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This article deals with magnetic nano-fluids, which are the part of transformer oil ITO 100 and their behavior is influenced by a permanent magnetic field. We performed an IRC analysis in the time domain on the three different samples. Measurements were made before and after radiation of an electromagnetic field. The main objective was to examine changes in the properties of the samples due to the influence of the electromagnetic field. The measurements depend on the orientation of the external magnetic field. This behavior occurs especially during the structuring of the nanoparticles in the sample exposed to the magnetic field. These processes change the polarization of the liquid because the nanoparticles concentration is contained in the fluid.

Light and lighting, with this need we encounter in everyday life. During the day, it fills this need sunlight but there are cases when it is necessary to illuminate interior spaces during the day. In another situation we face at night when it is necessary to illuminate indoor or outdoor spaces artificially. This need for interior lighting fills the artificial lighting and discipline that deals with the lighting is called lighting technique. Well as other industries also lighting, respectively lighting technology goes through the development of new technologies. This paper deals with lighting, specifically analyzing the effectiveness of relamping in terms of investment costs. The first part of the article is devoted to the basic theoretical knowledge of the field of lighting technology. Subsequently are characterized further light sources. The last part of the article is the analysis and compares costs for different light sources and from the perspective of the average and useful life. [ABSTRACT FROM AUTHOR]

Today's wireless time brings some comfort, but on the other hand the impact of electromagnetic fields is serious threat to people. Many studies dealt with the effects of electromagnetic fields on living organisms, but the results are not completely clear. General and scientific public is increasingly focused on the impact of electromagnetic fields on living organisms. This is closely related limit values for parameters characterizing exposure to electromagnetic fields, depending on the frequency range, as defined by the Ministry of Health Decree 534/2007 Z.z. on the details and requirements for sources of electromagnetic radiation and exposure limits citizens to electromagnetic radiation in the environment. This contribution therefore focuses on mapping the electric and magnetic fields in the environment. The environment was selected area with a higher concentration of people in Prešov. The mapping was performed in two frequency ranges from 1 MHz to 1 GHz and 1 GHz to 2 GHz. [ABSTRACT FROM AUTHOR]