The path similarity method for phase measurements disambiguation

We introduce the technique for phase measurements disambiguation based on the paths similarity identification. To obtain these paths, we use phase and amplitude measurements. By simulation, the performance of the presented approach is established. Its application for the phase measurements disambiguation is demonstrated by the example of the phase correlative direction finder for which the amplitude correlative direction finding mode is activated without any hardware changes

Marine mammals in macro-ecosystems of Far Eastern seas and adjacent waters of the North Pacific

The article discusses the role of marine mammals in marine and oceanic ecosystems on the example by Far Eastern seas with adjacent waters of the North Pacific, one of the regions of the World Ocean distinguished for high biological and fish capacity along with a high abundance of cetaceans and pinnipeds. Based on extensive data, published mostly by Russian experts, the authors calculated the following quantities of annual consumption of fish and invertebrates by marine mammals in the three Far Eastern seas: 14.6-18.2 million t in the early 20th century, 12.3-15.1 million t in the late 1970s, 22.7-28.8 million t in the pre-harvesting period, and 24.0-24.7 million t in the early 21st century (27.0-29.5 million t, if 3-5 million t in ocean waters off the Kuril Islands and Kamchatka are taken into account). More than a half of this quantity is composed by zooplankton and zoobenthos, and then by fish and squids. In too time scales of food consumption by fishes and large-sized invertebrates are much higher than these estimates: in the layer 0-1,000 m, 516 million t was consumed in the 1980s-1990s, 389 million t in 1991-1995, and 461 million t in 1996-2005. In the years of high abundance, large-sized walleye pollock alone consumed nearly 40 million t of small-sized fish and squid. Based on the data of 35-year-long ecosystem studies by TINRO-Center, the following biomass estimates have been obtained for the biota of the Far Eastern Economic Zone of Russia: 1,000 million t of meso- and macroplankton, 500 million t of zoobenthos, 100 million t of nekton, 5 million t of benthic fish, and 2.43 million t of large-sized benthic invertebrates, which are not included in the benthos. Against the background of these estimates and comparing the volume of food consumption by marine mammals concluded that marine mammals in the Far Eastern Russian waters noticeable in food webs, but their role does not rise to a level sufficient for the regulation of the powerful sea and ocean makroekosistem

Some aspects of biogeography with reference to zoning of the Far- Eastern Seas of Russia and adjacent waters of the Pacific Ocean

Formation of biogeography, its methodological features, and its status as interdisciplinary science combining biological and geographical aspects are discussed. There is noted that the descriptive period of biogeography has passed, and now any «manifestation of life on the globe» requires its explanation. These explanations are reduced to three non-adversarial restrictions: environmental (ecology), temporal (history of origin, evolution), and spatial (geography). General regularities of life distribution over the Earth surface are analyzed, in particular the features of pelagic organisms habitat, and the concept of «dynamic biogeography» is discussed. Latitudinal zoning of epi- and mesopelagic layers in the Far-Eastern Seas of Russia and adjacent Pacific waters is proposed on the basis of data about areas and distribution of 493 species of nekton (fishes and squids) for the 30-year period (1980-2009) obtained from 27 thousand trawl samples caught in 272 expeditions. This zoning uses a new approach related to the chorological direction in marine biogeography realized with the index of latitudinal zoning (ILZ). For this index calculation, all types of species areas (formerly expressed in verbal forms) were identified with numerical codes, which were averaged for all species in each sample, then the regions with certain ILZ values and borders between them were determined on the maps of ILZ distribution, and latitudinal zones and subzones were defined. There is found that the epipelagic layer of the Okhotsk and Bering Seas corresponds to the high-boreal latitudinal subzone and the epipelagic layer of the northwestern Japan Sea and the major part of Russian EEZ in the Pacific corresponds to the low-boreal latitudinal subzone. Fauna of nekton in the mesopelagic layer of all studied regions corresponds by its chorological structure to the low-boreal latitudinal subzone. So, zoning of epipelagic and mezopelagic layers is significantly different, with the fragmentation reducing with depth, possibly due to weakening of climatic factors influence. The biogeographical zoning is not literally zonal but corresponds to structure of the environments (water masses, fronts, currents, gyres, eddies, etc.)

Phase transformations in the system Cu-Zn-Al under conditions far from equilibrium

It is shown that the alloy Cu-Zn-Al is a multiphase material. Under equilibrium conditions this alloy can form an α-phase (FCC crystalline lattice) and a β-phase (simple cubic crystalline lattice) based on copper. The possibility of formation of a γ-phase due to a three-component alloy composition is revealed. It is established that different chemical composition of the copper-based solid solution (alloys with zinc or alloys with aluminum), different concentration of the second element in a solid solution leads to the fact that within the same type of the crystalline lattice there is a certain amount of α- and γ-phases, differing in the parameter value of the crystalline lattice. The possibility of formation of powder alloys with an x-ray amorphous and a nanocrystalline structure using the plasma chemical synthesis methods is demonstrated. A wide variety of binary phases, each with different concentrations of zinc and aluminum in a solid copper-based solution is revealed. These results indicate that plasma-chemical synthesis of metal alloy powders is accompanied by separation of elements. Powders of the ternary composition are not detected

Metabolic homeostasis in chronic helminth infection is sustained by organ-specific metabolic rewiring

