scholarly journals The Phenomenon of Electroohmic Transformation

2020 ◽  
Vol 21 (4) ◽  
pp. 743-748
Author(s):  
M.Y. Derevianchuk ◽  
A.A. Аshcheulov ◽  
D.A. Lavreniuk
Keyword(s):  
Electrical Conductivity ◽  
Electric Current ◽  
Measurement Technology ◽  
Transformation Coefficient ◽  
Plate Material ◽  
Electrically Conductive ◽  
Conductive Medium ◽  
Side Face ◽  
Geometrical Factors ◽  
Crystallographic Axes

Peculiarities of electric current distribution in an anisotropic electrically conductive medium are considered and dependences of its longitudinal and transverse components on geometrical factors are established. In the case of a rectangular plate of length a, height b, and width c, the selected crystallographic axes are located in the plane of the side face (a × b), and one of these axes is oriented at an angle α to the edge α. Application to the upper and lower end faces of the plate of some potential difference leads to the appearance of longitudinal and transverse components of the flowing electric current.  This leads to the possibility of transforming the electric current magnitude. The methods of optimizing the transformation coefficient magnitude which is determined by both the magnitude of the anisotropy of the electrical conductivity of the plate material and the coefficient of its shape k = a/b. The design variants of anisotropic electrically conductive transformers are proposed. The use of this transformation effect makes it possible to expand the practical use of electroohmic phenomena. This principle of transformation will expand the areas of its use in metrology and measurement technology.

scholarly journals Electric current transformation by anisotropic electrically conductive medium

2020 ◽  
pp. 28-32
Author(s):  
А. А. Аshcheulov ◽  
M. Ya. Derevianchuk ◽  
D. А. Lavreniuk ◽  
I. S. Romaniuk
Keyword(s):  
Electric Current ◽  
Plate Thickness ◽  
Transformation Coefficient ◽  
Electrically Conductive ◽  
Electric Circuits ◽  
High Transformation ◽  
Side Face ◽  
Transformer Design ◽  
Geometrical Factors ◽  
New Generation

The authors consider the aspects of electric current distribution in electrically conductive anisotropic medium and establish how geometrical factors affect its longitudinal and transverse components. In the case of an a×b×с rectangular plate, its selected crystallographic axes are located on the plane of the side face a×b, whereas one of these axes is oriented at an angle α to the edge a. Applying a certain potential difference to the upper and lower end faces of the plate causes the appearance of longitudinal and transverse components of the internal electric current. The paper demonstrates the possibility of transforming the magnitude of the electric current and a way to optimize this magnitude. The transformation coefficient of such a device is determined by the anisotropy of the electrical conductivity of the plate and the coefficient of its shape k = a/b. The authors consider a few versions of anisotropic dielectric transformer design and offer their equivalent electric circuits. Another suggested transformer design is spiral in shape, compact and is characterized by high transformation coefficient value n. For example, at external radius r1 = 12,5 mm, internal radius r2 = 2 mm, height b = 2 mm and plate thickness c = 2,0 mm, its transformation coefficient n = 103. The information is given on existing monocrystalline and artificial anisotropic materials that can be used for the proposed device. High-temperature superconducting materials characterized by a high value of residual resistance anisotropy hold special promise in this case. Using the described transformation effect will significantly expand the possibilities of practical application of the considered electroohmic phenomenon. This will lead to the emergence of a new generation of devices for microwave technology, electronics and power engineering.

