Tootfinder

#AmateurRadio Field Day is coming, and I am but a baby ham who wants to try to work #CW on field day, but would like a little practice first.
Morse Walker has an

The Acorn, our local newspaper, had a nice article on CVARC's Field Day...in the first photo, those are phone stations on the right, digital on the left, and CW operators in the next tent in the distance. I try to keep the digital and CW operators separated, because...well, if you know, you know. :wink:
https://www.

Self-cooling, blue-detuned dissipative Kerr microresonator soliton comb
Kenji Nishimoto, Kaoru Minoshima, Naoya Kuse
https://arxiv.org/abs/2508.00432 https://

Self-cooling, blue-detuned dissipative Kerr microresonator soliton comb
Dissipative Kerr solitons (DKSs) generated in high-Q microresonators driven by continuous-wave (CW) lasers provide chip-scale optical frequency combs composed of mutually coherent CW lines. However, their small mode volume makes them highly susceptible to thermal fluctuations, and the resulting thermo-refractive noise (TRN) perturbs the repetition rate $f_{\rm rep}$. Here, we experimentally demonstrate a blue-detuned DKS in a coupled-ring microresonator. By employing avoided-mode-crossing (AMX)…

Still really loving the Insta 360 camera, so easy to make nice things
https://youtu.be/c8YH-oBs-cw

Significance of soft-scale breaking on primordial black hole production in Coleman-Weinberg type supercooling-phase transition
He-Xu Zhang, Katsuya Hashino, Hiroyuki Ishida, Shinya Matsuzaki
https://arxiv.org/abs/2506.23752

Significance of soft-scale breaking on primordial black hole production in Coleman-Weinberg type supercooling-phase transition
Ultra-supercooling phase transitions can generate large overdensities in the Universe, potentially leading to the formation of primordial black holes (PBHs), which can also be a dark matter candidate. In this work, we focus on the supercooling phase transition for the scale symmetry breaking based on the effective potential of the Coleman-Weinberg (CW) type. We investigate the effect on the PBH production in the presence of an additional mass term for the CW scalar field, what we call a soft-sc…

Advancing Atmospheric Pollution Monitoring with Airborne THz Spectrometer
Candida Moffa, Alessandro Curcio, Camilla Merola, Daniele Francescone, Marco Magi, Massimiliano Coppola, Lucia Giuliano, Mauro Migliorati, Massimo Reverberi, Leonardo Mattiello, Massimo Petrarca
https://arxiv.org/abs/2507.00943

Advancing Atmospheric Pollution Monitoring with Airborne THz Spectrometer
This study details the development and validation of an airborne THz spectrometer designed for real-time, remote detection of atmospheric pollutants. The platform couples a stabilized unmanned aerial system (UAS) with a high-resolution terahertz continuous-wave (THz-CW) laser source and detector, enabling flexible, in situ spectroscopic analysis of dispersed atmospheric vapours. This proof-of-concept investigation confirms the feasibility of UAS-THz-CW systems for spatially resolved environment…

On operation and control of CW magnetrons for superconducting accelerators
G. Kazakevich, R. P. Johnson, I. Gonin, V. Yakovlev, Ya. Derbenev, H. Wang
https://arxiv.org/abs/2507.22215

On operation and control of CW magnetrons for superconducting accelerators
CW magnetrons, developed for industrial RF heaters, were suggested to feed RF cavities of superconducting accelerators due to higher efficiency and lower cost of RF power than provide traditionally used klystrons, IOTs or solid-state amplifiers. RF amplifiers driven by a master oscillator serve as coherent RF sources. CW magnetrons are regenerative RF auto generators with a huge regenerative gain. This causes regenerative instability with a notable noise when a magnetron operates as an auto gen…

this is very cool! you can embed UV glow powder into your body and have it glow in the dark after light exposure
[cw: blood, pictures of wounds] https://bioduck.me/2025/06/03/glow-powder-cuttings/
(via @…

Glow Powder Cuttings!
Glowing cuttings have been around for a while. Spyfoxls tried it many years ago. Now more people in the Biohackers Digital Discord have picked it up again and started sharing results. Several folks…

