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.

The shear behavior of corroded simply supported reinforced concrete beam

Abstract: The effect of corrosion of stirrups on shear strength of corroded re inforced concrete beam is an important problem that needs to be studied In this paper, through the experiment of 18 corroded reinforced concrete beams and 3 un corroded reinforced concrete beams, the effects of corrosion rate of stirrups on deformation, crack forming and development, bearing capacity and failure mechanism of the inclined section of simply supported reinforced concrete beam were investigated The test results s howed that: the corrosion of stirrups reduces the constraint of stirrups to conc rete; the grip action of aggregates at both sides of the crack are deteriorated as the diagonal crack develops rapidly; the influence of cracks in shear-compre ssion zone of concrete due to stirrup corrosion on shear strength of beam is qui te large; the failure mechanism of beam is determined by the shear-span ratio, rather than by the degree of stirrup corrosion; stirrup corrosion has significan t influence on the shear bearing capacity of the beam Based on this research an d using the ultimate equilibrium theory, the calculation model of shear bearing capacity of corroded simply supported reinforced concrete beam is established

Specifics of molecular structures of (565)macrotricyclic 3d-Metal chelates in the ternary systems M(II)-hydrazinecarbothioamide-2,4-Pentanedione according to DFT calculations

Abstract: The geometric parameters of the molecular structures and thermodynamic parameters of formation of macrotricyclic M(II) complexes (M = Mn, Fe, Co, Ni, Cu, and Zn) with the MN2S2 coordination core formed by the reactions of corresponding hexacyanoferrates(II) with hydrazinecarbothioamide H2N-HN-C(=S)-NH2 and 2,4-pentanedione H3C-C(=O)-CH2-C(=O)-CH3 in gelatin-immobilized matrix implants have been calculated by the B3LYP hybrid density functional theory method with the use of the 6-31G(d) basis set and the Gaussian 09 program package. The bond lengths and bond and torsion angles in these chelates have been reported. It has been shown that the Fe(II) and Ni(II) complexes are strictly planar, whereas the Mn(II), Co(II), and Cu(II) complexes are quasi-planar with a rather small deviation of the MN2S2 chelate core from coplanarity, and only the Zn(II) complex is pseudotetrahedral. The additional sixmembered chelate rings resulting from the above processes are almost planar in all chelates.

The interaction of rarefaction waves of a two-dimensional nonlinear wave system

Abstract: This paper is concerned with a two-dimensional Riemann problem for the nonlinear wave system which gives rise to an interaction of two planar rarefaction waves. This problem comes from the expansion of a wedge of gas with constant velocity into vacuum, which is often interpreted as the dam collapse problem in hydraulics. We establish the global existence of smooth solutions in the interaction region of rarefaction waves up to a non-trivial vacuum boundary.

Zirconia-based nanocrystals in the ZrO2-In2O3 system

Abstract: Zirconia-based ZrO2-In2O3 nanocrystals are prepared by hydrothermal treatment of coprecipitated zirconium oxyhydroxide and indium hydroxide. Indium oxide is shown to dissolve predominantly in cubic zirconia nanocrystals. Its solubility in nanocrystalline zirconia notably exceeds the equilibrium In2O3 solubility in ZrO2 single crystals.