Dielectric Constant, Power Factor, and Conductivity of the System Rubber-Calcium Carbonate

1942 ◽  
Vol 15 (4) ◽  
pp. 879-894
Author(s):  
Arnold H. Scott ◽  
Archibald T. McPherson

Abstract The results obtained in this investigation indicate that either the formula developed by Wiener (Formula 7) or the exponent formula (Formula 9) may be used for the computation of the dielectric constants of mixtures of calcium carbonate and rubber. Formula 7 may be preferred, since it gives some indication of the shape of the particles and state of dispersion of the powder. There was little difference between values of the dielectric constant and loss tangent at 1 kilocycle per second and at 100 kilocycles per second. The change of the loss tangent with the content of calcium carbonate was not large, but a direct relationship between loss tangent and percentage of calcium carbonate was indicated. The 1-minute-conductivity values increased continuously with increasing content of calcium carbonate when Vistanex was used as the base, but passed through a minimum when natural rubber was used.

2008 ◽  
Vol 381-382 ◽  
pp. 537-540
Author(s):  
J.W. Chen ◽  
Bor Kai Wang ◽  
Jimmy C. Hsu ◽  
G.N. Rao

We report the results of the broadband dielectric constant and loss tangent of the new complex perovskites Ba3MnTa2O9 with the test frequency f in different ranges from 1 kHz to 15 GHz. For the test frequency f below 1 MHz, the dielectric constant and loss tangent of the specimens were measured using a LCR meter with four-terminal configuration. The measurements at frequencies between 50 MHz and 1 GHz were performed by the lumped impedance method, which uses an impedance analyzer to measure the complex impedance of the specimen. At frequencies above 1 GHz, two samples with diameter 9 mm and different thicknesses (2.73 mm and 5.42 mm) were measured by a home-made Hakki-Coleman resonator. The TE011 resonant peaks were found and identified with an Agilent PNA net-work analyzer. The dielectric constants were found to remain almost constant with the test frequency at room temperature. The calculated values of the real part dielectric constants are 17.74 and 17.53 at 9.86 GHz and 15.43 GHz, respectively. The unloaded Q factors deduced from curve fitting of the peaks are both around 200.


Author(s):  
A. Ege Engin ◽  
Abdemanaf Tambawala ◽  
Madhavan Swaminathan ◽  
Swapan Bhattacharya ◽  
Pranabes Pramanik ◽  
...  

2016 ◽  
Vol 78 (6-2) ◽  
Author(s):  
See Khee Yee ◽  
Samsul Haimi Dahlan ◽  
Mohd Zarar Mohd Jenu ◽  
Chee Kiong Sia

This paper presents the method to predict the shielding effectiveness of cement powder mixed with different amount of graphite powder. Cement mixed with different percentage of graphite is prepared. Their dielectric constant and loss tangent are measured based on the transmission/reflection technique using APC7 connector. The measured data is fed into Artificial Neural Network (ANN) for training. When the training process is completed the neural network is used to predict the dielectric constant and loss tangent of cement-graphite mixture that contains different amount of graphite. The comparison shows that the trained neural network is very successful to predict the dielectric constant and loss tangent of cement-graphite mixture. The proposed graphical user interface has made the process of shielding effectiveness prediction becomes more user friendly especially for those designers who are not familiar with the analytical calculation of shielding effectiveness and dielectric measurement.


2012 ◽  
Vol 512-515 ◽  
pp. 1180-1183
Author(s):  
Qian Qian Jia ◽  
Hui Ming Ji ◽  
Shan Liu ◽  
Xiao Lei Li ◽  
Zheng Guo Jin

The (Ba, Sr)TiO3 (hereafter BST) ceramics are promising candidate for applying in tunable devices. MgO coated BST-Mg2TiO4 (BSTM-MT) composite ceramics were prepared to obtain the low dielectric constant, low dielectric loss, good dielectric constant temperature stability, and high tunability of BST ceramics. The Ba0.55Sr0.40Ca0.05TiO3 nanoparticles were coated with MgO using the precipitation method and then mixed with Mg2TiO4 powders to fabricate BSTM-MT composite ceramics. The morphologies, phases, elements, and dielectric properties of the sintered ceramics were investigated. The core-shell structure of BST powder wrapped with MgO was clearly observed from the TEM image. After sintered at 1100 °C for 2 h, the composite ceramics expressed dense microstructures from SEM images and two main phases BST and Mg2TiO4 were detected in the XRD patterns. The dielectric constant and loss tangent were both reduced after the coating. The reduced dielectric constant and loss tangent of BSTM-MT were 190, 0.0011 (2MHz), respectively. The ceramics exhibited the diffuse phase transition near the Curie temperature and the Curie temperature shifted from 10 °C to 5 °C after the coating. Since the continuous Ti-O bonds were disconnected with the MgO coating, the tunability was reduced to 15.14 % under a DC bias field of 1.1 kV/mm. The optimistic dielectric properties made it useful for the application of tunable capacitors and phase shifters.


2019 ◽  
Vol 29 (7) ◽  
pp. 501-503 ◽  
Author(s):  
Kangmin Zhou ◽  
Sylvain Caroopen ◽  
Yan Delorme ◽  
Michele Batrung ◽  
Maurice Gheudin ◽  
...  

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