University of Architecture, Civil Engineering and Geodesy

About: University of Architecture, Civil Engineering and Geodesy is a education organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Finite element method & Beam (structure). The organization has 3808 authors who have published 3822 publications receiving 30736 citations. The organization is also known as: Sofia Polytechnic.

Ab initio calculation of vibrational spectra of orthorhombic IV–VI layered crystals

Abstract: Phonon modes of IV–VI semiconductor crystals with the orthorhombic structure of the crystal lattice have been calculated from first principles using the linear response method. The calculations are compared with the results of theoretical calculations available in the literature for some of the crystals and with the experimental data obtained by IR and Raman spectroscopies. Equilibrium lattice parameters and phonon spectra are calculated for all the crystals.

New features in the MOGADOC database

Abstract: The development of the Molecular Gas-Phase Documentation database is briefly described. It has been developed from a unique literature compilation via the first client programs on computer mainframes and personal computers to a versatile HTML-based version, which can be run platform-independently by common Web browsers. In the database, the structural parameters for about 9200 organic, metalorganic, and inorganic compounds studied in the gas phase mainly by electron diffraction and microwave spectroscopy are given numerically, and the molecular structures can be visualized in many ways, particularly in three-dimensional representation. Moreover, the spectroscopic parameters (such as rotational and centrifugal distortion constants, dipole moments, nuclear quadrupole coupling constants, and barriers of hindered rotation) can be retrieved by keywords.

Stochastic Modeling of the Kinetics of Processing of Heterogeneous Systems

Abstract: Mathematical modeling of the kinetics of processing of heterogeneous media is discussed. It is demonstrated that the mathematical formalism of Markovian process theory in combination with methods of multiphase medium mechanics is usable for this purpose, and methods of constructing kinetic models are suggested. Kinetic models have been constructed for material treatment processes such as mixing and grinding, and the solution of the corresponding differential equations are presented. A method is suggested for solving the Kolmogorov-Fokker-Planck equation with the small parameter at the highest order derivative and cuspidal point taken into account. The validity of the constructed kinetic models is demonstrated.

Improvement of settlement calculations of building foundations by increasing the reliability of determining soil compressibility indices

Abstract: Ways to improve the methods of calculating the foundations bases’ settlements by increasing the reliability of determiningthe soil compressibility indices are substantiated. The complex approach to refinement of the buildings bases' settlements calculationby the layer summation method is investigated by accounting for the soil deformation modulus variability in the fullpressure range perceived by the base at loading; soil strength coefficient βZ; soil deformation anisotropy by elastic orthotropicmodel; tendencies to magnitude variation in the soil deformation modulus in depth of the body under the foundations andwithin the artificial bases built with the soil compaction. There was also proved the possibility of increasing the accuracy ofthe predicting method for the buildings' foundations base settling using the soil compression index and accounting for thepressure effect on the soil deformation parameters in depth of the compressible strata.