The influence of temperature on the electrical resistivity of the cellular polypropylene and the effect of activation energy
In this paper, we determine the surface and volume electrical resistivity of the 50 μm thick cellular polypropylen (VHD50), for the temperature range 393–453 K. For this we use a contemporary methodology, which consist of a voltage measurement across the sample, with a known current flowing through it. This methodology includes a three-electrode system, which allows us to estimate the resistivity of the samples, based on their corresponding total resistances. The electric fields applied for a time interval of 1 min are of the order of 200 kVm−1. The order of magnitude of surface and volume electrical resistivity is 1013 Ω and 1011 Ωm, respectively. For both types of the resistivity, the temperature dependence is an increasing or decreasing exponential function, depending on the type of the activation energy, (its average value for the temperature range mentioned above is 41,20 kJmol−1), totally confirmed by the corresponding theoretical interpretation, conditioned by the ionic conduction.The methodology and equipment used, as well as the satisfying accordance with the results, found out directly or indirectly with the consulted literature, confirm the high accuracy of experimental measurements.
Electrical Conduction of Polypyromellitimide Films at Temperatures of 120-180°C
A measurement of electric current is made on polypyromellitimide films of 25 µm thickness at temperatures of 120-180°C and electric fields 4-500 kV/cm over a time range of 10-3600 s. Since the low field conduction has been confirmed to be ionic, an attempt is made to fit the field-current plot to the theoretical curve for ionic conduction. As a result a good fitting is obtained, giving the jump distance of 80-115 Å and the apparent activation energy of 1.1 eV.
Global Islamic Politics
1. Introduction to Islam and Islamic Revivals. 2. Islam: A Vehicle for Political Action. 3. The Muslim Fundamentalists. 4. The Muslim Traditionalists. 5. The Muslim Modernists. 6. The Muslim Pragmatists. 7. Failure of Secular Ideologies and Developmental Crises. 8. Islamic Revivalism in the Arab-Israeli Context. 9. OPEC, OIC, and Islamic Politics. 10. The Islamic Revolution in Iran. 11. Islamic Revival in Central Asia. 12. Conclusion. Glossary of Islamic Terms.