perestroika

joined 1 year ago
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[–] perestroika@slrpnk.net 3 points 4 days ago* (last edited 4 days ago)

On individual scale, precisely that - a split type AC with one half indoors (or in a water tank) and the other half in an outdoor environement (air, water or ground).

If you're extracting heat from the environment, the machine lets the working fluid evaporate into the outdoor heat exchanger and compresses it back into the indoor heat exchanger. If you're cooling your premises - reverse that.

However, on a city scale, it's like "you've got a lot of sewage at 30 C" -> "your heat pump is a large building" -> "your sewage outflow is now at 10 C, but your underground heat reservoir gets charged to 140 C (stays liquid because of water column pressure), and you spend much less energy pumping the heat than you would spend heating the water directly".

[–] perestroika@slrpnk.net 8 points 4 days ago* (last edited 4 days ago)

I have had many encounters with cops, and I decide about the extent of cooperating with them on a case-by-case basis.

  • landlord is illegally evicting my mother's neighbour --> I call cops and they prove how useless they are at prevention, but the matter goes to court and the landlord gets convicted later, and it was my only time to testify in court
  • cops accuse me of ignoring their lawful order --> sorry, I was listening to music, didn't hear nothing, no comment, no comment, I admit nothing (nothing came of it)
  • cops intrude into the squat yard without knowing it's a squat --> "the ~~droids~~ drunken people you look for are elsewhere" --> the cops go elsewhere
  • cops raid the squat --> refuse to provide documents until threatened, require cops to provide their own ID, contest every statement and discuss the matter publicly in media
  • cops try to steal equipment during a demonstration --> pull the equipment back and yell to them a description of what it is (I assume they thought I was planting a bomb instead of packing up)
  • cops want to interview me about illegal demonstrations --> I politely tell them to fuck off, then call back and volunteer for the interview to convey the opinion of other anarchists :D
  • a new squat is being established --> establish a security perimeter that is watched with attention and never let cops close
  • an attempted squat gets burglarized and set on fire -> inform the fire brigade that a bottle of propane could be present (fortunately it was stolen), the fire brigade had better things to do than involve cops
  • a new squat gets burglarized --> pepper spray the burglar and take their tools, without involving cops
  • a new squat gets burglarized, episode N --> threaten the burglars and take their tools, without involving cops
  • cops try to fall into a hole in ground during a stupid training excercise --> tell the cops not to go there, as they might fall in (leave untold: it would be a major embarrasment for squatters to rescue them)
  • the squat is suddenly in the security perimeter of a NATO summit --> find some military lurking in the yard and invite them into the squat so they could be reasonably certain we don't have anything that shoots down planes :P (runway was about 250 m away)
  • a drunken person tries to SWAT me at a street party --> fully explain the situation to the SWAT team and later participate in amateur theatre with cops to get the drunken person safely removed from the police station :o
  • one drunken neighbour hits their spouse and when I forbid, hits me --> seeing that the neigbour has already paid for his deed since pepper was 100% effective and he'll feel extremely bad for many hours, I did not file a complaint to cops, although they were called and showed up
  • after two geniuses tried to steal my car, but fled after a warning shot --> I did not involve cops
  • after some person attacked his partner and hit her on street --> I pepper sprayed him, and since he took out a knife and attempted to come at me (I evaded, no harm occurred to me), I did call cops and make a complaint, as did the woman he had hit
  • cops call me about one neigbour's car --> I don't remember anything (I did actually remember, but wasn't in a mood for helping them repress a neighbour)
  • my car gets burglarized --> I ask the cops for info, they have none, I don't involve them beyond that

...etc.

[–] perestroika@slrpnk.net 4 points 2 weeks ago

P.S. I have once used DC to power a pump "directly". I use quotation marks because the pump (a water pump) was a brushless DC motor with an integrated controller. I used it on a field for removing water after a spring flood. Its controller accepted 24..48 V input, and it was powered from a 40 V solar panel brought on a wheelbarrow. :)

[–] perestroika@slrpnk.net 6 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

instead of powering the heat pump from the wall, the heat pump can be connected directly to a PV

I have no experience with this exact combination. I know that "batteryless" inverters exist, but most of them are on-grid inverters. In that scenario, all that matters is monitoring your production: if you don't want grid energy, you only run your system when your PV produces enough.

Another type of batteryless inverters are "pump inverters". Farmers seem to like them for pumping water from wells into water towers. A pump inverter can be configured to run at 50 Hz (or 60 Hz for North Americans) and 230..240 V (or 110 V for North Americans) alright, but it is not designed to power electronic devices, but dumb agricultural motors. There is considerable risk involved with powering a heat pump from a pump inverter, unless you find an exceptionally simple and dumb heat pump with very limited or resilient steering electronics.

