1992-2017: Radon and Progeny studies

Assistant Professor Dr.Louizi (Department of Medical Physics-National & Kapodistrian University of Athens) and Dr.Nikolopoulos initiated in 1992 research collaboration on the subject of radon focusing on passive indoor measurements in Greece. During that period several calibration experiments were conducted in a specially desgned radon calibration chamber (Mini Radon House), at that time, installed at the Nuclear Technology Section of the National Technological University of Athens. Soon after, the research extended to the measurement of radon progeny concentration in indoor places with active techniques. Product of this research was the collection of a large sample of active and passive measurements in Greece. The active measurements included, later, measurements of radon in water and radon in soil, introducing techniques for the discrimination of radon and thoron. During the last ten years, the radon research focused on thermal spas. After investigating the radon burden of various Greek Spas, the research extended to the dynamical semi-empirical modelling of the Lesvos, Loutraki and Ikaria spas. During the last five years, the research targeted also  to radon precursors detected prior to earthquakes. Very significant and novel findings were observed in this subject area including the recognition of the chaotic-fractal nature of three very signifcant signals of radon in soil detected prior to three signifcant earthquakes occurred in Greece.


1990-2017: Monte Carlo Simulation

Monte-Carlo modelling of medical imaging detectors initiated in 1992 through a collaboration with Prof.Dr. Tzanakos G (Physics Department-University of Athens) and Prof.Dr. Angelopoulos A. (Physics Department-University of Athens). Later, a very close collaboration started with Prof.Dr.Kandarakis I. (Department of Biomedical Engineering) and Prof.Dr.Panayiotakis G. (University of Patras). The collaboration extended and now includes also Assoc.Prof.Dr. Valais I. (Department of Biomedical Engineering) and Dr. Michail (Department of Medical Instrumentation Technology). Today (2017) modelling is implemented through (a) custom designed codes (GNU- gfortran, g++) (b) EGSnrcMP (c) GATE and to some extend (d) MCNP.


1998-2017: Radiation Detectors

The research aims in (a) investigating new phosphor and nanophosphor detectors for modern medical imaging systems in combination with different optical sensors, and, (b) developing computational Monte Carlo methods targeted to the applicability of phosphor and nanophosphor detectors in medical imaging. The outcomesenable (1) the suggestion of optimum phosphor detector-optical sensor combinations under various conditions, and, (2) suggestion of newMI detector designs especially with nanophosphors coupled to CMOS sensors. Whole activity is expected to affect (i) industrial medical imaging applications, and (ii) research of biomedical nanomaterial technology. These will benefit medical imaging industry, health care services, clinical applications and research. The collaboration include nowadays Assoc.Prof.Dr. Valais I. (Department of Biomedical Engineering), Dr. Michail (Department of Medical Instrumentation Technology), Prof. Dr. Tseles D. and Prof.Dr. Yannakopoulos P.


2005-2017: Electromagnetic Radiation and Radon Emissions from Geo-systems

Since 2005 a new collaboration started with Prof.Dr.Nomicos C. in the field of telemetric recording and analysis of electromagnetic and radon signals from Geo-systems. Since then, a lot of modelling research has been implemented on the field via: (A) Chaotic Analysis through(i) Spectral fractal wavelet and (ii) Spectral fractal fourier analysis; (B) Long-memory analysis through iii) the Hurst exponent (iv) Rescale Analysis and (v) Detrended fluctuation analysis; (C) Analysis of self-organisation through(vi)Shannon n-block entropy (vii) Shannon n-block entropy per letter (viii) Conditional entropy (ix) Tsallis entropy (x Normalised Tsallis entropy and (D) General signal analysis. Support-vector machines have been employed as well. The overall analysis is performed in the time or frequency domain, through gliding or sliding windowing and vialettering or time-evolution analysis. Today (2017), 8-10 channel-1-sec data are being continuously collected from 12 different elctromagnetic stations and two radon stations in Greece. New techniques are being investigated for the online discrimination and enabling of a true-alarm system. The microelectronics of the receiving station systems as well as the hardware of the receiving antennas are of special concern. The collaboration include nowadays Lect.Coulouras G., Dr. Petraki E., Prof. Yannakopoulos P. and others.


2009-2017: Electromagnetic Radiation and Digital Communications

Since 2009 new reasearch started on the field of Electromagnetic Radiation Emissions for Digital Communication Systems. The reserach activities include measurements in the following frequence ranges: (a) GSM; (b) DCS; (c) UMTS; (d) DECT; (e) WiFi. Measurements in the TV3, TV4, TV5 and TETRAPOL ranges have also been conducted. Of special concenrn are the Health effects of the mobile communications and the associated emission antenas. A very large dataset has already been collected and is continiously growing. The collaboration include nowadays Dr. Petraki E., Prof. Yannakopoulos P. and others.