scholarly journals Investigation on the Electrical Conductivity of Transformer Oil-Based AlN Nanofluid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. Dong ◽  
L. P. Shen ◽  
H. Wang ◽  
H. B. Wang ◽  
J. Miao
Keyword(s):  
Electrical Conductivity ◽  
Aluminum Nitride ◽  
Transformer Oil ◽  
Volumetric Fraction ◽  
Ambient Temperatures ◽  
Conductivity Model

Aluminum-nitride-(AlN)-transformer oil-based nanofluid was prepared by dispersing AlN nanoparticles in transformer oil. The composition-dependent electrical conductivity of AlN-transformer oil nanofluid was investigated at different ambient temperatures. The results indicate the nonlinear dependences of the electrical conductivity on volumetric fraction and temperature. In comparison to the pure transformer oil, the electrical conductivity of nanofluid containing 0.5% AlN nanoparticles has increased by 1057 times at 60°C. By considering the electrophoresis of the AlN nanoparticles, a straightforward electrical conductivity model is established to modulate and understand the experiment results.

Dielectric properties of Shell oil transformer oil with impurities of carbon nanotubes and fullerene C60

2021 ◽  
Vol 24 (04) ◽  
pp. 413-418
Author(s):  
O.V. Kovalchuk ◽  
◽  
I.P. Studenyak ◽  
T.M. Kovalchuk ◽  
E.A. Ayryan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Dielectric Properties ◽  
Fullerene C60 ◽  
Transformer Oil ◽  
C60 Fullerene ◽  
Cooling Efficiency ◽  
Fullerene Concentration ◽  
Multiwall Nanotubes

At the temperature 293 K, the influence of two types of nanoimpurities (carbon multiwall nanotubes and C60 fullerene) both separately and together on the dielectric properties of Shell oil transformer oil has been studied. It has been shown that these impurities do not significantly effect on the value of the dielectric permittivity of Shell oil, but more significantly increase its conductivity. It has been found that in the presence of nanotubes inside Shell oil, the dependence of its electrical conductivity on the fullerene concentration is nonmonotonic. The samples with the fullerene concentration 100 ppm have the highest conductivity. At the fullerene concentration 300 ppm, the conductivity of Shell oil with the impurities of carbon nanotube and C60 fullerene becomes almost equal to the electrical conductivity of Shell oil only with the impurities of carbon nanotubes. It has been suggested that C60 fullerene can be used to reduce the electrical conductivity of Shell oil with magnetic nanoparticles required to increase the cooling efficiency of transformers under the action of their own magnetic field.

scholarly journals An electrical conductivity model for fractal porous media

2015 ◽  
Vol 42 (12) ◽  
pp. 4833-4840 ◽  
Author(s):  
Wei Wei ◽  
Jianchao Cai ◽  
Xiangyun Hu ◽  
Qi Han
Keyword(s):  
Electrical Conductivity ◽  
Porous Media ◽  
Conductivity Model

scholarly journals How Physicochemical Parameters of Water Change with Distance in a Lake: Case Study Lake Bunyonyiinkigezi

2021 ◽  
Vol 7 (4) ◽  
pp. 1-22
Author(s):  
Mukasa Tebandeke I.Z ◽  
Karume I ◽  
Ssebuwufu J ◽  
Wasajja H.Z ◽  
Nankinga R ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Dissolved Oxygen ◽  
Oxygen Demand ◽  
Agricultural Practices ◽  
Aquatic Organisms ◽  
Total Hardness ◽  
Ambient Temperatures ◽  
High Chemical Oxygen Demand ◽  
Whatman Paper

Pollution resulting from unsustainable agricultural and urbanization activities in the Ruhezamyenda and Bunyonyi catchments are threatening lake Bunyonyi. These have led to high chemical oxygen demand (COD), electrical conductivity, turbidity, pH, iron (II) concentration and low dissolved oxygen (DO5). In this study we have investigated the how COD, turbidity, pH, concentration of iron, total suspended solids, total nutrients and DO5 of water changed with distance in lake. Water sampled from different distances in the lake filtered using Whatman paper at ambient temperatures was tested for COD, electrical conductivity, turbidity, total nutrients, iron, hardness and DO5. COD was 20.8±.0.03mg/L to 16 ± 0.03mg/L; total hardness was 16.5±0.2 mg/L to 18.6 ± 0.3 mg/L total nitrate was 103.5± 2 mg/L to 88 ± 3 mg/L; total phosphate was 100.8 ±.2.5 to 87± 3 mg/L; high TSS values from 3.4 ± 0.1 mg/L to 2.5 ± 0.1 mg/L showed contamination of water. As pH decreased from 8.3 ± 0.03 to 7.6 ± 0.04 revealed that bases were getting removed. The turbidity dropped from 25.7 ± 0.3 NTU to 20 ± 2 NTU due settling down of sediments. Iron (II) concentration ranging from 1.1± 0.1 to 0.8± 0.1 mgL-1 . Dissolved oxygen decreased from 7.9 ±0.3 mg/L to 4.8 ± 0.2 mg/L indicating surface water can uphold life of aquatic organisms. Total hardness ranged from 0.22± 0.05 to 0.19± 0.05 mg/L Electrical conductivity was high and ranged from 130± 5 to 150± 5 µS/cm indicating presence of electrolytes. Lake Bunyonyi water is not greatly polluted, but requires to be safe guarded against poor unsustainable agricultural practices, sewage draining from towns, schools and hotels in nearby settlements.

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