title: Microwave effect on diffusion: a possible mechanism for non-thermal effect.
abstract: In this study, we assume that microwave radiation affects hydrogen bonding between dipolar water molecules and through that diffusion in water at constant temperature. The experimental study was performed on the setup of two identical reservoirs filled with pure water and 0.9% NaCl solution and connected by a thin tube. Alterations of NaCl concentration in the reservoir initially filled with pure water were measured using the resistance of the solution as an indicator. The applied 450 MHz continuous-wave microwave field had the maximal specific absorption rate of 0.4 W/kg on the connecting tube. The standard deviation of water temperature in the setup was 0.02 °C during an experiment. Our experimental data demonstrated that microwave exposure makes faster the process of diffusion in water. The time required for reduction of initial resistance of the solution by 10% was 1.7 times shorter with microwave. This result is consistent with the proposed mechanism of low-level microwave effect: microwave radiation, rotating dipolar water molecules, causes high-frequency alterations of hydrogen bonds between water molecules, thereby affects its viscosity and makes faster diffusion.
authors.affiliation: a Department of Biomedical Engineering , Tallinn University of Technology , Tallinn , Estonia.
authors.forename: Hiie
authors.initials: H
authors.lastname: Hinrikus
authors.affiliation: a Department of Biomedical Engineering , Tallinn University of Technology , Tallinn , Estonia.
authors.forename: Jaanus
authors.initials: J
authors.lastname: Lass
authors.affiliation: a Department of Biomedical Engineering , Tallinn University of Technology , Tallinn , Estonia.
authors.forename: Denis
authors.initials: D
authors.lastname: Karai
authors.affiliation: a Department of Biomedical Engineering , Tallinn University of Technology , Tallinn , Estonia.
authors.forename: Kristjan
authors.initials: K
authors.lastname: Pilt
authors.affiliation: a Department of Biomedical Engineering , Tallinn University of Technology , Tallinn , Estonia.
authors.forename: Maie
authors.initials: M
authors.lastname: Bachmann
mesh_terms: D001921:Brain / Q000528:radiation effects; D004058:Diffusion; D004867:Equipment Design; D006801:Humans; D006860:Hydrogen Bonding; D008279:Magnetic Resonance Imaging; D008872:Microwaves; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D012965:Sodium Chloride
keywords: Diffusion in water; hydrogen bonding; low-level radiation; microwave effect; non-thermal mechanism