Internal Structure Research of Shungite by Broadband Ultrasonic Spectroscopy

2017 ◽  
Vol 755 ◽  
pp. 242-247 ◽  
Author(s):  
Elena B. Cherepetskaya ◽  
Alexander A. Karabutov ◽  
Vladimir A. Makarov ◽  
Elena A. Mironova ◽  
Ivan A. Shibaev ◽  
...  

The internal structure of plane-parallel plates of shungite is studied. The broadband ultrasonic pulses are used to measure the velocities of longitudinal and shear elastic ultrasonic waves. The accuracy of measurements is 0.3% in the case of longitudinal wave velocity and 0.5% in the case of shear wave velocity (scanning pitch over the surface of specimens was 0.5 mm). Local elastic moduli of shungite (Young modulus, shear modulus and Poisson's ratio) are uniquely determined from the velocities of elastic waves.

2017 ◽  
Vol 755 ◽  
pp. 44-51
Author(s):  
Anton S. Bychkov ◽  
Alexander A. Karabutov ◽  
Elena V. Savateeva ◽  
Yulia G. Sokolovskaya ◽  
Vasily P. Zarubin ◽  
...  

Theoretical assessments are given for the use of the through-transition technique of broadband ultrasonic spectroscopy to determine porosity of heterogeneous materials. Experimental measurements of local porosity of composites using the through-transition technique are presented. Dependences of elastic moduli on the concentration of hardening particles and porosity of metal matrix isotropic composite found. Experimental relationship between the phase velocity of longitudinal acoustic waves and the power of structural noise in samples of graphite epoxy composites is obtained.


Author(s):  
E. G. Pashuk ◽  
G. D Kardashova ◽  
Sh. A. Khalilov

The paper discusses the possibility of using resonant ultrasonic spectroscopy (RUS) as a source of information for the physics and technology of obtaining silicon carbide ceramics by the example of samples of the composition SiC ‒ 25 % AlN, obtained by the method of spark plasma sintering. The possibility of obtaining a complete set of elastic moduli (EM) of samples with an error of less than 1 % is shown. At the same time, the requirements for surface quality are significantly reduced. The revealed functional relationship between EM and porosity makes it possible to create a non-destructive method of porosity control and calculate the elastic moduli at zero porosity (i. e., the elastic modulus of the ceramic matrix EM0). Comparison of EM0 samples obtained at different parameters of the technological process allows determining their optima values..


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
A. Andreev ◽  
A. Popolitov ◽  
A. Sleptsov ◽  
A. Zhabin

AbstractWe investigate the structural constants of the KP hierarchy, which appear as universal coefficients in the paper of Natanzon–Zabrodin arXiv:1509.04472. It turns out that these constants have a combinatorial description in terms of transport coefficients in the theory of flow networks. Considering its properties we want to point out three novel directions of KP combinatorial structure research: connection with topological recursion, eigenvalue model for the structural constants and its deformations, possible deformations of KP hierarchy in terms of the structural constants. Firstly, in this paper we study the internal structure of these coefficients which involves: (1) construction of generating functions that have interesting properties by themselves; (2) restrictions on topological recursion initial data; (3) construction of integral representation or matrix model for these coefficients with non-trivial Ward identities. This shows that these coefficients appear in various problems of mathematical physics, which increases their value and significance. Secondly, we discuss their role in integrability of KP hierarchy considering possible deformation of these coefficients without changing the equations on $$\tau $$ τ -function. We consider several plausible deformations. While most failed even very basic checks, one deformation (involving Macdonald polynomials) passes all the simple checks and requires more thorough study.


2019 ◽  
Vol 38 (2019) ◽  
pp. 264-272 ◽  
Author(s):  
Nguyen Quang Hoc ◽  
Bui Duc Tinh ◽  
Nguyen Duc Hien

AbstractThis paper studies on the dependence of the mean nearest neighbor distance, the Young modulus E, the bulk modulus K, the rigidity modulus G and the elastic constants C11, C12, C44 on temperature, pressure, the concentration of substitution atoms and the concentration of interstitial atoms for alloy AuCuSi (substitution alloy AuCu with interstitial atom Si) with FCC structure by the way of the statistical moment method (SMM). The numerical results for alloy AuCuSi are compared with the numerical results for main metal Au, substitution alloy AuCu, interstitial alloy AuSi, other calculated results and experiments.


