Random block stability and anchoring design for underground caverns in a hydro-power station

Random blocks in underground tunnels and in grand power caverns are the unstable blocks cut by random joints or fractures in the bedrock. Designers often reinforce these blocks by using systematic anchors however their length and space are difficult to determine because of the randomness of blocks position and the indeterminacy of the blocks geometric characters. By the study of geological conditions and the rock structure of the underground caverns in the hydropower station, the regularities of distribution of the possible random joints were concluded. This enabled the random blocks to be orientated by combining joints with other joints, or combining joints with I and II definite structural planes. The geometric characteristics and stabilities of the random blocks were determined by using stability calculations according to block theory. From this the optimal anchor length could be defined, which could be referred to as a theoretical base for the length of the systematic anchors.published_or_final_versionThe 10th IAEG International Congress: Engineering Geology for Tomorrow's Cities, Nottingham, United Kingdom, 6-10 September 2006. In Proceedings of the 10th IAEG International Congress, 2006, p. 547-55

Lowering and raising operators for the free Meixner class of orthogonal polynomials

We compare some properties of the lowering and raising operators for the classical and free classes of Meixner polynomials on the real line

Analysis of an anti-dip landslide triggered by the 2008 Wenchuan earthquake in China

published_or_final_versio

Nicotine metal complexes: synthesis, characterization and bioactivities of some main group and some transition metals

A number of some main group and transition metal nicotine complexes were synthesized and fully characterized using detailed structural and spectroscopic analysis techniques such as elemental analysis, molar conductivities, magnetic susceptibilities, IR, Raman and NMR techniques. Moreover, scanning electron micrographs and thermogravimetric analyses were also done. Cytotoxic activities of the binary nicotine metal complexes were tested and evaluated against HepG2 (human hepatocellular carcinoma), HPC3 (human prostate cancer), and HCT116 (human colorectal carcinoma) tumor cell lines. The antioxidant activities were examined by free radical scavenging assay. The antimicrobial activities of the synthesized complexes were evaluated against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) microbes. The relationship between the chemical structure of the synthesized complexes and their biological influence as antimicrobial drugs was studied and evaluated.                     KEY WORDS: Nicotine metal complexes, Cytotoxicity, Antioxidant, Antimicrobial   Bull. Chem. Soc. Ethiop. 2020, 34(3), 501-521. DOI: https://dx.doi.org/10.4314/bcse.v34i3.

Effective-mass Klein-Gordon Equation for non-PT/non-Hermitian Generalized Morse Potential

The one-dimensional effective-mass Klein-Gordon equation for the real, and non-\textrm{PT}-symmetric/non-Hermitian generalized Morse potential is solved by taking a series expansion for the wave function. The energy eigenvalues, and the corresponding eigenfunctions are obtained. They are also calculated for the constant mass case.Comment: 14 page

The Double-Time Green's Function Approach to the Two-Dimensional Heisenberg Antiferromagnet with Broken Bonds

We improved the decoupling approximation of the double-time Green's function theory, and applied it to study the spin-${1\over 2}$ two-dimensional antiferromagnetic Heisenberg model with broken bonds at finite temperature. Our decoupling approximation is applicable to the spin systems with spatial inhomogeneity, introduced by the local defects, over the whole temperature region. At low temperatures, we observed that the quantum fluctuation is reduced in the neighborhood of broken bond, which is in agreement with previous theoretical expectations. At high temperatures our results showed that the quantum fluctuation close to the broken bond is enhanced. For the two parallel broken bonds cases, we found that there exists a repulsive interaction between the two parallel broken bonds at low temperatures.Comment: Revtex, 6 pages, 5 Postscript figures (include

Low Temperature Measurements by Infrared Spectroscopy in CoFe2_2O4_4 Ceramic

In this paper results of new far-infrared and middle-infrared measurements (wavenumber range of 4000cm-1 - 100cm-1) in the range of the temperature from 300K to 8K of the CoFe2O4 ceramic are presented. The bands positions and their shapes are the same in the wide temperature range. The quality of the sample was investigated by X-ray, EDS and EPMA studies. The CoFe2O4 reveals the cubic structure (Fd-3m) in the temperature range from 85K to 360 K without any traces of distortion. On the current level of knowledge the polycrystalline CoFe2O4 does not exhibit phase transition in the temperature range from 8 K to 300 K.Comment: 10 pages, 6 figure