Opisthorchiasis, is a hepatobiliary disease caused by flukes of the trematode family Opisthorchiidae. A chronic form of the disease implies a prolonged coexistence of a host and the parasite. The pathological changes inflicted by the worm to the host’s hepatobiliary system are well documented. Yet, the response to the infection also triggers a deep remodeling of the host systemic metabolism reaching a new homeostasis and affecting the organs beyond the worm location. Understanding the metabolic alternation in chronic opisthorchiasis, could help us to pinpoint pathways that underlie infection opening possibilities for the development of more selective treatment strategies. Here, with this report we apply an integrative, multicompartment metabolomics analysis, using multiple biofluids, stool samples and tissue extracts to describe metabolic changes in Opisthorchis felineus infected animals at the chronic stage. We show that the shift in lipid metabolism in the serum, a depletion of the amino acids pool, an alteration of the ketogenic pathways in the jejunum and a suppressed metabolic activity of the spleen are the key features of the metabolic host adaptation at the chronic stage of O. felineus infection. We describe this combination of the metabolic changes as a “metabolically mediated immunosuppressive status of organism” which develops during a chronic infection. This status in combination with other factors (e.g., parasite-derived immunomodulators) might increase risk of infection-related malignancy

Emergent Ising degrees of freedom in frustrated two-leg ladder and bilayer s=1/2s=1/2 Heisenberg antiferromagnets

Based on exact diagonalization data for finite quantum Heisenberg antiferromagnets on two frustrated lattices (two-leg ladder and bilayer) and analytical arguments we map low-energy degrees of freedom of the spin models in a magnetic field on classical lattice-gas models. Further we use transfer-matrix calculations and classical Monte Carlo simulations to give a quantitative description of low-temperature thermodynamics of the quantum spin models. The classical lattice-gas model yields an excellent description of the quantum spin models up to quite large temperatures. The main peculiarity of the considered frustrated bilayer is a phase transition which occurs at low temperatures for a wide range of magnetic fields below the saturation magnetic field and belongs to the two-dimensional Ising model universality class.Comment: 17 pages, 8 figure

On steadyness of stereotypes in conceptions on marine ecology of pacific salmons (Oncorhynchus spp.)

Some conceptions on marine ecology of pacific salmons (Oncorhynchus spp.), established in the second half of the last century, are discussed from critical position, as overemphasizing of the sea surface temperature influence on distribution of salmons and formation of their year-classes strength, deficiency of food (particularly in winter time) and fierce competition for food, pink salmon «suppression» over other salmon species and own adjacent generations, limited carrying capacity of the Subarctic zone for salmons, distortion of the epipelagic communities structure in the North Pacific by mass artificial reproduction of chum salmon, etc. Most of these ideas have not been confirmed by the data of long-term monitoring in complex marine expeditions conducted by Pacific Fish. Res. Center (TINRO) in the Far-Eastern Seas and adjacent North Pacific waters since the 1980s till nowadays. The data show that pacific salmons are very ecologically plastic species with wide temperature range of habitat. Salmons are able to considerable vertical migrations crossing easily the temperature gradient zones and different water masses. They have wide feeding spectra. Migrating dispersed, they successfully get their ration, even in vast areas with relatively low concentration of prey (macroplankton and small nekton). Total biomass of all species of pacific salmons in the North Pacific does not exceed 4-5 million tons (1.5-2.0 million tons in the Russian waters), whereas the stocks of other mass species of nekton are hundreds of millions of tons. The salmons consume 1.0-5.0 % of the total consumption by nekton in the epipelagic layer in the western Bering Sea, 0.5-1.0 % in the Okhotsk Sea, 5.0-15.0 % at East Kamchatka, and less than 1 % in the Pacific waters at Kuril Islands, So, the role of pacific salmons in trophic nets of the Subarctic waters is rather moderate. Therefore, neither pink salmon, nor chum salmon can be seriously considered as the species responsible for reorganization of large ecosystems and fluctuating of other mass nekton species

Path-building and localization system for mobile robotic platforms based on Raspberry Pi

The paper demonstrates a system for detection of location of robotic platform FESTO Robotino and optimal route building. It processes data from the camera and transmits control signals to the control system of the robot. The whole system is based on Raspberry Pi. It detects robot's current coordinates, current angular rotation, angular difference (difference between current and previous angular rotation) and displacement of the robot in its own coordinate system. It uses an ArUco marker, placed on the top of the mobile robot for that. System also builds an optimal path, when moving from one point of the surface to another, according to the permeability of the surface. The authors set the permeability of testing surfaces. Using that, a weighted graph is built through the centers of particular surfaces, which are detected via an algorithm on Raspberry Pi. The optimal path is constructed through the edges of the graph via modified Dijkstra algorithm

The structure and properties of boron carbide ceramics modified by high-current pulsed electron-beam

The present work is devoted to numerical simulation of temperature fields and the analysis of structural and strength properties of the samples surface layer of boron carbide ceramics treated by the high-current pulsed electron-beam of the submillisecond duration. The samples made of sintered boron carbide ceramics are used in these investigations. The problem of calculating the temperature field is reduced to solving the thermal conductivity equation. The electron beam density ranges between 8…30 J/cm2, while the pulse durations are 100…200 μs in numerical modelling. The results of modelling the temperature field allowed ascertaining the threshold parameters of the electron beam, such as energy density and pulse duration. The electron beam irradiation is accompanied by the structural modification of the surface layer of boron carbide ceramics either in the single-phase (liquid or solid) or two-phase (solid-liquid) states. The sample surface of boron carbide ceramics is treated under the two-phase state (solid-liquid) conditions of the structural modification. The surface layer is modified by the high-current pulsed electron-beam produced by SOLO installation at the Institute of High Current Electronics of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia. The elemental composition and the defect structure of the modified surface layer are analyzed by the optical instrument, scanning electron and transmission electron microscopes. Mechanical properties of the modified layer are determined measuring its hardness and crack resistance. Research results show that the melting and subsequent rapid solidification of the surface layer lead to such phenomena as fragmentation due to a crack network, grain size reduction, formation of the sub-grained structure due to mechanical twinning, and increase of hardness and crack resistance