291 research outputs found

    An attachment for an optical spectrometer for measuring the concentration profile and coefficient of impurity distribution in a crystal

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    An attachment for an optical spectrometer is described enabling automated measurements of the impurity distribution in a crystal. For analysis of the Nd3+ ion distribution over a LiYF4 crystal, it is shown that the attachment provides a high resolution when obtaining data on the optical quality of a crystal and the impurity concentration profile and reliably determines the impurity distribution coefficient. © 1997 MAEe cyrillic signK Hayκa/Interperiodica Publishing

    Dynamics of physical properties of soils and humus reserves in salted soils under desertification

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    The dynamics of the physical properties and reserves of humus in saline soils of an arid semi-desert zone is presented. The basis for the research was observational data for 2010-2022. in a typical hilly landscape of the Astrakhan region. A grid of 100 × 100 m was laid. Soil studies were carried out at the grid nodes along the sampling layers. We studied the change in physical properties (soil moisture; salt content according to the amount of dense residue; soil density; filtration coefficient; soil porosity; moisture reserve), humus reserves and salt state of saline soils under desertification. Comparative analysis showed that negative changes have taken place in the study area and it can be stated that the processes of soil degradation and desertification are intensively developing. It has been established that in the soil layer of 0–40 cm there was a significant reduction in soil moisture reserves against the background of an increase in maximum air and soil surface temperatures, as well as changes in the hydrological regime because of the embankment of the territory. Dehumification processes are observed. The most clearly negative trend was revealed for meadow solonchaks. The change in the hydrological regime of the territory because of embankment contributes to an increase in the areas of automorphic soils in the landscape and a reduction in the areas of meadow soils. An increase in the degree of salinity and compaction was recorded for automorphic zonal soils. The physical destruction of the Baer's hills exacerbates the processes of degradation and the development of desertification in such conditions

    2D Spectroscopy of Candidate Polar-Ring Galaxies: I. The Pair of Galaxies UGC 5600/09

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    Observations of the pair of galaxies VV 330 with the SCORPIO multimode instrument on the 6-m Special Astrophysical Observatory telescope are presented. Large-scale velocity fields of the ionized gas in H-alfa and brightness distributions in continuum and H-alfa have been constructed for both galaxies with the help of a scanning Fabry Perot interferometer. Long-slit spectroscopy is used to study the stellar kinematics. Analysis of the data obtained has revealed a complex structure in each of the pair components. Three kinematic subsystems have been identified in UGC 5600: a stellar disk, an inner gas ring turned with respect to the disk through ~80degrees, and an outer gas disk. The stellar and outer gas disks are noncoplanar. Possible scenarios for the formation of the observed multicomponent kinematic galactic structure are considered, including the case where the large-scale velocity field of the gas is represented by the kinematic model of a disk with a warp. The velocity field in the second galaxy of the pair, UGC 5609, is more regular. A joint analysis of the data on the photometric structure and the velocity field has shown that this is probably a late-type spiral galaxy whose shape is distorted by the gravitational interaction, possibly, with UGC 5600.Comment: 18 pages, 6 figure

    Study of the structure and kinematics of the NGC 7465/64/63 triplet galaxies

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    This paper is devoted to the analysis of new observational data for the group of galaxies NGC 7465/64/63, which were obtained at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) with the multimode instrument SCORPIO and the Multi Pupil Fiber Spectrograph. For one of group members (NGC 7465) the presence of a polar ring was suspected. Large-scale brightness distributions, velocity and velocity dispersion fields of the ionized gas for all three galaxies as well as line-of-sight velocity curves on the basis of emission and absorption lines and a stellar velocity field in the central region for NGC 7465 were constructed. As a result of the analysis of the obtained information, we revealed an inner stellar disk (r ~ 0.5 kpc) and a warped gaseous disk in addition to the main stellar disk, in NGC 7465. On the basis of the joint study of photometric and spectral data it was ascertained that NGC 7464 is the irregular galaxy of the IrrI type, whose structural and kinematic peculiarities resulted most likely from the gravitational interaction with NGC 7465. The velocity field of the ionized gas of NGC 7463 turned out typical for spiral galaxies with a bar, and the bending of outer parts of its disk could arise owing to the close encounter with one of galaxies of the environment.Comment: 20 pages, 6 figure

