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Precise evaluation of the near-field generated by transmitters operating in the radio frequency (RF) range (30 MHz to 6 GHz) is still an engineering challenge not only requiring sophisticated tools but also involving different procedures with a multitude of parameters to be considered. This paper reviews the state-of-the-art of near-field evaluation with emphasis on compliance testing of handheld RF transmitters with safety limits Similar tools and techniques can be utilized for the analysis and optimization of antennas operating in complex environments as well as for evaluation of special electromagnetic compatibility and interference problems occurring in the near-field of transmitters. Another area of applications is the analysis, evaluation and optimization of exposure setups used in RF safety research to investigate possible basic, therapeutic or adverse health effects from non-ionizing radiation.

Crawford TEM cells are often used to expose cell cultures or small animals in order to study the effects caused by high-frequency fields. They are self-contained, easy-to-use setups that provide a rather homogeneous field distribution in a large area around its center, corresponding approximately to far-field conditions. However, a number of conditions must be met if such TEM cells are intended to be used for in vitro experiments. For instance, poor interaction with the incident field must be maintained to avoid significant field disturbances in the TEM cell. This is best achieved with E-polarization, i.e., when the E-field vector is normal to the investigated cell layer lining the bottom of a synthetic Petri dish. In addition, E-polarization provides the most homogeneous field distribution of all polarizations within the entire layer of cells. In this paper, we present a detailed dosimetric assessment for 60 and 100 mm Petri dishes as well as for a 48-well titer plate at 835 MHz. The dosimetry was performed by using numerical computations. The modeling and the simplifications are validated by a second numerical technique and by experimental measurements. For thin liquid layers, an approximation formula is provided with which the induced field strength for many other experiments conducted in Petri dishes can be assessed reliably.

The benefit of using software development methods should be a gain in regularity and clarity in software projects. Classical approaches are designed for medium to big team size with a distinctly separated and static role description combined with a top down development process. Agile methods mainly focus on small teams with low budget project size, and a fixed deadline with a bottom up development process. In this paper we present a combined approach for projects with multiple small teams growing together to a medium size project with a hard deadline and low budget – called Agile Methodology for Intelligent Agents Componentware (aMIAC). The approach will be introduced and applied within a case study.

Environmental sciences Europe : ESEU 28, 20 (2016). doi:10.1186/s12302-016-0088-3, Published by Springer, Berlin ; Heidelberg