Thank you very much, PROF. Dr.JENSEN and your team for bringing these series of lectures that are easily comprehensible to biologists. As you have rightly pointed out in your first lecture, these kinds of topics, explained by physics people, most of the times are not understandable to biologists because they narrate mainly with the physics background. With increasing advancements in technology, more and more bridges are built between biological sciences and biophysics and biochemistry that are helpful in the understanding of life. On behalf of NeoBotanists @G+, we express our heartfelt thanks for your simple, slow narration with the meticulous preparation to make the presentation easily comprehensible.
1. TMP can't start at atmosphere pressure, well, they can spin but they do nothing...and you burn the driver because you draw too much current. 2. They don't have 3 rotors, they have many rotors interlaced with stators, just as in a jet engine compressor stage.
you're right big dog. I work with these all the time. After he said these things, I immediately went to the comments to see if anyone else pointed this out.
Hey Grant great videos! Quick comment, The water molecule at 6 minutes is shown as HO2 and not H20. The ions should be OH- and H+ ions, no? Simple thing, but maybe easy to fix...
It's supposed to be H20; even if we erroneously believed it was HO2, after breaking apart, OH- and O- would both go towards the positive electrode. If instead we imagine H20 breaking apart, the intuition he uses (minus the typos) holds.
🎯 Key Takeaways for quick navigation: 00:05 *Different vacuum pumps are used in electron microscopes to achieve ultra-high vacuum, including mechanical, oil diffusion, turbo molecular, and ion getter pumps.* 04:10 *Mechanical pumps gradually remove gases from the column but create vibrations and require maintenance, while oil diffusion pumps utilize heated oil to capture and remove gas molecules more efficiently.* 05:59 *Turbo molecular pumps utilize spinning propellers to bat gas molecules out, and ion getter pumps achieve high vacuums by capturing ions accelerated towards oppositely charged electrodes.* 07:33 *The vacuum system in electron microscopes is complex, with different pumps working together to achieve and maintain ultra-high vacuum levels. Proper sequence and control of pumps are essential for effective vacuum operation.* Made with HARPA AI
Turbo pumps cannot pump at atmospheric pressure, Turbomolecular pumps only work if they are below x10-2 Torr, if they have a molecular drag stage its absolute backing pressure goes up to just around 1 Torr still far from atmospheric. Turbo pumps are so overrated, its like the pure breed horse of vacuum pumps, so flashy and expensive, it gets the job done, fast but, its only advantage over to old poor mule (aka diff oil pumps which carried mankind to what it is now) is versatility and electrical efficiency but those advantages are seriously countered by its up front cost, maintenance expertise, cost of spare parts and fragility. Long life to diffusion pumps! no they aren't that dirty, a good baffle cuts down backstreaming to extreme low levels, put a cryo trap (still cheaper than turbopump controller!) and it totally eliminates it, enabling you to reach pressures down to x10-11 Torr (thinking the vacuum system was designed for UHV operation in the fist place). They can work with backing pressures of up to .6 Torr and they are so simple that can be repaired and even fully build from scratch on a modest workshop. Oil diffusion pumps are almost indestructible you can drop a screw inside and it will still keep working, the oil lasts a looong time if you take care of venting procedures, there is a white paper about the reliability of vacuum pumps in it i read a diff pump worked on an particle accelerator for 10 years with no maintenance and oil changes at all! Turbo pumps are great but the amount of overhype is getting ridiculous, so much unnecessary $$$ spent just because vacuum companies talk wonders about its latest cash milking tech. The only places i have seen a turbo pump justified is, surface measurement, large particle accelerators and semiconductor fabrication, for everything else its just wasted money.
@@cayetanopenaloza5734 water molecule HO2??? are you seriosly?? I've heard that physicists are are not good in chemistry, but... it's H2O!! Everybody who even far from science knows that water has formula H2O! Is this really caltech?)))
