Eleni Drakaki

Publications (10) View all

• Article: Educational x-ray experiments and XRF measurements with a portable setup adapted for the characterization of cultural heritage objects

  I Sianoudis, E Drakaki, A Hein
  [show abstract] [hide abstract]
  ABSTRACT: It is common to modify valuable, sophisticated equipment, originally acquired for other purposes, to adapt it for the needs of educational experiments, with great didactic effectiveness. The present project concerns a setup developed from components of a portable system for energy dispersive x-ray fluorescence spectroscopy (EDXRF). Two educational modules have been developed on the basis of this setup. Module 1 comprises a series of x-ray laboratory exercises investigating basic principles, such as the verification of Moseley's law, Compton's law and the Lambert–Beer law. Module 2 concerns the calibration of the XRF with reference materials, aiming to get quantitative measurements of the elemental composition of objects of cultural interest. The application of the calibrated experimental setup is demonstrated with indicative measurements of metal objects and pigments of wall paintings, in order to discuss their spectra, and their qualitative and quantitative analyses. The setup and the applied experiments are designed as an educational package of laboratory exercises on the one hand for students in natural sciences, and on the other for the education of students who will work in the field of cultural heritage, such as conservation science or archaeological science.
  European Journal of Physics 03/2010; 31(3):419. · 0.82 Impact Factor
• Article: Laser-induced fluorescence and reflectance spectroscopy for the discrimination of basal cell carcinoma from the surrounding normal skin tissue.

  E Drakaki, E Kaselouris, M Makropoulou, A A Serafetinides, A Tsenga, A J Stratigos, A D Katsambas, C Antoniou
  [show abstract] [hide abstract]
  ABSTRACT: The object of this study was to investigate whether laser-induced skin autofluorescence (LIF) and/or light reflectance spectra could provide a useful contrast between basal cell carcinoma (BCC) tissues and the surrounding healthy skin. Unstained human skin samples, excised from humans undergoing biopsy examination, were irradiated with a nitrogen laser (lambda = 337 nm) for excitation of autofluorescence and a tungsten halogen lamp for the reflectance measurements. The ex vivo spectroscopic results were correlated with the histopathology images to distinguish the areas of BCC from those of the surrounding health skin. A simple spectral analysis technique was also applied for better skin diagnosis. In conclusion, it seems that LIF and reflectance spectra could be used to differentiate neoplastic from normal skin tissue using an appropriate classification model analysis.
  Skin pharmacology and physiology 05/2009; 22(3):158-65. · 2.92 Impact Factor
• Article: In vitro fluorescence measurements and Monte Carlo simulation of laser irradiation propagation in porcine skin tissue.

  E Drakaki, M Makropoulou, A A Serafetinides
  [show abstract] [hide abstract]
  ABSTRACT: In dermatology, the in vivo spectral fluorescence measurements of human skin can serve as a valuable supplement to standard non-invasive techniques for diagnosing various skin diseases. However, quantitative analysis of the fluorescence spectra is complicated by the fact that skin is a complex multi-layered and inhomogeneous organ, with varied optical properties and biophysical characteristics. In this work, we recorded, in vitro, the laser-induced fluorescence emission signals of healthy porcine skin, one of the animals, which is considered as one of the most common models for investigations related to medical diagnostics of human cutaneous tissues. Differences were observed in the form and intensity of the fluorescence signal of the porcine skin, which can be attributed to the different concentrations of the native fluorophores and the variable physical and biological conditions of the skin tissue. As the light transport in the tissue target is directly influencing the absorption and the fluorescence emission signals, we performed Monte Carlo simulation of the light distribution in a five-layer model of human skin tissue, with a pulsed ultraviolet laser beam.
  Lasers in Medical Science 08/2008; 23(3):267-76. · 2.00 Impact Factor
• Article: An approach to Poiseuille's law in an undergraduate laboratory experiment

  I A Sianoudis, E Drakaki
  [show abstract] [hide abstract]
  ABSTRACT: The continuous growth of computer and sensor technology allows many researchers to develop simple modifications and/or refinements to standard educational experiments, making them more attractive and comprehensible to students and thus increasing their educational impact. In the framework of this approach, the present study proposes an alternative experimental setup, which allows the confirmation of Hagen–Poiseuille's law, governing the flow of real fluids through tubes, a law with numerous important applications in both technology and medicine. In the proposed educational procedure, experimental measurements of fluid outflow are performed with the use of a motion sensor and a suitable computer program, allowing the determination of both the hydrostatic pressure and the flow rate. The dependence of the flow rate on parameters such as viscosity of the fluid, length and radius of the tube and the pressure difference between the ends of the tube are also studied, providing a laboratory activity which is useful and attractive for first year students, especially those of technologically oriented departments.
  European Journal of Physics 03/2008; 29(3):489. · 0.82 Impact Factor
• Source

  Available from: Elias Chatzitheodoridis

  Article: Laser studies of metallic artworks

  E. Drakaki, M. Kandyla, E. Chatzitheodoridis, I. Zergioti, A. A. Serafetinides, A. Terlixi, E. Kouloumpi, A. P. Moutsatsou, M. Doulgerides, V. Kantarelou, et al
  [show abstract] [hide abstract]
  ABSTRACT: Museum curators and archaeologists use analytical science to provide important information on artworks and objects. For example, scientific techniques provide information on artwork elemental composition, origin and authenticity, and corrosion products, while also finding use in the day-to-day conservation of many historical objects in museums and archaeological sites around the world. In this work two special cases are being discussed. In the first part of our work, physicochemical studies of an icon on a metal substrate were carried out using non-destructive, qualitative analysis of pigments and organic-based binding media, employing various microscopic and analytical techniques, such as Optical Fluorescence Microscopy, XRF, and Gas Chromatography. In the second part of our work, laser cleaning of late Roman coins has been performed using a Q-switched Nd:YAG laser (1064 nm, 6 ns) and a GaAlAs diode laser (780 nm, 90 ps). The corrosion products have been removed, while we observe increased concentrations in Ag, which is the main material of the silver plating found in late Roman coins.
  Applied Physics A: Materials Science & Processing. 01/2010; 101:349.