CHESS Compact Wiggler construction report
Alexander Temnykh, Ivan Temnykh
https://arxiv.org/abs/2505.24585 https://arxiv.org/pdf/2505…

CHESS Compact Wiggler construction report
We developed, built, characterized on bench and beam-tested a permanent magnet (PM) Compact Wiggler (CW) prototype with a hydraulic assist gap-controlling mechanism. The prototype is of ~50cm long, 20cm wide and 40cm high and weights ~50kg. Magnetic structure has a 76.2mm period. At 6.5mm minimal gap the structure demonstrated ~2.3 Tesla peak field. At this gap, the magnet arrays attract each other with 7,990 N (1,796 lbf) force. Hydraulic system is employed to balance the attractive forces. He…

Taken just a few minutes ago. Where?
CW guesses or answers. Be as precise as possible.
#osint #geolocation #CatchMeIfYouCan

Useful info to our instance members (and anyone really) about the "mutual aid spam":
https://enby.life/notes/a9de58bd33

Hazelnoot (@hazelnoot)
CW: fedi PSA, spam, mutual aid scam (📎1)

🇵🇱 Cześć! Jestem Łukasz. Trójka z przodu. Warszawa. Na fedi mniej-więcej od 2021 r. Łączę dwa konta w jedno i od tej pory będzie tu więcej polskojęzycznych postów (a jeśli obserwowałxś mnie na polskojęzycznym koncie, to dostaniesz więcej treści po angielsku 😄).
Mam kilka równoległych żyć.
Przez większość czasu buduję rzeczy w internetach, głównie z użyciem TypeScriptu, Reacta i całej reszty tego jazzu. Ciągle jednak lubię generatory stron statycznych i stary dobry HTML/CSS.
W innym życiu jestem fotografem-dokumentalistą i fotoreporterem. Interesuje mnie aktywizm, sztuka, kultura, polityka oraz wszystko, co jest ciekawe, a dzieje się na ulicach miast. Dużo uwagi poświęcam protestom i demonstracjom w Polsce, zwłaszcza dotyczącym praw człowieka i kwestii społecznych. Interesuje mnie też sztuka uliczna, zwłaszcza taka, która niesie ze sobą mocne komunikaty.
Zdarza mi się blogować i tłumaczyć teksty. Wiele lat temu napisałem dwie książki o WordPressie. Obecnie jednak wolę gdzieś wyjść niż spędzać jeszcze więcej czasu przed ekranem.
Okazjonalnie zdarza mi się postować o zdrowiu psychicznym i polityce. Staram się używać CW kiedy to możliwe.
Postuję po polsku i angielsku w zależności od tematu.
No i... chyba tyle. Miło Cię widzieć!
#introduction #witajswiecie #przywitanie #wprowadzenie

Note to self: remember that content warnings don't exist in Bluesky, so you may want to think if you want to bridge stuff you'd put here on the Fediverse under a CW.

Exotic presentations of quaternion groups and Wall's D2 problem
Tommy Hofmann, John Nicholson
https://arxiv.org/abs/2507.15999 https://arxiv.org/pdf/25…

Exotic presentations of quaternion groups and Wall's D2 problem
The D2 problem of C. T. C. Wall asks whether every finite cohomologically 2-dimensional CW-complex is homotopy equivalent to a finite 2-complex. Several potential counterexamples have been proposed, the longest standing of which is a CW-complex constructed by Cohen and Dyer whose fundamental group is a quaternion group of order 32. We show that this CW-complex is homotopy equivalent to the presentation 2-complex of a presentation constructed by Mannan-Popiel, thus showing it is not a counterexa…

#HamRadio achievement unlocked!
I have previously successfully activated #POTA parks by "hunting" CW (answering people in other parks calling out to connect to anyone who can hear them), and by calling CQ on SSB (using voice to call out for any station to come back to me) as well…

Swan modules and homotopy types after a single stabilisation
Tommy Hofmann, John Nicholson
https://arxiv.org/abs/2507.21975 https://arxiv.org/pdf/2507.2197…

Swan modules and homotopy types after a single stabilisation
We study Swan modules, which are a special class of projective modules over integral group rings, and their consequences for the homotopy classification of CW-complexes. We show that there exists a non-free stably free Swan module, thus resolving Problem A4 in the 1979 Problem List of C. T. C. Wall. As an application we show that, in all dimensions $n \equiv 3$ mod $4$, there exist finite $n$-complexes which are homotopy equivalent after stabilising with multiple copies of $S^n$, but not after …

Bloody assholes.

