scholarly journals Fracture Related Electromagnetic Emission Measurement and Excess Noise Analysis of Reinforced Composites

2014 ◽  
Vol 3 ◽  
pp. 116-121 ◽  
Author(s):  
Robert Macku ◽  
Pavel Koktavy ◽  
Tomas Trcka ◽  
Jiri Sicner
Keyword(s):  
Noise Analysis ◽  
Electromagnetic Emission ◽  
Excess Noise ◽  
Emission Measurement ◽  
Reinforced Composites

Experimental Studies of Excess Noise Sources in Concrete Based Materials as a Limiting Factor for Electromagnetic Emission Measurement

2013 ◽  
Vol 592-593 ◽  
pp. 529-532
Author(s):  
Robert Macků ◽  
Pavel Koktavý ◽  
Tomas Trčka ◽  
Vladimir Holcman
Keyword(s):  
Flicker Noise ◽  
Noise Analysis ◽  
Experimental Studies ◽  
Electromagnetic Emission ◽  
Dielectric Materials ◽  
Excess Noise ◽  
Limiting Factor ◽  
Emission Measurement ◽  
Noise Sources ◽  
Geometrical Properties

This paper deals with excess noise sources in dielectric materials. We focus especially on the concrete samples that are frequently tested to ensure information about the reliability and level of degradation. Nevertheless, the testing methods are limited mainly by the proper contact creation, signal detection and noise defined sensitivity. Our efforts are directed to the noise properties assessment. It turns out that the Johnson-Nyquist noise and the 1/f (flicker) noise are generated in the different regions with the different response to the internal or external electric field. In addition the noise analysis is affected by the internal polarization phenomena and the material residual humidity. This issue in connection with the sample geometrical properties and the dielectric noise measurement methodology take part in this paper.

Avalanche photodiode punch-through gain determination through excess noise analysis

2009 ◽  
Vol 106 (6) ◽  
pp. 064507 ◽  
Author(s):  
Han-Din Liu ◽  
Huapu Pan ◽  
Chong Hu ◽  
Dion McIntosh ◽  
Zhiwen Lu ◽  
...  
Keyword(s):  
Noise Analysis ◽  
Avalanche Photodiode ◽  
Excess Noise

scholarly journals On the Issues of Spatial Modeling of Non-Standard Profiles by the Example of Electromagnetic Emission Measurement Data

2022 ◽  
Vol 14 (1) ◽  
pp. 574
Author(s):  
Emiliia Iakovleva ◽  
Margarita Belova ◽  
Amilcar Soares ◽  
Anton Rassõlkin
Keyword(s):  
Spatial Modeling ◽  
Measurement Data ◽  
Electromagnetic Emission ◽  
Spatial Modelling ◽  
Emission Measurement ◽  
Spatial Anisotropy ◽  
Tectonic Faults ◽  
Active Tectonic ◽  
Pulsed Electromagnetic ◽  
The Cost

This paper examines the possibility of the spatial modelling of the Earth’s natural pulsed-electromagnetic-field measured values, which form a closed profile without the data inside. This geophysical method allows us to map active tectonic movement which breaches the integrity of pipes. During the experiment, 4.5 km of profiles were measured in the Admiralteysky district of St. Petersburg, Russia. Regular electromotive force (EMF) values and anomalous EMF values were obtained, ranging from 0 to 900 µV and above 900 µV, respectively. The anomalous values are associated with tectonic faults in the bedrock. The data obtained are characterized by complex spatial anisotropy associated with the development of two groups of tectonic faults of different orientations. The authors have considered the problems of the spatial modeling of the data obtained. The main problems, the solutions to which should allow the obtaining of adequate models, have been identified. Based on the analysis of the measurement results, geological features of the studied areas, as well as variography, the following possible solutions were proposed: changing the measurement technique; dividing the data array according to the main directions of anisotropy; the need to introduce additional correction coefficients. The problem revealed in this article requires further research on the basis of the obtained results, which will reduce the cost and timing of such studies, and, as a result, give an opportunity to take into account active tectonic disturbances during the construction and scheduled maintenance of underground utilities, which is especially important within the framework of the concept of sustainable development.

Phase identification in SiC whisker reinforced Al2O3-R2O3-based composites

1992 ◽  
Vol 50 (1) ◽  
pp. 152-153
Author(s):  
C.M. Sung ◽  
K.J. Ostreicher ◽  
M.L. Huckabee ◽  
S.T. Buljan
Keyword(s):  
Analytical Electron Microscopy ◽  
Phase Identification ◽  
Reinforced Composites ◽  
Ion Milling ◽  
X Ray ◽  
Binary Oxides ◽  
Analytical Electron ◽  
The Matrix ◽  
Second Phases ◽  
Convergent Beam

A series of binary oxides and SiC whisker reinforced composites both having a matrix composed of an α-(Al, R)2O3 solid solution (R: rare earth) have been studied by analytical electron microscopy (AEM). The mechanical properties of the composites as well as crystal structure, composition, and defects of both second phases and the matrix were investigated. The formation of various second phases, e.g. garnet, β-Alumina, or perovskite structures in the binary Al2O3-R2O3 and the ternary Al2O3-R2O3-SiC(w) systems are discussed.Sections of the materials having thicknesses of 100 μm - 300 μm were first diamond core drilled. The discs were then polished and dimpled. The final step was ion milling with Ar+ until breakthrough occurred. Samples prepared in this manner were then analyzed using the Philips EM400T AEM. The low-Z energy dispersive X-ray spectroscopy (EDXS) data were obtained and correlated with convergent beam electron diffraction (CBED) patterns to identify phase compositions and structures. The following EDXS parameters were maintained in the analyzed areas: accelerating voltage of 120 keV, sample tilt of 12° and 20% dead time.

Sign in / Sign up

Export Citation Format

Share Document