The electromagnetic field (EMF) is an environmental factor affecting living organisms. The aim of this study was to demonstrate the effect of an extremely low frequency electro- magnetic field (ELF-EMF) on selected chemical components of the honeybee (Apis mellifera L.) using Fourier Transform Infrared (FTIR) spectroscopy. The FTIR method provides information on the chemical structure of compounds through identification and analysis of functional groups. The honeybees were treated with EMF at a frequency of 50 Hz and magnetic induction of 1.6 mT for 2, 6, 12, 24 and 48 hours. Analysis of FTIR spectra showed that EMF exposure longer than 2 hours induced changes in the structure of chemical compounds, especially in the IR region corresponding to DNA, RNA, phospholipids and protein vibrations, compared to control samples (bees not EMF treated). The results confirm the effect of EMF on bees depending on the duration of exposure.
The presented results describe the effect of severe plastic deformation on the structure and mechanical properties of AA5083 and AA5754 alloys. Both materials were subjected to single hydrostatic extrusion (HE) and cumulative hydrostatic extrusion in the case of AA5083 and a combination of plastic deformation by equal-channel angular pressing (ECAP) with the next HE for AA5754. After the deformation, both alloys featured a homogeneous and finely divided microstructure with average grain size deq = 140 nm and 125 nm for AA5083 and AA5754, respectively. The selection of plastic forming parameters enabled a significant increase in the UTS tensile strength and YS yield stress in both alloys – UTS = 510 MPa and YS = 500 MPa for alloy AA5083 after cumulative HE, and 450 MPa and 440 MPa for alloy AA5754 after the combination of ECAP and HE, respectively. It has been shown on the example of AA5083 alloy that after the deformation the threads of the fasteners made of this material are more accurate and workable at lower cutting speeds, which saves the cutting tools. The resultant properties of AA5083 and AA5754 alloys match the minimum requirements for the strongest Al-Zn alloys of the 7xxx series, which, however, due to the considerably lower corrosion resistance, can be replaced in many responsible structures by the AA5xxx series Al-Mg alloys presented in this paper.