146 research outputs found

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

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    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

    Cool spots on the surface of the active giant PZ Mon

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    Based on the multiband (BVRIJHKL) photometric observations of the active red giant PZ Mon performed for the first time in the winter season of 2017-2018, we have determined the main characteristics of the spotted stellar surface in a parametric three-spot model. The unspotted surface temperature is Teff=4730 K, the temperature of the cool spots is Tspot=3500 K, their relative area is about 41%, and the temperature of the warm spots is Twarm=4500 K with a maximum relative area up to 20%. The distribution of spots over the stellar surface has been modeled. The warm spots have been found to be distributed at various longitudes in the hemisphere on the side of the secondary component and are most likely a result of its influence.Comment: 5 pages, 7 figure

    Influence of laser surface hardening on corrosion properties of Al-Zn-Si cast alloy

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    This work is focused on the effect of the laser surface treatment (laser power 50 and 80 W) on microstructure and corrosion properties of self-hardened AlZn10Si8Mg cast alloy used for engine and vehicle constructions. The electrochemical impedance spectroscopy (EIS) technique and Nyquist plots in a 1M NaCl test solution at 20 °C were carried out. A detailed corrosion study showed that corrosion resistance samples with laser layer were marginally less; probably the presence of chloride ions significantly damaged the Al2O3 film and caused the formation of NaAlO2

    Influence of laser surface hardening on corrosion properties of Al-Zn-Si cast alloy

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    This work is focused on the effect of the laser surface treatment (laser power 50 and 80 W) on microstructure and corrosion properties of self-hardened AlZn10Si8Mg cast alloy used for engine and vehicle constructions. The electrochemical impedance spectroscopy (EIS) technique and Nyquist plots in a 1M NaCl test solution at 20 °C were carried out. A detailed corrosion study showed that corrosion resistance samples with laser layer were marginally less; probably the presence of chloride ions significantly damaged the Al2O3 film and caused the formation of NaAlO2

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

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    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

    Assessing cytokine status of patients with chronic endometritis combined with endometrial hyperplastic processes in reproductive period

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    The goal of our study was to examine local and serum cytokine level involved in regulating inflammation in patients with chronic endometritis combined with endometrial hyperplastic processes. On admission, all patients underwent hysteroscopy with separate diagnostic curettage followed by histological examination of samples isolated from the uterine and cervical canal mucosa. Such manipulations were indicated due to abnormal uterine bleeding as well as suspected endometrial pathology based on ultrasound examination. According to the histological examination data of the endometrial samples, all patients were divided into two groups: group I contained 45 women with CE combined with PEG without atypia; group II — 38 patients with morphologically verified CEE combined with AEG without atypia. Level of IL-1P, IL-2, IL-6, IFNy, TNFa in biological fluids (aspirate from the uterus; serum) was measured by using enzyme-linked immunosorbent assay. We found that in both groups (91.1% and 89.6%, respectively) the vast majority of patients was hospitalized due to abnormal uterine bleeding. Oligomenorrhea alternated with intermenstrual bleeding (66.7% and 71.2%, respectively) and dominated in pattern of menstrual cycle disorders in the examined patients, whereas 11 (24.4%) and 7 (18.4%) patients from group I and II, respectively, were noted to suffer from severe menstrual bleeding. Overall, analyzing the data on cytokine level both in the uterine aspirate and serum evidences about ongoing inflammatory process found at examination time point. Upon that, such process was not only local, but also exhibited signs of a systemic inflammatory response. The data on cytokine level in the uterine aspirate from patients with CE coupled to PGE or CGE without atypia point at local inflammatory process characterized by significantly increased concentration of IL-ф, IL-2, IL-6, TNFa and IFNy. At the same time, higher level of IL-ф and IFNy in patients from group II might indicates that degree of morphological changes in the endometrium could affect the level of local cytokine production. Thus, the data obtained evidence that immune changes in chronic endometritis combined with non-atypical endometrial hyperplastic processes mostly occur locally. In this regard, measuring cytokine concentration in the uterine aspirate is a diagnostic predictor and serves as a sign for monitoring therapeutic effectiveness of therapy in this cohort of patients

    Study of fertility and cytogenetic variability in androgenic plants (R0 and R1) of alloplasmic introgression lines of common wheat

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    Anther culture is one of the methods to obtain DH lines of wheat. A limitation of this method can be cytogenetic instability in plants R0, leading to a decrease in fertility or sterility. In this study, we have investigated the fertility of R0, the fertility and cytogenetic variability of R1 in alloplasmatic introgression lines of common wheat in order to develop a cytogenetically stable DH lines with introgressions from different species. Lines 311/134, 311/FL, 311/IR with the cytoplasm from H. vulgare were studied. 311/134 carries the wheat-rye 1RS.1BL and wheatwheatgrass 7DL-7Ai translocations; 311/FL has the 1RS.1BL translocation and probably introgressions from A. glaucum; and 311/IR has the wheat-rye 1RS.1BL and wheat-Ae. speltoides T2B/2S#2 translocations. Green seedlings developed in anther culture for all lines. Differences between the lines in the ability for androgenesis and in the level of fertility in R0 and R1 have been revealed. Depressed androgenesis, low fertility and high aneuploidy were observed in 311/IR. It has been proposed that the reason for this is cytogenetic instability in gametes, which is caused by Gc genes located on T2B/2S#2. 63.3 % of 311/134 and 311/FL R1 plants that were grown from low seed-set R0 plants were aneuploids. Fertile R0 regenerant plants were identified that segregated in R1 for fertility and chromosome numbers. It has been demonstrated that DH lines are best developed from highfertility R1 plants with 2n = 42 irrespective of fertility in R0

    The perspective soft spring wheat variety Semenovna is the result of international cooperation

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    The research is aimed at studying economically valuable traits and genetic control of resistance to leaf-stem diseases, photoperiodic reaction and short stemming of soft spring wheat variety Semenovna, created by scientists of the Omsk Agrarian Scientific Center (Russia) and the North Kazakhstan Agricultural Experimental Station (Kazakhstan). Using methods of state variety testing, molecular genetics and in vitro methods, morphological features of a new variety, features of its development have been described, the yield level at different ecological test points for three years (2015-2017) has been analyzed. The studies conducted at two ecological points made it possible to select a medium-sized promising line of soft spring wheat (Lutescens 354/04-6), which was transferred to the State Registration Service of the Republic of Kazakhstan and after two years of testing was included into the State Register of the Republic of Kazakhstan under the name Semenovna (patent No. 1023). In terms of grain quality, it was at the level of valuable wheat, exceeded the standard in protein content by 1-2 % and raw gluten by 3-4 %. The new medium-ripe Semenovna variety combines increased yield (2.73-4.40 t/ha) with resistance to drought (resistance index Ir = 0.57), brown and stem rust (IU = 0.00-0.23). The genotype of the variety contains wheat-rye translocation 1RS.1BL (with a cluster of Lr26/Sr31/Pm8/Yr9 genes). The medium-stem variety carries the Rht8b allele in its genotype (174 bp)  and is photosensitive to the length of the day (allele 414 bp). The parameters of ecological plasticity of the new variety are determined: linear regression coefficient (bi = 1.08), stability index (σd2 = 0.27)
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