slowforward.net/2024/08/23/man…

slowforward

2024-08-23 07:31:01

t.ly/73tsy

slowforward.net/2024/08/23/man…

#000000 #CarloBellinvia #CentroScritture #ECS #EdizioniCentroScritture #LuciaManetti

due nuovi libri, di lucia manetti e di carlo bellinvia, per le edizioni centroscritture

Visita l'articolo per saperne di più.

^slowforward

slowforward.net/2024/08/22/ope…

slowforward

2024-08-22 20:43:55

BADA festival / Brancaleone / d.i.y. prints & stuff
instagram.com/p/C9cblsntwGP/

per inviare proposte (entro il 31 agosto):
docs.google.com/forms/d/e/1FAI…
_

slowforward.net/2024/08/22/ope…

#autoproduzioni #Bada #BadaFestival #Brancaleone #dIY_ #diy #editoria #festival #ffffff #fumetti #proposte

BADA Festival on Instagram: "🦜 OPEN CALL -----> BADA 2024 🦜 Fill the form for join us with your DIY prints and stuff! Call ends 31 August!! You will receive an answer by September 8 ❤️‍🔥 See you in October! 🦜🦜💚💜 (Link form in Bio)"

555 likes, 7 comments - badafestival on July 15, 2024: "🦜 OPEN CALL -----> BADA 2024 🦜 Fill the form for join us with your DIY prints and stuff! Call ends 31 August!! You will receive an answer by September 8 ❤️‍🔥 See you in October! 🦜🦜💚💜 (Link f…

^Instagram

[Hans Rosenberg] knows a thing or two about RF PCB design and has provided a three-part video demonstration of some solid rules of thumb. We will cover the first part here, and leave the other two for the more interested readers!

The design process begins with a schematic diagram, assuming ideal conductors. Advanced software tools can extract the resistive, inductive, and capacitive elements of the physical wiring to create a parasitic model that can be compared to the desired schematic. The RF designer’s task is to optimize the layout to minimize differences and achieve the best performance to meet the design goals. However, what do you do when you don’t have access to such software?

[Hans] explains that at low frequencies, return current flows through all paths, with the lowest resistance path taking most of the current. At higher frequencies, the lowest inductance path carries all the current. In real designs, a ground plane is used instead of an explicit return trace for the lowest possible impedance.
You really wouldn’t design an RF circuit like this.
[Hans] shows the effect of interrupting the signal return path on a physical test PCB. The result is pretty bad, with the current forced to detour around the hole in the ground plane. A nanoVNA shows a -20 dB drop at 4 GHz, where the ground plane has effectively become an antenna. Energy will be radiated out, causing signal loss, but worse, it will create an EMC hazard with an unintended transmission.

Additionally, this creates an EMC susceptibility, making the situation worse. Placing a solder blob to bridge the gap directly under the signal trace is all that’s required to make it a continuous straight path again, and the performance is restored.

Floating planes are also an issue in RF designs, causing signal resonance and losses. One solution is to pull back the planes near the signal or stitch them to the ground plane with vias placed closely on either side of the signal trace. However, such stitching may slightly affect transmission line impedance and require tweaking the design a little. The next two parts of the series expand on this, hammering home the importance of good ground plane design. These are definitely worth a watch!

PCB design is as much art as science, and we’ve discussed this subject a lot. Here’s our simple guide to rocking RF PCB designs. There’s also a lot of devil in that detail, for example when understanding edge-launch SMA connectors.

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Secondo i media, Xiaomi potrebbe presto introdurre nei suoi telefoni una funzione di rilevamento delle telecamere nascoste. L’azienda si sta ora preparando a lanciare HyperOS 2.0 e la funzionalità potrebbe diventarne parte.

Secondo XiaomiTime, HyperOS 2.0 conterrà probabilmente una funzionalità che consentirà ai dispositivi supportati di rilevare telecamere nascoste utilizzando segnali di rete locale wireless (WLAN). Questa funzionalità, ad esempio, può essere utile per i viaggiatori che spesso si fermano in luoghi sconosciuti.

