scholarly journals Error Assessment and Mitigation Methods in Transient Radar Method

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 263
Author(s):  
Ali Pourkazemi ◽  
Salar Tayebi ◽  
Johan H. Stiens

Transient Radar Method (TRM) was recently proposed as a novel contact-free method for the characterization of multilayer dielectric structures including the geometric details. In this paper, we discuss and quantify the intrinsic and systematic errors of TRM. Also, solutions for mitigating these problems are elaborated extensively. The proposed solution for error correction will be applied to quantify experimentally the thickness of several single-layer dielectric structures with thicknesses varying from larger to smaller than the wavelength. We will show how the error correction method allows sub-wavelength thickness measurements around λ / 5 .

Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.


2021 ◽  
pp. 002199832199087
Author(s):  
Hussain Najmi ◽  
Jocelyn Luche ◽  
Thomas Rogaume

Multilayer composite materials are frequently used in aircraft interiors. Even though they have high properties (such as physical, chemical and mechanical properties), their application is limited due to lack of knowledge of their decomposition process and on the interaction between different layers in fire. In the present work, two types of composites with 3 and 4 layers are studied. The fire characterization of multilayer composite is studied in 3 different phases using ISO-5660 cone calorimeter at two heat fluxes (35 and 50 kW.m−2). Phase-I mainly concentrates on the decomposition of single layer materials (paint, laminate and honeycomb) while in phase-II and phase-III, different assemblies are formed using a single layer material and studied in the same experimental configuration. In all the three phases, back surface temperatures of the materials or assemblies are measured and analyzed with different gas productions which allow to understand the dynamics of the decomposition process. The finding from the cone calorimeter study suggests that the ignition primarily depends on the top layer behavior of the composite. The permeability analysis on the top layer of the composite confirms that decomposed layer of paint offers more resistance to the volatile gases escaping from the composite. At the end of the study, thermal conductivity is determined and the ignition temperature of both the composite is determined.


2021 ◽  
Vol 263 ◽  
pp. 105817
Author(s):  
Jie Yang ◽  
Qingquan Liu ◽  
Gaoying Chen ◽  
Xuan Deng ◽  
Li Zhang

2013 ◽  
Vol 562-565 ◽  
pp. 809-812 ◽  
Author(s):  
Xiao Qing Liu ◽  
Jun Lin Xie ◽  
Feng He ◽  
Hu Yang

The characterization technique of glass-ceramics by TEM was discussed by comparing the effects of single layer carbon film technique and double layers carbon film technique on the microstructure of Li-Al-Si glass-ceramics. The results show that double layers carbon film technique can improve glass-ceramics sample’s conductivity, reduce the induction of elctron beam on glass-ceramics, and avoid the temperature increasing of glass-ceramics particles caused by the charges aggregation on the particles’ surface when TEM electron beam hit down, prevent glass-ceramics from crystallization and the transformation of microstructurec. So, compared with single layer carbon film technique, double layers carbon film technique is more suitable for the research of microsture of glass-ceramics by TEM.


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