This https://arxiv.org/abs/2312.13227 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Relative cell complexes in closure spaces
We give necessary and sufficient conditions for certain pushouts of topological spaces in the category of Cech's closure spaces to agree with their pushout in the category of topological spaces. We prove that in these two categories, the constructions of cell complexes by a finite sequence of closed cell attachments, which attach arbitrarily many cells at a time, agree. Likewise, the constructions of CW complexes relative to a compactly generated weak Hausdorff space that attach only finitely m…

Baby's First #AmateurRadio #FieldDay! I ran the GOTA station for a few minutes to warm it up, and again in the early morning after the night crew were done for a handful of QSOs, but I spent many hours in the CW tent. At the start I just froze up and needed lots of help from th…

🇺🇦 #NowPlaying on KEXP's #SoundsOfSurvivance
CW Ayon:
🎵 Bounce, Boogie, and Bump
#CWAyon
https://cwayon.bandcamp.com/album/bounce-boogie-bump
https://open.spotify.com/track/6vl9GFjDlZznI7iNRrPBYV

A Fox-Neuwirth Basis for the Sinha Spectral Sequence
Andrea Marino
https://arxiv.org/abs/2505.22958 https://arxiv.org/pdf/2505.22958

A Fox-Neuwirth Basis for the Sinha Spectral Sequence
Recently, Sinha defined a spectral sequence approximating the (co)homology of the space of long knots in R^m modulo immersions, stemming from a cosimplicial structure on the compactified configuration spaces à la Kontsevich. We provide an equivalent cosimplicial structure on (the barycentric subdivision of) a regular CW complex with cells indexed by Fox-Neuwirth trees. As a corollary, we give a combinatorial presentation of the Sinha Spectral Sequence in terms of Fox-Neuwirth trees for all dim…

I don't know what to say about this new Mortal Kombat trailer (cw: gore). I've played the original game back when it was forbidden in Germany due to the violence.
This latest incarnation seems to push the right buttons for some fans. To me it just looks like obvious CGI gore and camera moves. Somebody is saying a line from the original video game. But what else can you do with this franchise? This is probably true to form.

The configuration functor of a punctured space
Eduard Looijenga, Andreas Stavrou
https://arxiv.org/abs/2507.14366 https://arxiv.org/pdf/2507.14366

The configuration functor of a punctured space
Let $U$ be a space whose one point compactification $U^*$ is a CW-complex for which the added point $*$ is the only $0$-cell. We observe that the configuration space $Conf_n(U)$ of $n$ numbered distinct points in $U$ has no closed support homology in degree $

Quantitative Macromolecular Proton Fraction Imaging using Pulsed Spin-Lock
Qianxue Shan (Department of Imaging and Interventional Radiology), Ziqiang Yu (Department of Imaging and Interventional Radiology), Baiyan Jiang (Department of Imaging and Interventional Radiology, Illumination Medical Technology Limited), Jian Hou (Department of Imaging and Interventional Radiology), Qiuyi Shen (Department of Imaging and Interventional Radiology), Winnie CW Chu (Department of Imaging and Interv…

Quantitative Macromolecular Proton Fraction Imaging using Pulsed Spin-Lock
Purpose: Recent studies have shown that spin-lock MRI can simplify quantitative magnetization transfer (MT) by eliminating its dependency on water pool parameters, removing the need for a T1 map in macromolecular proton fraction (MPF) quantification. However, its application is often limited by the requirement for long radiofrequency (RF) pulse durations, which are constrained by RF hardware capabilities despite remaining within specific absorption rate (SAR) safety limits. Methods: To addres…