Sembra che con questa funzione gli utenti dei telefoni Xiaomi saranno in grado di identificare i dispositivi sospetti connessi alla rete Wi-Fi locale. A giudicare dagli screenshot presentati, puoi cercare dispositivi nascosti con un solo tocco.

Si ritiene che la nuova funzionalità sia ispirata da Ingram, un programma Python che sembra rilevare le telecamere vulnerabili.

L'articolo Xiaomi pronta a lanciare la funzione di rilevamento delle telecamere nascoste proviene da il blog della sicurezza informatica.

La recente acquisizione di BreachForums da parte di IntelBroker segna un cambiamento significativo nell’ambito del cybercrime. Questa transizione di potere avviene in un momento cruciale per il forum, che ha recentemente attraversato un periodo di stagnazione e inefficienza sotto la precedente amministrazione. L’arrivo di IntelBroker come nuovo proprietario promette di rinnovare e rafforzare la piattaforma, portando con sé una gestione più attiva e coinvolta.

Intelbroker è un individuo (o un gruppo di hacker criminali) operante nel dark web, tra le risorse underground quali xss, Breachforums, Exposed. Si tratta di un attore di minacce operante nel gruppo di hacker “Cyberniggers“, ed è attivo sia nelle categorie di hacktivismo che nella criminalità informatica, soprattutto come Inital Access Broker (IaB).

Come accennato in precedenza, in prima linea tra CyberNiggers è un membro di lunga esperienza nell’orchestrazione di attacchi informatici di alto profilo. Operando come Initial Access Broker (IaB), IntelBroker è specializzato nell’identificazione e nella vendita dell’accesso ai sistemi compromessi, aprendo la strada a varie attività dannose.

Nonostante l’identità collettiva dei CyberNiggers, IntelBroker si distingue come attore di minacce individuali. Questa distinzione solleva interrogativi sulla portata delle loro capacità e sulle motivazioni che guidano i loro sforzi individuali.

Stato di BreachForums sotto la precedente amministrazione

BreachForums, storicamente riconosciuto come uno dei principali punti di riferimento per la comunità del cybercrime, ha subito un progressivo declino a causa della gestione inefficace del precedente proprietario. Le principali criticità riscontrate includevano:

• Assenza di leadership: Il precedente amministratore era spesso assente, provocando ritardi significativi nella risoluzione di controversie tra utenti e nella gestione delle richieste tecniche e operative del sito.
• Mancanza di intervento tempestivo: La scarsa presenza amministrativa ha portato a un accumulo di problemi non risolti, che hanno minato la fiducia degli utenti e compromesso l’efficacia operativa del forum.
• Stagnazione della comunità: A causa della gestione inefficace, il forum ha registrato un calo nell’attività e nell’afflusso di nuovi membri, portando a una perdita di slancio all’interno della comunità.

L’avvento di IntelBroker: Una leadership rinnovata

L’ingresso di IntelBroker come nuovo proprietario e amministratore rappresenta un punto di svolta per BreachForums. Le caratteristiche distintive della sua leadership includono:

• Coinvolgimento attivo: IntelBroker è noto per il suo approccio diretto e partecipativo nella gestione della comunità. La sua presenza costante e il suo impegno attivo sono stati accolti positivamente dagli utenti, che vedono in lui una figura capace di riportare ordine e disciplina al forum.
• Reputazione consolidata: IntelBroker gode di un alto livello di rispetto e fiducia all’interno della comunità. Questo elemento è cruciale per garantire un ambiente sicuro e stabile, soprattutto in un contesto come quello del cybercrime, dove la credibilità del leader è fondamentale.
• Focus sulla sicurezza e sull’integrità: La gestione di IntelBroker si preannuncia orientata a mantenere elevati standard di sicurezza e integrità del forum, elementi essenziali per il successo e la longevità della piattaforma.

