In situ microwave characterization of nonplanar dielectric objects

2000 ◽  
Vol 48 (3) ◽  
pp. 388-394 ◽  
Author(s):  
V.V. Varadan ◽  
K.A. Jose ◽  
V.K. Varadan
Keyword(s):  
Microwave Characterization ◽  
Dielectric Objects

Synthesis and Microwave Characterization of Polypyrrole-PVC Blends

1992 ◽  
Vol 247 ◽  
Author(s):  
F. Jousse ◽  
P. Hourquebie ◽  
C. Deleuze ◽  
L. Olmedo
Keyword(s):  
In Situ Growth ◽  
Oxidizing Agent ◽  
Direct Link ◽  
Reaction Parameters ◽  
Solvent Nature ◽  
Microwave Characterization ◽  
Agent Control ◽  
Thermoplastic Blends

ABSTRACT.: Thermoplastic blends have been created by in situ growth of polypyrrole in an insulating PVC matrix. This type of synthesis gives a level of conductivity of the order of 10−5 to 1 S/cm for concentrations of less than 15% (in weight). A study of the synthetic conditions shows that the reaction parameters (solvent, nature of oxidizing agent) control the eventual properties of the blend (structure, conductivity level). The microwave characterization of these materials has allowed us to establish a direct link between the method of processing and the radioelectric properties.

In situ microwave characterization of microwire composites with external magnetic field

2012 ◽  
Vol 100 (19) ◽  
pp. 192903 ◽  
Author(s):  
F. X. Qin ◽  
C. Brosseau ◽  
H. X. Peng ◽  
H. Wang ◽  
J. Sun
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Microwave Characterization

In-situ microwave characterization of planar/nonplanar specimens

1999 ◽  
Author(s):  
Vasundara V. Varadan ◽  
K. A. Jose ◽  
Vijay K. Varadan
Keyword(s):  
Microwave Characterization

In situ microwave characterization of microwire composites under mechanical stress

2011 ◽  
Vol 99 (25) ◽  
pp. 252902 ◽  
Author(s):  
Faxiang Qin ◽  
C. Brosseau ◽  
H. X. Peng
Keyword(s):  
Mechanical Stress ◽  
Microwave Characterization

scholarly journals Preparation of Microwave Multi-Adsorbent Nanocomposites Based on Copper, Iron Carbonyl, Carbon Nanofiber, Graphite Nanoflake and Polypyrrole

2020 ◽  
Vol 1 (3) ◽  
pp. 42-55
Author(s):  
Seyed Hossien Hosseini ◽  
Ali Azimi ◽  
Sadat Hosseini Sama
Keyword(s):  
Carbon Nanofiber ◽  
In Situ Polymerization ◽  
Light Weight ◽  
Network Analyzer ◽  
Vibrating Sample Magnetometer ◽  
Carbonyl Carbon ◽  
Microwave Absorbing Properties ◽  
Microwave Characterization

The composites of Cu, Carbonyl iron (CI), carbon nanofiber (CNF), graphite nanoflake (GNF)/polypyrrole (PPy) and [(Cu-CI-CNF-GNF) 0.5-PAA]-PPy0.5 were synthesized via different methods by in-situ polymerization on the surface of nanoparticles (NPs) with core-shell structure. This paper describes a method for polyacrylic acid (PAA) coating of NPs in aqueous solution. Then PPy coating was performed by template polymerization on NPs-PAA. Morphology, magnetic and conductivity properties were observed via scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and four probe method, respectively. The microwave characterization of nanocomposite was evaluated through arch test based on a network analyzer. The PPy nanocomposites possessed the excellent microwave multi absorbers properties in 2-18 GHz. It was also found that nanocomposites with 50% w/w and light weight exhibit good microwave absorbing properties in 2-3 GHz and 5-14 GHz frequency, so can be used to cellphone, radio frequency and radar shielding.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

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