Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Elias Chatzitheodoridis has a total of 251 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Connecting Meteorite Spectra to Lunar Surface Composition Using Hyperspectral Imaging and Machine Learning

    by Fatemeh Fazel, Mojtaba Raouf, Bernard Foing, Fons Verbeek, Amirmohammad Chegeni, Elias Chatzitheodoridis

    We present an innovative, cost-effective framework integrating laboratory Hyperspectral Imaging (HSI) of the Bechar010 Lunar meteorite with ground-based lunar HSI and supervised Machine Learning(ML) to generate high-fidelity mineralogical maps. A 3mm thin section of Bechar010 was imaged under a microscope with a 30mm focal length lens at 150mm working distance, using 6x binning to increase the signal-to-noise ratio, producing a data cube (X × Y × λ = 791×1024×224, 0.24mm × 0.2mm resolution) across 400-1000}nm (224 bands, 2.7nm spectral sampling, 5.5nm full width at half maximum spectral resolution) using a Specim FX10 camera. Ground-based lunar HSI was captured with a Celestron 8SE telescope (3km/pixel), yielded a data cube (371×1024×224). Solar calibration was performed using a Spectralon reference ({99}\% reflectance {

  • Open Access

    Connecting Meteorite Spectra to Lunar Surface Composition Using Hyperspectral Imaging and Machine Learning

    by Fatemeh Fazel Hesar, Mojtaba Raouf, Amirmohammad Chegeni, Peyman Soltani, Bernard Foing, Elias Chatzitheodoridis, Michiel J. A. de Dood, Fons J. Verbeek

    We present an innovative, cost-effective framework integrating laboratory Hyperspectral Imaging (HSI) of the Bechar 010 Lunar meteorite with ground-based lunar HSI and supervised Machine Learning (ML) to generate high-fidelity mineralogical maps. A 3 mm thin section of Bechar 010 was imaged under a microscope with a 30 mm focal length lens at 150 mm working distance, using 6x binning to increase the signal-to-noise ratio, producing a data cube (X × Y × λ = 791×1024×224, 0.24 mm × 0.2 mm resolution) across 400 nm to 1000 nm (224 bands, 2.7 nm spectral sampling, 5.5 nm full width at half maximum spectral resolution) using a Specim FX10 camera. Ground-based lunar HSI was captured with a Celestron 8SE telescope (3 km/pixel), yielded a data cube (371×1024×224). Solar calibration was performed using a Spectralon reference (99% reflectance < 2% error) ensured accurate reflectance spectra. A Support Vector Machine (SVM) with a radial basis function kernel, trained on expert-labeled spectra, achieved 93.7% classification accuracy (5-fold cross-validation) for olivine (92% precision, 90% recall) and pyroxene (88% precision, 86% recall) in Bechar 010. LIME analysis identified key wavelengths (e.g., 485 nm, 22.4% for M3; 715 nm, 20.6% for M6) across 10 pre-selected regions (M1 to M10), indicating olivine-rich (Highland-like) and pyroxene-rich (Mare-like) compositions. SAM analysis revealed angles from 0.26 rad to 0.66 rad, linking M3 and M9 to Highlands and M6 and M10 to Mares. K-means clustering of Lunar data identified 10 mineralogical clusters (88% accuracy), validated against Chandrayaan-1 Moon mineralogy Mapper (M3) data (140 m/pixel, 10 nm spectral resolution). A novel push-broom HSI approach with a telescope achieves 0.8 arcsec resolution for lunar spectroscopy, inspiring full-sky multi-object spectral mapping.

