On experimental setup in bioelectromagnetics

Bioeffects created by electromagnetic field (EMF) are the subject of intensive studies. This paper critically considers estimations of exposure to EMF in bioelectromagnetic experiments. Results of calculations presented herein show the significant role of the presence of conducting bodies (the exposure system) near an object under test on EMF energy absorption as well as mutual interactions between simultaneously exposed objects. Our aims herein are twofold: firstly to find a way to refer measurement results to free-space conditions in order to enable comparison of results obtained in different laboratories, and secondly to show that EMF energy absorption in any exposed object is different and that this difference is a function of the size of the exposure system, the number of exposed objects, and the particular properties (i.e., the electromagnetic structure) of the objects. In the authors’ opinion the existence of interactions caused by the presence of the exposure system and other exposed objects is a reason why remarkable differences are observed between experiments performed even under supposedly identical conditions. The presented considerations and conclusion suggest wider participation of physicists and engineers in bioelectromagnetic experiments in order to ensure the correctness of metrological aspects of these experiments.     

Mutual interactions in bioelectromagnetics

This paper discusses mutual interactions phenomena especially in the case of Transverse ElectroMagnetic (TEM) cell applications as an exposure system in technical and biomedical studies. In many publications is described problem of influence of an object upon the electromagnetic field (EMF) distribution inside a exposure system while inverse effect—influence of exposure system on tested object is overlooked. The problem plays primary role if a correlation between investigations carried out in an enclosure (e.g. TEM cell) and that in the free space is looked for.     

Limitations in the SAR Use

Summary The paper discusses several aspects of the practical application of the SAR. It is shown that the unit is an ideal solution for basic research and laboratory experiments. SAR is directly nonmeasurable unit. Although methods and devices based upon indirect SAR measurements may widen our knowledge about EM energy distribution and absorption within a body. It is shown that for practical applications the temperature SAR measurement methods are not sensitive enough while methods based upon E(H) measurement are less accurate than traditional approaches. As a result of assumption SAR = 4 W/kg as a basic restriction the present protection standards are illogical and nonrealiazable. A return to traditional units (E, H, S) in the standards and surveying metrology is suggested.     

Agricultural and non-agricultural directions of bio-based sewage sludge valorization by chemical conditioning

Environmental Science and Pollution Research - This literature review outlines the most important—agricultural and non-agricultural—types of sewage sludge management. The potential of...     

Non-stationary electromagnetic field measurements accuracy improvement

Electromagnetic field (EMF) measurements, for labor safety and environment protection purposes, are performed in the near-field. Inaccuracy of the far-field EMF measurements oscillates around ±1 dB or bit worse; in the near-field measurements, errors at the level of ±6 dB must be sometimes accepted. In the case of non-stationary EMF measurements, their sense may be changed from quantitative to qualitative ones. In order to make it possible an estimation of the non-stationary EMF measurement accuracy, it is proposed new method of the meters calibration. The method is based upon a standard excitation with identical signal as the measured one. A set for the purpose includes a pulse generator (of frequency and pulse rating identical with the radiation source) and computer-controlled amplitude modulator that reflects the radiation pattern of an antenna (e.g. radar one) and its rotations. Contrary to calibration using monochromatic continuous wave (CW) excitation, proposed method should be repeated for any radiation source. The disadvantage is compensated by a possibility to estimate (additional) error of the method. Calculations show it at the level of 10%.