Prospettive future per BreachForums

Con IntelBroker al timone, BreachForums si prepara a entrare in una nuova fase di sviluppo. Le aspettative per il futuro includono:

• Rinnovata crescita della comunità: Si prevede un aumento delle attività e dell’afflusso di nuovi membri, grazie alla ritrovata fiducia nella gestione del forum.
• Miglioramento della governance: Con una leadership più attiva e responsabile, il forum dovrebbe vedere un miglioramento nella gestione delle controversie e delle operazioni quotidiane, portando a una maggiore soddisfazione degli utenti.
• Rafforzamento della posizione nel cyber underground: La nuova amministrazione potrebbe consolidare la posizione di BreachForums come piattaforma leader per il cybercrime, attirando un numero crescente di utenti e risorse.

Conclusione

L’acquisizione di BreachForums da parte di IntelBroker rappresenta un’opportunità di rinascita per la piattaforma. Con una gestione più dinamica e attenta, il forum è destinato a recuperare la vitalità perduta e a consolidare il suo ruolo nel panorama del cybercrime.

La comunità osserva con interesse i primi passi di IntelBroker nella sua nuova veste di leader, consapevole che da questa transizione dipenderà il futuro del forum.

L'articolo IntelBroker assume la guida di BreachForums: Un nuovo capitolo per la gestione del cybercrime proviene da il blog della sicurezza informatica.

Gli specialisti di PatchStack hanno scoperto una vulnerabilità critica nel plugin LiteSpeed ​​Cache per WordPress, che consente di ottenere i diritti di amministratore sul sito.

Il bug colpisce potenzialmente più di 5 milioni di siti che utilizzano questo plugin. Anche Wordfence si è unito al rapporto di PatchStack e ha emesso il proprio avviso sulla vulnerabilità.

LiteSpeed ​​​​Cache è un popolare plug-in di memorizzazione nella cache per WordPress con oltre 5 milioni di installazioni attive.

L’errore riguarda tutte le versioni del plugin fino alla versione 6.4 inclusa, il cui aggiornamento è stato rilasciato il 13 agosto. Si consiglia vivamente agli utenti di aggiornare il plug-in all’ultima versione (6.4.1) il prima possibile per evitare potenziali attacchi.

La vulnerabilità relativa all’elevazione dei privilegi CVE-2024-28000 (punteggio CVSS: 9,8) consente a un utente malintenzionato non autenticato di ottenere l’accesso a livello di amministratore, il che rende possibile scaricare e installare plug-in dannosi. Un criminale informatico può falsificare un ID utente e accedere come amministratore utilizzando l’API REST /wp-json/wp/v2/users. Tali azioni portano al pieno controllo del sito vulnerabile.

Il problema è che la funzione di simulazione utente nel plugin utilizza un hash debole. Questo hash viene generato in base a un numero casuale, facile da prevedere poiché dipende dal tempo con una precisione di un microsecondo. Di conseguenza, ci sono solo un milione di possibili valori hash. Inoltre, il generatore di numeri casuali non è crittograficamente sicuro e l’hash non è protetto da misure aggiuntive come il salting o il collegamento a una richiesta o a un utente specifico.

Vale la pena notare che la vulnerabilità non può essere sfruttata sui siti WordPress che funzionano sulla piattaforma Windows, poiché la funzione di generazione dell’hash dipende dal metodo PHP sys_getloadavg(), che non è implementato su Windows.

L'articolo 5 milioni di siti WordPress a rischio a causa del Plugin LiteSpeed ​​Cache proviene da il blog della sicurezza informatica.

È durata pochi mesi la latitanza di Salvatore Roberto Perricciolo, l’ultimo di un presunto sodalizio criminale di sedici persone di diverse nazionalità, condannate in via definitiva con la conferma in Cassazione della condanna della Corte d’Appello di Perugia dell’ottobre 2022.
L’uomo, quarantaquattro anni, di origine calabrese, latitante alla vigilia della sentenza di condanna emessa dalla Corte di Cassazione il 13 febbraio di quest’anno, è stato arresto a Capodistria, in Slovenia, dove si era rifugiato. La pena inflitta ammonta a 21 anni di reclusione, con una pena residua da scontare di circa quindici anni.