  • Open Access

    Connecting Meteorite Spectra to Lunar Surface Composition Using Hyperspectral Imaging and Machine Learning

    by Fatemeh Fazel Hesar, Mojtaba Raouf, Amirmohammad Chegeni, Peyman Soltani, Bernard Foing, Elias Chatzitheodoridis, Michiel J.A. de Dood, Fons J. Verbeek

    We present an innovative, cost-effective framework integrating laboratory Hyperspectral Imaging (HSI) of the BECHAR 010 lunar meteorite with ground-based lunar HSI and supervised Machine Learning (ML) to generate high-fidelity mineralogical maps. A \SI{3}{\milli\metre} thin section of BECHAR 010 was imaged under a microscope with a \SI{30}{\milli\metre} focal length lens at \SI{150}{\milli\metre} working distance, using 6x binning to increase the signal-to-noise ratio, producing a data cube (X $\times$ Y $\times$ $\lambda$ = $791 \times 1024 \times 224$, \SI{0.24}{\milli\metre} $\times$ \SI{0.2}{\milli\metre} resolution) across \SIrange{400}{1000}{\nano\metre} (224 bands, \SI{2.7}{\nano\metre} spectral sampling, \SI{5.5}{\nano\metre} FWHM spectral resolution) using a Specim FX10 camera. Ground-based lunar HSI was captured with a Celestron 8SE telescope (\SI{3}{\kilo\metre}/pixel), yielded a data cube ($371 \times 1024 \times 224$). Solar calibration was performed using a Spectralon reference (\SI{99}{\percent} reflectance \SI{< 2}{\percent} error) ensured accurate reflectance spectra. A Support Vector Machine (SVM) with a radial basis function kernel, trained on expert-labeled spectra, achieved \SI{93.7}{\percent} classification accuracy (5-fold cross-validation) for olivine (\SI{92}{\percent} precision, \SI{90}{\percent} recall) and pyroxene (\SI{88}{\percent} precision, \SI{86}{\percent} recall) in BECHAR 010. Local Interpretable Model-agnostic Explanations (LIME) identified key wavelengths (e.g., \SI{485}{\nano\metre}, \SI{22.4}{\percent} for M3; \SI{715}{\nano\metre}, \SI{20.6}{\percent} for M6) across 10 pre selected regions (M1 to M10), indicating olivine-rich (Highland-like) and pyroxene-rich (Mare-like) compositions. Spectral Angle Mapper (SAM) analysis revealed angles from \SI{0.26}{\radian} to \SI{0.66}{\radian}, linking M3 and M9 to Highlands and M6 and M10 to Mares. K-means clustering of lunar data identified 10 mineralogical clusters (\SI{88}{\percent} accuracy), validated against Chandrayaan-1 Moon mineralogy Mapper ($\rm M^3$) data (\SI{140}{\metre}/pixel, \SI{10}{\nano\metre} spectral resolution). A novel push-broom HSI approach with telescope, achieves 0.8 arcsec resolution for lunar spectroscopy, inspiring full-sky multi-object spectral mapping.

  • Top Cited Papers
    Open Access

    Microbial Bioleaching of Critical Metals from Spent Lithium-Ion Batteries: A Biohydrometallurgical Approach

    by Kyriaki Kiskira, Lamprini-Areti Tsakanika, Aristeidis Kritikos, Konstantina Papadopoulou, Elias Chatzitheodoridis, Gerasimos Lyberatos, Maria Ochsenkühn-Petropoulou

    Biohydrometallurgical processing of spent lithium-ion batteries offers a low-impact route for critical metal recovery compared with conventional hydrometallurgy. In this work, the iron-oxidizing bacterium Acidithiobacillus ferrooxidans was evaluated for the bioleaching of cobalt (Co), nickel (Ni), lithium (Li) and copper (Cu) from pyrolyzed industrial black mass derived primarily from LiCoO2-based batteries, containing both LiCoO2 and LiNiO2 layered oxide phases. Batch experiments were conducted in 9K medium at 30 °C, varying pulp density (1%–2%, w/v), inoculum volume (10–20 mL in 200 mL medium) and initial pH (with and without adjustment). At 1% pulp density and 10% v/v inoculum, metal recoveries after 6–7 days reached about 64%–70% Co, 57%–72% Ni, 52%–60% Li and 81%–100% Cu, with most dissolution occurring in the first 6 days. Higher inoculum loads without initial pH adjustment increased Li recovery up to 79%, but did not further improve Co and Cu, indicating a trade-off between microbial activity, metal toxicity and ferric iron availability. The temporal evolution of pH and metal dissolution is consistent with indirect redoxolysis by biogenic Fe3+ and sulfuric acid generated during ferrous iron and elemental sulfur oxidation. Overall, the results confirm the feasibility of A. ferrooxidans-assisted bioleaching as a green option for Co, Ni, Li and Cu recovery from spent LiCoO2 batteries and provide operating windows for subsequent process optimization and scale-up.