    NGC 7468: a galaxy with an inner polar disk

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    We present our spectroscopic observations of the galaxy NGC 7468 performed at the 6-m Special Astrophysical Observatory telescope using the UAGS long-slit spectrograph, the multipupil fiber spectrograph MPFS, and the scanning Fabry-Perot interferometer (IFP). We found no significant deviations from the circular rotation of the galactic disk in the velocity field in the regions of brightness excess along the major axis of the galaxy (the putative polar ring). Thus, these features are either tidal structures or weakly developed spiral arms. However, we detected a gaseous disk at the center of the galaxy whose rotation plane is almost perpendicular to the plane of the galactic disk. The central collision of NGC 7468 with a gas-rich dwarf galaxy and their subsequent merging seem to be responsible for the formation of this disk.Comment: 8 pages, 6 figures, accepted in Astronomy Letters, 2004, vol 30., N 9, p. 58

    Screening of powdery mildew resistant barley accessions from Ethiopia for tolerance to abiotic stressors

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    Background. Analyzing the adaptive potential of cultivated barley with the aim of using new genotypes selected and developed in the process of work is a priority trend in scientific research. The Ethiopian barleys adapted to a variety of soil and climate conditions are characterized by many valuable biological and agronomic traits. Of particular value are genotypes that combine resistance to harmful organisms and environmental stressors.Materials and methods. The collection accessions of Ethiopian barley possessing powdery mildew resistance were studied for tolerance to adverse edaphic factors (chloride salinity and high content of toxic aluminum ions in the soil). Resistance to abiotic stressors was assessed in laboratory experiments. In the study of salt tolerance, a ‘roll-based’ assessment technique was used, which takes into account the inhibition of root growth under salt (NaCl) stress conditions, compared with the reference conditions without salinization. Aluminum sensitivity of barley accessions was diagnosed in the early stages of plant development using the root test.Results and conclusions. A polymorphism of Ethiopian barleys for resistance to adverse edaphic factors was revealed. Twentyone new sources of barley resistance to toxic aluminum ions were identified, of which accessions k-8552 and k-22933 were classified as highly resistant. Accessions k-17554, k-19975, k-20029, k-20048, k-22752, k-23450 and k-25009 proved resistant to soil salinization. Barley accessions k-17554, k-22752 and k-25009 were characterized by complex resistance to powdery mildew, toxic aluminum ions, and chloride soil salinity

    Investigation of antiparkinsonian activity of new imidazole-4,5-dicarboxylic acid derivatives on the experimental model of catalepsy

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    To study the antiparkinsonian activity of new ligands of the glutamate NMDA receptor complex -1,2-substituted imidazole-4,5-dicarboxylic acids - on an experimental model of catalepsy caused by haloperidol intraabdominal injections in rat

    Assessment of biodamage resistance of various concrete grades

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    © 2016, International Journal of Pharmacy and Technology. All rights reserved.At estimation of modern mineral construction materials resistance to Aspergillus niger; Aureobasidium pullulans; Trichoderma sp. it was shown that 28-day exposure of test samples with micromycetes according to GOST 310.4-81 does not reduce their chemical stability coefficient. Analysis of growth rate of selected micromycetes in solid Czapeck-Daux medium allows to relate them to r-strategists. At cultivation of microscopic fungi in liquid Czapeck-Daux medium one-, two-and tribasic (acetic, oxalic, apple and citric) organic acids were identified. High rate of micromycetes growth and formation of wide range of organic acids during their growth gives the basis for supposition that at long-lasting contact of microscopic fungi with construction materials the damage of the latter cannot be excluded
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