3,544 research outputs found

    Sidereal anisotropy of cosmic rays

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    The data of the ionization chamber in Yakutsk for 1954 to 1984 are analyzed. A false sidereal variation caused by the second spherical harmonic in cosmic ray distribution was found and it has the amplitude 0.020 plus or minus 0.002%. The sidereal anisotropy with a very small amplitude (not more than 0.005%) was observed to exist

    Elasticity-mediated self-organization and colloidal interactions of solid spheres with tangential anchoring in a nematic liquid crystal

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    Using laser tweezers and fluorescence confocal polarizing microscopy, we study colloidal interactions of solid microspheres in the nematic bulk caused by elastic distortions around the particles with strong tangential surface anchoring. The particles aggregate into chains directed at about 30 degrees to the far field director and, at higher concentrations, form complex kinetically trapped structures. We characterize the distance and angular dependencies of the colloidal interaction forces.Comment: 6 pages, 5 figure

    Change of cosmic ray anisotropy with solar activity

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    Muon telescope data at various depths underground in Yakutsk within energy range 10 to 300 GeV for 1957 to 1984 are analyzed. The 22-year variation of the interplanetary magnetic field aligned component is found. The variation is caused by interaction of heliomagnetosphere with the local galactic field and interstellar wind

    Sensitivity of depth of maximum and absorption depth of EAS to hadron production mechanism

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    Comparison of experimental data on depth of extensive air showers (EAS) development maximum in the atmosphere, T sub M and path of absorption, lambda, in the lower atmosphere of EAS with fixed particle number in the energy region eV with the results of calculation show that these parameters are sensitive mainly to the inelastic interaction cross section and scaling violation in the fragmentation and pionization region. The data are explained in a unified manner within the framework of a model in which scaling is violated slightly in the fragmentation region and strongly in the pionization region at primary cosmic rays composition close to the normal one and a permanent increase of inelastic interaction cross section. It is shown that, while interpreting the experimental data, disregard of two methodical points causes a systematic shift in T sub M: (1) shower selection system; and (2) EAS electron lateral distribution when performing the calculations on basis of which the transfer is made from the Cerenkov pulse FWHM to the depth of shower maximum, T sub M

    DESERT: Decision Support System for Evaluating River Basin Strategies

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    An integrated PC-based software package for decision support in water quality management on a river basin scale has been developed. The software incorporates a number of useful tools, including an easy-to-use data handling module with a dBase style database engine, simulation and calibration of hydraulics and water quality, display of computed data with the help of external spreadsheet software, and optimization based on dynamic programming algorithm. The main utility of the package is to provide useful and powerful instrument for water quality assessment and decision making in emission control, including selection of wastewater treatment alternatives, standard setting and enforcement at the river basin level. Two versions of the decision support software are presented, the current version and development of a follow-up program with extended features

    CARS polarized microscopy of three-dimensional director structures in liquid crystals

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    We demonstrate three-dimensional vibrational imaging of director structures in liquid crystals using coherent anti-Stokes Raman scattering (CARS) polarized microscopy. Spatial mapping of the structures is based on sensitivity of a polarized CARS signal to orientation of anisotropic molecules in liquid crystals. As an example, we study structures in a smectic material and demonstrate that single-scan CARS and two-photon fluorescence images of molecular orientation patterns are consistent with each other and with the structure model.Comment: 5 pages, 4 figures, published in Appl. Phys. Lett. 91, 151905 (2007

    Towards single-electron metrology

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    We review the status of the understanding of single-electron transport (SET) devices with respect to their applicability in metrology. Their envisioned role as the basis of a high-precision electrical standard is outlined and is discussed in the context of other standards. The operation principles of single electron transistors, turnstiles and pumps are explained and the fundamental limits of these devices are discussed in detail. We describe the various physical mechanisms that influence the device uncertainty and review the analytical and numerical methods needed to calculate the intrinsic uncertainty and to optimise the fabrication and operation parameters. Recent experimental results are evaluated and compared with theoretical predictions. Although there are discrepancies between theory and experiments, the intrinsic uncertainty is already small enough to start preparing for the first SET-based metrological applications.Comment: 39 pages, 14 figures. Review paper to be published in International Journal of Modern Physics

    The activity of copper-containing enzymes in the birch leaves in the conditions of the built environment

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    © 2016, International Journal of Pharmacy and Technology. All rights reserved.In work dynamics of cupriferous enzymes in leaves of silver birch which is constant object of green construction in the anthropogenous environment is shown. Many researches indicate interrelation of adaptive opportunities of a vegetable organism and functioning of enzymatic system, including cupriferous enzymes of a poliphenoloxidaza and ascorbinatoxidaza. Activity of an ascorbinatoxidaza was determined by a method which is based on property of ascorbic acid to absorb light with a maximum at the wavelength of 265 nanometers. About activity of enzyme judged by reduction of size of optical density, considering that the oxidation level of ascorbic acid is proportional to amount of enzyme. Activity of a poliphenoloxidaza was determined by spectrotometric method which is based on measurement of optical density of products of reaction which are formed at oxidation of pyrocatechin for a certain period. During all vegetative period, plants in the conditions of the urban environment, had an increase in activity of a poliphenoloxidaza with achievement of the maximum value in August. In both years of observations (2014 and 2015) there was a decrease of the activity of an ascorbinatoxidaza in leaves during active vegetation of plants, and in the native habitat, on the contrary, its increase. The minimum values of activity of this enzyme are noted in August in the near-road plantings

    Features of operation of the plant pigment system in a man-made environment

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    © 2016, International Journal of Pharmacy and Technology. All rights reserved.The paper shows the dynamics of photosynthetic pigment content in the leaves of native and introduced species of woody plants within the urban environment conditions. Fine-leaved linden and pendent birch growing in the plantations of sanitary protection zones of industrial enterprises and at main planting the content of chlorophyll a and b is reduced during the growing season in comparison with the plantation plants of conditional control zones, but at the same time the content of carotenoids with antioxidant properties and a protective function is increased. Balsam poplar in main plantations has an increased content of chlorophylls and carotenoids in June, but then their decrease takes place. The representatives of maple genus had a significant decrease of chlorophyll a content in leaves throughout the observation period in the city plantations. Chlorophyll b content increase was observed in leaves of the aboriginal species-Norway maple-in main plantations at the beginning of active vegetation period in 2015, and among the plantations of sanitary protection zones and in industrial enterprises and in plantations in July 2014, compared with the plantings of conditional control zones, which indicate its participation in adaptive reactions. Ashleaved maple-an introduced species-is characterized by b chlorophyll content reduction during an active vegetation period, compared with the indicators of conditional control zone during the same interval. Besides, the leaves of maple species demonstrate carotenoid content increase in June
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