Efficiency losses are small anyway, but mostly happen during battery storage or when voltage needs to rise or drop considerably (e.g. a transition of 700 -> 24 V or 24 -> 240 V would cause a small efficiency loss).

I’ve heard that a PV can directly power a compressor

This seems unlikely as the compressor would have to be a brushed DC motor. That kind of motors don't last long, they wear out their brushes. Long-lasting motors are brushless, and those generally cannot be run on DC power. For example, a "brushless DC" motor is essentially a three-phased AC motor, just its controller (full of smartness and MOSFET transistors) accepts DC input.

If you have a good technical overview of your heat pump system, maybe you can locate a point where regulated DC can be fed into the system, but that would be hacking. Alternatively, maybe a niche market already exists for DC-powered heat pumps, e.g. for caravans, trucks or ships? But on niche markets, prices typically aren't good for you. :(

[–] perestroika@slrpnk.net 4 points 3 weeks ago (1 children)

Relays: my use for truck relays is switching on heaters in my thermal storage water tank. Not big ones, though - I use relays rated for 24V and 40A of current. Since they are old, I have applied a safety margin and only let 25 A flow through them, so each of them handles 24 x 25 = 600 W.

As for using DC appliances: benefits do exist. If a household has a low voltage DC battery bank (some do, some don't) then dropping the battery voltage a few times to power car parts comes with a smaller efficiency loss. In my household, DC appliances are used for lighting, communications, computing, cooling food, pumping water and soldering electronics. The rest goes via AC. I think a car air conditioner could cool some small storage room decently. With big living rooms, it would have difficulty since it's a small device.

[–] perestroika@slrpnk.net 2 points 3 weeks ago* (last edited 3 weeks ago)

it would (as far as i understand with high school chemistry) be strictly more efficient to electrolyse rust directly

I'm not a chemist either, but I do know a bit of chemistry.

Typically, you need a solution of NaOH (sodium hydroxide) to directly reduce iron oxide in an electrolysis cell. If your iron oxide contains impurities, those may react with NaOH and ruin the fun. Also, if you have exposure to CO2, your NaOH will gradually degrade, producing NaHCO3 and losing potency.

My impression: wet electrolysis is great for making high purity iron, but it would be hard to make it work for energy storage.

[–] perestroika@slrpnk.net 8 points 3 weeks ago* (last edited 3 weeks ago) (5 children)

Relays can be used for anything, and a car contains a fair number.

You can make a pulse jet engine from a muffler parts, but a solarpunk society would probably not do that. :)

Copper brake pipe and cooling radiators can be used as heat exchangers for other stuff.

Air conditioner parts can be reverse-used for Stirling engines or to pump heat in other contexts.

[–] perestroika@slrpnk.net 2 points 3 weeks ago* (last edited 3 weeks ago)

Wow, really interesting tools. :)

But sadly not for me - I left biology behind at some point and have fallen off the sleigh so badly that I'd probably need a year of study before I could use this tool for something less than practical (e.g. make a bacterium glow in the dark).

[–] perestroika@slrpnk.net 5 points 1 month ago* (last edited 1 month ago)

This one didn't have rocket boosters, but was also nice: :)

( it traveled 180 km on one charge, back in 2009 :D )

[–] perestroika@slrpnk.net 3 points 1 month ago* (last edited 1 month ago) (1 children)

Wow. :)

I was expecting something with rotor sails, but I click, and it's a fancy new derivative of schooners. :)

As a result, I guess that rotating masts aren't optimal after all - too much moving mass, impossible to take down during a hurricane, etc.

I also guess that this sailboat has a fairly good motor, for use during total lack of wind (rare) or storms that would damage sails or masts.

 

This is not just a "happy birthday" post for Linux, but also a reminder that despite it becoming big and professional, the freedom to tinker with Linux remains accessible.

I had to use this freedom recently when I discovered that V4L video pipelines could buffer up to 32 frames both on the encoder and decoder (unacceptable, we demand minimum latency!) so it was again time to recompile the kernel. :)

My previous time to recompile parts of Linux had been a week ago. Some hacker had discovered a way of tricking their WiFi card beyond the legally permitted power - with what I understand as thermal compensation settings. Wanting to taste the sweet extra milliwatts, I noticed that nobody was packaging that driver as a binary, so the only way to get it was to patch and recompile its kernel module.