  • Open Access

    Microbial Bioleaching of Critical Metals from Spent Lithium-Ion Batteries: A Biohydrometallurgical Approach

    by Kyriaki Kiskira, Lamprini-Areti Tsakanika, Aristides Kritikos, Konstantina Papadopoulou, Elias Chatzitheodoridis, Gerasimos Lyberatos, Maria Ochsenkühn-Petropoulou

    Biohydrometallurgical processing of spent lithium-ion batteries offers a low-impact route for critical metal recovery compared with conventional hydrometallurgy. In this work, the iron-oxidizing bacterium Acidithiobacillus ferrooxidans was evaluated for the bioleaching of cobalt (Co), nickel (Ni), lithium (Li) and copper (Cu) from the black mass of spent LiCoO₂ batteries. Batch experiments were conducted in 9K medium at 30 °C, varying pulp density (1-2 %, w/v), inoculum volume (10-20 mL in 200 mL medium) and initial pH (with and without adjustment). At 1 % pulp density and 10 % v/v inoculum, metal recoveries after 6-7 days reached about 64-70 % Co, 57-72 % Ni, 52-60 % Li and 81-100 % Cu, with most dissolution occurring in the first 6 days. Higher inoculum loads without initial pH adjustment increased Li recovery up to 79 %, but did not further improve Co and Cu, indicating a trade-off between microbial activity, metal toxicity and ferric iron availability. The temporal evolution of pH and metal dissolution is consistent with indirect redoxolysis by biogenic Fe³⁺ and sulfuric acid generated during ferrous iron and elemental sulfur oxidation. Overall, the results confirm the feasibility of A. ferrooxidans-assisted bioleaching as a green option for Co, Ni, Li and Cu recovery from spent LiCoO₂ batteries and provide operating windows for subsequent process optimization and scale-up.


  • Sensing technologies for the challenging Lunar environment

    by Elias Chatzitheodoridis, Christos D. Georgiou, Martin Ferus, Electra Kalaitzopoulou, Hector-Andreas Stavrakakis, Ioannis Markopoulos, Malgorzata Holynska


  • Mars as a Science Base: Towards a Small Permanent Outpost

    by Elias Chatzitheodoridis, Jean-Pierre de Vera, Akos Kereszturi, Nigel Mason, Carmen Possnig, Mikko Puumala, Oskari Sivula, Michel Viso, Gisela Detrell, Ondřej Ditrych, et al.


  • Perspectives for Crewed Missions to Mars: Exploration from Orbit and/or Short Stay

    by Elias Chatzitheodoridis, Jean-Pierre de Vera, Akos Kereszturi, Nigel Mason, Carmen Possnig, Mikko Puumala, Oskari Sivula, Michel Viso, Jacques Arnould, Gisela Detrell, et al.


  • Towards Permanent Settlements on Mars (from 1000 to 100,000 People)

    by Elias Chatzitheodoridis, Philippe Clerc, Akos Kereszturi, Nigel Mason, Erik Persson, Carmen Possnig, Lucie Poulet, Mikko Puumala, Oskari Sivula, John Robert Brucato, et al.


  • NoRCEL's Engagement in Africa: The AstroScience Exploration Network (ASEN)

    by Sohan Jheeta, Martin Dominik, Elias Chatzitheodoridis, Oleg Kotsyurbenko, Miryam Palacios-Pérez, Sávio Torres de Farias, Kathy McGrath, Ahya Rezaei, Mukesh C. Bhatt, Richard Gordon

    The AstroScience Exploration Network (ASEN) is the latest innovative initiative from the Network of Researchers on the Chemical Emergence of Life (NoRCEL). Materializing on the vibrancy of the African continent, recognizing its people as a key asset, and building on specific strategic advantages, ASEN will funnel the appetite for scientific knowledge through an educational hub that paves the way for the Global South to come to the fore in new global endeavors and will eventually help build a variety of career paths in a diversifying economy.