Tootfinder

I appreciate folks pinging me that my site is down.
The host took it down and, assuming I’m reading these dashboard messages correctly, it was in response to more than a million bot requests.
I have no idea when they will restore it. And I have a lot of IRL stuff this morning, so I’m just gonna leave it be.
In the meantime, the most recent Wayback archive is 18 July:

Adrian Roselli — Consultant, Writer, Speaker
alt: It’s me, but I’m made of polymers. I stand 4 inches tall, my joints are hinged, my face is a rictus of dull PVC. I am restrained against a cardboard wall by a transparent bubble of plastic holding me fast alongside divots bearing the tools of my trade —…

Revisiting Safe Temperature for Environmental Accelerated Aging of Additively Manufactured Polymers
Keven Alkhoury, Nikash Long, Justin Moustouka, Nour Mousbah, Irine Chenwi, James LeBlanc, Vikas Srivastava
https://arxiv.org/abs/2608.12288 https://arxiv.org/pdf/2608.12288 https://arxiv.org/html/2608.12288
arXiv:2608.12288v1 Announce Type: new
Abstract: Accelerated aging is widely used to study the long-term behavior of materials within laboratory time scales, particularly for materials exposed to solvent environments over extended periods. This is especially important for additively manufactured (AM) polymers, whose increasing use in naval and commercial undersea applications requires reliable methodologies for assessing durability under in-service conditions. A common approach relies on elevating the temperature below the glass transition or melting temperature to accelerate degradation. However, the temperature limits for accelerated aging of AM polymers remain poorly understood, particularly because temperatures beyond a threshold may activate deformation and degradation mechanisms that are absent under service conditions. To address this gap, this paper investigates fused deposition modeling (FDM) Acrylonitrile Butadiene Styrene (ABS) exposed to saltwater and deionized (DI) water to establish a temperature threshold for accelerated aging in aqueous environments and propose a methodology for determining such thresholds. Controlled geometries and varying print directions were employed to explicitly probe the underlying mechanisms. We show that samples exposed to temperatures above the threshold exhibit pronounced shrinkage and warping along the printing direction due to the relaxation of process-induced internal stresses. These observations establish an accelerated-aging temperature threshold of 50$^\circ$C for ABS, beyond which additional mechanisms absent under service conditions become active. Additionally, the resulting geometric distortions are masked in thick geometries but become highly pronounced in thin structures. Moreover, solvent ionic content strongly influences water uptake, with saltwater reaching saturation in 1 day, whereas DI water did not reach saturation even after 30 days and exhibited greater mass uptake.
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Product idea: playground equipment made from static dissipative polymers so you don't get shocked when coming down the slide

Universality in the deswelling of tangentially active polymer chains in dilute solutions
Suryansh Tripathi, Aritra Santra
https://arxiv.org/abs/2608.11972 https://arxiv.org/pdf/2608.11972 https://arxiv.org/html/2608.11972
arXiv:2608.11972v1 Announce Type: new
Abstract: Dilute solutions of linear polymer chains with tangentially active monomeric beads are simulated using a Brownian dynamics (BD) algorithm over a range of solvent quality in the crossover regime between $\theta$ and athermal solvents. The conformational changes with increasing P{\'e}clet number ($Pe$) (which is proportional to the strength of activity) suggest deswelling of the chains resulting in a collapse of the radius of gyration data to a random walk (RW) statistics at a unique value of $Pe$, independent of the solvent quality. The swelling behaviour of active polymers in the crossover regime relative to their size at the $\theta$ state is found to follow the same universal characteristics as that of passive polymer chains. Furthermore, based on polymer blob theory we present a novel scaling of the thermal blob size with tangential activity of the monomeric beads. Altogether, this work establishes a connection between the configurational properties of active polymers and scaling laws in polymer physics, which provides a useful framework to study the dynamics of activity induced motion of polymeric molecules for various biophysical applications.
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