Finally of course, thanks to Linux we have countless open-source drivers and if you want to venture onto the path that Linus Torvalds took - of building an operating system - congratulations, you have less obstacles in your way. :) Some people have taken this path with the Circle project and you can compile your homebrew and bare-metal kernel for a Raspberry Pi with reasonable effort, and it can even draw on the screen, write to serial ports and flip GPIO lines without reverse-engineering anyone's trade secrets. :)

[–] perestroika@slrpnk.net 10 points 1 month ago* (last edited 1 month ago)

Regarding infiltration of the police - a similar theme played out in Greece during the 2008 economic crisis, when Golden Dawn vied for power - they tried hard to infiltrate the police, and succeeded to a considerable degree.

At some point, they made a mistake, though - GD thugs killed a popular leftist rapper named Pavlos Fyssas. He was able to point out who stabbed him. His death caused widespread rioting. Rioting incapacitated GD temporarily by blocking and damaging their party offices while the security service raided high-ranking members for evidence (apparently they didn't manage to infiltrate counterintelligence and in the confusion probably couldn't dispose of evidence even if they knew of incoming raids) ...and evidence was plentiful. They were banned and leaders got meaningful sentences in courts.

Only in a country where entering the police force requires lengthy studies to obtain a diploma (and background checks), is there some chance of random bozos not worming their way in. Most states of the US aren't such a place, sadly.

[–] perestroika@slrpnk.net 6 points 1 month ago* (last edited 1 month ago) (2 children)

Yep, indeed, I'm already discovering differences too. :) A good document for techies to read seems to be here.

https://reticulum.network/manual/understanding.html

I also think I see a problem on the horizon: announce traffic volume. According to this description, it seems that Reticulum tries to forward all announces to every transport node (router). In a small network, that's OK. In a big network, this can become a challenge (disclaimer: I've participated in building I2P, but ages ago, but I still remember some stuff well enough to predict where a problem might pop up). Maintenance of the routing table / network database / is among the biggest challenges when things get intercontinental.

 

In the article, researchers modeled the passage of the solar system through the galactic interstellar medium, components of which move at differing velocities and orbits.

They found that approximately 2-3 megayears ago, the solar system most likely entered a cloud of mainly cold hydrogen, and the density of the cloud was such that it should have considerably compressed the heliosphere (Sun's bubble of radiation and fields). Earth would have been outside the heliosphere either permanently or periodically. Currently the heliosphere ends far beyond the most distant planet, at approximately 130 Earth-Sun distances (astronomical units).

This would have greatly subdued the influence of solar wind on Earth, at the same time exposing the planet to interstellar cosmic rays. It is further speculated that studies which analyze Earth climate during the aforementioned period may benefit from accounting for this possibility.

Researchers sought confirmation for their model from geological records and found some, in the isotope content of iron and plutonium in sediments: iron 60 and plutonium 244 aren't produced by processes on Earth, so an influx would mean that solar wind no longer sufficed to beat back interstellar gas and dust (the latter containing radioisotopes from supernova explosions).

"By studying geological radioisotopes on Earth, we can learn about the past of the heliosphere. 60Fe is predominantly produced in supernova explosions and becomes trapped in interstellar dust grains. 60Fe has a half-life of 2.6 Myr, and 244Pu has a half-life of 80.7 Myr. 60Fe is not naturally produced on Earth, and so its presence is an indicator of supernova explosions within the last few (~10) million years. 244Pu is produced through the r-process that is thought to occur in neutron star mergers22. Evidence for the deposition of extraterrestrial 60Fe onto Earth has been found in deep-sea sediments and ferromanganese crusts between 1.7 and 3.2 Ma (refs. 23,24,25,26,27), in Antarctic snow [28] and in lunar samples [29]. The abundances were derived from new high-precision accelerator mass spectrometry measurements. The 244Pu/60Fe influx ratios are similar at ~2 Ma, and there is evidence of a second peak at ~7 Ma (refs. 23,24)."

 

I feared he would be martyred, when he returned to Russia after getting poisoned by the FSB and helping Bellingcat track down the agents who poisoned him (nobody in power did anything about them). Back then, his life was saved by a pilot deciding to make an emergency landing and a doctor suspecting a neurotoxin.

What finally took his life will be difficult to ascertain due to lack of transparency - a remote location, an extremely authoritarian system, war, politically controlled law enforcement and courts. Still, a day before death, Navalny appeared in court for another potential addition to his already 19-year sentence - in good spirits.

During Navalny's imprisonment, the regime made a sustained effort to break that spirit, issuing a constant stream of disciplinary punishments (a total of 27 times): for not placing his hands behind his back, for incorrectly introducing himself, for uttering a profanity, for failing to clear leaves in the yard, for citing the European Court of Human Rights’ demand for his release, for addressing the guard without using a patronym, and for declining to wash the fence.

