It’s perhaps not fair, but even if you have the best idea for a compelling video, few things will make people switch off than poor lighting. Good light and plenty of it is the order of the day when it comes to video production, and luckily there are many affordable options out there. Affordable, that is, right up to the point where you need batteries for remote shoots, in which case you’d better be ready to open the purse strings.

When [Dane Kouttron] ran into the battery problem with his video lighting setup, he fought back with these cheap and clever cordless tool battery pack adapters. His lights were designed to use Sony NP-F mount batteries, which are pretty common in the photography trade but unforgivably expensive, at least for Sony-branded packs. Having access to 20 volt DeWalt battery packs, he combined an off-the-shelf battery adapter with a 3D printed mount that slips right onto the light. Luckily, the lights have a built-in DC-DC converter that accepts up to 40 volts, so connecting the battery through a protection diode was a pretty simple exercise. The battery pack just slots right in and keeps the lights running for portable shoots.

Of course, if you don’t already have DeWalt batteries on hand, it might just be cheaper to buy the Sony batteries and be done with it. Then again, there are battery adapters for pretty much every cordless tool brand out there, so you should be able to adapt the design. We’ve also seen cross-brand battery adapters which might prove useful, too.

hackaday.com/2024/12/12/good-l…

As part of a phosphorescence detector, [lcamtuf] has been working with photodiodes. The components, like all diodes, have some capacitance at the junction, and this can limit performance. That’s why [lcamtuf] turned to bootstrapping to make that parasitic capacitance almost disappear.

The technique appears in several Analog Devices datasheets that presents a mystery. An op amp circuit that would normally limit changes to about 52 kHz has an unusually-placed JFET and claims to boost the bandwidth to 350 kHz.

The JFET turns out to be in a voltage-follower configuration. The photodiode sees approximately the same voltage on both terminals, so the internal capacitor can’t charge and, therefore, doesn’t impose any limits on rate of change.

Of course, a better way to think of it is that tiny changes cause an immediate response to counteract them, and so the capacitor’s charging and discharging are kept to a minimum.

It really isn’t important that the capacitor is not charged, but rather that the capacitor doesn’t increase or decrease charge. This leads to a second design, which imposes a DC bias voltage on the diode but prevents any signal from causing the capacitor to change from its precharged value.

Photodiodes seem exotic, but honestly, all semiconductor diodes are photodiodes if you let the light get to them. It seems that capacitors and op amps are always at loggerheads.

hackaday.com/2024/12/12/the-di…

On December 11th, the FCC announced that the band around 6GHz would be open to “very low-power devices.” The new allocation shares space with other devices already using these frequencies. The release mentions a few limitations over the 350 MHz band (broken into two segments). First, the devices must use a contention-based protocol and implement transmit power control. The low-power devices may not be part of a fixed outdoor infrastructure.

The frequencies are 6.425-6.525 GHz, 6.875-7.125 GHz and the requirements are similar to those imposed on 802.11ax in the nearby U-NII-5 and U-NII-7 bands.

In her remarks, Chairwoman Jessica Rosenworcel said, in part:

But powerful innovation in wireless does not only come from licensed spectrum. Unlicensed spectrum matters, too. In fact, our lives run on unlicensed spectrum. We use it for everything from connecting at work and home with Wi-Fi to supply chain management in warehouses and delivery trucks, from maximizing our workouts with fitness trackers and earbuds to making our homes smarter and more efficient.

I like to think of unlicensed spectrum as an invisible force in our economy. Wi-Fi alone will foster $769 billion in economic growth in 2024. That number is projected to rise 21 percent
in 2025 and as high as 67 percent by 2027 when the latest version of Wi-Fi will be in available in millions of devices.

. . .

We made it possible to access airwaves without licenses, to innovate without permission, and to develop low-power wireless technologies that
have changed the way we live and work.