Microscopic Electrical Conductivity of Nanodiamonds after Thermal and Plasma Treatments

MRS Advances ◽  
2016 ◽  
Vol 1 (16) ◽  
pp. 1105-1111 ◽  
Author(s):  
Jan Čermák ◽  
Halyna Kozak ◽  
Štěpán Stehlík ◽  
Vladimír Švrček ◽  
Vincent Pichot ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Electric Current ◽  
Amorphous Carbon ◽  
Rf Plasma ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Atomic Force ◽  
Plasma Treatments ◽  
Hydrogenated Amorphous

ABSTRACTAtomic force microscopy (AFM) is used to measure local electrical conductivity of HPHT nanodiamonds (NDs) dispersed on Au substrate in the as-received state and after thermal or plasma treatments. Oxygen-treated NDs are highly electrically resistive, whereas on hydrogen-treated NDs electric current around -200 pA at -2 V is detected. The as-received NDs as well as NDs after an underwater radio-frequency (RF) plasma or laser irradiation (LI) treatments contain both electrically conductive (two types: highly and weakly conductive) and highly resistive particles. The higher conductivity is attributed to H-terminated (RF) or graphitized (LI) NDs. The lower conductivity is attributed to NDs with hydrogenated amorphous carbon shell.

Polypyrrole/PU hybrid hydrogels: electrically conductive and fast self-healing for the potential application in body-monitor sensor

2021 ◽  
Author(s):  
Zhanyu Jia ◽  
Guangyao Li ◽  
Juan Wang ◽  
shouhua Su ◽  
Jie Wen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Potential Application ◽  
Self Healing ◽  
Electrically Conductive ◽  
Sensor Application ◽  
Hybrid Hydrogels ◽  
Health Monitor

Conductivity, self-healing and moderate mechanical properties are necessary for multifunctional hydrogels which have great potential in health-monitor sensor application. However, the combination of electrical conductivity, self-healing and good mechanical properties...

scholarly journals Electrically Conductive Networks from Hybrids of Carbon Nanotubes and Graphene Created by Laser Radiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1875
Author(s):  
Alexander Yu. Gerasimenko ◽  
Artem V. Kuksin ◽  
Yury P. Shaman ◽  
Evgeny P. Kitsyuk ◽  
Yulia O. Fedorova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Laser Irradiation ◽  
Flexible Electronics ◽  
Threshold Energy ◽  
Wavelength Region ◽  
Hybrid Nanostructures ◽  
Graphene Sheets ◽  
Electrically Conductive ◽  
Walled Carbon Nanotubes

A technology for the formation of electrically conductive nanostructures from single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT), and their hybrids with reduced graphene oxide (rGO) on Si substrate has been developed. Under the action of single pulses of laser irradiation, nanowelding of SWCNT and MWCNT nanotubes with graphene sheets was obtained. Dependences of electromagnetic wave absorption by films of short and long nanotubes with subnanometer and nanometer diameters on wavelength are calculated. It was determined from dependences that absorption maxima of various types of nanotubes are in the wavelength region of about 266 nm. It was found that contact between nanotube and graphene was formed in time up to 400 fs. Formation of networks of SWCNT/MWCNT and their hybrids with rGO at threshold energy densities of 0.3/0.5 J/cm2 is shown. With an increase in energy density above the threshold value, formation of amorphous carbon nanoinclusions on the surface of nanotubes was demonstrated. For all films, except the MWCNT film, an increase in defectiveness after laser irradiation was obtained, which is associated with appearance of C–C bonds with neighboring nanotubes or graphene sheets. CNTs played the role of bridges connecting graphene sheets. Laser-synthesized hybrid nanostructures demonstrated the highest hardness compared to pure nanotubes. Maximum hardness (52.7 GPa) was obtained for MWCNT/rGO topology. Regularity of an increase in electrical conductivity of nanostructures after laser irradiation has been established for films made of all nanomaterials. Hybrid structures of nanotubes and graphene sheets have the highest electrical conductivity compared to networks of pure nanotubes. Maximum electrical conductivity was obtained for MWCNT/rGO hybrid structure (~22.6 kS/m). Networks of nanotubes and CNT/rGO hybrids can be used to form strong electrically conductive interconnections in nanoelectronics, as well as to create components for flexible electronics and bioelectronics, including intelligent wearable devices (IWDs).

scholarly journals Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Caroline O’Keeffe ◽  
Laura Rhian Pickard ◽  
Juan Cao ◽  
Giuliano Allegri ◽  
Ivana K. Partridge ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Fibre ◽  
Electromagnetic Interference ◽  
Design Tool ◽  
Electrically Conductive ◽  
Current Collection ◽  
Wide Range ◽  
Predictive Design ◽  
The Right ◽  
Metal Wires

AbstractConventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.

