Electrical conductivity of dilute aqueous phosphate solutions and phosphoric acid at elevated temperatures and pressures

2007 ◽  
Vol 11 (4) ◽  
pp. 136-140 ◽  
Author(s):  
G. Whitehead
Keyword(s):  
Electrical Conductivity ◽  
Phosphoric Acid ◽  
Elevated Temperatures ◽  
Phosphate Solutions

Electrical conductivity and thermopower of phosphoric acid doped polyaniline

1997 ◽  
Vol 84 (1-3) ◽  
pp. 789-790 ◽  
Author(s):  
Chul Oh Yoon ◽  
Jong Hyun Kim ◽  
Hyun Kyung Sung ◽  
Hosull Lee
Keyword(s):  
Electrical Conductivity ◽  
Phosphoric Acid ◽  
Doped Polyaniline

Non-Destructive Evaluation of Creep Damage in a Nickel Base Super-Alloy Turbine Bucket

2009 ◽  
Author(s):  
Hector Carreon
Keyword(s):  
Electrical Conductivity ◽  
Eddy Current ◽  
Elevated Temperatures ◽  
Damage Zone ◽  
Creep Damage ◽  
Turbine Engine ◽  
Turbine Component ◽  
Nickel Base ◽  
Turbine Bucket ◽  
Super Alloy

Due to elevated temperatures, excessive stresses and severed corrosion conditions, turbine engine components are subject to creep processes that limit the components life such as a turbine bucket. The failure mechanism of a turbine bucket is related primarily to creep and corrosion and secondarily to thermal fatigue. As a result, it is desirable to assess the current condition of such turbine component. This study uses the eddy current (EC) nondestructive evaluation technique in an effort to monitor the creep damage in a nickel base super-alloy, 7FA stage 2 turbine bucket after service. The experimental results show significative electrical conductivity variations in eddy current images on the creep damage zone of nickel base super-alloy samples cut from a turbine bucket. Thermoelectric power (TEP) measurements were also conducted in order to obtain a direct correlation between the presence of material changes due to creep damage and the electrical conductivity measurements.

scholarly journals Multicomponent non-aqueous electrolytes for high temperature operation of supercapacitors

2020 ◽  
Vol 61 (1) ◽  
pp. 67-75
Author(s):  
Mikhail V. Astakhov ◽  
◽  
Ludmila A. Puntusova ◽  
Ruslan R. Galymzyanov ◽  
Ilya S. Krechetov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Propylene Carbonate ◽  
Boiling Point ◽  
Elevated Temperatures ◽  
Specific Conductivity ◽  
Ethylene Carbonate ◽  
Aqueous Electrolytes ◽  
Cyclic Carbonates ◽  
High Boiling Point

Multicomponent non-aqueous electrolytes based on cyclic carbonates and tetraethylammonium tetrafluoroborate have been developed for the operation of supercapacitors at elevated temperatures. Propylene carbonate, which has a high dielectric constant and a high boiling point, was used as the main solvent of electrolytes. However, a significant drawback of propylene carbonate is its high viscosity, which leads to decrease in the electrical conductivity of electrolytes based on it compared to electrolytes based on acetonitrile. To increase the electrical conductivity, an additional component was introduced into the electrolyte – a cosolvent with the necessary set of properties. When choosing cosolvents, two approaches were used. In the first case, to increase the dielectric permittivity of the liquid phase, ethylene carbonate having a higher dielectric constant than propylene carbonate was introduced into the electrolyte. This approach made it possible to significantly increase the electrical conductivity of the electrolyte and to achieve high resource stability of the supercapacitor. The values of the specific capacitance and energy of the supercapacitor with the introduction of ethylene carbonate in the electrolyte practically did not change. In the second case, butyl acetate, which has a low viscosity but has a moderate polarity and a sufficiently high boiling point, was used as a co-solvent. In this case, not only an increase in the electrical conductivity of the electrolyte was observed, but also a significant increase in the capacitive characteristics of the supercapacitor. It is shown that the use of a mixture of cyclic carbonates and esters as a solvent in the composition of the electrolyte can increase its specific conductivity by 40%, and the specific energy consumption of a supercapacitor by 20%. The developed electrolytes provide long-term operation of supercapacitors both at room temperature and at elevated temperatures up to 80 °С.

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