2004 ◽  
Vol 16 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Masahiro Nakajima ◽  
◽  
Fumihito Arai ◽  
Lixin Dong ◽  
Toshio Fukuda

A method is presented for pico-Newton (pN) order force measurement using a carbon nanotube (CNT) probe, which is calibrated by electromechanical resonance. A CNT probe is constructed by attaching a CNT to the end of a tungsten needle or an atomic force microscope (AFM) cantilever using nanorobotic manipulators inside a field-emission scanning electron microscope (FE-SEM). Conductive electron-beam-induced deposition (EBID) is used for the fixation of CNTs with an internal vaporized precursor W(CO)6. For manipulating them easily and quickly, CNTs are dispersed in ethanol by ultrasonic waves and oriented on copper electrodes by electrophoresis. The elastic moduli of CNT probes are calibrated for use as a force measurement probe by electrically exciting at fundamental frequency. We analyzed the resolution of force measurement using a CNT probe. This force measurement can be used to characterize the mechanical properties of nanostructures and to measure friction or exfoliation forces in nanometer order.


2015 ◽  
Vol 770 ◽  
pp. 179-184
Author(s):  
Elena P. Tesleva

The article studies the elastic properties of anisotropy and interatomic anharmonicity in a two-component Cu3Au alloy with positional order-disorder within the high temperature interval of 300 К and 725 К. It provides calculations on velocities of purely transverse and longitudinal elastic waves, elastic moduli (Young’s, shear, adiabatic bulk moduli) and Poisson’s ratios based on the stiffness constants сij(T) of the crystal. Sound velocity values were employed for determining the temperature changes of Grüneisen parameter along the crystallographic directions [100], [110] and [111].


2013 ◽  
Vol 592-593 ◽  
pp. 688-691
Author(s):  
Pavel Tofel ◽  
Pavel Škarvada ◽  
Josef Sikula ◽  
Gabriel Cséfalvay

Each material contains defects and in-homogeneities in a structure volume. It has influence on the properties of material (conductivity, mass density, mechanical properties). Interaction of the ultrasonic waves with defects or in-homogeneities in the solid state is not clear. Electro-ultrasonic spectroscopy can help to clarify this phenomenon. The electro-ultrasonic spectroscopy describes defects and un-homogeneities inside the sample structure. This method is quite different from electro-acoustic effect. Ultrasonic signal is in range from 20 kHz to 150 kHz. Ultrasonic signal changes geometry of the sample in elastic range only. The sizes of cracks are changing also in the sample volume. Conductivity near the area of cracks is strongly changing due to ultrasonic vibrations. It has influence on resistance of the sample which is changing along with a frequency of ultrasonic vibrations. The amplitude of the resistance change depends on the material, number of cracks, size of cracks and Eigen frequencies of the sample excited by ultrasonic wave. We applied the electro-ultrasonic spectroscopy on two types of varistors. It can be useful for understanding the relation between microstructure and mechanical properties of these types of varistors.


2014 ◽  
Vol 682 ◽  
pp. 519-524 ◽  
Author(s):  
Elena P. Tesleva ◽  
Tatiana Belkova

The article studies the elastic properties of anisotropy and interatomic anharmonicity in a two-component Cu3Au alloy with positional order-disorder within the temperature interval of 4.2 К and 300 К. It provides calculations on velocities of purely transverse and longitudinal elastic waves, elastic moduli (Young’s, shear, adiabatic bulk moduli) and Poisson’s ratios based on the stiffness constants сij(T) of the crystal. Sound velocity values were employed for determining the temperature changes of Grüneisen parameter along the crystallographic directions [100], [110] and [111].


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