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Joined 11 months ago
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Cake day: April 13th, 2024

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  • The article opens with saying only 25% of the fuel’s energy gets used by the motor, 75% is in the heat of the exhaust. I’ll take that as a given. Let’s assume a small motor (in this inventions favour) with a nominal power of only 60 kW, running only at half tilt, 30 kW.

    That gives us 90 kW in the exhaust heat by the numbers of the article. So the 56 W it captured in the simulation would be 0.046% of the total 120 kW power being converted by burning the fuel, raising the efficiency from 25% to 25.046%.

    The headline is so massively overstated it’s basically just a lie. If the device was built, not just simulated, and you’d manage to substitute part of the alternator’s ouput with the thermoelectic generator’s output, the effect on fuel economy would be below the measurable level.



  • This is stupid. Google is doing it with their normal process, labeling the USA as a sensitive country in their system and changing the label only for the sensitive snowflakes. So there is no harm to Mexicans in Mexico. (this was wrong, it’s show globally in parenthesis, see below)

    What sort of damages would she assert anyway? That her country suffers in a significant way from a Google Maps label that can only be seen from the sensitive country? How so?

    And if it’s a political move what is she hoping to achieve? Google will never cave to the USA before Mexico, they depend more on their US operations than their Mexican ones. So she can’t achieve anything politically. Does she want to draw even more attention to a losing fight? A losing fight over mere symbolism no less? Why?







  • I’m working on long range stuff so I’m not so familiar with PON specifically. Maybe I made some bad assumptions. Stable at -30 dBm receive sounds really impressive.

    The one I was talking about is this, with 18.5 dB total budget, that is, min +4.5 dBm transmit, and min -14 dBm receive. This one is built with an APD.

    In my kind of application, without splitter, this will get you about 30-40 km. We’ve got one of a slightly older type with 18 dB budget running between Fribourg and Bern for example.

    I realize that PON stuff is quite different with the time slitting and I think wavelenght splitting too, at least in XGS-PON, but I was thinking the pure laser and diode physics would need to be the same.

    For -25 dBm minimum the most similar of the ones we currently have would be this one which manages -26.9 dBm and is one of the ones with a SOA built in, or for the 10G stuff this one, which manages min -23 dBm but with only an APD and no SOA.

    I’m thinking their 50G stuff must be closer to 100G than 10G transceiver design. So I wonder if they manage to make it without SOA.