Spectral Properties of the Differential Operators of the Fourth-Order with Eigenvalue Parameter Dependent Boundary Condition

We consider the fourth-order spectral problem y4 x−qxy x λyx, x ∈ 0, l with spectral parameter in the boundary condition. We associate this problem with a selfadjoint operator in Hilbert or Pontryagin space. Using this operator-theoretic formulation and analytic methods, we investigate locations in complex plane and multiplicities of the eigenvalues, the oscillation properties of the eigenfunctions, the basis properties in Lp0, l, p ∈ 1, ∞, of the system of root functions of this problem

The Oscillation Properties Of The Boundary Value Problem With Spectral Parameter In The Boundary Condition

The spectral problem is investigated for the fourth order ordinary differential operator with spectral parameter in the boundary conditions. The oscillation properties of the eigenfunctions of this problem are established

On oscillation properties of the eigenfunctions of a fourth order differential operator

The spectral problem for a fourth order ordinary differential operator is investigated. The oscillation properties of the eigenfunctions and their derivatives are established

Study on the Structure and Morphology of Iron Nanopowders Obtained by the Method of Electric Explosion of Wires

This article presents the results of comprehensive study on the structure and morphology of iron nanopowders synthesized by electric explosive evaporation of metal wire. The results of scanning and transmission electron microscopy showed that nanoclusters have a spherical shape with an average diameter of 65 nm. It was revealed based on the analysis of the diffraction patterns that nanoparticles of nanopowders obtained in electric explosion have a crystal lattice with a parameter less than a standard cell. The results of computer experiments are in good agreement with the findings of X-ray analysis. However, the question about the reasons of distortion of the crystal lattice of nanoclusters remains controversial

Prognostic resources of mineral deposits by geophysical methods

In the framework of non-equilibrium statistical thermodynamics a relation between the concentration of component of the ore to its physical properties.On the basis of this communication formulas for calculation of the differentiated and predicted stocks of deposits of minerals are received on the basis of the geophysical data. Methods of magnetic investigation, electric investigation, gravitational investigation and seismic prospecting, and also nuclear physical methods are considered. A comparison of the calculated expected resources with proven for a number of fields in Kazakhstan. The proposed method allows to perform predictive assessment of stocks of deposits in the early stages of prospects with using the results of geophysical methods, while it has a rapidity and to be sufficiently accurate. Non-equilibrium thermodynamics, geophysical methods, and estimated resources, deposits of minerals

Synthesis of Carbon Nanofibers on Copper Nanopowders by Low-Temperature CVD

The article presents the results of experiments on the synthesis of carbon nanofibers by thermal chemical vapor deposition using copper nanopowders obtained by electric explosion of wire as catalysts. Stable growth of carbon nanofibers was carried out at temperatures significantly lower than normally used. The process parameters that are optimal for low-temperature growth of carbon nanofibers have been identified during the performed experiments. The synthesized samples have different diameters and morphology (from spiral to direct). Copper clusters are both at the ends and inside the fibers. The results of IR spectroscopy indicate that the structure of the obtained carbon nanofibers is polymeric. X-ray analysis revealed the presence of a halo on the diffraction patterns at small values of the angle 2θ, which proves that the grown structures have an amorphous nature. There are no groups that are responsible for long-range order in all Raman spectra. Studies by transmission electron microscopy showed that nanostructures do not have an internal channel and nanofibers are solid

Investigation of SiC and C Nanostructures Obtained by MWCVD

The results of experiments on the synthesis of SiC and C nanostructures by chemical vapor deposition in microwave plasma are presented in this article. The single crystal silicon plates with orientations [100] and [111] which previously passed chemical purification were used as substrates. Also, the substrates of porous silicon were prepared in order to activate the surface during the synthesis. The synthesis temperature ranged from 700 to 900 °C in steps of 100 °C. The pressure in the chamber was changed depending on the power of the plasma. Studies by scanning electron microscopy (SEM) showed that formed nanostructures have a diameter of 200‒350 nm and a rough surface. The formation of nanostructures on the polished Si occurs on the SiC buffer layer. Analysis of SEM images of the samples shows that growth of NS on the surface of porous silicon is more widespread in contrast to the polished Si. The results of X-Ray spectral microanalysis showed that the carbon content in samples of nanostructures on polished Si varies from 10 to 20% and remains constant on porous silicon ~ 25%. The results of studies by Raman scattering confirmed that SiC film with structure of 3C-SiC is formed on the polished Si. Besides, the presence of main carbon peaks on both types of substrates in the range of 1338.2 and 1583 cm‒1 should be noted, which correspond to the carbon nanostructures

Study of Operating Characteristics of Pyrotechnic Reserve Power Source Based on Magnesium and Zinс

This paper presents the results of studies of operating parameters of pyrotechnic reserve power source (PRPS). This battery was activated by the pyrotechnic compositions contained in the electrodes. Once the ignition impulse worked, the pyrotechnic compositions took fire immediately and melted the electrolyte. Then the rest pyrotechnic compositions served as anode and cathode. The battery began to discharge. The following characteristics of PRPS were evaluated during the study: release time to operating regime of the electric current, the duration of the PRPS work and initiation temperature of PRPS. A detailed evaluation of the Mg/LiF/PbF2 electrochemical system and Zn/LiF/PbF2 one is undertaken. Test results show that the electric current value using powder of zinc and granular zinc in these experiments was 0.179 A and 0.1 A, respectively, and the operating time at these values of elecrtic current was 40 and 151 sec, respectively

THE EPIDEMIOLOGICAL SITUATION ON CHOLERA IN THE REPUBLIC OF KAZAKHSTAN IN 2011

The analysis of registered cholera cases that occurred during 1993-2008 showed that all epidemic cases of cholera in Kazakhstan were imported. The toxigenic cholera microbes were isolated from the water reservoirs which started in the neighbor country. The spatial distribution of non-toxic cholera vibrio has the regional features. The climatic and anthropogenic factors affect the distribution of the cholera vibrio in the Kazakhstan. The results of the analysis show that the complex approach has to be used for cholera epidemiological monitoring