To investigate a supposed relationship between exposure by mobile phone base stations and wellbeing, an epidemiological cross sectional study is carried out within the German Mobile Telecommunication Research Program. In a parallel project, a method for the classification of electromagnetic exposure due to mobile phone base stations has been developed. This is based on the results of measurements of high frequency immissions in the interior of more than 1100 rooms and at outdoor locations, the calculation of the emissions of mobile phone antennas under free space propagation conditions and empirically determined transmission factors for the propagation of electromagnetic waves in different types of residential areas for passage of walls and windows. Standard tests (correlation-test, kappa-test, Bland-Altman-Plot, analysis of sensitivity and specificity) show that the method for computational exposure assessment developed in this project is applicable for a first classification of exposures due to mobile phone base stations in epidemiological studies.

The performance of new dielectric ceramic resonators (DRs) for continuous wave (cw) X-band electron paramagnetic resonance (EPR) spectroscopy is investigated at room temperature and low temperatures (77, 6 K). The DRs with high dielectric constants of about e r ¼ 80, featuring low residual paramagnetic impurities, have been developed and produced on the basis of barium lanthanide titanates solid solutions with the general formula Ba 6Àx Ln 8þ2x=3 Ti 18 O 54 (Ln = Sm, Nd) that demonstrate at once low dielectric losses in the microwave range (tan d ¼ 7-14 9 10 -4 at 10 GHz) and appropriate temperature stability of the dielectric constant (s e ¼ AE5 ppm/K). They were optimized for samples with small dimensions and can be used in commercial Oxford instruments flow cryostats if the coupling is done via cavity resonators. We found a maximal EPR signal enhancement by a factor up to 74 at 6 K. The increases of quality and filling factors as well as that of the microwave (mw) B 1 -field in the resonator setup are discussed in dependence on temperature. We show that the absolute sensitivity gain must be related to that increase in the mw field and the remaining relative gain of the SNR is Electronic supplementary material The online version of this article (Applied Magnetic Resonanceabout 18 for small samples. The developed DRs have shown a good potential in EPR application as reliable and easy-to-use components allowing research of thin films and in particular small crystalline structures.

No abstract

No abstract