Investigate of Electrical Conductivity of Shape-Memory Polymer Filled with Carbon Black

2008 ◽  
Vol 47-50 ◽  
pp. 714-717 ◽  
Author(s):  
Xin Lan ◽  
Jin Song Leng ◽  
Yan Ju Liu ◽  
Shan Yi Du
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Shape Memory ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Recovery Process ◽  
Thermomechanical Properties ◽  
Electrically Conductive ◽  
New System

A new system of thermoset styrene-based shape-memory polymer (SMP) filled with carbon black (CB) is investigated. To realize the electroactive stimuli of SMP, the electrical conductivity of SMP filled with various amounts of CB is characterized. The percolation threshold of electrically conductive SMP filled with CB is about 3% (volume fraction of CB), which is much lower than many other electrically conductive polymers. When applying a voltage of 30V, the shape recovery process of SMP/CB(10 vol%) can be realized in about 100s. In addition, the thermomechanical properties are also characterized by differential scanning calorimetery (DSC).

Heterogeneous Preparation of Cellulose/Ag/Polyaniline Conductive Composite and its Electrical Property

2012 ◽  
Vol 182-183 ◽  
pp. 254-258
Author(s):  
Zhong Li Zhao ◽  
Zun Li Mo ◽  
Zhong Yu Chen
Keyword(s):  
Electrical Conductivity ◽  
Electrical Property ◽  
Conductive Network ◽  
High Electrical Conductivity ◽  
Electrically Conductive ◽  
Conductive Composite

Cellulose/Ag/polyaniline conductive composite with rather excellent electrical conductivity was heterogeneously synthesized in this paper. The UV-Vis analysis indicated that homogeneous nanoAg particles deposited on the surface of cellulose in the form of globe particles. They offered some electrons to polyaniline chains. This behavior resulted to the facts that more polyaniline embedded on cellulose and an integrated electrically conductive network formed. Consequently, the high electrical conductivity of the composite was observed. The value was 3.48 S/cm, which was higher two magnitudes than the electrical conductivity of cellulose/polyaniline composite (2.15×10-2S/cm), and even was higher than the electrical conductivity of pure polyaniline (0.142 S/cm). This paper provided a facile method for the preparation of cellulose/Ag/ polyaniline composite with favorable electrical conductivity.

Preparation and Characterization of Porous Si-Coated SiC Fiber Media

2004 ◽  
Vol 449-452 ◽  
pp. 233-236 ◽  
Author(s):  
Jun Suh Yu ◽  
B.S. Lee ◽  
Sung Churl Choi ◽  
Ji Hun Oh ◽  
Jae Chun Lee
Keyword(s):  
Electrical Conductivity ◽  
Silicon Content ◽  
Porous Si ◽  
Electrically Conductive ◽  
Electrode Distance ◽  
Sic Fiber ◽  
Effective Electrical Conductivity ◽  
The One ◽  
Fiber Preforms

Electrically conductive porous Si/SiC fiber media were prepared by infiltration of liquid silicon into porous carbon fiber preforms. The series rule of mixture for the effective electrical conductivity was applied to the disc shaped samples to estimate their silicon content, effective electrical conductivity and porosity. The electrical conductivity was estimated by assuming the disc sample as a plate of equivalent geometry, i.e., same thickness, electrode distance and volume. As the volumetric content of silicon in a sample increases from 0.026% to 0.97%, the estimated electrical conductivity increases from 0.17 S/cm to 2.09 S/cm. The porosity of the samples measured by Archimedes principle was in the range of 75~83% and 1~4% less than the one estimated by the series rule of mixture for the effective electrical conductivity.

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