L’arresto è stato eseguito al culmine di una capillare e complessa attività investigativa coordinata dal Procuratore Generale di Perugia, in collaborazione con il Nucleo Investigativo dei Carabinieri di Fermo, l’Ufficio interforze di Polizia Giudiziaria alle dirette dipendenze dello stesso Procuratore Generale, e il Raggruppamento Operativo Speciale dei Carabinieri di Ancona.

L’operazione ha avuto carattere internazionale e ha interessato diversi Paesi europei, con la collaborazione di uffici inquirenti stranieri, in particolare con la Procura di Capodistria ed anche con l’Agenzia dell’Unione europea per la cooperazione giudiziaria penale (Eurojust) e S.i.r.e.ne (Supplementary Information Request at the National Entry) che funge da centro nazionale di contatto per lo scambio di informazioni supplementari.

Salvatore Roberto Perricciolo era residente da anni nel Fermano, condannato in via definitiva per diversi reati, è stato riconosciuto al vertice di un’associazione per delinquere dedita all’acquisto, al trasporto e alla successiva rivendita di svariati chili di cocaina nelle province di Macerata, Ancona e Fermo. In tale contesto si è reso inoltre responsabile di ulteriori delitti, tra i quali reati contro il patrimonio, rapine, in particolare ai danni di spacciatori; truffe, appropriazioni indebite, falsi documentali per acquisire illegalmente autovetture da commercializzare, estorsioni, sia ai danni degli acquirenti di droga inadempienti che verso terzi, detenzione illecita di armi e munizioni, fino al sequestro di persona, lesioni e violenza privata. In alcuni casi è stato sorpreso in luoghi pubblici in possesso di mitra e pistole. Con altro procedimento, attualmente pendente presso la Corte di Appello di Perugia, in ordine alla sola rideterminazione della pena, lo stesso è stato ritenuto responsabile di reati di natura mafiosa.

L’arresto, effettuato in territorio sloveno da personale della polizia criminale slovena in coordinamento con personale del Ros di Ancona è stato possibile grazie ad una intensa attività tecnica di acquisizione di numerosi tabulati telefonici, intercettazioni telefoniche e ambientali, oltre che pedinamenti. Il latitante è ora in attesa di essere estradato in Italia.

#Armadeicarabinieri

The PlayStation 4 was a popular enough console, but it was a home console. If you wanted to play at a friend’s house, you had to unplug all your cables and haul the whole lot over there. Unless, that is, you built something along the lines of [Rudd van Falier]’s Portable GameStation.

It’s not a super-complicated build, but it is a well-executed one. It combines laser cut acrylic with 3D-printed brackets to produce a housing that looks clean, sharp, and of almost commercial quality. That’s the benefit of laser-cutting—it avoids all the ugly problems of layer lines. From there, [Rudd] simply set about stuffing the PS4 motherboard inside, along with placing the relevant ports and vents in the housing where needed. A screen with inbuilt speakers was then attached to complete the build. The one thing it’s missing is a set of batteries for playing it on the bus. This thing needs mains power to run.

We’d love to see [Rudd] take another stab at the concept, making it fully independent from cables. It’s definitely possible. Who wouldn’t want to play some Persona 5 Royal on the train, anyway? Video after the break.

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Charli XCX’s new album has made waves worldwide with its ravey beats and bold lyrics. And who better than Elon Musk to embody the fearless “brat” attitude?

euractiv.com/section/digital/p…

When WiFi first came out, it was a super exciting time. The technology was new, and quite a bit less secure back then—particularly if not configured properly. That gave rise to the practice of wardriving—driving around with a computer, looking for unsecured networks, often just for the fun of it. [Simon] has been examining this classic practice from a modern perspective.

He’s been at the game for a long time—from back in the days when you might head out with a thick old laptop, a bunch of PCMCIA cards, and dangly antennas. It’s much more advanced these days, given we’ve got WiFi on all different bands and Bluetooth devices to consider to boot. Heck, even Zigbee, if you’re hunting down a rogue house full of Internet of Things gadgets.