Sounds like hacking to us. We remember when 6 GHz was nearly impossible to use, and hams building stuff using Gunn diodes to hit over 10 GHz was super edgy. Now, there’s a lot going on up there. It still isn’t trivial to design for frequencies that high.

hackaday.com/2024/12/12/the-6g…

Nuclear fission is a powerful phenomenon. When the conditions are right, atomic nuclei split, releasing neutrons that then split other nuclei in an ongoing chain reaction that releases enormous amounts of energy. This is how nuclear weapons work. In a more stable and controlled fashion, it’s how our nuclear reactors work too.

However, these chain reactions can also happen accidentally—with terrifying results. Though rare, criticality incidents – events where an accidental self-sustaining nuclear chain reaction occurs – serve as sobering reminders of the immense and unwieldy forces we attempt to harness when playing with nuclear materials.

Too Much Already

Criticality in a large mass and with a neutron reflector. Credit: Wikimedia Commons, public domain
A criticality incident is when a nuclear fission chain reaction is caused by accident. The cause is usually quite simple. When it comes to fissionable material, like radioactive isotopes of uranium, there is a certain critical mass at which a chain reaction will occur. At this point, the natural radioactive decay of the material will release enough neutrons such that one might strike and split another atom. This then releases further neutrons, which split more atoms, and the chain reaction continues.

Calling it critical mass is a simplified way of saying it. More realistically, the critical mass depends on more factors—the shape of the radioactive material plays a role, too. As does the presence of any neutron reflectors that could bounce neutrons back towards more atoms to split.

Long story short, if you put too much fissionable material in one place, you’re asking for trouble. If it gets to that critical point and the chain reaction starts, it’s going to release a ton of radiation in a split second.
The Slotin experiment is one of the most well-known criticality incidents. Credit: Los Alamos National Laboratory
The most famous example of a criticality incident occurred when Louis Slotin was working with the Demon Core at Los Alamos back in 1946. The story has been told many a time, including on these hallowed pages. Start there if you’re curious, before we look at some more recent disasters.

America’s nuclear program hasn’t just had one awkward mistake like this. It’s had a few. One of the most serious criticality accidents in history occurred on December 30, 1958, once again at the Los Alamos National Laboratory in New Mexico. Chemical operator Cecil Kelley was processing plutonium-containing liquids in a large mixing tank as per his regular duties.
The mixing tank which Kelley was operating was filled with a concentration of uranium 200 times higher than expected. Credit: Los Alamos National Laboratory
The tank was used for recovering and reusing plutonium solutions from various experiments, and was expected at that time to contain less than 0.1 grams of plutonium per liter of solution. Unbeknownst to Kelley, the tank actually held a far greater quantity of plutonium—over 3 kilograms—due to improper transfers of waste materials to the tank. The fluid in the tank wasn’t homogenous, either—there was a denser layer of aqueous solution at the bottom, topped with a lighter layer of organic solution which contained more of the plutonium.

The tank was already close to a critical state at rest. When Kelley switched on the mixer inside, the blades formed a vortex, pushing the dense aqueous layer of fluid outwards. In turn, the more plutonium-rich organic fluid was drawn to the center of the vessel, where it promptly went critical.

As Kelley stood on a ladder viewing the mixing tank, there was a sudden bright flash of blue light. A huge surge of neutron and gamma radiation flooded the room, delivering Kelley a lethal dose in a split second. His death was harrowing, and he passed away just 35 hours after the accident. While investigations were undertaken into the matter, there has never been a public explanation for how the excessively high concentration of plutonium ended up in the tank.
When the mixer was turned on, the plutonium-rich layer of solution was brought closely together to the point where a criticality incident occurred. Credit: KDS4444, CC BY 3.0
Fast forward to 1999, when carelessness caused a similar incident in Tokaimura, Japan. At a uranium processing facility, technicians were tasked with preparing a batch of fuel. Official regulations mandated that a uranyl nitrate solution be stored in a buffer tank, and added to a precipitation tank in controlled increments. However, as per a company operations manual that was unapproved by regulators, technicians were mixing chemicals in stainless steel buckets instead, rather than using the buffer tank that was designed to prevent criticality incidents. The crew were pouring the liquid directly into the precipitation tank, which had a cylindrical geometry that was favorable for inducing criticality.

