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Thermographic Inspection in the Electric Industry

Abstract

The traditional inspection of fittings used in the electrical industry is a cumbersome, dangerous process in terms of safety and operation. However, with the spread of thermography, these tests can be performed simpler, faster, and more safely through electrical connections. This article presents the possibilities, measurement difficulties and the advantages of thermography analysis [1-2].

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Synthesis of mono layer graphene oxide from sonicated graphite flakes and their Hall effect measurements

Abstract

Graphene, a single atom thick sheet is considered a key candidate for the future nanotechnology, due to its unique extraordinary properties. Researchers are trying to synthesize bulk graphene via chemical route from graphene oxide precursor. In the present work, we investigated a safe and efficient way of monolayer graphene oxide synthesis. To get a high degree of oxidation, we sonicated the graphite flakes before oxidation. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results confirmed graphene oxide formation and high degree of oxidation. Raman spectroscopy and atomic force microscopy (AFM) results revealed a monolayer of graphene oxide (GO) flakes. The sheet like morphology of the GO flakes was further confirmed by scanning electron microscopy (SEM). The Hall effect measurements were performed on the GO film on a silica substrate to investigate its electrical properties. The results obtained, revealed that the GO film is perfectly insulating, having electrical resistivity up to 8.4 × 108 (Ω·cm) at room temperature.

Open access
Method for Emissivity Estimation of Metals

=4468&-path%5B%5D=1466 [3] Liedquist L.: A radiometric method for measurement of emissivity of metallic surfaces . Non Nuclear Energies Workshop on Optical Property Measurement Techniques, Ispra, 1987. 277–280. [4] Wen C. D., Mudawar I.: Experimental investigation of emissivity of aluminum alloys and temperature determination using multispectral radiation thermometry (MRT) algorithms . Journal of Materials Engineering and Performance, 11/5. (2002) 551–562. https://doi.org/10.1361/105994902770343818 [5] Filep E., Kutasi N., Kenéz L.: A Sapientia

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Mechanical and Microstructural Features of Ceramic Hollow Spheres

Abstract

In this study two different types of hollow sphere were examined by mechanical, geometrical and microstructural measurements, and the fracture force, geometrical properties and chemical composition were determined. The diameter of the „01 globocer” type specimens was 2.37 mm on average, while the value for the „03 globocer” type specimens was 6.88 mm, both were smaller than the nominal diameter. The average deviation from the circularity of the 01 globocer specimens was 8 %, the value for the 03 globocer specimens was 6 %, while the average wall porosity was 53±3 % and 56±3 % respectively. The surface of the hollow spheres was uneven, which has an impact on the contact surfaces during pressure tests, which affects the fracture force values. The average value of the fracture force of 01 globocer spheres was 42 N, and of 03 globocer hollow spheres was 288 N. The diameter had a bigger impact on the fracture force values of the type 01 specimens than in the case of 03.

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Effects of Additive Manufacturing on the Mechanical and Corrosion Properties of Austenic Stainless Steel

Anyag adatlap, 316L. (2019. 02.2 0.) www.eos.info/material-m [10] MSZ EN ISO 6892-1:2016 Fémek. Szakítóvizsgálat. 1. rész: Vizsgálat szobahőmérsékleten (ISO 6892-1:2016) [11] ASTM G102 - 89(2015): Standard Practice for Calculation of Corrosion Rates and Related Information from Electrochemical Measurements . [12] Absora L., Ashour A. F., Mitchell S. C., Youseffi M.: Corrosion of mild steel and 316L austenitic stainless steel with different surface roughness in sodium chloride saline solutions. WIT Transactions on Engineering Sciences, Vol 65

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The impact of medium frequency pulsed magnetron discharge power on the single probe Langmuir measurements and resulted plasma parameters

probes collecting charged particles from discharge plasma [ 15 - 18 ]. The simplicity of a single Langmuir probe measurement equipment, consisting of regulated voltage source, ammeter and conductive tip immersed in plasma, makes this technique very attractive. In principle, the current-voltage (I-V) characteristic of a single Langmuir probe can provide (after some data processing) electron density ne, electron temperature T e and plasma potential V p [ 19 , 20 ]. Unfortunately, the measured I-V data are often affected by the experimental conditions and

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Analysis of MIS equivalent electrical circuit of Au/Pd/Ti-SiO2-GaAs structure based on DLTS measurements

Abstract

In this paper MIS equivalent electrical circuit of Au/Pd/Ti-SiO2-GaAs has been analyzed by a comparison of the results obtained from admittance and DLTS spectroscopy. Two groups of peaks with different magnitude and different gate voltage dependence have been observed in DLTS and admittance spectra. Based on the analysis of the peaks behavior, it has been concluded that they are associated with the response of bulk traps and interface states, respectively. In order to characterize bulk traps and interface states responsible for the occurrence of two groups of peaks in normalized conductance spectra we have used the equivalent circuit with two CPE-R branches. The time constant values estimated for both peaks from admittance analysis have been compared with the time constant determined from DLTS analysis. Some discrepancies have been noted between the time constants obtained for interface states whereas the time constants for bulk traps were compatible. It has been also demonstrated that when conductance peaks overlap, the admittance experimental data can be fitted by the equivalent electrical model with only one CPE-R branch. However, in this case incomplete information about the analyzed process has been obtained despite the fact that all model validity criteria can be fulfilled and the model seems to be correct.

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Scanning capacitance microscopy characterization of AIIIBV epitaxial layers

reliable and well documented measurement methodology. In this paper the crucial aspects of obtaining proper SCM measurement conditions for GaAs, InGaAs and AlGaN/GaN/Si device structure characterization were discussed and the results presented. 2 Experimental The measurements were performed using Veeco Multimode V atomic force microscope equipped with scanning capacitance microscopy mode setup. The detailed description of SCM measurement principles could be found in [6] . Here, it is worth mentioning that the measurement output – SCM signal – is defined as dC

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Effect Y substitution on the microstructure, transport and magnetic proprieties of Bi2Sr2Ca1Cu2O8+δ superconducting ceramics

force balances the Lorentz force. Moving of vortices causes thermal dissipation which may destroy superconductivity. Near Tc, the resistive transition corresponds to the “flux flow” dissipative regime [ 6 , 7 ] where the Lorentz force dominates [ 1 ]. Thermal dissipation is possible also when the pinning force dominates and is caused by “flux creep” [ 8 ] which is more evident in magnetic measurements [ 4 , 5 ]. On the other hand, doping by cation has been intensively studied in order to understand the mechanism of high Tc superconductivity and to improve the

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Experimental and theoretical approaches on thermal and structural properties of Zn doped BSCCO glass ceramics

to determine the lattice parameters of the samples, with CuKα radiation in the range of 3° ≤2θ≤70° at a scan speed of 2°/min. Phase structure and lattice parameters were obtained by using Bruker-EVA 10.0.1.0 version analyzing program with ICDD PDF2-2002 library. The mean values of lattice parameters of the Bi 1.8 Sr 2 Ca 2 Cu 3.2-x Zn x O 10+δ samples were determined from the high angle (0 0 1) peaks of the XRD measurements. Leo EVO-40 VPX scanning electron microscope was used to determine the surface morphology of the samples. Hereafter, the produced samples were

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