The research of the maximum wind speed in Tomsk and calculations of dynamic load on antenna systems

The work is concerned with calculations and analysis of the maximum wind speed in Tomsk city. The data for analysis were taken from the TOR-station located in the north-eastern part of the city. The TOR-station sensors to measure a speed and a direction of wind are installed on the 10-meter meteorological mast. Wind is measured by M-63, which uses the standard approach and the program with one-minute averaging for wind gusts recording as well. According to the measured results in the research performed, the estimation of the dynamic and wind load on different types of antenna systems was performed. The work shows the calculations of wind load on ten types of antenna systems, distinguished by their different constructions and antenna areas. For implementation of calculations, we used methods developed in the Central Research and Development Institute of Building Constructions named after V.A. Kucherenko. The research results could be used for design engineering of the static antenna systems and mobile tracking systems for the distant objects

Experimental assessment of drag reduction by traveling waves in a turbulent pipe flow

We experimentally assess the capabilities of an active, open-loop technique for drag reduction in turbulent wall flows recently introduced by Quadrio et al. [J. Fluid Mech., v.627, 161, (2009)]. The technique consists in generating streamwise-modulated waves of spanwise velocity at the wall, that travel in the streamwise direction. A proof-of-principle experiment has been devised to measure the reduction of turbulent friction in a pipe flow, in which the wall is subdivided into thin slabs that rotate independently in the azimuthal direction. Different speeds of nearby slabs provide, although in a discrete setting, the desired streamwise variation of transverse velocity. Our experiment confirms the available DNS results, and in particular demonstrates the possibility of achieving large reductions of friction in the turbulent regime. Reductions up to 33% are obtained for slowly forward-traveling waves; backward-traveling waves invariably yield drag reduction, whereas a substantial drop of drag reduction occurs for waves traveling forward with a phase speed comparable to the convection speed of near-wall turbulent structures. A Fourier analysis is employed to show that the first harmonics introduced by the discrete spatial waveform that approximates the sinusoidal wave are responsible for significant effects that are indeed observed in the experimental measurements. Practical issues related to the physical implementation of this control scheme and its energetic efficiency are briefly discussed.Comment: Article accepted by Phys. Fluids. After it is published, it will be found at http://pof.aip.or

Low and high frequency fatigue tests of nodular cast irons

The paper deals with the comparison of fatigue properties of nodular cast iron at low and high frequency cyclic loading. The specimens from three melts of nodular cast iron with different microstructure and mechanical properties were used for experiments. Fatigue tests were carried out at low and high frequency sinusoidal cyclic push-pull loading (stress ratio R = –1) at ambient temperature (T = 20 ± 5 °C). Low frequency fatigue tests were carried out using the fatigue experimental machine Zwick/Roell Amsler 150HFP 5100 at frequency f ≈ 120 Hz; high frequency fatigue tests were carried out using the ultrasonic fatigue testing device KAUP-ZU at frequency f ≈ 20 kHz

Macrozoobenthos communities along the marine pipeline route at the Lunskoye field (shelf of northeastern Sakhalin) and their long-term variability

Results of benthos surveys conducted along the marine pipeline at the Lunskoe oilfield in July of 2006-2010 are presented. The sediment samples were taken at 59 stations with the depth 0-45 m by van Veen grab (0.05 m2, 0.11 m2, 0.25 m2), 1-3 samples per each station, in total 375 samples. Macrozoobenthos was extracted from the sampled sediments by seawater washing through 1 mm sieve and preserved by 4 % buffered formaldehyde. Its species composition, biomass and abundance were determined according to standard techniques. Eight phyla and 257 species of macrozoobenthos are identified in the surveyed area, mainly amphipods (103 species) and polychaetes (60 species). Its mean biomass amounts to 192.2 ± 12.1 g/m2, the mean distribution density - 28331.8 ± 3055.9 ind./m2. Cumaceans and amphipod crustaceans dominate by their number and bivalve molluscs and cumaceans - by their biomass. Six benthic communities are revealed by the hierarchical agglomerative method of multidimensional clustering with group-average linking of Bray-Curtis similarities, after 4th root transformation of the species biomass values (PRIMER software). Type of the bottom sediments and depth are the main factors determining characteristics and distribution patterns of the benthic assemblages

Macrozoobenthos communities in the area of marine pipeline route at Piltun-Astokhskoye oil field (shelf of northeastern Sakhalin) and their long-term variability

Results of macrozoobenthos surveys (in total 86 stations, 432 sediment samples) in the area of marine pipeline route at Piltun-Astokhskoye oil field in July of 2007-2010 are presented. The sediment samples were collected by van Veen sampler (1-3 samples per site from the area 0.05 m2, 0.11 m2, or 0.25 m2) at the depth 0-45 m. The samples were washed by sea water through the sieve with mesh 1 mm, and the residues including macrobenthos were preserved by 4 % buffered formaldehyde for later processing with total identification of macrozoobenthos (species composition, abundance and biomass) in the laboratories of Far-Eastern Research Hydrometeorological Institute and Institute of Marine Biology in Vladivostok, following to standard techniques. The data were analysed using the PRIMER software including multidimensional cluster analysis of samples by hierarchical agglomerative method of group-average linking based on Bray-Curtis similarity of the macrozoobenthos species composition by biomass. In total, 272 species of macrozoobenthos are identified at the surveyed area, with the highest species number for amphipods (86 species) and polychaetes (72 species). Mean total abundance of macrozoobenthos is 26556.4 ± 2660.9 ind/m2, its mean total biomass is 669.7 ± 40.3 g/m2. Cumaceans and amphipod crustaceans are the most numerous groups; sea-urchins, bivalves and cumaceans have the highest biomass. Five benthic communities are defined by cluster analysis. There is concluded that the bottom sediments and depth are the main factors determining the characteristics and distribution patterns of benthic assemblages at present time

Breather Modes Induced by Localized RF Radiation: Analytical and Numerical Approaches

Numerical computations and collective variables approach are applied to analytical and numerical study of spatially localized excitations of one-dimensional magnetic system in external high-frequency magnetic field. It is demonstrated the hysteresis character of dependence for amplitude of local soliton-like states on external field magnitude. The system shows a variety of interesting nonlinear phenomena such as periodicity doubling and chaos