Victoria Atanassova
@issp.bas.bg
Laser, atomic, molecular and plasma physics
Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences
My professional background encompasses extensive research in the application of advanced optoelectronic techniques for the preservation of cultural heritage, with a primary focus on laser cleaning, material characterization, and identification through various methods such as laser-induced breakdown spectroscopy, Fourier-transformed infrared spectroscopy, colorimetry, etc. My research portfolio extends to diverse materials, including contemporary artwork, archaeological ceramics, stone, metal, and more. In addition, I have a research interest in the application of ultra-short laser pulses. My work extends to the modification of optical coatings, polymers, and various materials, with practical applications in diverse fields such as biomedicine, optical industry, green technologies, and many more.
EDUCATION
2012-2017 - PhD in wave physics at Institute of Solid State Physics, Bulgarian Academy of Sciences
2010-2012 - Master in Quantum Electronics and Laser Equipment at Faculty of Physics, Sofia University "St. Kliment Ohridski"
2006-2010 - Bachelor in Physics at Faculty of Physics, Sofia University "St. Kliment Ohridski"
RESEARCH, TEACHING, or OTHER INTERESTS
Multidisciplinary, Atomic and Molecular Physics, and Optics, Physics and Astronomy, Conservation
Scopus Publications
Scopus Publications
Victoria Atanassova, Vani Tankova, Valentin Mihailov, and Angelina Pirovska
MDPI AG
Throughout history, ceramics have been the most abundant artifacts in archaeological discoveries. Within the Neolithic period in present-day Bulgaria, skilled artisans applied additional materials to decorate their pottery, evolving in composition and application techniques such as painting or incrustation. This study is focused on the investigation of white pigments used in decorating Early and Late Neolithic pottery from Madzherito, Kaloyanovets, and Hadzhidimitrovo—archaeological sites located in the Thracian Valley, Central South Bulgaria, affiliated with the cultural groups of Karanovo I and IV. Thirteen ceramic sherds were investigated through archaeometric techniques, including Fourier-transformed infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) and laser-induced breakdown spectroscopy (LIBS). LIBS data underwent further analysis using principal component analysis (PCA). The results revealed that calcite, enriched with diverse fillers like quartz, clays, feldspars, and metal oxides, was the primary raw material for white decoration throughout the entire period. Talc emerged as an addition to calcite in the paint of two Early Neolithic sherds. The presence of hydroxyapatite and kaolinite in Late Neolithic pottery was also observed. The inclusion of supplementary ingredients in the primary formula for crafting white decorations signifies either the emergence of novel trends in manufacturing techniques or serves as evidence of vessels imported from adjacent territories.
Victoria Atanassova, Monica Dinu, Sultana-Ruxandra Polizu, and Roxana Radvan
MDPI AG
The present paper reports the multi-analytical approach for the removal of thick layers of metallic overpaints from a Brancovan iconostasis of the “Holy Trinity” church in Măgureni, România, which was built in 1694. After a restoration procedure at the beginning of the 20th century, the polychrome sculpture of the frame, which was initially gilded with a thin silver foil, was covered with a thick metallic overpaint layer imitating silver and gold. Currently, the conservation project of the church is focused on restoring the original aspect; thus, the overpainting that presented strong oxidation and soiling was removed. The adopted conservation methodology involved physicochemical characterization of the pictorial layers via optical microscopy, laser-induced breakdown spectroscopy, and Fourier-transform infrared spectroscopy, followed by the removal of the overpaints. The cleaning tests were performed by evaluating several methods in order to find the proper regime that would help preserve as much of the underlying polychrome layers as possible. Based on the tests, it was decided that the best solution was to use laser cleaning for the rough removal of the metallic paint overlayers and finalizing with chemical cleaning.
Ioana Gomoiu, Roxana Cojoc, Robert Ruginescu, Simona Neagu, Madalin Enache, Gabriel Maria, Maria Dumbrăvician, Ioana Olteanu, Roxana Rădvan, Lucian-Cristian Ratoiu,et al.
