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Date submitted2016-09-18
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Date accepted2016-11-04
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Date published2017-02-22
Development of methods of analytical geometry of a sphere for solving geodesy and navigation tasks
- Authors:
- G. I. Khudyakov
The article develops ideas and formulas of analytical geometry for spherical surface of the Earth globe in relation to main tasks of global geodesy and navigation. It examines peculiarities of sphere inner geometry and properties of its primary, secondary and higher-order curves. It was proved that spherical hyperbola and parabola are spherical ellipses with specific parameters. The Cartesian ordinates were introduced into the sphere and the relation between them and polar spherical coordinates was established. With the help of central projection of sphere points on tangential plane the corresponding elliptical plane with beltrami ordinates was introduced. The article describes main formulas of analytical geometry for projected elliptical plane, which correspond to geometry of projected sphere. It also introduces several formulas for primary, secondary and higher-order curves for this sphere.
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Date submitted2015-10-18
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Date accepted2015-12-01
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Date published2016-08-22
Effect of surface geometry and insolation on temperature profile of green roof in Saint-Petersburg environment
- Authors:
- S. A. Ignatev
- D. S. Kessel
The paper addresses an issue of creating an environment favorable for the life in megacities by planting vegetation on the rooftops. It also provides information about rooftop greening practices adopted in other countries. The issues of ‘green roof’ building in climatic conditions of Saint Petersburg and roof vegetation impact on the urban ecosystem are examined. Vegetation composition quality- and quantity-wise has been proposed for the roof under research and a 3D model of this roof reflecting its geometric properties has been developed. A structure of roof covering and substrate qualitative composition is presented. An effect of rooftop geometry on the substrate temperature is explored. The annual substrate temperature and moisture content in different parts of the roof have been analyzed. Results of thermal imaging monitoring and insolation modelling for different parts of green roof surface are presented.
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Date submitted2014-11-19
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Date accepted2015-01-12
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Date published2015-10-26
Scientific heritage of academician Nikolay Semenovich Kurnakov
- Authors:
- O. A. Dubovikov
Once N.V.Lipin, a professor of mathematics at the Leningrad Mining Institute, told N.S.Kurnakov that M.V.Lomonosov had complained about his lack of familiarity with mathematics. The outstanding scientist replied «That’s absolutely true, and I have already told you about it: we all need mathematics, and the more chemistry develops, the more it needs a mathematical justification». According to one scenario of the international nongovernmental organization, the Club of Rome, there will be a three-fold decrease in the world’s raw materials resources and multifold volume reduction in industrial production by the middle of the 21st century. Another scenario claims that raw materials will reduce only by one third, and the volume of industrial production will remain at the level of the beginning of the century. Not only the first scenario, but also the second one forecasts industrial stagnation. It is unacceptable for dynamic and sustainable development of the technological civilization. Intensively developing economies in China, India, Brazil and Russia defy the forecast of the Club of Rome, as it has not taken into account the possibility of scientific and technological progress in reducing energy consumption and using alternative sources, as well as the increased technological potential of the humanity. Due to depletion of the main sources of energy (oil and gas), many experts link the future of the world’s power industry with the possible use of solid energy resources. From the environmental point of view solid fuel gasification technology is the most preferable. As the calorific value of producer gas is relatively low in comparison with natural gas, some research of possible use of producer gas (as an alternative to natural gas which is available not in all regions) at Russian industrial enterprises has been conducted.
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Date submitted2009-09-15
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Date accepted2009-11-02
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Date published2010-06-25
Mathematical modeling of stress-strain state of the mined seam deposits
- Authors:
- A. P. Gospodarikov
- M. A. Zatsepin
Development of bedded deposits is associated with man-caused distortion of specific environment – the rock massifs, which are very complicated in their composition, can vary significantly in mechanical properties and is characterized with a wide variety of laws and techniques to assess its stress-strain state.
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Date submitted2008-10-20
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Date accepted2008-12-22
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Date published2009-12-11
Analytical continuation of geophysical fields by continued fractions method
- Authors:
- K. M. Ermokhin
The most close to reality geophysical field description is the approximation of the fraction-rational type. In this case the presence of poles in the lower half space corresponds adequately to the denominator zeros. This article contains the theory and algorithm of realization of this conception. The proposed method is called – Continued Fraction Continuation Method.