Transformation of polarons to bipolarons in disordered matter

The polaron to bipolaron transition in disordered media under the influence of a broadband ac electric field is suggested: ac conductivity vs. frequency measurements in disordered media with inhomogeneous disorder induce spatio-temporal fluctuations of the density of polarons yielding polaron to bipolaron transformation. The external field results in the transition, alternatively to an increasing doping level. The assertion is confirmed by performing successive complex impedance measurements in disordered media. A systematic increase of the real part of the ac conductivity in the frequency domain, followed by mutual reduction of the magnetic inductivity of conducting polypyrrole, are explained.Comment: 8 pages plus 3 figures. Accepted for publication in Applied Physics Letter

Effect of composition on the dielectric relaxation of zeolite-conducting polyaniline blends

The complex permittivity of conducting polyaniline and zeolite - polyaniline blends was measured in the frequency range 0.01 to 2000000 Hz from room temperature to liquid nitrogen temperature. A loss peak is detected for 25, 35 and 50 wt % zeolite blends. Its position in the frequency domain, activation energy and intensity is a function of composition. The experimental results are interpreted through the competing multiple role of zeolite: as being less conducting than polyaniline, it impedes the electric charge flow by dividing large conducting polyaniline regions into smaller pieces, subsequently provides short-range pathways and, moreover, enriches the blend in interfaces separating zeolite from polyaniline.Comment: Accepted for publication in J. Appl. Phy

Pressure dependence of the dielectric loss in semi-conducting polypyrrole aged at room temperature

The effect of physical aging of semi-conducting polypyrrole at ambient temperature for two years duration on the dielectric loss at various pressures is investigated. Changes of the dielectric loss spectra and the modification of the values of the activation volume for relaxation are interpreted through the division of chain clusters into smaller components and the reduction of the size of the conductive grains.Comment: Synthetic Metals (in print

Analysis of the financial implications of solar panels and battery storage integration in the port infrastructure of Heraklion

The European Union (EU) aims to significantly reduce greenhouse gas (GHG) emissions by 2050, necessitating an extensive energy transition across numerous industries and economic sectors. Urban ports are a key sector affected by this transition. As ports increasingly adopt electric-powered infrastructure (such as cold ironing, reefers, stackers, and cranes), their reliance on the electrical grid grows, potentially leading to higher operational costs. This creates a challenge of achieving the required transition in a cost-effective manner. This paper addresses this issue by proposing a photovoltaic (PV) and battery installation to meet electricity demands, focusing on determining the optimal system size, cost, and expected earnings. The study utilizes electricity consumption data from the port of Heraklion for 2021 and solar data from a nearby photovoltaic park in Heraklion, Crete. The methodology's results include determining the appropriate PV capacity and battery storage, with an estimated annual profit of €165,818.44

Dielectric properties of Granodiorite partially saturated with water and its correlation to the detection of seismic electric signals

Transient electric signals emitted prior to earthquake occurrence are recorded at certain sites in the Earth's crust termed sensitive. These field observations enforce the laboratory investigation of the dielectric response of rocks forming these localities. The dielectric relaxation of granodiorite rock coming from such a sensitive locality (Keratea, Greece) reveals, through complex impedance spectroscopy, that the activation volume for relaxation of this rock is negative which so far has been reported only rarely. This result, however, supports a theoretical model on the pre-seismic electric signals and is likely to be correlated with the sensitivity of the site and hence with the selectivity