The tank soon ended up with over 16 kg of uranium inside, well over the 2.4 kg limit set by regulators. As the seventh bucket was added, the tank went critical with a bright blue flash. Radiation alarms wailed as neutron levels shot up to 15,000 times normal. Three technicians received extreme radiation doses with severe ill effects; two of the three later died. The facility was irradiated, with residents in surrounding areas having to evacuate in the immediate aftermath.

Much like the Los Alamos event, the cause of the problem was simple. The technicians simply combined too much fissile material in one place.

youtube.com/embed/r3fWhW_NsMs?…

CRITICALITY (1969) is a British documentary on the danger of criticality incidents, and how to avoid them. If you work with nuclear materials, you’ve ideally been educated with something more up-to-date. Still, the basic physics was well-understood back then, and the lessons here largely ring true today.
If you see someone arranging nuclear materials like this for a quick photo, you’d be well advised to tell them to stop. Credit: Los Alamos National Laboratory, Department of Energy
Los Alamos suffered an embarrassing incident in more recent times, too, though thankfully a near miss. Back in 2011, technicians had arranged a number of plutonium rods on a table in order to take a photo—the intent being to celebrate their successful production. A supervisor returning to the area noticed the close assembly of the rods and quickly instructed they be separated, lest a criticality incident occur. Disaster was averted before the dreaded blue flash occurred, but it was yet another harrowing example where fundamental safety rules around criticality had been ignored.

Lessons

So what can these unfortunate incidents teach us? Strict limits and controls on fissionable materials are key. Standard procedures that control the flow of fissionable material are important to achieve this. The Tokaimura incident showed how bypassing these protocols even briefly can be disastrous. Beyond that, it’s important that those working with these materials are cognicent of the risks at all times. Even something as simple as bringing together a few rods to take a photo could cause a major incident through carelessness.

But perhaps the biggest lesson is respecting the sheer power of fission itself. When a chain reaction starts, things go wrong fast. By the time the blue flash has told you something’s happened, it’s all too late. Radiation levels have spiked through the roof and the damage is done. There is no early warning sign in these cases. Proper procedure is the only real way to avoid disaster.

Fssion remains a fickle phenomenon that is not to be trifled with. When we do trifle with it, either by honest accident or gross negligence, the results can be swift and brutal. Each of these criticality incidents was a stern reminder to humanity to maintain the utmost vigilance and safeguards when working with fissionable materials. Failure to do so always ends up the same way.

hackaday.com/2024/12/12/its-cr…

Il messenger di Telegram ha pubblicato dati sul blocco di gruppi e canali che violano le politiche e la legislazione della piattaforma. Sul sito ufficiale dell’azienda è apparsa una scheda con le statistiche.

Nel 2024 sono stati bloccati 15,3 milioni di gruppi e canali. Tra questi ci sono quasi 702mila comunità associate alla diffusione di materiale sugli abusi sessuali sui minori e circa 129mila gruppi e canali con orientamento terroristico. Inoltre, sono stati rimossi più di 100 milioni di contenuti terroristici.

Il sito web dell’azienda riporta che Telegram blocca ogni giorno decine di migliaia di gruppi e canali, eliminando milioni di contenuti vietati. Le violazioni identificate includono incitamento alla violenza, distribuzione di materiale pedopornografico e commercio di beni illegali.

Si chiarisce che il processo di moderazione prevede l’elaborazione dei reclami degli utenti e il monitoraggio proattivo. Dal 2015 queste misure vengono realizzate utilizzando tecnologie di machine learning. Nel 2024 Telegram ha introdotto nuovi strumenti basati sull’intelligenza artificiale, che hanno permesso di aumentare l’efficienza nell’identificazione e nel blocco dei materiali vietati.

Ricordiamo che ad inizio di agosto, il fondatore di Telegram è stato arrestato in Francia nell’ambito di un’indagine relativa a crimini quali la distribuzione di immagini di abusi sessuali su minori, traffico di droga e frode. Dopo questo incidente, Durov ha difeso attivamente la sua piattaforma, poiché milioni di post e canali dannosi vengono cancellati ogni giorno.