They also transfered him to the far north and previously used sleep deprivement against him. I tend to assume that they also killed him, either directly or indirectly.

He was definitely not the perfect politician, but did things which a common politician never dares to do, which suggests having some principles. When they came for anarchists, he didn't forget them, but also spoke for anarchists.

 

Background: yesterday, there was heated discussion in the thread "military-industrial complex is a supervillain of causing the climate crisis" (link).

Among others, the thread creator posted a comment to the Guardian article "The climate costs of war and militaries can no longer be ignored", commenting it thusly:

If you want more context or won’t take my word on how militarism will kill is all, you can read this article.

I replied, a copy of my reply is below for your judgement. My reply got moderated by someone with the reason "Comment does not address intent of original post and promotes weapons industry / war in Ukraine."

I think my comment both addressed the topic, did not promote the weapons industry but helping Ukraine defend itself (ironically, tools for military self-defense come from the weapons industry) and did not promote the war (in fact, I noted that war is expensive, resource-intensive and stupid), but did explain the dynamics of war and revolutions.

I consider this moderator misconduct, likely motivated by their political views - and have asked a server administrator to talk with the moderator involved, to ascertain if they can refrain from using moderator powers as a political club to hit people, or to secure their demotion from a moderating role.

The removed post, for your judgement:


The article is fine, and I second the recommendation to read it, but from the article to the slogan you present, things do not follow a logical path.

Yes, war is both an incredibly expensive activity (diverting money that could be used) and a resource-intensive activity (the money goes into actual materials that almost surely destroy something or get destroyed) and an incredibly stupid activity (and it can snowball)...

...but the problem is that successful unilateral disarmament during a war tends to result in a situation called "defeat". If the defeat is not an attack being defeated, but defense being defeated, that is called a "conquest". Now, letting a conquest succeed has a historical tendency of the conqueror having more experience at conquest, and more resources to conquer with... which has, several times in history, lead to another conquest or a whole series of conquests. A regional war in Ukraine resulting in Ukraine being taken over by Russia has a high probability of producing:

  1. a bigger regional war later, in which Russia, using its own resources and those of Ukraine, proceeds to another country, gets into a direct conflict with NATO and then indeed there is a risk of a global war
  1. an encouraging effect after which China, noting that international cooperation against the agressor was ultimately insufficient, and deeming itself better prepared than Russia, decides that it can take Taiwan with military force

However, a war ending with inability to show victory tends to produce a revolution in the invading country. For example, World War I produced a revolution in Russia and subsequently a revolution in Germany, with several smaller revolutions in between, empires collapsing and a brief bloom of democracy in Europe, before the Great Depression and the rise of fascism ate all the fruits. The Falklands War produced a revolution in Argentina. The Russo-Japanese war produced the 1905 near-revolution in Russia.

It is better for Ukraine to not get conquered. It is better for Russia to be unable to conquer Ukraine. That result is also better for everyone around them. It's even better globally because it sets a precedent of large-scale cooperation defeating an agressive superpower, discouraging agressive superpowers from undertaking similar wars until memory starts fading again.

Unfortunately, until we see indications that Russian society is getting ready to stop the war (this could involve starting negotiations on terms palatable to Ukraine, a change of leadership, a withdrawal, a revolution, etc)... the path to achieving that outcome remains wearing out the agressor: producing enough weapons and delivering them to Ukraine.

Ultimately, both sides in a war wear each other down. The soldiers most eager to fight are killed soonest. The people most unwilling to get mobilized or recruited, and soldiers most unwilling to fight - they remain alive. If they are pressed forever, some day they will make the calculation: there are less troops blocking the way home than in the trenches of the opposing side. After that realization, they eventually tend to mutiny. Invading troops tend to do that a bit easier than defending troops, because they sense less purpose in their activity. In the long run, if nothing else happens, that will happen. There is just (probably, regrettably) no particularly quick shortcut to getting there.

 

This article is about fixing, but with a twist - it's about fixing trains that their manufacturer sabotaged. :D

In Poland, it took the hacker crew "Dragon Sector" months of work to find a software "time bomb" that was sabotaging "Impuls" trains manufactured by Newag, once their maintenance was handed over to another company.

Let this be a reminder to everyone about closed source technology and critical infrastructure.

 

Living off grid often correlates with poorly accessible locations - because that's where the infrastructure is not.

On certain latitudes, especially near bodies of water, especially in remote locations - do not ask who the snow comes for - it always comes for you (and with a grudge). So, what ya gonna do?

