Tootfinder

Open Gas-Cell Transmission Electron Microscopy at 50 pm Resolution
Idan Biran, Frederik Dam, Sophie Kargo Kaptain, Ruben Bueno Villoro, Maarten Wirix, Christian Kisielowski, Peter C. K. Vesborg, Jakob Kibsgaard, Thomas Bligaard, Christian D. Damsgaard, Joerg R. Jinschek, Stig Helveg
https://arxiv.org/abs/2508.04294

Open Gas-Cell Transmission Electron Microscopy at 50 pm Resolution
Transmission electron microscopy (TEM) has reached ~ 50 picometer resolution in a high vacuum, enabling single-atom sensitive imaging of nanomaterials. Extending this capability to gaseous environments would allow for similar visualizations of nanomaterial dynamics under chemically reactive conditions. Here, we examine a new TEM system that maintains 50 pm resolution at pressures up to 1 mbar, demonstrated using nanocrystalline Au immersed in N2. The system features an open gas-cell with a four…

Safe bet that on any given afternoon, 25-50% of the people who teach intro classes at Brown CS are out riding a bike. Sometimes we even run into each other! And since it's Andy van Dam that people really want to see, not me, here's a shot of just him w/ his new bike.

The Klamath has long been my favorite river in California (and a bit of Oregon.)
A week ago I was at the mouth of the Klamath in Redwood National Park/Prairie Creek State park.
I'm glad the Coho salmon are returning to the Klamath so quickly (of all the varieties of salmon, Coho is my favorite. The creek behind my house once supported Coho, but they are essentially gone, although there are occasional reports.)

"Norway’s police intelligence agency PST is blaming “pro-Russian hackers” for what it calls “sabotage” to a dam at Bremanger in Western Norway last spring. The alleged hackers gained control of a system that allowed water to pour out of the dam for around four hours in April.
14.08.2025
https://www.

Swimming pool at the bottom of the gorge in Treman State Park
#photo #photography #laowa #9mm

Had a chance to fly with L, certified flight instructor at University of #NorthDakota. The Homme Dam on the Park River, and boulder piles in a field near Pisek, ND, in this glaciated terrain.

The ALPINE-CRISTAL-JWST survey: spatially resolved star formation relations at $z\sim5$
C. Accard, M. B\'ethermin, M. Boquien, V. Buat, L. Vallini, F. Renaud, K. Kraljic, M. Aravena, P. Cassata, E. da Cunha, P. Dam, I. de Looze, M. Dessauges-Zavadsky, Y. Dubois, A. Faisst, Y. Fudamoto, M. Ginolfi, C. Gruppioni, S. Han, R. Herrera-Camus, H. Inami, A. M. Koekemoer, B. C. Lemaux, J. Li, Y. Li, B. Mobasher, J. Molina, A. Nanni, M. Palla, F. Pozzi, M. Rela\~no, M. Romano, P. Sawant, J. …

The ALPINE-CRISTAL-JWST survey: spatially resolved star formation relations at $z\sim5$
Star formation governs galaxy evolution, shaping stellar mass assembly and gas consumption across cosmic time. The Kennicutt-Schmidt (KS) relation, linking star formation rate (SFR) and gas surface densities, is fundamental to understand star formation regulation, yet remains poorly constrained at $z > 2$ due to observational limitations and uncertainties in locally calibrated gas tracers. The [CII] $158 {\rm μm}$ line has recently emerged as a key probe of the cold ISM and star formation in t…

Nano-resolved sensing of 3D electromagnetic fields via single emitters' extreme variation of enhanced spontaneous emission
R. Margoth C\'ordova-Castro, Dirk Jonker, Cl\'ement Cabriel, Mario Zapata-Herrera, Bart van Dam, Yannick De Wilde, Robert W. Boyd, Arturo Susarrey-Arce, Ignacio Izeddin, Valentina Krachmalnicoff
https://

Nano-resolved sensing of 3D electromagnetic fields via single emitters' extreme variation of enhanced spontaneous emission
Controlling quantum light-matter interactions at scales smaller than the diffraction limit at the single quantum emitter level is a critical challenge to the goal of advancing quantum technologies. We introduce a novel material platform that enables precise engineering of spontaneous emission changes in molecular single emitters through 3D nanofields. This platform is based on a 3D hollow plasmonic nanomaterial arranged in a square lattice, uniformly scalable to the centimeter scale while maint…

Spatial, Spectral and Temporal Response of High Intensity Laser Plasma Mirrors
Sk Rakeeb, Animesh Sharma, Sagar Dam, Ameya Parab, Amit Lad, Yash. M. Ved, Amita Das, G. Ravindra Kumar
https://arxiv.org/abs/2506.18425

Spatial, Spectral and Temporal Response of High Intensity Laser Plasma Mirrors
Plasma-based optics have emerged as a powerful platform for manipulating and amplifying ultra-intense laser pulses. However, the inherently nonlinear and dynamic nature of plasma leads to significant spatial, spectral, and temporal modulations when driven at relativistic intensities. These modifications can dramatically alter the structure of the reflected laser pulses, posing challenges for their use in applications such as vacuum ultraviolet (VUV) and X-ray generation, as well as relativistic…

Hyperuniformity near jamming transition over a wide range of bidispersity
Duc T. Dam, Takeshi Kawasaki, Atsushi Ikeda, Kunimasa Miyazaki
https://arxiv.org/abs/2507.12738

Hyperuniformity near jamming transition over a wide range of bidispersity
We numerically investigate hyperuniformity in two-dimensional frictionless jammed packings of bidisperse systems. Hyperuniformity is characterized by the suppression of density fluctuations at large length scales, and the structure factor asymptotically vanishes in the small-wavenumber limit as $S(q) \propto q^α$, where $α> 0$. It is well known that jammed configurations exhibit hyperuniformity over a wide range of wavenumbers windows, down to $q^{\ast}σ\approx 0.2$, where $σ$ is the partic…

Multi-Queue SSD I/O Modeling & Its Implications for Data Structure Design
Erin Ransom, Andrew Lim, Michael Mitzenmacher
https://arxiv.org/abs/2507.06349

Multi-Queue SSD I/O Modeling & Its Implications for Data Structure Design
Understanding the performance profiles of storage devices and how best to utilize them has always been non-trivial due to factors such as seek times, caching, scheduling, concurrent access, flash wear-out, and garbage collection. However, analytical frameworks that provide simplified abstractions of storage performance can still be accurate enough to evaluate external memory algorithms and data structures at the design stage. For example, the Disk Access Machine (DAM) model assumes that a stora…

Impulsive excitation of a solid by extreme contrast, high intensity femtosecond laser pulses
Sagar Dam, Jian Fuh Ong, Sk Rakeeb, Ameya Parab, Aparajit C, Anandam, Amit D Lad, Yash M Ved, M Krishnamurthy, Kazuo A Tanaka, G Ravindra Kumar
https://arxiv.org/abs/2508.13649

Impulsive excitation of a solid by extreme contrast, high intensity femtosecond laser pulses
We present the ultra-fast dynamics of the interaction between a high-intensity extreme contrast (expected to be around 1e-18 at hundreds of picoseconds timescale) femtosecond laser and a solid. Simultaneous measurements of probe Doppler spectrometry and reflectivity in pump-probe experiments reveal the presence of extreme pressure in the solid density region, which triggers a long-lived (about 15 ps) strong inward shock. Hydrodynamic simulations accurately replicate these observations, providin…