Diffusion of Charged Species in Metal Oxides and Polymeric Solids Using AC Impedance Technique

2011 ◽  
Vol 312-315 ◽  
pp. 1216-1221
Author(s):  
Norlida Kamarulzaman ◽  
Roshidah Rusdi ◽  
Nor Diyana Abdul Aziz ◽  
Lili Widarti Zainudin ◽  
Zurina Osman
Keyword(s):  
Electrical Properties ◽  
Metal Oxides ◽  
Analytical Techniques ◽  
Ac Impedance ◽  
Impedance Method ◽  
Electrical Measurements ◽  
Charged Species ◽  
Impedance Technique ◽  
Properties Of Materials ◽  
Kinetics Of

The diffusion of charged species in solids is a very important part of the study of the electrical properties of materials. Electrical measurements using alternating current (ac) impedance is a powerful technique to study diffusing species in metal oxides as well as polymers. Three case studies are being presented here whereby the electrical properties of LiTaO3, Poly[2-methoxy-5-(2’-ethylhexyloxy)-(p-phenylenevinylene)] (MEH-PPV) and its composite are being studied using the same ac impedance technique. LiTaO3 is a metal oxide while MEH-PPV is a polymer. They are very different and therefore present very good examples for the versatility and power of ac impedance method. Electrical parameters such as conductivity and conduction behaviours of the conducting species can be extracted from the studies. The kinetics of the diffusing species can be elucidated by using proper analytical techniques.

scholarly journals Electrical Properties of Sunflower Achenes

2014 ◽  
Vol 17 (4) ◽  
pp. 109-113 ◽  
Author(s):  
Ján Novák ◽  
Ivan Vitázek
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Moisture Content ◽  
Electric Field ◽  
Loss Tangent ◽  
Dielectric Heating ◽  
Electrical Measurements ◽  
Engineering Research ◽  
Dielectric Constant And Loss ◽  
Properties Of Materials

Abstract This work contains the results of measuring the electrical properties of sunflower achenes. The interest in electrical properties of biological materials resulted in engineering research in this field. The results of measurements are used for determining the moisture content, the surface level of liquid and grainy materials, for controlling the presence of pests in grain storage, for the quantitative determination of mechanical damage, in the application of dielectric heating, and in many other areas. Electrical measurements of these materials are of fundamental importance in relation to the analysis of quantity of absorbed water and dielectric heating characteristics. It is a well-known fact that electrical properties of materials, namely dielectric constant and conductivity, are affected by the moisture content of material. This fact is important for the design of many commercial moisturetesting instruments for agricultural products. The knowledge of dielectric properties of materials is necessary for the application of dielectric heating. The aim of this work was to measure conductivity, dielectric constant and loss tangent on samples of sunflower achenes, the electrical properties of which had not been sufficiently measured. Measurements were performed under variable moisture content and the frequency of electric field ranging from 1 MHz to 16 MHz, using a Q meter with coaxial probe. It was concluded that conductivity, dielectric constant and loss tangent increased with increasing moisture content, and dielectric constant and loss tangent decreased as the frequency of electric field increased.

scholarly journals Possible Applications of Focussed Impedance Method (FIM) in Biomedical and Other Areas of Study

2013 ◽  
Vol 4 (1) ◽  
pp. 67-74 ◽  
Author(s):  
K Siddique-e Rabbani ◽  
M Abdul Kadir
Keyword(s):  
Electrical Impedance ◽  
Medical Physics ◽  
Analytical Techniques ◽  
Target Object ◽  
Impedance Method ◽  
Target Point ◽  
Physical Change ◽  
Phantom Measurements ◽  
Impedance Technique ◽  
Physical Mixtures

Focused Impedance Method (FIM) based on 8, 6 and 4 electrode configurations have been innovated and developed for measuring the electrical impedance of a localised zone in a volume conductor, all based on tetrapolar impedance technique. The zone localization in FIM has been visualized through equipotential distributions, current density at the target point and perturbation produced at the potential measuring electrodes. The predicted behaviour has been verified though phantom measurements and analytical techniques by different groups. FIM is particularly sensitive and useful if the electrical impedance of a target object in the sensitive zone changes between two sets of measurements. This can be either due to a physical change in the target object, or, if its impedance has frequency dependence, through a change in the measurement frequency. In medical applications FIM is being developed for studying stomach and bladder emptying, localized lung function, detection of cervical and oral cancer, etc. FIM may have applications in industry to study physical mixtures of liquids and gases in pipelines and tanks, in geology to detect groundwater and other minerals, in oceanography, and in many other applications. Thus FIM appears to have a huge potential for application in different areas. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14689 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 67-74

Material and Mechanical Aspects of CMAS Damage Progression on Thermal Barrier Coatings and its Non-Destructive Detection

2016 ◽  
Vol 879 ◽  
pp. 720-725 ◽  
Author(s):  
Yukie Hayashi ◽  
Siddharth Lokachari ◽  
Satoshi Yamagishi ◽  
Masakazu Okazaki
Keyword(s):  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Ac Impedance ◽  
Elastic Stiffness ◽  
Impedance Method ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Damage Progression ◽  
Impedance Technique ◽  
Vibrating Reed