Today, when he’s out researching the wireless landscape, he uses devices like the Flipper Zero, the Raspberry Pi, and a Google Pixel 5 running the WiGLE WiFi Wardriving app. [Simon] notes that the latter is the easiest way to get started if you’ve got an Android phone. Beyond that, there’s software and hardware out there these days that can do amazing things compared to the simple rigs of yesteryear.

If you’re out looking for free internet these days, wardriving might be a bit pointless given it’s available in practically every public building you visit. But if you’re a wireless security researcher, or just curious about what your own home setup is putting out, it might be worth looking at these tools! Happy hunting.

As Neuralink works towards getting its brain-computer interface technology approved for general use, it now has two human patients who have received the experimental implant. The second patient, [Alex], received the implant in July of 2024 and is said to be doing well, being able to play games like Counter Strike 2 without using his old mouth-operated controller. He’s also creating designs in Fusion 360 to have them 3D printed.

This positive news comes after the first patient ([Noland Arbaugh]) suffered major issues with his implant, with only 10-15% of the electrodes still working after receiving the implant in January. The issue of electrode threads retracting was apparently a known issue years prior already.

We analyzed Neuralink’s claims back in 2019, when its founder – [Elon Musk] – was painting lofty goals for the implant, including reading and writing of brains, integration with AIs and much more. Since that time Neuralink has been mostly in the news for the many test animals which it euthanized during its test campaign prior to embarking on its first human test subjects.

There also appears a continuing issue with transmitting the noisy data from the electrodes, as it is far more data than can be transmitted wirelessly. To solve this seemingly impossible problem, Neuralink has now turned to the public with its Neuralink Compression Challenge to have someone make a miraculous lossless compression algorithm for it.

With still many challenges ahead, it ought to be clear that it will take many more years before Neuralink’s implant is ready for prime-time, but so far at least it seems to at least make life easier for two human patients.

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Permanent magnets aren’t typically switchable. They’re always doing their magnet thing. However, if you align them with a bunch of other magnets in just the right way, you can create a permanent magnet that you can effectively switch on and off. [Andrew Klein] has done just that with his 3D-printed magnetic switch design.

The concept is simple enough. The design consists of a 3D-printed housing in two parts, top and bottom. When set into one orientation, the housing holds two arrays of magnets in opposite orientations. This effectively cancels out their magnetic fields and allows you to move the assembly around as if it’s pretty much not magnetic at all. However, rotate the device to its alternative orientation, and the magnets poles are aligned. This effectively combines their magnetic fields and makes the assembly act as one big large magnet.

These devices are useful if you want to create magnetic clamps or fixtures that can be attached and detached at will from ferrous surfaces. Being able to effectively “switch the magnet off” is much easier than trying to wrench a powerful magnet from a metal plate, after all.

You can do something similar with electromagnetic techniques, too! Video after the break.

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If you’re running a big factory, you’ve probably got a massively expensive contract with a major programmable logic controller (PLC) manufacturer. One shudders to think about the cost of the service subscription on that one. If you’re working on a smaller scale, though, you might consider a DIY PLC like this one from [Mr Innovative.]

PLCs are rarely cutting-edge; instead, they’re about reliability and compliance with common industry standards. To that end, this design features the ATmega328P. Few other microcontrollers are as well understood or trusted as that one. The device is compatible with RS232 and RS485 and will run off 24 VDC, both of which you would find in a typical industrial environment. It offers 24 V digital inputs and outputs, as well as analog inputs and outputs from 0 to 10 V. [Mr Innovative] demonstrates it by hooking up a DWIN human-machine interface (HMI) for, well… human interaction, and a variable frequency drive to run a motor.

If you want to run a basic industrial-lite system but can’t afford the real industrial price tag, you might enjoy tinkering around at this level first. It could be a great way to get a simple project up and running without breaking the bank. Video after the break.

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Drive along nearly any major road in the United States and it won’t be long before you see evidence of the electrical grid. Whether it’s wooden poles strung along the right of way or a line of transmission towers marching across the countryside in the distance, signs of the grid are never far from view but often go ignored, blending into the infrastructure background and becoming one with the noise of our built environment.