Combined frequency comb and continuous wave cavity-enhanced optical-optical double-resonance spectrometer in the 1.7 ${\mu}$m range
Vinicius Silva de Oliveira, Adrian Hj\"alt\'en, Isak Silander, Andrea Rosina, Michael Rey, Kevin K. Lehmann, Aleksandra Foltynowicz
https://arxiv.org/abs/2506.17669

Combined frequency comb and continuous wave cavity-enhanced optical-optical double-resonance spectrometer in the 1.7 $μ$m range
We present an optical-optical double-resonance (OODR) spectrometer based on a 3.3 $μ$m continuous wave pump and two cavity-enhanced probes: a frequency comb tunable in the 1.64 - 1.8 $μ$m range, and a comb-referenced continuous wave (CW) laser tunable in the 1.6 - 1.75 $μ$m range. The comb probe provides broad spectral coverage (bandwidth up to 7 THz) for simultaneous detection of many sub-Doppler OODR transitions with sub-MHz line position accuracy, while the CW probe allows targeting indiv…

I tried hunting POTA with five different #HamRadio antenna arrangements while taking a short holiday at the beach over the past few days. I tried the built-in antenna on my KX3, a 20m vertical with radials on a deck, the same vertical with radials stuck with a stake into the top of a sand dune, and two inverted-V 40m end-fed half wave arrangements on a spiderbeam, a north/south and an e…

I wish I'd known of this video before I started trying to hunt #POTA. It's so helpfully thorough and systematic. The past few days would have been a lot easier for me if I'd watched it before.
Anyone here who is learning #CW and thinking of trying to hunt POTA, this is totally worth yo…

A New cw-NMR Q-meter for Dynamically Polarized Targets for Particle Physics
J. D. Maxwell, J. Brock, C. Cuevas, H. Dong, C. D. Keith, J. J. Pierce
https://arxiv.org/abs/2506.14637

A New cw-NMR Q-meter for Dynamically Polarized Targets for Particle Physics
Polarized solid targets produced via Dynamic Nuclear Polarization rely on Continuous-Wave Nuclear Magnetism Resonance measurements to accurately determine the degree of polarization of bulk samples polarized to nearly 100%. Since the late 1970's phase sensitive detection methods have been utilized to observe the magnetization of a sample as a small change in inductance under RF excitation near the Larmor frequency of the nuclear species of interest, using a device known as a Q-meter. Liverpool …

This https://arxiv.org/abs/2502.13276 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

CW-complexes and minimal Hilbert vector of graded Artinian Gorenstein algebras
I introduce a geometric interpretation of the set of standard graded Artinian Gorenstein algebras of codimension $n$ and degree $d$: the standard locus, which is a subset of the projective space of degree $d$ polynomials in $n$ variables, and I characterize it. Under opportune hypothesis, I prove that the locus of full Perazzo polynomials is the union of the minimal dimensional irreducible components of the standard locus and it is pure dimensional subset. On the other hand, I associate to any …

Lense-Thirring Precession Modulates Repeated Lensing of Continues Gravitational Wave Source from AGN Disks
Yu-Zhe Li, Wen-Long Xu, Yi-Gu Chen, Wei-Hua Lei
https://arxiv.org/abs/2506.04196

Lense-Thirring Precession Modulates Repeated Lensing of Continues Gravitational Wave Source from AGN Disks
Gravitational lensing of gravitational waves (GWs) offers a novel observational channel that complements traditional electromagnetic approaches and provides unique insights into the astrophysical environments of GW sources. In this work, we investigate the repeated lensing of continuous gravitational wave (CW) sources in active galactic nucleus (AGN) disks by central supermassive black holes (SMBHs), focusing on the imprint of SMBH spin via the Lense-Thirring (LT) effect. Although typically wea…

