• Nikolaos (Nikos) Cheimarios.

Research

Education.


Honors and awards

Research.


From a broad perspective, my research revolves around scientific software development, numerical solution of partial differential equations, transport phenomena, non-linear phenomena, stochastic processes, molecular simulations, high performance computing (HPC).

Multiscale modeling in CVD processes.

My research focuses on combining models from different scales in order to efficiently study, control and propose advantageous operating windows of the CVD process of concern. I combine macro-scale models, i.e. models based on partial differential equations (transport phenomena - continuum regime) with ballistic transport and Kinetic Monte Carlo models, in the micro- and nano- scales respectively. For a brief outline of our work please check pages 5-9 of ECCOMAS Newsletter .

Non-linear (systemic) analysis analysis.

I combine different computational methods, such as Recursive Projection Method (RPM) and arc-length continuation in order to enable commercial software to perform certain non-linear analysis tasks. The computational tools developed are independent of the underlying physical/chemical system. I have used them to efficiently study non-linear phenomena in CVD processes; from buoyancy induced phenomena to symmetry breaking and periodic (in time) flows. This work was partially funded by OSRAM Opto semiconductors during my post doc years.

Polymer properties via Monte Carlo methods.

Polymer properties are hard to compute with conventional molecular methods (such as molecular dynamics) especially when the architecture of the polymer chains is complex or the size of the system is too big. In these cases the relaxation times are too large, so the simulations become too expensive or even impossible. In the R&D department of Scienomics SARL, I have designed and developed Chameleon. Chameleon implements the so-called connectivity altering Monte Carlo moves which can efficiently used for computing the properties of large, realistic, complex polymer systems.

High performance (HPC) computing.

Speed does count! For that, I use HPC tools and methodologies - both CPU (MPI, pThreads) and GPU (CUDA, openCL) based - during software development to exploit modern HPC capabilities and to efficiently accelerate my computations. From a more practical aspect, I have designed and currently co-administrate Andromeda, a hybrid CPU/GPU cluster.

Scientific software development.

Besides Chameleon, I have designed and currently developing Apothesis, an open source software based on the kinetic Monte Carlo method. Apothesis is designed for the analysis of the surface phenomena encounter in CVD and atomic layer deposition (ALD) processes. It is still in development and only the core of the software is uploaded in github. I develop in C++, Java and python. For user interfaces (UI) I use Qt and zk framework.

Publications.


As my PhD advisor (who - as he told me - was told by his PhD advisor) says: "if it is not published, it is not science".

In journals.

I have co-authored 17 journal publications. I put only my two last publications here. For the rest you are welcome to check my Google scholar.

  1. (invited/review) N.Cheimarios, G. Kokkoris and A.G. Boudouvis “Multiscale Modeling in Chemical Vapor Deposition Processes: Models and Methodologies”, Archives of Computational Mechanics in Engineering, (2020), https://doi.org/10.1007/s11831-019-09398-w.
  2. O.Alexiadis, N, Cheimarios, L.D. Peristeras, A. Bick, V.G. Mavratzas, D.N. Theodorou, J.R, Hiill and X. Krokidis “Chameleon: A generalized, connectivity altering software for tackling properties of realistic polymer systems”, accepted for publication in WIREs Computational Molecular Science, (2019), https://doi.org/10.1002/wcms.1414.

In books.

  1. N. Cheimarios, S. Garnelis, G. Kokkoris, A. G. Boudouvis, “Multiscale modeling of chemical vapor deposition of silicon.” In “Computer Aided Chemical Engineering”, Vol.29, pp. 131-135, E.N. Pistikopoulos et al., Eds., Elsevier, 2011.
  2. N. Cheimarios, G. Kokkoris and A.G. Boudouvis “Multiscale modeling in chemical vapor deposition processes.” In “Honorary Volume dedicated to the memory of Professor N. Spyrellis”, pp. 87-95, M. Loizidou et al., Eds., NTUA, Athens, Greece, 2009 (in Greek).

In conference proceedings.

I have 13 publications in conference proceedings and 25 presentations. I have detailed them in my CV.

Other publications.

  1. G.Kokkoris, N. Cheimarios, A.G. Boudouvis, "Computational Microscope" for chemical engineering processes, PROMITHEAS , NTUA, 2018 (in Greek).
  2. N. Cheimarios, S. Garnelis, G.Kokkoris and A.G. Boudouvis “ A computational framework for multiscale analysis of chemical vapor deposition processes”. ECCOMAS Newsletter, pp. 5-9, November 2011.

Teaching.


I have assisted in the teaching of Transport phenomena I (Fluid dynamics), Computer programming (Matlab, Fortran), Technical drawing with AUTOCAD in NTUA, School of Chemical Engineering from 2008 to 2012. I have co-taught the course Process and device simulation in the Interdepartmental Program for Graduate Studies in Microelectronics in NCSR “Demokritos” from 2009 to 2012. I have assisted in the undergraduate diploma thesis supervision of 7 undergraduate students (2009-2014), 2 graduate students (2009, 2010), 1 PhD student (2016) and two Erasmus students (2008).

This is me.


Nikolaos (Nikos) Cheimarios

Research scientist - Scientific software developer

I was born on May, 28th, 1981 in Athens, Greece. I am married to Theodora and we have two wonderful daughters, Efi and Mirto. I love cinema, listening to music, boxing (in Fight Academy), diving and Christmas!

Feel free to contact me.


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E-mails:

nixeimar@chemeng.ntua.gr
cheimarios@novamechanics.com