Over here, a tractor being incomplete (it is great folly to go into winter with an incomplete tractor), snow is handled by an electric microcar. Since the microcar is made of thin sheet metal and plastic, it cannot carry a plow... but the rear axle being solid steel, it can pull one.

The plow is one year old, and was previously pulled by a gasoline car. It is made of construction steel: 8 mm L-profiles shaped like a letter A with double horizontal bars. The point of connection on top ensures it doesn't lift too much while plowing. It's currently fixed with an unprofessional and temporary C-clamp (there will be an U-bolt soon). It is pulled with a chain.

If snow is heavy, the L-profiles lift the plow on top of snow, and you have to plow the same road many times. Sometimes it veers off sideways. Generally, you have to catch the snow early with this system - if you're late, you're stuck. :)

Not many advantages, but dirt cheap. Don't go plowing public roads with such devices - it is nearly invisible to fellow drivers, and cops would get a seizure.

 

Some Chinese researchers have found a new catalyst for electrochemically reducing CO2. Multiple such catalysts are known, but so far, only copper favours reaction products with a carbon chain of at least 2 carbons (e.g. ethanol).

The new catalyst requires a specific arrangement of tin atoms on tin disulphate substrate, seems to work in a solution of potassium hydrogen carbonate (read: low temperature) and is 80% specific to producing ethanol - a very practical chemical feedstock and fuel.

The new catalyst seems stable enough (97% activity after 100 hours). Reaction rates that I can interpret into "good" or "bad" aren't found - it could be slow to work. The original is paywalled, a more detailed article can be found at:

Carbon-Carbon Coupling on a Metal Non-metal Catalytic Pair

Overall, it's nice to see some research into breaking down CO2 for energy storage, but there is nothing practical (industrial) on that front yet, only lab work.

 

To make no excessive claims, I have to admit I burnt a fair bit of wood during the night. In the morning however, around 9 o'clock, the solar fence (nominal power 2400 W) was giving 600 W and steaming vigorously. By 10 o'clock, it had thawed and gave 940 W. Later, other panel arrays took over and wattage decreased. The energy was used to run a heat pump.

P.S. Knowing that server resources aren't infinite, I hosted the image externally, I hope that hosting on "postimages.org" works smoothly.

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submitted 1 year ago* (last edited 1 year ago) by perestroika@slrpnk.net to c/abolition@slrpnk.net
 

The short war which Azerbaijan waged against Armenian-populated Karabakh after a months-long blocade is over (Armenian separatists lost, and will likely get ethnically cleansed out of the region)...

...but in the aftermath, it's worth pointing out that several high-profile Azeris did speak against their government starting a war - and were repressed.

The most worrisome case is the chairman of the confederation of trade unions, Afiaddin Mammadov. A provocateur who had previously injured himself threw a knife at him, and cops arrested him immediately after that, claiming he had injured the provocateur.

 

To my knowledge, this is the second time a sample is returned from an asteroid to Earth - only preceded by Hayabusa-2 fetching a sample from asteroid Ryugu. The capsule has been found and the sample stabilized with nitrogen. Fetching the sample required 7 years, studying it will require a bit of time too.

It is too early to speculate whether interesting discoveries will follow, but Bennu is considered to be an interesting asteroid - likely not a break-up product, but something that represents the original composition of the solar system.

Bennu is also considered a hazardous space object, ranked high on the Palermo scale of impact risk and kinetic yield, so knowing what it's made of can be practically worthwhile.

More information here:

https://en.wikipedia.org/wiki/OSIRIS-REx

 

The inverse vaccine, described in Nature Biomedical Engineering, takes advantage of how the liver naturally marks molecules from broken-down cells with “do not attack” flags to prevent autoimmune reactions to cells that die by natural processes.

PME researchers coupled an antigen — a molecule being attacked by the immune system— with a molecule resembling a fragment of an aged cell that the liver would recognize as friend, rather than foe. The team showed how the vaccine could successfully stop the autoimmune reaction associated with a multiple-sclerosis-like disease.

 

Most people would typically think than smelling a scent (unless it's a powerful poison or medicament) won't change much in a person's health... but apparently, a variation in the scent environment has effect on the human brain, especially if the person is already old and their senses are degrading. It has also been observed that viral infections damaging a person's olfactory nerves result in changes to the brain - with less input, the neural networks involved with scent tend to atrophy. Coinidentally, some neural networks involved with scent recognition are also involved with memory.

Prios studies already support the idea that training one's sense of smell helps older people avoid cognitive deterioration. This study brings highly significant statistical results and adds one bit - wakefulness is not required to benefit. Apparently, the stimulation a person receives from feeling different scents bypasses sleep (or maybe, even improves the quality of sleep).

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