Youtube comment handling is so annoying.
HRCC talked about Field Day, including some mention of CW. So I mentioned my Morse Walker Field Day simulator work, and Josh pinned my comment.
I have now twice posted followup comments mentioning QRZ and my call sign, hoping that people can find the simulator from my QRZ page, without posting a link, and Youtube keeps silently deleting the comments. Argh.
I have no idea what it is triggering on.
Meanwhile,

Link Bundles of Compact Toric Varieties of Real Dimension 8
Shahryar Ghaed Sharaf
https://arxiv.org/abs/2507.12309 https://arxiv.org/…

Link Bundles of Compact Toric Varieties of Real Dimension 8
The main goal of this work is to determine the Betti numbers of the links of isolated singularities in a compact toric variety of real dimension 8, using the CW-structure of the links. Additionally, we construct the intersection spaces associated with these links. Using the duality of the Betti numbers of intersection spaces, we conclude that, similar to the case of toric varieties of real dimension 6, the Betti numbers of the links contain only one non-combinatorial invariant parameter. In the…

Squeaking in at the end of @… week #HC29S — I played #POTA today, hunting CW park-to-park, to test my new QRP linked …

A tunable, continuous-wave 130-mW laser at 213 nm
Lukas M\"oller, Stephan Hannig, Stefan Truppe, Simon Stellmer
https://arxiv.org/abs/2506.08709 https…

A tunable, continuous-wave 130-mW laser at 213 nm
We present a tunable, continuous-wave (CW) laser system emitting at 213 nm, based on the frequency quadrupling of a single Ti:sapph laser. The setup features two sequential, cavity-enhanced second-harmonic generation (SHG) stages. The first stage uses an LBO crystal and achieves a conversion efficiency of over 80%, yielding up to 3.3 W at 426 nm. The second stage employs a Brewster-cut BBO crystal with an elliptical beam waist to mitigate UV-induced degradation, producing up to 130 mW of deep U…

Free actions on products of real projective spaces
Ergun Yalcin
https://arxiv.org/abs/2506.04067 https://arxiv.org/pdf/2506.04067

Free actions on products of real projective spaces
We prove that if $G=(\mathbb{Z}/2)^r$ acts freely and cellularly on a finite-dimensional CW-complex $X$ homotopy equivalent to $\mathbb{R}P ^{n_1} \times \cdots \times \mathbb{R} P ^{n_k}$ with trivial action on the mod-$2$ cohomology, then $r \leq μ(n_1)+ \cdots + μ(n_k )$ where for each integer $n\geq 0$, $μ(n)=0$ if $n$ is even, $μ(n)=1$ if $n\equiv 1$ mod 4, and $μ(n)=2$ if $n\equiv 3$ mod 4. This proves a homotopy-theoretic version of a conjecture of Cusick.

@… #HC24S — Over the past few days, I made and improved a PR adding Field Day support to the Open Source #MorseWalker #CW …

On measure homology of mildly wild spaces
Thilo Kuessner, Janusz Przewocki, Andreas Zastrow
https://arxiv.org/abs/2506.03368 https://…

On measure homology of mildly wild spaces
We prove injectivity of the canonical map from singular homology to measure homology for certain ``mildly wild" spaces, that is, certain spaces not having the homotopy type of a CW-complex, but having countable fundamental groups.

The MIST-1 and MIST-2 multicusp ion sources for high-current H$_2^ $ beams
Daniel Winklehner, Samuel Engebretson, Jarrett Moon, Joshua Villarreal, Philip Weigel, Eleanor Winkler, Parker landon
https://arxiv.org/abs/2507.03155

The MIST-1 and MIST-2 multicusp ion sources for high-current H$_2^+$ beams
We present two iterations of the Multicusp Ion Source Technology at MIT (MIST) sources, designed to fulfill the requirements of the HCHC-XX cyclotron design. The HCHC-XX is a novel compact cyclotron accelerating H$_2^+$. Beam is injected through a radio-frequency quadrupole buncher-accelerator (embedded in the cyclotron yoke) and utilizes so-called vortex motion during acceleration. If successful, it will deliver 10 mA of protons at 60 MeV in CW mode. This scheme requires a low-emittance, high-…