167 research outputs found

    National risks within institutional transformation: socio-economic aspects

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    The article examines the institutional conditions and factors of national risk formation in the context of national economy development. The author is focused on the social aspects of the institutional environment transformation, the role of government, business and society at national risk managemen

    City as an Object of Ecological and Economic Researches: the Example of Russian Cities

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    The growth of environmental pollution especially in big cities dictates the need to search for the reasons of this trend, most of which refer to the economic sphere. The aim of this work is not only to describe the state of environment in Russian cities with the population of 100 thousand inhabitants and more, but also to reveal the main economic factors that influence on the intensity of their environmental pollution. The ecological and economic analysis of Russian cities, fulfilled in this work, helped to identify the most unfavourable of them in terms of the level of environmental impact. The low quality of environment in these cities is largely due to natural and climatic conditions (bad conditions for contaminants dispersion) and specifics of their economic development: functioning of large industrial enterprises of ferrous and non-ferrous metallurgy, petro chemistry, construction industry. The conclusion is that to improve the environmental quality in these cities comprehensive social, environmental and economic solutions are required

    Stability of multi-electron bubbles in liquid helium

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    The stability of multi-electron bubbles in liquid helium is investigated theoretically. We find that multi-electron bubbles are unstable against fission whenever the pressure is positive. It is shown that for moving bubbles the Bernoulli effect can result in a range of pressures over which the bubbles are stable.Comment: 7 pages, 5 figure

    Electric field induced strong localization of electrons on solid hydrogen surface: possible applications to quantum computing

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    Two-dimensional electron system on the liquid helium surface is one of the leading candidates for constructing large analog quantum computers (P.M. Platzman and M.I. Dykman, Science 284, 1967 (1999)). Similar electron systems on the surfaces of solid hydrogen or solid neon may have some important advantages with respect to electrons on liquid helium in quantum computing applications, such as larger state separation ΔE\Delta E, absence of propagating capillary waves (or ripplons), smaller vapor pressure, etc. As a result, it may operate at higher temperatures. Surface roughness is the main hurdle to overcome in building a realistic quantum computer using these states. Electric field induced strong localization of surface electrons is shown to be a convenient tool to characterize surface roughness.Comment: 4 pages, 3 figure

    Quantum Point Contacts and Coherent Electron Focusing

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    I. Introduction II. Electrons at the Fermi level III. Conductance quantization of a quantum point contact IV. Optical analogue of the conductance quantization V. Classical electron focusing VI. Electron focusing as a transmission problem VII. Coherent electron focusing (Experiment, Skipping orbits and magnetic edge states, Mode-interference and coherent electron focusing) VIII. Other mode-interference phenomenaComment: #3 of a series of 4 legacy reviews on QPC'

    The KHOLOD Experiment: A Search for a New Population of Radio Sources

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    Published data from long-term observations of a strip of sky at declination +5 degrees carried out at 7.6 cm on the RATAN-600 radio telescope are used to estimate some statistical properties of radio sources. Limits on the sensitivity of the survey due to noise imposed by background sources, which dominates the radiometer sensitivity, are refined. The vast majority of noise due to background sources is associated with known radio sources (for example, from the NVSS with a detection threshold of 2.3 mJy) with normal steep spectra ({\alpha} = 0.7-0.8, S \propto {\nu}^{- \alpha}), which have also been detected in new deep surveys at decimeter wavelengths. When all such objects are removed from the observational data, this leaves another noise component that is observed to be roughly identical in independent groups of observations. We suggest this represents a new population of radio sources that are not present in known catalogs at the 0.6 mJy level at 7.6 cm. The studied redshift dependence of the number of steep-spectrum objects shows that the sensitivity of our survey is sufficient to detect powerful FRII radio sources at any redshift, right to the epoch of formation of the first galaxies. The inferred new population is most likely associated with low-luminosity objects at redshifts z < 1. In spite of the appearance of new means of carrying out direct studies of distant galaxies, searches for objects with very high redshifts among steep and ultra-steep spectrum radio sources remains an effective method for studying the early Universe.Comment: 13 pages, 10 figure

    Longitudinal Assessment of Growth in Hypoplastic Left Heart Syndrome: Results From the Single Ventricle Reconstruction Trial

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    Background: We sought to characterize growth between birth and age 3 years in infants with hypoplastic left heart syndrome who underwent the Norwood procedure. Methods and Results: We performed a secondary analysis using the Single Ventricle Reconstruction Trial database after excluding patients 2 SD below normal). Failure to find consistent risk factors supports the strategy of tailoring nutritional therapies to patient‐ and stage‐specific targets. Clinical Trial Registration URL: http://clinicaltrials.gov/. Unique identifier: NCT00115934
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