Durov è riuscito a evitare la detenzione pagando una cauzione di 5 milioni di euro. Secondo l’accordo, dovrà recarsi alla stazione di polizia due volte a settimana e rimanere in Francia fino alla conclusione del processo. L’imprenditore è stato interrogato per la prima volta il 6 dicembre in un tribunale di Parigi per un caso di moderazione insufficiente nel messenger di Telegram, ha scritto 20Minuti con riferimento all’AFP.

Durov è arrivato in tribunale con i suoi avvocati David-Olivier Kaminsky e Christoph Ingren. L’uomo d’affari ha rifiutato di commentare in dettaglio, dicendo solo che ha fiducia nel sistema giudiziario francese. L’avvocato di Kaminsky ha definito assurda la posizione dell’accusa secondo cui Durov era coinvolto in crimini commessi tramite Telegram.

L'articolo Telegram Mostra i Muscoli sulla Moderazione! bloccati 15 milioni di canali nel 2024 proviene da il blog della sicurezza informatica.

agenparl.eu/2024/12/11/millepr…

(AGENPARL) – mer 11 dicembre 2024 MILLEPROROGHE, COLUCCI (M5S): SU AUTONOMIA E LEP GOVERNO PERSEVERA E VA CONTRO CONSULTA
ROMA, 11 dic. – “Nel testo bollinato del decreto Milleproroghe all’articolo 16 il governo trasferisce presso il dipartimento per gli Affari regionali e le Autonomie, quindi al ministro Calderoli, l’attività istruttoria per la determinazione dei livelli essenziali delle prestazioni (LEP) e dei relativi costi e fabbisogni standard, fino al 31 dicembre 2025. Quindi, il Governo persevera nell’errore di avocare a sè la determinazione dei Lep, calpestando il Parlamento e soprattutto la Corte Costituzionale che, nella recente sentenza sulla legge per l’Autonomia Differenziata, ha bocciato questa possibilità. Vorremmo anche capire cosa significa che l’attività istruttoria è trasferita “presso” e non “al” dipartimento, il Comitato per la determinazione dei LEP, presieduto dal prof. Cassese, è stato licenziato o semplicemente trasferito presso il Ministero? Sarebbe doveroso il suo scioglimento, a seguito della sentenza della Corte Costituzionale che ha bocciato la legge Calderoli e le collegate norme contenute nella legge di Bilancio 2023. In ogni caso questa contenuta nel dl Milleproroghe è un’operazione a dir poco spregiudicata, tenuto conto che la legge Calderoli è stata bocciata dalla Corte in tutti i suoi pilastri portanti, e lo è ancor di più se si considera che l’attività istruttoria si riferisce alla determinazione delle sole materie Lep e non anche, come pure ha stabilito la Corte, delle materie non Lep nelle parti in cui incidano su diritti sociali e civili. E’ proprio il caso di dire che non c’è peggior sordo di chi non vuol sentire. Al governo e alla maggioranza lo hanno ricordato tantissimi cittadini che hanno firmato per cancellare l’Autonomia, poi la Consulta con la sentenza che smantella la legge Calderoli. Se vogliono perseverare, prenderanno altre batoste e purtroppo a pagare saranno i cittadini che assistono a questo scempio istituzionale che può avere drammatiche ricadute sulla loro vita quotidiana”.
Lo afferma il capigruppo M5S nella commissioni Affari Costituzionali della Camera Alfonso Colucci.
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MILLEPROROGHE, COLUCCI (M5S): SU AUTONOMIA E LEP GOVERNO PERSEVERA E VA CONTRO CONSULTA

(AGENPARL) - Roma, 11 Dicembre 2024(AGENPARL) – mer 11 dicembre 2024 MILLEPROROGHE, COLUCCI (M5S): SU AUTONOMIA E LEP GOVERNO PERSEVERA E VA CONTRO CONSULTA ROMA, 11 dic.

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