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Georgios Varnavides @gvarnavides.bsky.social · 22/07/2025

The code to generate the Smith / Carlson / N6 tiles is adapted from Ned Batchelder's brilliant blog post: nedbatchelder.com/blog/202208/... Also, here's the picture of the mentioned quilt and its FFT!

Quilt with Smith tiles pattern and vibrant colors (left), and its FFT (right).

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Georgios Varnavides @gvarnavides.bsky.social · 21/07/2025

Went to a cool BAMPFA exhibit this weekend, on African American quilt making! Recognized one of the patterns as a Truchet tiling, and wanted to know what its FFT would look like. Would the symmetry pop up? Would the diffuse scattering?? That led to this fun exploration of Smith/Carlson/N6 tilings 🧪

a 2x3 grid of Smith / Carlson / N6 tiles (top) and their corresponding FFT (bottom). The patterns exhibit considerable amount of diffuse scattering.

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Georgios Varnavides @gvarnavides.bsky.social · 03/07/2025

This fully-funded 4-yr PhD is part of a broader collaboration with ASML, ARCNL, and TU Delft, combining computational imaging, BSE/SE modeling, and inverse algorithms for high-res, low-voltage SEM! #SEM #phd #computationalimaging #electronmicroscopy #curiousbeams @imphys-tudelft.bsky.social

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Georgios Varnavides @gvarnavides.bsky.social · 03/07/2025

🚨 We’re hiring! Join the Curious Beams Lab at TU Delft as one of our first PhDs and help develop the next generation of diffractive imaging in SEM — pushing surface-sensitive nanoscale characterization to new limits 🔬🧪 Please repost & share with your network! 🙏 careers.tudelft.nl/job/Delft-Ph...

careers.tudelft.nl

PhD Position Developing Diffractive Imaging in Scanning Electron Microscopy for Inspection/Metrology

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Georgios Varnavides @gvarnavides.bsky.social · 23/06/2025

Introducing the Curious Beams Lab — where we use electron beams and advanced algorithms to image the structure and function of materials at the nanoscale 🔬 PhD & postdoc openings coming soon — stay tuned! #TUDelft #ElectronMicroscopy #ComputationalImaging

$Curious Beams Lab Logo: Converged electron probe revealing a nanobeam diffraction pattern, in the style of an engineering drawing blueprint.$

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Georgios Varnavides @gvarnavides.bsky.social · 23/06/2025

Thrilled to finally share that I'll be joining TU Delft this fall as an Assistant Professor in the Imaging Physics department 🙌🏼 Excited to join such a vibrant, cross-disciplinary community and grateful to the mentors and colleagues who've supported me along the way 🙏🏼 @imphys-tudelft.bsky.social

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Georgios Varnavides @gvarnavides.bsky.social · 12/06/2025

The main takeaway is that formulating it this way, it follows that tcBF/parallax is a quadratic approximation to phase-compensated SSB (upsampling then follows naturally from that).

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Georgios Varnavides @gvarnavides.bsky.social · 12/06/2025

The formalism in-fact is slightly different, looping over the virtual BF images instead of spatial frequencies. Pseudocode and discussion here: www.elementalmicroscopy.com/articles/EM0... and full code here: github.com/ophusgroup/q...

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Georgios Varnavides @gvarnavides.bsky.social · 12/06/2025

Haha, indeed -- if only we had a better name for "phase-compensated" SSB (meaning using the complex-valued aperture overlap gamma function, here doi.org/10.1016/j.ul...).

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Georgios Varnavides @gvarnavides.bsky.social · 12/06/2025

Split figures are great for papers. For talks, interactive sliders are better 🙌 Here, demoing the upsampling capabilities of tilt-corrected BF STEM and direct ptychography on a beam-sensitive MOF dataset! elementalmicroscopy.com/articles/EM0... 🧪🔬

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Georgios Varnavides @gvarnavides.bsky.social · 15/05/2025

Super proud of this work, which showcases modern scientific publishing for open science 🧪 Inspired by the insights of the interactive CTF widgets, we propose a novel phase-retrieval algorithm which achieves robust information transfer on sub-sampled datasets 🙌 @elementalmicrosc.bsky.social

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Reposted by Georgios Varnavides

Elemental Microscopy @elementalmicrosc.bsky.social · 02/02/2025

Hey there 🦋🧪, we're a new open access microscopy journal and wanted to introduce ourselves! EM aims to modernize scientific publishing for microscopy, by prioritizing open science, transparency, and accessibility and using open-source formats and interactive notebooks 🙌 @curvenote.com @mystmd.org 🚀

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Georgios Varnavides @gvarnavides.bsky.social · 24/01/2025

Attending the APMC 2025 in Brisbane, and interested in learning how to simulate and analyze 4D-STEM data? There's still time to register for the 4D-STEM workshop and learn about strain and orientation mapping, differential phase contrast, ptychography, and more! www.apmc13-2025.org/conference-w...

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Georgios Varnavides @gvarnavides.bsky.social · 10/01/2025

Needed to demonstrate this fun example of solving Sudoku puzzles with projection set algorithms for a workshop I'm teaching. Continuously impressed with how easy it is to get to a working demo with wasm + @marimo.io slides 🙌 🧪 marimo.io/p/@gvarnavid...

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Reposted by Georgios Varnavides

Curvenote® @curvenote.com · 06/12/2024

Monday 9th 15:00 Open Science Pavilion - Big Screen, Exhibit Hall Join @row1.ca for a session on Publishing Computational Research Session #OpenScience #Jupyter @mystmd.org

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Reposted by Georgios Varnavides

Berkeley Lab @berkeleylab.lbl.gov · 26/11/2024

🧪Constrained optimization tiling of the Cal bears logo, using simulated differential phase-contrast imaging of strontium titanate atoms. 🔬 Captured for @molecularfoundry.bsky.social #Nano Art Contest. 📷 Georgios Varnavides, @ucberkeleyofficial.bsky.social More: foundry.lbl.gov/2024/10/21/a...

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Georgios Varnavides @gvarnavides.bsky.social · 19/11/2024

Hello 🧪🦋 New here, so figured I’d introduce myself! I’m a postdoctoral researcher @berkeleylab.bsky.social exploring the mesmerizing corners of diffractive imaging ✨ Short clip of my new favourite teaching demo: nanofabricated Fourier atlas by @hovden.bsky.social lab 🙌 📸: @juliedactyl.bsky.social

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