But there’s one part of the electrical grid that, despite being more widely distributed and often relegated to locations off the beaten path, is hard to ignore. It’s the electrical substation, more than 55,000 of which dot the landscape of the US alone. They’re part of a continent-spanning machine that operates as one to move electricity from where it’s produced to where it’s consumed, all within the same instant of time. These monuments of galvanized steel are filled with strange, humming equipment of inscrutable purpose, seemingly operating without direct human intervention. But if you look carefully, there’s a lot of fascinating engineering going on behind those chain-link fences with the forbidding signage, and the arrangement of equipment within them tells an interesting story about how the electrical grid works, and what the consequences are when it doesn’t.

From The Ground Up

The most basic function of a substation is to transform voltages, either stepping up the voltage from the point of production for efficient transmission over long distances, or stepping voltages down from transmission systems to feed regional or local distribution systems. That makes substations conceptually simple, but as is always the case in engineering, the details are where things get interesting.

While the equipment mounted above the ground is the easiest part of a substation to observe, what you don’t see is arguably far more important, at least in terms of safety. A note to frame the discussion: we’ll be concentrating on open-air substations, rather than substations that are inside a structure, which are an important and interesting part of the grid, but harder to observe casually.

Substations must have an extensive grounding system, both for worker safety and to provide the needed neutral reference. Most substations use a grid of thick copper conductors buried just below the surface, tied together at regular intervals to ground rods extending 25 feet (7 meters) or more into the soil below. Horizontal and vertical conductors are tied together with exothermically welded connections or cold-forged fittings to form low-impedance electrical connections between every element of the grid. The grounding grid spreads out under the entire area of the substation, and everything is bonded into the ground system by heavy, low-impedance braided straps.

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Over the grounding grid is a layer of crushed rock about 6 inches (15 cm) thick. The gravel serves several functions, including aiding water drainage and inhibiting weed growth. But the main function is worker safety in the event of a ground fault, which could cause a lethal voltage difference between the above-ground equipment and the earth. The high resistivity of the gravel (3,000 to 5,000 ohm-meters) compared to the soil makes it less likely that a worker will conduct these voltages through their body. Also, gravel reduces the possibility of lethal voltages between one foot and the other while walking, or step voltages.

Every substation also has a fence or physical barrier of some sort. Most are imposing structures of heavy-duty chain-link topped with razor wire, but in some residential areas, a more decorative option might be used to appease the neighbors. Some substations also have sound barriers, to reduce the incessant 60 Hz hum of the equipment within that could annoy nearby residents. The characteristic hum has also been known to attract bears, who apparently think they’ve found the world’s largest beehive. A sturdy barrier is critical to avoiding unpleasant consequences for the bear, or for those with a greedy eye on the multiple tons of copper most substations contain.

Rule of Threes

Of the above-ground equipment in the substation, the most visually striking structures are those that support and terminate the wires coming into and leaving the yard. These are loosely referred to as “high side” and “low side” lines based on the voltages they carry. A substation might have a 345 kV high side to receive power from a transmission line and several 25 kV lines on the low side feeding different local distribution lines. Some substations will also have multiple high-side feeds from different transmission lines, or may have multiple low-side inputs from wind or solar plants that the substation will combine into one or more high-side transmission lines.

Overview of the high side of a wind farm substation. From the right: transformer with corona caps on output bushings; 3-phase circuit breakers; PTs and VTs for monitoring; high-side lines on tower with surge arrestors on each phase. Source: Adbobestock, by [JJ Gouin]One way to tell the high-side and low-side lines apart is by the size of their insulating bushings. Bushings are used to electrically and physically separate conductors from enclosures and supports, and the longer the bushing, the higher the voltage. Bushings are made from ceramic, glass, or polymers, and generally have stacks of circular fins that reduce the possibility of electrical discharge from the line to something with a lower potential. The highest voltage bushings are often fitted with special corona caps, which are circular cages that reduce the possibility of corona discharges from the relatively sharp tip of the bushing.

