Hello!
I’m João Marcos, a Physicist (PhD) specialized in Applied Nuclear Physics. My main topics of research includes: soil redistribution assessment through Gamma-Ray Spectrometry (GRS); build regression models using X-Ray Fluorescence (XRF), and Mid-Infrared Spectroscopy (MIRS) to predict soil fertility parameters; development of data fusion models combining GRS, XRF, and MIRS to explore the synergy between these techniques in evaluating soil health; and, applying geostatistical tools to analyze the spatial distribution of soil parameters and their relationship with erosion and movement processes. I am currently working at the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture as a Consultant for the Soil and Water Management and Crop Nutrition Laboratory (SWMCNL).
Recently, I have been working on Bayesian calibration models for XRF, applying orthogonal regression techniques that account for uncertainties in both measured and certified values. This approach improves accuracy and uncertainty quantification compared to traditional least-squares calibration, offering a more robust representation of the relationship between signal and concentration.
I have also collaborated on different research projects that combine spectroscopic techniques with environmental and archaeological studies. I contributed extensively to a study analyzing the chemical composition of rainwater following extreme drought and wildfire events in southern Brazil, employing TXRF to characterize elemental concentrations across multiple locations. In another project on pottery sherds from the Ventarrón-Collud Archaeological Complex in Peru, I contributed with the GRS analyses, complementing other spectroscopic and mineralogical techniques applied to understand material composition and post-depositional processes.
For GRS, I have experience working with HPGe, NaI(Tl), and CZT detectors, and have developed custom codes to convert raw spectral files into computer-friendly formats, aiming to establish a more complete and flexible framework for data processing and analysis.
I have been an active member of the Applied Nuclear Physics Group at UEL since 2020. During my PhD, I spent a semester at the International Atomic Energy Agency (IAEA), as an STEP fellow, working alongside researchers at the Nuclear Science and Instrumentation Laboratory (NSIL) and the Soil and Water Management and Crop Nutrition Laboratory (SWMCNL).
I am currently interested in advancing the use of spectroscopic techniques in environmental and soil studies, with a focus on data analysis, data fusion, and modeling.
Quick Overview
- Current Role: Consultant, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture
- Research Interests: Applied Nuclear Physics, Spectroscopic Techniques, Soil Redistribution, Data Fusion, Multivariate Analysis, Predictive Modeling, Quantitative Analysis.
- Key Programming & Tools: Python, Julia, LaTeX.
- Education: PhD in Physics (UEL), M.S. in Physics (UEL), B.S. in Physics (UEM).
- Full CV: View my complete Curriculum Vitae
Research Highlights
Here are some of my key research areas and contributions:
- Soil Redistribution: Using GRS, XRF, and MIRS to study soil movement and composition in agricultural areas.
- Data Fusion & Multivariate Analysis: Applying exploratory and predictive models to integrate multiple spectral datasets.
- Calibration & Modeling: Implementing Bayesian calibration and calibration transfer between detectors to improve measurement reliability.
- Spectral Data Processing: Developing Python-based tools for deconvolution, conversion, and handling of GRS and CZT spectra.
- Applied Spectroscopy: Contributing to environmental, archaeological, and biological sample analyses.
You can explore my academic output in detail in the Publications and Book Chapters sections. My full list of presentations is available on the Talks page.
Contact
Feel free to reach out to me at jmflopes.pro@gmail.com.