54 research outputs found
Kinetic Characteristics, Phase and Structural Changes in Electrical Materials and Devices
Electron-microscopic and X-ray studies have revealed that the ability of lead-acid storage batteries to adopt charge due to physico-chemical processes occurring in the lead paste and on the border of the “shunt-paste” depends dramatically on both the initial moisture content in the lead paste and keeping enhanced humidity in the exposure chamber for plates.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3365
Mechanisms of Microwave Absorption in Carbon Compounds from Shungite
According to SEM, X-ray phase analysis, Raman scattering data features of nanostructural changes in shungite carbon structure were found when processing shungite in 52 % hydrofluoric acid. It is found that conductivity increases up to the values of electrical graphite and absorption of microwave radiation also increases at frequencies up to 40 GHz, which, along with dielectric losses, is due to intense processes of both scattering at laminar carbon structures and absorption of electromagnetic energy.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3365
Influence of Structural Features and Physico-chemical Properties of Metal-carbon Nanocomposites with Ferromagnetic Metal Inclusions on Microwave Radiation
Metal-carbon nanocomposites on the basis of polyacrylonitrile and compounds of metals (Fe, Ni, Co)
synthesized at IR-heating and studied by SEM, X-ray phase analysis, Raman scattering, IR Fourier spec-troscopy are characterized by the carbon nanostructured amorphous graphite matrix with uniformly dis-tributed nanoparticles of metals (10-30 nm), their oxides and compounds – FeNi3 and FeCo, multilayered
carbon nanotubes (~ 7-22 nm), and in the composition of Fe-Co / C fullerene-like formations – C60. All
nanocomposites feature high absorption of electromagnetic waves in the frequency range 20-40 GHz. Two
absorption mechanisms are proposed: dielectric loss in the amorphous carbon matrix and scattering of
electric and magnetic components by ferromagnetic inclusions. Absorption was – 8.68 dB for Fe-Ni / C,
– 12.93 dB for Fe / C, and – 7.07 dB for Ni / C and for Fe-Co / C was found to be maximum in the whole
range studied (more than – 40 dB) with a peak of – 52.83 dB at 24.27 GHz, which is explained probably by
both high nanocomposite electric conductivity 2 S / m and high specific magnetization of phase FeCo.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3625
Kinetic Characteristics, Phase and Structural Changes in Electrical Materials and Devices
Electron-microscopic and X-ray studies have revealed that the ability of lead-acid storage batteries to adopt charge due to physico-chemical processes occurring in the lead paste and on the border of the “shunt-paste” depends dramatically on both the initial moisture content in the lead paste and keeping enhanced humidity in the exposure chamber for plates.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3365
Tight-binding study of high-pressure phase transitions in titanium: alpha to omega and beyond
We use a tight-binding total energy method, with parameters determined from a
fit to first-principles calculations, to examine the newly discovered gamma
phase of titanium. Our parameters were adjusted to accurately describe the
alpha Ti-omega Ti phase transition, which is misplaced by density functional
calculations. We find a transition from omega Ti to gamma Ti at 102 GPa, in
good agreement with the experimental value of 116 GPa. Our results suggest that
current density functional calculations will not reproduce the omega Ti-gamma
Ti phase transition, but will instead predict a transition from omega Ti to the
bcc beta Ti phase.Comment: 3 encapsulated Postscript figures, submitted to Phyical Review
Letter
A New Mechanism for the Alpha to Omega Martensitic Transformation in Pure Titanium
We propose a new direct mechanism for the pressure driven alpha to omega
martensitic transformation in pure titanium. A systematic algorithm enumerates
all possible mechanisms whose energy barriers are evaluated. A new, homogeneous
mechanism emerges with a barrier at least four times lower than other
mechanisms. This mechanism remains favorable in a simple nucleation model.Comment: 4 pages, 4 figure
Mechanical Alloying of Ti–Fe Alloys Using Severe Plastic Deformation by High-Pressure Torsion
Structure and phase state of Zr-1% Nb and Zr-2.5% Nb alloys loaded by spherically converging shock waves
Deformation Behavior of a Copper Single Crystal upon Loading by Spherically Converging Shock Waves
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