Something that stands out about most substations is that there seem to be three copies of each piece of equipment. Each set of high-side lines comes into the substation in a set of three, there are often three transformers (or one transformer with three input bushings and three output bushings), and all of the gear between the input and the output seems to be in triplicate. This is thanks to the three-phase electrical system in North America. Electrical transmission and distribution systems are all three-phase power, and while residential customers rarely enjoy such service to the home, commercial and industrial installations almost universally have it.

While the high-side and low-side lines entering and leaving the substation are generally — but not always — overhead wires, inside the substation, most of the components are connected by a series of overhead busbars. Busbars are simply pieces of metal pipe, often galvanized steel or aluminum and usually in groups of three, which are attached to equipment bushings either directly or via jumper wires. Busbars have the advantage of not sagging or swaying in the wind, but do have a few disadvantages, too. When busbars get hot they expand, and since they’re rigid and supported firmly on each end they’ll either buckle or break their supports. That means busbars have to be provided with expansion joints.

Another potential failure mode for busbars is ice damage, which I witnessed back in the 1980s. During a late winter thaw, meltwater had accumulated in a busbar at a substation near my home. When the temperature dropped precipitously that night, the freezing water exerted enough pressure to burst the busbar, which caused a fault on one of the phases bad enough to trip the entire substation. This knocked out power to the entire town and resulted in the local utility asking for help from my volunteer fire company.

The substation techs used the enormous generator on our truck to power a welder so they could make an impromptu repair to the busbar and restore power. It was a long, bitterly cold night, but I got to walk around inside a substation and check things out. It was pretty cool.

Plenty of Protection

That brings up the topic of control and protection. The vast majority of the equipment inside a substation is devoted to circuit protection, in the form of circuit breakers, fuses, reactors, and capacitors, followed by the equipment needed to control and monitor the circuits. Lightning protection is also vital, since a nearby strike can induce currents that can permanently damage equipment. Protection starts at the top with static lines on the highest part of transmission towers that are designed to catch discharges and run them directly to ground. Static lines are now often hybrid cables called OPGW, or optical ground wire, which has one or more optical fiber pairs at its core. These fibers are used for control and communications between substations; some utilities even lease the extra pairs out to communications providers.

Circuit breakers play a last-ditch role in substation protection, and are capable of disconnecting the entire substation in a catastrophic fault. They’re pretty easy to spot thanks to their angled bushings, usually two per breaker with one breaker per phase, although some breakers have three bushings each. The breakers are just super-sized versions of those in your home panel and work in a similar way, albeit tripping at a much higher current — often 5,000 amps or more. They also have to switch very rapidly, a tough job when there’s enough voltage to keep an arc going between the contacts even when they’re fully separated. So circuit breakers are often filled with a dielectric gas such as sulfur hexafluoride (SF6), a liquid dielectric like mineral oil, or even evacuated completely. Air blast breakers which literally blow the arc out are also used.

Another interesting bit of control equipment in the yard is the voltage regulators, which are essentially autotransformers that can adjust the voltage on a phase within a small percentage range. These are easily recognizable as a set of three tall cylinders, each bearing a large dial on the top. The dial shows how much voltage is being boosted or bucked, and is usually angled downward for easier reading from the ground. Substation switchyards also often contain banks of high-voltage capacitors, which adjust the power factor and compensate for noise on the line. Capacitor banks are usually located on the distribution side of a substation along with neutral grounding reactors, which are large, cylindrical inductors that are connected in series between the neutral of a transformer and ground and limit current if there’s a phase-to-ground fault.

Sprinkled liberally around the substation are instrumentation transformers whose entire job is to monitor the flow of current into and out of almost every piece of equipment. Current transformers, or CTs, are just permanently installed, beefed-up versions of the clamp meter you might use for measuring current in an electrical panel and work pretty much the same way, with current in the conductor under measurement inducing a proportional current in a toroidal coil. Voltages are measured with voltage transformers (VTs), the most common of which is the capacitive voltage transformer, or CVT. These use high-voltage capacitors as a voltage divider and a transformer to isolate and further step down the voltage to a reasonable instrumentation range. The outputs of instrumentation transformers are generally piped into a supervisory control and data acquisition (SCADA) system that remotely monitors and controls everything in the substation, right down to alarm contacts on the fence gates.

