Decreasing the electric permittivity of cement by graphite particle incorporation

Carbon ◽  
2017 ◽  
Vol 122 ◽  
pp. 702-709 ◽  
Author(s):  
Alexander S. Haddad ◽  
D.D.L. Chung
2021 ◽  
Author(s):  
Michał Mierczak ◽  
Jerzy Karczewski

AbstractThe article describes the establishment of the location of agate geodes using the GPR method in the area of the Simota gully (Lesser Poland Voivodeship). Agates (a multicolored variety of gemstone of chalcedony group) have multifaceted values that informed their study. Traditional methods of geode location are less reliable, hence the attempt to use the GPR method. Measurements were taken at two study test sites with subsurface geology of weathered melaphyre and pyroclastic deposits using a GPR system (ProEx). A high-frequency antenna (1.6 GHz) was used along with the pre-established profiles of lengths of 6-m and 10-cm intervals. Furthermore, simple soil tests using the soil sampler tool were made prior to the GPR measurement. The GPR results show significant high attenuation of the electromagnetic energy interpreted to be due to clay components of the regolith. Advanced signal processing procedures (such as the attribute of the signal) were used on the data for better enhancement that aided interpretation. Other anomalies depicted on the radargrams were thought to be the presence of roots, pieces of melaphyres-targeted agates. Furtherance to ascertain the reflection coefficients as recorded on the GPR data, in situ samples (root pieces, melaphyres, agates) taken were tested in the laboratory for electric permittivity property. Based on the interpretation results, several agate geodes were dug out from the ground.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 518
Author(s):  
N. Suresh Kumar ◽  
K. Chandra Babu Naidu ◽  
Prasun Banerjee ◽  
T. Anil Babu ◽  
B. Venkata Shiva Reddy

Metamaterials are the major type of artificially engineered materials which exhibit naturally unobtainable properties according to how their microarchitectures are engineered. Owing to their unique and controllable effective properties, including electric permittivity and magnetic permeability, the metamaterials play a vital role in the development of meta-devices. Therefore, the recent research has mainly focused on shifting towards achieving tunable, switchable, nonlinear, and sensing functionalities. In this review, we summarize the recent progress in terahertz, microwave electromagnetic, and photonic metamaterials, and their applications. The review also encompasses the role of metamaterials in the advancement of microwave sensors, photonic devices, antennas, energy harvesting, and superconducting quantum interference devices (SQUIDs).


2014 ◽  
Vol 186 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Naphtali M. Mokgalapa ◽  
Tushar K. Ghosh ◽  
Sudarshan K. Loyalka

2008 ◽  
Vol 23 (29) ◽  
pp. 4709-4719 ◽  
Author(s):  
SAMINA S. MASOOD ◽  
MAHNAZ HASEEB

We calculate the second-order corrections to vacuum polarization tensor of photons at low temperatures, i.e. T ≪ 1010 K (T ≪ me). The thermal contributions to the QED coupling constant are evaluated at temperatures below the electron mass that is T < me. Renormalization of QED at these temperatures has explicitly been checked. The electromagnetic properties of such a thermal medium are modified. Parameters like electric permittivity and magnetic permeability of such a medium are no more constant and become functions of temperature.


Joule ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 393-414
Author(s):  
Tao Gao ◽  
Yu Han ◽  
Dimitrios Fraggedakis ◽  
Supratim Das ◽  
Tingtao Zhou ◽  
...  

2010 ◽  
Vol 150-151 ◽  
pp. 1546-1550 ◽  
Author(s):  
Xiang Zhu He ◽  
Xiao Wei Zhang ◽  
Xin Li Zhou ◽  
Zhi Hong Fu

This paper presented the composite coatings of nickel with graphite particle on the aluminum substrate using a nickel sulfamate bath. Effects of graphite particle concentration on the surface morphologies of the composite coatings were investigated. The inclusion of graphite particle into metal deposits was dependent on many process parameters, including particle concentration, current density, pH and temperature. Results of SEM and XRD demonstrated that graphite particle had successfully deposited on that nickel matrix; besides, the surface morphology of coatings obtained from sulfamate bath containing 2g/L graphite particle dispersed more uniformly than the ones with higher concentration.


Carbon ◽  
2006 ◽  
Vol 44 (12) ◽  
pp. 2590-2592 ◽  
Author(s):  
F. Vieira ◽  
I. Cisneros ◽  
N.G. Rosa ◽  
G.M. Trindade ◽  
N.D.S. Mohallem

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