Una Trivanovic, PhD Candidate at ETH Zürich, Seeking an Academic Position

UNA TRIVANOVIC, ETH Zurich, Switzerland

     Abstract Number: 17
     Working Group: Meet the Job Seekers

Abstract
I began my graduate studies at the University of British Columbia supervised by Prof. Rogak researching the size and morphology of soot aerosols from marine engines using alternative fuels [1] and effects of fuel, water [2] and salt [3] on soot from gas flares. Currently, I am a PhD Candidate at ETH Zürich supervised by Prof. Pratsinis. During my PhD, I developed a method for generating aircraft-like soot by enclosed spray combustion (ESC) of various jet fuels [4]. This soot has similar mobility, primary particle size, d_p, organic carbon to total carbon ratio and effective density to that measured from real aircrafts. The large mass of generated soot allows for characterization of its specific surface area revealing that it is largely non-porous. To understand the dynamics of ESC-generated soot, flame temperatures and soot size distribution were measured within the flame and compared to previously validated models of soot agglomeration and surface growth [5]. At small heights above the burner (HAB) soot grew through surface growth. By HAB ~5 cm, agglomeration took over as the primary particle growth mechanism, also confirmed by constant Raman spectra at HAB >5 cm. Furthermore, a correlation was observed between the median d_p and Raman disorder to graphitic peak ratios indicating that soot with larger d_p had more ordered nanostructures. This trend was observed in previous work on soot from gas flares [2]. Thanks to the high-throughput of ESC, X-ray diffraction could easily be performed to corroborate this finding. Specifically, the soot crystallite length increased and its interlayer distance decreased as the median d_p increased. Such analysis leads to novel ways for reducing the soot generated by jet fuel combustion as my ongoing PhD research gradually reveals. I expect to graduate by early 2024 at which time I will be interested in an academic position.

References:
[1] U. Trivanovic, J.C. Corbin, A. Baldelli, W. Peng, J. Yang, P. Kirchen, J.W. Miller, P. Lobo, S. Gagné, S.N. Rogak, J. Aerosol Sci. 2019, 138, 105448.
[2] U. Trivanovic, T.A. Sipkens, M. Kazemimanesh, A. Baldelli, A.M. Jefferson, B.M. Conrad, M.R. Johnson, J.C. Corbin, J.S. Olfert, S.N. Rogak, Fuel. 2020, 279, 118478.
[3] T.A. Sipkens, U. Trivanovic, A. Naseri, O.W. Bello, A. Baldelli, M. Kazemimanesh, A.K. Bertram, L. Kostiuk, J.C. Corbin, J.S. Olfert, S.N. Rogak, J. Aerosol Sci. 2021, 158, 105826.
[4] U. Trivanovic, G.A. Kelesidis, S.E. Pratsinis, Aerosol Sci. Technol. 2022, 56, 732–743.
[5] U. Trivanovic, M. Pereira Martins, S. Benz, G.A. Kelesidis, S.E. Pratsinis, Fuel. 2023, 342, 127864.