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Iwan A.,Electrotechnical Institute Warsaw
Renewable and Sustainable Energy Reviews

In this review, liquid crystalline (LC) polyazomethines (PAZs) with aliphatic-aromatic moieties were investigated, taking into consideration their thermal, structural, optical and electrical properties. Liquid crystalline polymers with imine bonds in the main or side chains were analysed. The optical properties of LC polyazomethines, including UV-vis absorption, photoluminescence (PL) and thermoluminescence (TL), were studied, taking into consideration the polymer structure. Finally, the electrical properties, including the photovoltaic properties of a bulk heterojunction (BHJ) and monolayer devices based on LC polyazomethines, were investigated and compared with PAZ, which did not exhibit LC properties. In this review article, the recent research trend on LC polyazomethines is summarised. © 2015 Elsevier Ltd. All rights reserved. Source

Krajewski W.,Electrotechnical Institute Warsaw
Electric Power Systems Research

The paper deals with the numerical estimation of the electromagnetic field exposure during live-line working (LLW) on a terminal tower of a 110. kV line. The above tower is equipped with cable heads, lightning arresters and vertical cabling. This vertical cabling connects the overhead HV line with underground one. Distributions of the electric and magnetic fields in the LLW zones as well as the electric field (eddy currents) induced in the worker's organism are computed with an author's own software package. This software is based on a numerical technique that combines the boundary element and charge simulation methods. Presented computational results are related to the current European and Polish regulations regarding the workers' exposure to the electromagnetic fields. © 2016 Elsevier B.V. Source

The investigation of the surface properties changes at micrometer and nanometer scale, due to the presence of various factors such as: temperature, solar radiation or magnetic field, requires suitable diagnostic methods. Atomic force microscopy (AFM) is one of the most popular measurement techniques providing necessary resolution. As complex experiments may require multiple moving of the sample between instruments and AFM, one can find quantitative comparison of the results unreliable when the measurements are performed without precise positioning of investigated surface and different areas are analyzed. In this work, the utilization of the nanoscratching method in terms of development of the nanomarkers set is presented, as the solution for precise positioning of the sample in order to perform the multi-step imaging of small surface area (1 ?m×1 ?m). Various materials were used to verify the versatility of the developed method. Also, the observation of the influence of the UV radiation on the polycarbonate sample was demonstrated as the example proving the application potential of the approach. Source

Sikora A.,Electrotechnical Institute Warsaw
Measurement Science and Technology

A sophisticated experiment requiring multiple micrometer-scale scanning of the same area of a sample may be performed easily if special positioning features on the surface are available. A set of nanomarkers developed using a nanoscratching technique can provide an efficient, submicron-accurate solution allowing us to investigate various phenomena. In this paper, the analysis of the roughness estimation repeatability is presented in terms of defining the accuracy of the area of interest. The obtained results confirmed the possibility of the repeatable positioning of the sample in an atomic force microscope, providing area roughness determination repeatability with a standard distribution smaller than 3%. As an example, the observation of light-caused surface degradation is presented. Also, the utilization of nanomarkers in determining the magnetic domain's rearrangement angle with an accuracy better than 0.5° is shown. © 2014 IOP Publishing Ltd. Source

Kazmierkowski M.P.,Warsaw University of Technology | Moradewicz A.J.,Electrotechnical Institute Warsaw
IEEE Industrial Electronics Magazine

Recently, contactless (or contact-free) energy transfer (CET) systems have become more widely developed and investigated [1][4]. This innovative technology brings about new possibilities of supplying mobile devices with electrical energy by allowing elimination of cables, connectors, and/or slip rings. This increases reliability and maintenance-free operation of such systems in critical applications such as aerospace, biomedicine, multisensors, and robotics. © 2007-2011 IEEE. Source

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