers and Conductivity Mechanism

This paper is focused on the effect of the stabilizing component SiO2 on the type and concentration of active sites in SnO2/SiO2 nanocomposites compared with nanocrystalline SnO2. Previously, we found that SnO2/SiO2 nanocomposites show better sensor characteristics in CO detection (lower detection limit, higher sensor response, and shorter response time) compared to pure SnO2 in humid air conditions. Nanocomposites SnO2/SiO2 synthesized using the hydrothermal method were characterized by low temperature nitrogen adsorption, XRD, energy dispersive X-ray spectroscopy (EDX), thermo-programmed reduction with hydrogen (TPR-H2), IR-, and electron-paramagnetic resonance (EPR)-spectroscopy methods. The electrophysical properties of SnO2 and SnO2/SiO2 nanocomposites were studied depending on the oxygen partial pressure in the temperature range of 200–400 °C. The introduction of SiO2 results in an increase in the concentration of paramagnetic centers Sn3+ and the amount of surface hydroxyl groups and chemisorbed oxygen and leads to a decrease in the negative charge on chemisorbed oxygen species. The temperature dependences of the conductivity of SnO2 and SnO2/SiO2 nanocomposites are linearized in Mott coordinates, which may indicate the contribution of the hopping mechanism with a variable hopping distance over local states

Nanocomposites SnO₂/SiO₂ for CO Gas Sensors: Microstructure and Reactivity in the Interaction with the Gas Phase

Nanocomposites SnO2/SiO2 with a silicon content of [Si]/([Sn] + [Si]) = 3/86 mol.% were obtained by the hydrothermal method. The composition and microstructure of the samples were characterized by EDX, XRD, HRTEM and single-point Brunauer-Emmet-Teller (BET) methods. The surface sites were investigated using thermal analysis, FTIR and XPS. It is shown that the insertion of silicon dioxide up to the value of [Si]/([Sn] + [Si]) = 19 mol.% stabilizes the growth of SnO2 nanoparticles during high-temperature annealing, which makes it possible to obtain sensor materials operating stably at different temperature conditions. The sensor properties of SnO2 and SnO2/SiO2 nanocomposites were studied by in situ conductivity measurements in the presence of 10–200 ppm CO in dry and humid air in the temperature range of 150–400 °C. It was found that SnO2/SiO2 nanocomposites are more sensitive to CO in humid air as compared to pure SnO2, and the sample with silicon content [Si]/([Sn] + [Si]) = 13 mol.% is resistant to changes in relative air humidity (RH = 4%–65%) in the whole temperature range, which makes it a promising sensor material for detecting CO in real conditions. The results are discussed in terms of the changes in the composition of surface-active groups, which alters the reactivity of the obtained materials

SnS₂ Nanosheets as a Template for 2D SnO₂ Sensitive Material: Nanostructure and Surface Composition Effects

Two-dimensional nanosheets of semiconductor metal oxides are considered as promising for use in gas sensors, because of the combination of a large surface-area, high thermal stability and high sensitivity, due to the chemisorption mechanism of gas detection. In this work, 2D SnO2 nanosheets were synthesized via the oxidation of template SnS2 nanosheets obtained by surfactant-assisted one-pot solution synthesis. The 2D SnO2 was characterized using transmission and scanning electron microscopy (TEM, SEM), X-ray diffraction (XRD), low-temperature nitrogen adsorption, X-ray photoelectron spectroscopy (XPS) and IR spectroscopy. The sensor characteristics were studied when detecting model gases CO and NH3 in dry (RH25 = 0%) and humid (RH25 = 30%) air. The combination of high specific-surface-area and increased surface acidity caused by the presence of residual sulfate anions provides a high 2D SnO2 sensor’s signal towards NH3 at a low temperature of 200 °C in dry air, but at the same time causes an inversion of the sensor response when detecting NH3 in a humid atmosphere. To reveal the processes responsible for sensor-response inversion, the interaction of 2D SnO2 with ammonia was investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in dry and humid air at temperatures corresponding to the maximum “positive” and maximum “negative” sensor response

Active Sites on Nanocrystalline Tin Dioxide Surface: Effect of Palladium and Ruthenium Oxides Clusters

Active sites of nanocrystalline tin dioxide materials with variable particle size, surface area, and catalytic modifiers were studied. Effect of palladium and ruthenium oxides clusters on the activity and concentration of tin dioxide surface centers was evaluated by temperature-programmed desorption techniques using probe molecules, FTIR spectroscopy, EPR, and thermogravimetric methods. The surface site concentration decrease was observed with an increase of SnO₂ particle size and BET area decrease. The active sites of SnO₂ were found to be selectively promoted by the additives. Accumulation of surface OH groups including hydroxyl spin centers and Broensted acid sites was characteristic for SnO₂/PdO_<i>x</i> nanocomposites as a result of water chemisorption enhancement due to proposed electronic clusters–support interaction. Ruthenium oxide was shown to increase the concentration of chemisorbed oxygen species via oxygen spillover route

Active Sites on Nanocrystalline Tin Dioxide Surface: Effect of Palladium and Ruthenium Oxides Clusters

Active sites of nanocrystalline tin dioxide materials with variable particle size, surface area, and catalytic modifiers were studied. Effect of palladium and ruthenium oxides clusters on the activity and concentration of tin dioxide surface centers was evaluated by temperature-programmed desorption techniques using probe molecules, FTIR spectroscopy, EPR, and thermogravimetric methods. The surface site concentration decrease was observed with an increase of SnO₂ particle size and BET area decrease. The active sites of SnO₂ were found to be selectively promoted by the additives. Accumulation of surface OH groups including hydroxyl spin centers and Broensted acid sites was characteristic for SnO₂/PdO_<i>x</i> nanocomposites as a result of water chemisorption enhancement due to proposed electronic clusters–support interaction. Ruthenium oxide was shown to increase the concentration of chemisorbed oxygen species via oxygen spillover route