Speaker Abstracts

Prof. Rama Govindarajan

Title: Small steps towards understanding particulate flows

Abstract: Particulate flows like dust-storms and snow avalanches are impossible to solve exactly for, and so we need to develop analytical and numerical techniques to obtain an understanding of them. I will discuss why this is a hard problem, and discuss a few simplified problems.

References:

  1. Sedimentation dynamics of bodies with two planes of symmetry. Harshit Joshi & Rama Govindarajan. Physical Review Letters, 134, 014002, 2025.
  2. Explicit Runge-Kutta algorithm to solve non-local equations with memory effects: case of the Maxey-Riley-Gatignol equation. Divya Jaganathan, Rama Govindarajan, Vishal Vasan, arXiv: 2308.09714. Quarterly of Applied Mathematics, LXXXIII, 1, 135–158, https://doi.org/10.1090/qam/1693, 2025.
  3. Mechanism of instability in non-uniform dusty channel flow. Anup Kumar & Rama Govindarajan, Journal of Fluid Mechanics, 997, A77, 2024.
  4. Trapping and extreme clustering of finitely dense inertial particles near a rotating vortex pair. Saumav Kapoor, Divya Jaganathan and Rama Govindarajan, Journal of Fluid Mechanics, 996, A44, 2024.

 

Prof. Meheboob Alam
Title: Routes to Turbulence in Suspension Taylor-Couette Flow
Abstract:  I’ll discuss experimental results on the pattern transition routes towards two distinct turbulent states in Taylor-Couette flow for a neutrally-buoyant particulate suspension.
References
     1. Smith, M. B.; Michl, J. Chem. Rev. 2010, 110, 6891-6936.

Dr. Sunil Laxman

Title: Economic frameworks to understand amino acid production and exchange in and between cell

Abstract: Our lab works to understand the chemical logic and organizational principles of metabolic networks in cells. To understand this, we use interdisciplinary approaches to study how metabolites are sensed, to address systems level organizations of metabolic networks, and to build frameworks to understand resource allocation strategies in cells. In the first part of this talk, I will outline recently published studies that build frameworks based on classical supply-demand economic principles to understand cellular responses. Through this we have addressed how cells prioritize different amino acids during nutrient limitation, and identify clear hierarchies of priority for cells to restore amino acids. In the second part of this talk, I will present new, unpublished studies that collectively build a quantitative understanding of amino acids as an economy – both inside and outside a cell. Through these studies, we define the nature and amounts of amino acids that can be exchanged effectively, and address how some types of auxotrophs can form successful, inter-dependent cell communities. I will further present a biochemical logic for why some amino acids may not be frequently exchanged, because of unique metabolic requirements within cells. I will end by suggesting how such first principles based quantitative studies of amino acid production and exchange may be used to construct synthetic cell communities, or for metabolic engineering efforts to make cell factories.

References

  1. Gupta R, Adhikary S, Dhalpatraj N, Laxman S. Nature Communications. 2024, Volume 15, article number 7254.
  2. Ahmad M. S. et al under preparation 2025

 

Prof. M. Eswaramoorthy

Title: Adaptive Pores: Gating of ion transport in mesoporous silica through reversible pore engineering

Abstract: Non-covalent and dynamic covalent methods were used to reversibly modify the pore size and philicity of mesoporous silica. In the non-covalent approach, the strong, charge-transfer interactions between pyranine and viologen moieties were used for reversible pore engineering.The fast binding of donors enabled quick and facile functionalization at room temperature. The viologen based charge transfer modules were employed in electrostatic gating of ion transport through the nanochannels (<10 nm) in mesoporous silica. The polarity of ion transport was switched from anion selective to cation selective through ambipolar stage by controlling the extent of pyranine bound to the viologen. The modularity of the approach enables modification of nanopores with custom designed compositions, components and functions.

References:

  1.  B. V. V. S. Pavan Kumar, K. V. Rao, T. Soumya, S. J. George and M. Eswaramoorthy, , J. Am. Chem. Soc., 135, 10902 – 10905 (2013)
  2. B. V. V. S. Pavan Kumar, K. Venkata Rao, S. Sampath, S. J. George and M. Eswaramoorthy, Angew. Chem. Int. Ed., 53, 13073-13077 (2014).
  3. B. V. V. S. Pavan Kumar, K. P Sonu, K. V Rao, S Sampath, S. J George, M. Eswaramoorthy, ACS Applied Materials & Interfaces 10 (28), 23458-23465 (2018)

 

Prof Manoj Varma

Title: Single entity sensing using solid-state nanopores

Abstract: Solid-state nanopores provide an excellent system for single molecule sensing with great flexibility in tailoring the pore diameter to suit different targets. In this talk I will describe our recent efforts to enhance the chemical selectivity of solid-state nanopores using DNA origami. Using our hybrid nanopores we have been able to read mono-nucleotide repeats representing a major milestone for solid-state nanopore technology. I will further describe our work in enhancing the mechanical robustness of these devices for improving their practical utility in sensing applications through modification of membrane geometry. Finally, I will describe how this technology can be extended for single-cell studies demonstrating this platform for single-entity sensing where the entity may range from a single molecule to a single cell.