Thermal barrier coatings (TBCs) on turbine blades in gas turbine engines are in some cases damaged at high temperatures exceeding 1200°C by calcium-magnesium-alumino-silicates (CMAS) resulting from the ingestion of siliceous minerals. In this study, material interaction between molten CMAS and yttria-stabilized zirconia (YSZ) was investigated using a single crystal YSZ material and a synthetic CMAS product. Reaction between the molten CMAS and YSZ was significant at high temperature resulting in the infiltration of CMAS into the dense bulk-YSZ. The extent of interaction between CMAS and YSZ was found to be dependent on the crystallographic plane of the YSZ. The change in elastic stiffness due to the CMAS infiltration was also found by using a vibrating reed technique. The CMAS infiltrated layer had elastic stiffness higher by approximately five times of the non-infiltrated one. An attempt to detect the CMAS damage progression was also made through an AC impedance method. The proposed AC impedance technique is expected to be a useful technique to evaluate the CMAS infiltration as well as the associated delamination of TBC top coat.

scholarly journals Electrical Prope Rties of Popcorn Grains

2013 ◽  
Vol 16 (2) ◽  
pp. 43-46
Author(s):  
Ján Novák
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Moisture Content ◽  
Electric Field ◽  
Loss Tangent ◽  
Dielectric Heating ◽  
Electrical Measurements ◽  
Engineering Research ◽  
Dielectric Constant And Loss ◽  
Properties Of Materials

Abstract This work contains the results of measuring the electrical properties of popcorn grains. Interest in electrical properties of biological materials resulted in engineering research in this field. The results of measurements are used for determining the moisture content, the surface level of liquid and grainy materials, for controlling the presence of pests in grain storage, for a quantitative determination of mechanical damage, in applications of dielectric heating, and in many other cases. Electrical measurements on these materials are of fundamental importance in relation to the analysis of quantity of absorbed water and dielectric heating characteristics. It is a well-known fact that electrical properties of materials, namely dielectric constant and conductivity, are affected by the moisture content of material. This fact is important for the design of many commercial moisture-testing instruments for agricultural products. The knowledge of dielectric properties of materials is necessary for the application of dielectric heating. The aim of this work was to perform the measurements of conductivity, dielectric constant and loss tangent on samples of popcorn grains, the electrical properties of which had not been sufficiently measured. Measurements were performed under variable moisture content and the frequency of electric field in the range from 1 MHz to 16 MHz, using a Q meter with a coaxial probe. It was concluded that conductivity, dielectric constant and loss tangent increased with increase of moisture content, and dielectric constant and loss factor decreased as the frequency of electric field increased.

scholarly journals Preparation and piezoresistivity of carbon nanotube-coated sand reinforced cement mortar

2020 ◽  
Vol 9 (1) ◽  
pp. 1445-1455
Author(s):  
Song Gao ◽  
Jianlin Luo ◽  
Jigang Zhang ◽  
Fei Teng ◽  
Chao Liu ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Cement Mortar ◽  
Aqueous Suspension ◽  
Ac Impedance ◽  
Stress Sensitivity ◽  
Multiwall Carbon Nanotube ◽  
Impedance Technique ◽  
Reinforced Cement ◽  
Coated Sand ◽  
Mechanical Strengths

Abstract Water and sand were used as the medium of multiwall carbon nanotube (MCNT) and prepared MCNT aqueous suspension and MCNT suspension-coated sand, respectively; afterwards, they were introduced into cement mortar (MNT/CM, MNTSM), respectively. Next, mechanical strengths and piezoresistive properties (DC resistivities (ρ v), AC impedances (Z r)) under cyclic loadings (σ c) of two types of MNT/CM and MNTSM nanocomposites were investigated to explore the intrinsic and self-sensing behaviors. Results reveal that MCNT can be evenly and well-coated on sand, which favors to achieve its intrinsic self-sensing property. Although the fraction changes in ρ v and Z r under the same σ c of MNTSM are both lower than those of MNT/CM, the stress sensitivity of MNTSM is only −1.16%/MPa (DC resistivity), −1.55%/MPa (AC impedance); its sensing linearity and stability (2.53, 2.45%; 2.73, 2.67%) are superior to those of MNT/CM (4.94, 2.57%; 3.78, 2.96%). Piezoresistivity using AC impedance technique is helpful to acquire balanced sensing sensitivity and stability while applied as intrinsic sensors in infrastructure.

scholarly journals Channel Impulse Response at 60 GHz and Impact of Electrical Parameters Properties on Ray Tracing Validations

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 393
Author(s):  
Huthaifa Obeidat ◽  
Atta Ullah ◽  
Ali AlAbdullah ◽  
Waqas Manan ◽  
Omar Obeidat ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Ray Tracing ◽  
Impulse Response ◽  
Line Of Sight ◽  
Indoor Propagation ◽  
60 Ghz ◽  
Environment Design ◽  
Electrical Parameters ◽  
Concrete Walls ◽  
Properties Of Materials

This paper outlines a study of the effect of changing the electrical properties of materials when applied in the Wireless InSite (WI) ray-tracing software. The study was performed at 60 GHz in an indoor propagation environment and supported by Line of Sight (LoS) and Non-LoS measurements data. The study also investigates other factors that may affect the WI sensitivity, including antenna dimensions, antenna pattern, and accuracy of the environment design. In the experiment, single and double reflections from concrete walls and wooden doors are analysed. Experimental results were compared to those obtained from simulation using the WI. It was found that materials selected from the literature should be similar to those of the environment under study in order to have accurate results. WI was found to have an acceptable performance provided certain conditions are met.

Influence of selected metal oxides on the oxidation kinetics of graphite

1985 ◽  
Vol 86 ◽  
pp. 7-15 ◽  
Author(s):  
S. Sampath ◽  
N.K. Kulkarni ◽  
D.M. Chackraburtty
Keyword(s):  
Metal Oxides ◽  
Oxidation Kinetics ◽  
Kinetics Of
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