The Diva Treatment

Since the primary job of the substation is changing one voltage to another, the main power transformers are the centerpiece of the switchyard. In a lot of ways, transformers are the divas of the substation — they’re expensive to procure, require a lot of maintenance, and the show won’t go on until they’re happy. The transformers are easy to spot, since they’re generally the largest pieces of equipment in the yard. In keeping with the rule of threes, there are usually three identical units, one for each phase, although some transformers have windings for all three phases in a single massive enclosure.
138 kV transformer in a wind farm substation. High-side to the left, low-side to the right, with all three phases in a single enclosure. Note the cooling radiators on each side; the tank just visible at the back is an oil conservator, which is basically a pressurized reservoir for the oil to expand and contract. Source: SpeedFreakLS1.
Almost all substation transformers are filled with mineral oil, which acts as a liquid dielectric and helps cool the transformer thanks to giant radiators and fans for forced-air cooling. A large transformer can hold thousands of gallons of oil, an environmental disaster waiting to happen if there should be a leak, which given some recent rural substation attacks is not unthinkable. That makes secondary containment a necessity, with deep pits dug around the transformer foundation pads. The pits are lined with thick plastic sheets and backfilled with gravel. They’re designed to contain the entire volume of oil if necessary, and sump pumps with oil separators keep rainwater from accumulating in the pit.

In keeping with the diva treatment, transformers require constant monitoring to ensure they operate at their peak. Aside from the instrumentation used to measure their electrical status, transformers need to have their oil checked regularly for chemical changes that could indicate internal problems like arcing and overheating. This can either be performed by a technician visiting the substation and taking samples of the oil, or through online dissolved gas analysis (DGA), which uses a compact gas chromatograph to automatically sample the oil and measure the amount of acetylene, ethylene, and methane dissolved within it. Continuous measurements are collected via SCADA and provide a much more accurate picture of transformer health than monthly or quarterly sampling.

And finally, to push the diva metaphor even further, transformers are often provided with pressure-relief devices to protect the system in the event of an explosion within the transformer enclosure. PRDs can be as simple as a burst disc that shatters under increased pressure, but are more commonly sensors that detect and characterize the pressure wave from an internal explosion as it propagates through the oil. If the pressure wave looks like a catastrophic internal failure has occurred, the SCADA system will disconnect the transformer, in an attempt to save it from irreparable damage.

Uno yacht di lusso, il Bayesian, che si inabissa il 19 agosto a poche centinaia di metri dal porto di Palermo. Fin qui non ci sarebbe nulla di eccezionale. Le cose cambiano non appena si conosce l’identità delle persone a bordo e, purtroppo, delle vittime. Tra queste, la più illustre è senz’altro il magnate britannico […]
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When you were five, you probably spotted your best friend running at “a million miles an hour” when they beat everybody at the local athletics meet. You probably haven’t seen anything that fast snice. According to NASA, though, a group of citizen scientists spotted a celestial object doing just that!

The group of citizen scientists were involved in a NASA program called Backyard Worlds: Planet 9. They were working on images from NASA’s Wide-field Infrared Explorer mission. Scanning through stored images, Martin Kabatnik, Thomas P. Bickle, and Dan Caselden identified a curiously speedy object termed CWISE J124909.08+362116.0. There are lots of fast-moving objects out in space, but few quite as fast as this one. It’s quite literally zooming through the Milky Way at about 1 million miles per hour.

It’s unclear exactly what the object is. It appears light enough to be a low-mass star, or potentially a brown dwarf—somewhere in between the classification of gas giant and star. It also has suspiciously low iron and metallic content. The leading hypothesis is that CWISE J1249 might have been ejected from a supernova, or that it got flung around a pair of black holes.

For now, it remains a mystery. It’s a grand discovery that really highlights the value of citizen science. If you’ve been doing your own rigorous scientific work—on NASA’s data or your own—do let us know!