MDPI AG
This study highlights the decomposing role through the hydrolytic activities of fungi isolated from natural environments represented by brackish and hypersaline lakes in Romania. Novel strains belonging to the Penicillium, Aspergillus, and Emericellopsis genera were isolated and screened for the ability to produce extracellular hydrolytic enzymes, i.e., proteases, lipases, amylases, cellulases, xylanases, and pectinases. According to salt requirements, they were classified as moderate halophilic and halotolerant strains. Agar plate-based assays with Tween 80, slide cultures with organic deposits, and quantitative evaluation allowed the selection of Aspergillus sp. BSL 2-2, Penicillium sp. BSL 3-2, and Emericellopsis sp. MM2 as potentially good decomposers of organic matter not only in lakes but also on deposits covering the mural paintings. Experiments performed on painted experimental models revealed that only Penicillium sp. BSL 3-2 decomposed Paraloid B72, transparent dispersion of casein, beeswax, sunflower oil, and soot. Moreover, using microscopic, spectroscopic, and imaging methods, it was proved the efficiency of Penicillium sp. BSL 3-2 for decomposition of organic deposits artificially applied on frescoes fragments.
V Atanassova, L Ghervase, and I M Cortea
IOP Publishing
Abstract This contribution presents a study on the efficiency of the laser removal of black permanent marker tags from a contemporary graffiti painting. The effect of two wavelengths – 1064 nm and 532 nm, on the marker inks and the graffiti paints was investigated using optical microscopy and colorimetric measurements. Preliminary characterization of the marker inks and the paints by FTIR and XRF analyses was also performed. The results confirm that the materials’ response to laser radiation depends on their particular chemical composition.
Victoria Atanassova, Luminița Ghervase, Ioana Maria Cortea, Valentin Mihailov, Vani Tankova, and Vassil Nikolov
Informa UK Limited
Abstract This report presents pilot research of archaeological pottery excavated in the Early-Neolithic settlement of Chavdar located in the Pirdop-Zlatitsa field, Bulgaria (first half of VI mill BC). The object of investigation is a red-slipped ceramic fragment decorated on both sides with white paint. A multi-analytical approach including optical microscopy, laser-induced breakdown spectroscopy, X-ray fluorescence spectroscopy, and Fourier-transform infrared spectroscopy was undertaken to obtain comprehensive information contributing to the archaeological interpretation. The observations identified the qualitative chemical composition of the ceramic body and the pigment used for the decoration and gave implications on the temperature and the atmospheric conditions at which the vessel has been fired.
Victoria Atanassova, Ivan Kostadinov, and Petya Penkova
Author(s)
Victoria Atanassova, Ivan Kostadinov, Stefan Karatodorov, Georgi Avdeev, and Petya Penkova
SPIE
This study is focused on the selective laser removal of chlorine-containing corrosion products from artificially corroded samples of copper, brass and steel. Its goal is to find an efficient methodology for laser cleaning of historical metallic objects. The laser treatment is done with two laser sources: Q switched Nd:YAG laser generating nanosecond pulses at 1 Hz repetition rate in the IR (1064 nm) and the green (510.6 nm) spectral range, and copper bromide vapor laser (CuBrVL) generating nanosecond pulses at 20 kHz repetition rate in the green (510.6 nm) spectral range. The cleaning is performed in dry and wet conditions. The surfaces before and after the treatment are characterized using optical microscopy (OM), x-ray fluorescence spectroscopy (XRF), x-ray diffraction spectroscopy (XRD), and laser-induced breakdown spectroscopy (LIBS).
Victoria Atanassova, Ivan Kostadinov, Peter Zahariev, Margarita Grozeva, and Ilko Miloushev
SPIE
In present days graffiti is a common problem that many restorers have to deal with due to both its unaesthetic appearance and damaging nature for the surface beneath. We report laser cleaning of graffiti paints (black, white, blue, green and red) on limestone and granite. The efficiency of two laser systems is compared: high repetition rate (20 kHz) Copper Bromide Vapor Laser (CuBrVL) generating wavelength 510.6 nm and low repetition rate (up to 10 Hz) Q-switched Nd:YAG laser generating fundamental wavelength 1064 nm and its second harmonic 532 nm. The surface condition of the stone samples before and after cleaning is evaluated by means of optical microscopy. On that base, suitable working parameters are chosen in order to avoid under- or over-cleaning.