(6fa) Modeling across Disparate Spatiotemporal Scales – Enabling Answers to Grand Engineering Challenges

My braoder research interest is to conduct theoretical/simulation studies to develop a fundamental understanding about transport phenomena at the solid/metal surface or interface relevant to energy and electronics applications. My training in graduate and postdoctoral research is in developing surface mass transport models across disparate spatiotemporal scales and will serve as the foundation for pursuing my future research interests. Surface transport has ubiquitous applications in Chemical Engineering, from thin film growth to heterogeneous catalysis. Alongside traditional fields there are emerging areas of interdisciplinary nature, like the plasma-material interface in a fusion reactor where surface transport plays an important role and the underlying physics is mostly unexplored. The structural and thermomechanical response of the plasma-facing materials that are exposed to the harsh plasma environment inside the nuclear reactor and damaged by the high fluxes of helium atoms produced by nuclear fusion – is one of the major limitations toward realizing nuclear fusion. Considering its future potential and current impediments in realizing that potential, nuclear fusion is widely recognized as one of the grand challenges for engineering and applied science in the 21st century. Another grand challenge in the field of energy application is to improve the solar cell efficiency for making solar energy economically viable; an idea for enhancing efficiency, which is worth exploring, involves developments of nanocrystalline active photovoltaic materials and integrating these nanostructures into a system that can transmit the energy into a circuit. Transferring core Chemical Engineering knowledge to another field to address such grand challenges is an exciting research proposition for me.

Theory, computation, and experiment taken together to probe the structure, chemistry, and function of new and complex materials is a comprehensive approach to address such a grand problem. However, connecting an atomic-scale (fusion reaction) or quantum-scale phenomenon (photon absorption and emission of charge carriers in photovoltaics) to experimentally/operationally relevant spatial and temporal scales will require O(300 Million years) wallclock time of atomic-scale simulations, using current state-of-the-art supercomputing facilities. And modeling/simulation challenges will increase by several folds if we make the models realistically accurate by taking materials heterogeneity and imperfection into account. Systematic development of atomistically-informed multiscale mass and energy transport model(s) can bridge the gap between atomistic modeling and experimental data, and my research will focus precisely on the development of such an approach.

Teaching Interests: I am comfortable with teaching any of the core Chemical Engineering undergraduate and graduate courses, including courses of interdisciplinary nature. The only exception is courses which require substantial background in bioengineering or the life sciences. I will particularly be interested in teaching transport phenomena and fluid mechanics to graduate students. In addition to core courses, based on my academic and research experience, I would like to design two specially structured courses for first-year graduate students, one on Mathematical and Statistical Methods for Chemical Engineering (including design of experiments): an introductory graduate-level course to support the needs of students interested in experimental research, and another one on Computational Methods in Materials Science: an introductory graduate-level course to prepare engineering students for computational research in the interdisciplinary arena of materials science and engineering.

Postdoctoral Project: “Modeling of Plasma-Surface Interactions and Radiation Damage Dynamics;” Advisor: Prof. Brian D. Wirth, University of Tennessee Knoxville and Oak Ridge National Laboratory.

PhD Dissertation: “Analysis of External-Field-Driven Surface Stabilization and Patterning;” Advisor: Prof. Dimitrios Maroudas, University of Massachusetts, Amherst.

Research Experience:

My academic and research career path has traversed through many fields of Chemical Engineering and covered the entire spectrum of simulation scales, from the atomic level to the chemical plant scale. Nevertheless, my graduate and postdoctoral research have been focused on development of multiscale models, hierarchically parametrized coarse-grained models, using atomistic information through molecular-dynamics (MD) simulations and/or first-principles density functional theory (DFT) calculations, which are experimentally validated, for surface mass transport in diverse systems of interest and applications. For example, a part of my Ph.D. thesis research was focused on developing a model to facilitate external-field-driven complex nanopattern formation strategies starting from single-layer islands of a conducting material on crystalline conducting substrates, including current-driven formation of nanowires. In my postdoctoral research, I focus on developing an atomistically informed model to predict the structural and morphological evolution of plasma-facing material components in the fusion reactor. My current projects involve extensive collaborations with research institutes and national laboratories including close collaborations with experimentalists from Oak Ridge and Sandia National Laboratories. Also, as a part of a DOE-funded Scientific Discovery through Advance Computing (SciDAC) project, I have acquired proficiency in high-performance computer simulations in leadership computing facilities. Before joining the UMass Amherst Chemical Engineering Ph.D. Program, I have worked on a collaborative research project with Honeywell UOP to develop system identification and model predictive control strategies for an industrial fluidized bed polymerization reactor.

