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AbstractIn this paper, a new model of transverse mixing in a rotating drum is derived from dynamic data collected from an experimental rig. Since the active layer has often been declared as the zone that is responsible for the mixing of solids in a rolling bed, the active layer was characterized so that its properties could be predicted for a wide range of experimental conditions. The mixing model consisted of two correlations, one to predict the mixing rate in the drum and the other to predict the final contact between the two materials. These correlations were linked back to the operational variables of the drum, such as the drumfs loading, size and rotational velocity. By combining these two correlations the time required to fully mix the material in the drum could be predicted. The mixing model was tested against independent data and good agreement was observed between the experimentally derived results and those predicted by the mixing model. Furthermore, this mixing model was designed such that it would be easily applicable to different sized drums. The extrapolation ability was tested on different smaller‐sized drums and found to agree considerably with experimental results.

The operation of the group of dependent electrical receivers with two-step periodic graphs of electrical loading is considered. The model of the correlation function of such graph is given and is used to obtain analytical expressions to determine the averaged variance of the group graph of electrical load.

This review covers the main examples of fuel-free light-driven micro/nanomotors and their different swimming styles, highlighting the most important parameters to consider when designing photocatalytic-based devices with a high propulsion efficiency.

Hardening of structural elements and plasticity loss are observed for reactor elements which operate for a long time. In some cases, this results in a change of the asymmetry of multi-cycle loading of structures and a reduction of their service life. The diagram of limit states in the presence of fatigue with high asymmetry is confirmed experimentally for samples made of 08Kh18N10T austenitic steel, for which the true breaking strength is adopted as the average limit stress in a cycle.

The surface of a VNIITU-1 carbon mesoporous hemosorbent is modified with poly-N-vinylpyrrolidone, which possesses its own antibacterial activity. The modification is performed in two steps: (1) impregnation of the monomer, N-vinylpyrrolidone, and the initiator in an aqueous solution and (2) polymerization in an inert atmosphere. The composition of products produced during polymerization reaction is analyzed by NMR 13C. The texture characteristics, the relief and the morphology, and the content of nitrogen in the initial and modified sorbents are studied by current physicochemical methods. Bench tests show that the contact with the modified sorbent leads to a decrease in the amount of Staphylococcus aureus bacterial cells and inhibition of their growth in comparison with the initial carbon sorbent.

The results are described for experimental studies of interference originating in high-frequency paths of overhead power transmission lines of voltage of 35 kV and above, with location monitoring of the OHLs for the purpose of detecting damage and ice on the wires. The types of interference caused by weather conditions are discussed, and the features of electrical interference and methods of eliminating them are examined. Crosstalk caused to the location sensing by equipment of high-frequency technological communication is analyzed during transmission of signals of relay protection, automated equipment, telemetry, and telephony, and measures for decreasing their effect are discussed. A method is examined for extracting the reflected location pulses against the background of asynchronous fluctuational interference using coherent averaging of reflectograms, and its effectiveness is assessed.

Abstract Chilled beams provide sensible cooling to an occupied space by using chilled water flowing through modular beams mounted to a room ceiling. Previous studies show that active chilled beam systems can achieve larger sensible cooling than all-air systems. However, most studies have focused on active chilled beams and little information is available for performance of passive chilled beam (PCB) under varied ventilation conditions. The objective of the present study is to investigate ventilation and air conditioning performance of combined PCB and displacement ventilation systems. Using a validated and verified computational fluid dynamics (CFD) model, parametric analyses were performed to examine the ventilation and air conditioning performance depending on five major operating parameters: 1) ventilation strategy, 2) PCB cooling output, 3) supply air temperature, 4) supply diffuser type, and 5) internal heat source arrangement. The results show that thermal comfort and ventilation performance of a combined PCB-DV system notably vary with the PCB cooling output and supply air temperature. When the PCB cooling output increases from 33% to 53% of the total cooling load, air change effectiveness decreases from 1.6 to 1.2 and vertical temperature difference decreases from 4.0 °C to 1.5 °C in the breathing zone. However, spatial heat source distribution has a marginal effect on the air mixing and temperature distribution. The results suggest that a relatively high PCB cooling output (>50% of the total cooling) combined with a low supply air temperature (e.g., 17 °C) could disrupt thermal stratification of displacement ventilation and increase draft rate in the occupied zone.

The paper presents a comparative analysis of design and thermal parameters of various types of solar collectors, including Russian-manufactured ones. It is shown that over the last 15 years, the massdimensional characteristics and thermotechnical excellence of flat-plate solar collectors have remained virtually unchanged, the manufacturing technologies of such collectors have not sufficiently improved, the collectors have reached parameters close to limiting ones. In terms of thermal excellence, Russian-manufactured collectors are highly competitive with foreign models. Evacuated tubular solar collectors currently on the market can be divided into several types, of which the most efficient are U-shaped heat removal pipe Sydneytube collectors. Popular heat pipe Sydney-tube collectors, which are considered promising, are significantly less efficient.