Teaching Experience:

I have extensive teaching experience, mostly in the capacity of teaching assistant (TA) for undergraduate and graduate level courses, including some laboratory courses. I have TAed Chemical Engineering Analysis (graduate level), Chemical Reactor Engineering (graduate level), Introduction to Statistics and Design of Experiments (undergraduate level) with regular responsibilities of holding office hours, grading homework assigfnments, and preparing solution sets for assignments and exams. In addition to these, I have guest-lectured a graduate-level Chemical Reactor Engineering course at UMass Amherst (I was nominated for the departmental TA award by the students). Moreover, for Introduction to Statistics and Design of Experiments offered to ~650 freshman students, I had special responsibility as the head TA to host regular training sessions for 32 other TAs for the course. Finally, I have mentored graduate students in the research groups where I conducted my Ph.D. research and currently conducting my postdoctoral research.

Publications:

1. D. Dasgupta, R. Kolasinski, L. Du, D. Maroudas, and B. D. Wirth, “Modeling of nano-fuzz formation in helium-ion-irradiated tungsten,” (Manuscript in preparation).
2. D. Dasgupta, A. Kumar, and D. Maroudas, “ Complex pattern formation from current-driven dynamics of single-layer homoepitaxial islands on crystalline conducting substrates,” Surface Science 669, 25-33 (2018).
3. A. Kumar, D. Dasgupta, and D. Maroudas, “Complex pattern formation from current-driven dynamics of single-layer homoepitaxial islands on crystalline conducting substrates,” Physical Review Applied 8, Article No. 014035, 14 pages (2017).
4. A. Kumar, D. Dasgupta, and D. Maroudas, “Surface nanopattern formation due to current-induced homoepitaxial nanowire edge instability,” Applied Physics Letters 109, Article No. 113106, 4 pages (2016).
5. A. Kumar, D. Dasgupta, C. Dimitrakopoulos, and D. Maroudas, “Current-driven nanowire formation on surfaces of crystalline conducting substrates,” Applied Physics Letters 108, Article No. 193109, 5 pages (2016).
6. L. Du, D. Dasgupta, and D. Maroudas, “Weakly nonlinear theory of secondary rippling instability in surfaces of stressed solids,” Journal of Applied Physics 118, Article No. 035303, 14 pages (2015).
7. L. Du, D. Dasgupta, and D. Maroudas, “Stabilization of the surface morphology of stressed solids using simultaneously applied electric fields and thermal gradients,” Journal of Applied Physics 116, Article No. 173501, 12 pages (2014).
8. L. Du, D. Dasgupta, and D. Maroudas, “Stabilization of the surface morphology of stressed solids using thermal gradients,” Applied Physics Letters 104, Article No. 181901, 4 pages (2014).
9. D. Dasgupta and D. Maroudas, “Surface nanopatterning from current-driven assembly of single-layer epitaxial islands,” Applied Physics Letters 103, Article No. 181602, 4 pages (2013).
10. D. Dasgupta, G. I. Sfyris, and D. Maroudas, “Current-driven morphological evolution of single-layer epitaxial islands on elastic substrates,” Surface Science 618, L1-L5 (2013).

• This work was highlighted by the editor and a perspective article on this work was written by Prof. Yannis G. Kevrekidis in the same issue of the journal.

11. G.I. Sfyris, D. Dasgupta, and D. Maroudas, “The effect of a thermal gradient on the electromigration–driven surface morphological stabilization of an epitaxial thin film on a compliant substrate,” Journal of Applied Physics 114, Article No. 023503, 13 pages (2013).
12. D. Dasgupta, G. I. Sfyris, M. R. Gungor, and D. Maroudas, “Electromigration- driven complex dynamics of void surfaces in stressed metallic thin films under a general biaxial mechanical loading,” Journal of Applied Physics 112, Article No. 083523, 10 pages (2012).
13. D. Dasgupta, G. I. Sfyris, M. R. Gungor, and D. Maroudas, “Surface morphological stabilization of stressed crystalline solids by simultaneous action of applied electric and thermal fields,” Applied Physics Letters 100, Article No. 141902, 4 pages (2012).
14. D. Dasgupta and S. C. Patwardhan, “NMPC of a continuous fermenter using Wiener-Hammerstein model developed from irregularly sampled multi-rate data,” IFAC Proceedings Volumes 43(5), 637-642 (2010).
15. U. Sarkar, D. Dasgupta, T. Bhattacharya, S. Pal, and T. Chakroborty, “Dynamic simulation of activated sludge based wastewater treatment processes: Case studies with Titagarh Sewage Treatment Plant, India,” Desalination 252(1-3), 120-126 (2010).
16. S. Pal, U. Sarkar, and D. Dasgupta, “Dynamic simulation of secondary treatment processes using trickling filters in a sewage treatment works in Howrah, West Bengal, India,” Desalination 253(1-3), 135-140 (2010).