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SteamyTea

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Everything posted by SteamyTea

  1. How about banning lobbying from/by/to. Or even more radical, policy makers must have a course on the topic they are making policy on. It need not be 'degree level', just a basic understanding.
  2. https://www.cfsnet.co.uk/s-n2pstk-002/2-part-polyurethane-foam-part-a-part-b-2kg-kit/ Why not just roll it around the garden.
  3. Easy, smoke tests. I shall buy 200 Marlboro and come around and test every room.
  4. Think you are right, I zoomed in a bit more on the phone screen. It seems to have that waxy sheen to it. k-value of 0.032 then.
  5. There seems to be a lot. https://scholar.google.co.uk/scholar?q=effects+of+elevated+co2+concentration+on+sleep+cycle&hl=en&as_sdt=0&as_vis=1&oi=scholart
  6. Looks a bit like EPS. EPS has a k-value to 0.036. PIA-brochure-Fundamentals-Symbols-and-Terminology-of-EPS-Thermal-Insulation.pdf
  7. How timely, from this weeks comic. Why do plastic clothes pegs fade and get brittle in the sun? One reader draws on his chemistry days to explain why some types of plastic become fragile after exposure to ultraviolet light 16 April 2025 Caroline Burrows/Alamy Last Word is New Scientist’s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email lastword@newscientist.com I recently bought plastic multi-coloured clothes pegs, which have slowly disintegrated in the sun except for the yellow ones. Why? Peter Holness Hertford, Hertfordshire, UK The phenomenon that destroyed the non-yellow clothes pegs is called “unzipping”. Many years ago, a chemistry colleague told me about it. His explanation was that the sun emits high-energy photons capable of breaking chemical bonds. This explains things like sunburn and curtains faded by sunlight. Most plastics are polymers, which are made from smaller units called monomers that link together through chemical bonds. Polyvinyl chloride (PVC), for example, consists of repeating vinyl chloride subunits. In turn, the subunits consist of carbon, hydrogen and chlorine atoms. Sunlight has been known to unzip PVC by dislodging hydrogen and chlorine atoms, creating hydrochloric acid and causing further erosion of plastic subunits. Unzipping potentially affects other plastics, too. It can be slowed or prevented by introducing certain chemical additives to the material. So, one possible explanation for the survival of the reader’s yellow pegs is stabilising additions of this sort. Another explanation for the disintegrating pegs involves both light absorption and heat. The colour of the plastic affects the amount of light reflected or absorbed, and hence heat, with darker colours absorbing more than lighter shades, such as yellow. But without chemical and spectroscopic analysis, it is impossible to know whether the reader’s yellow pegs were protected by their colour or additives, or perhaps a combination of both.
  8. A while back, and on another topic, @saveasteading commented about making data files smaller. I did a brief description about that happens, but thought I would spend a few minutes showing some real examples. The data file I used was some electrical grid data from 2012 to 2025, averaged, minimumed and maximumed at the half hour level. This created a large spreadsheet (I know, should be using a database) that was 227,954 rows by 75 columns, with 17,089,587 data points in it. I saved the file in 3 different formats: Comma Separated Value, .csv, a basic text file that is good for importing text based data. Open Document Spreadsheet, .ods, this is the format that LibreOffice Calc uses by default. Microsoft Excel Spreadsheet, .xlsx, as this is used by a lot of people, and probably by far the best spreadsheet package still. I then separately compressed all three files, then compressed and encrypted to see what the difference in size was. Finally I compressed and encrypted all three files into one .zip file. As expected the .csv file was the smallest of the uncompressed files, same when compressed, with encrypting making no difference in size. Compressing and encrypting all three files into one made no difference to overall size. So what have I learnt. No need to compress files individually, better of doing them all into one file, and encrypting makes no difference to size, so may as well encrypt. Results below:
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  9. I thought Excel opened them now. I shall save a copy as an .xls and post it up. DHW Cylinder (Excel).xlsx
  10. I was a bit bored on yesterday's car journey, so I started to let my mind wonder onto important things. So I have taken a stab at making a DHW calculator based on cylinder volume and insulation levels. The main points are in the pop out comment boxes. The variables are internal cylinder height and diameter, insulation k-value, insulation thickness, top of cylinder water temperature, base of cylinder water temperature, minimum useful delivery temperature and the room that the cylinder is in ambient temperature (the cylinder base temperature is the same). I am not sure if it is correct, but if anyone wants to check, there is a password in the comments, then you can see the inner workings. Feel free to suggest any changes. DHW Cylinder.ods
  11. It is starting to sound like an Ugandan Hotel.
  12. I could have dropped off that used blue rubber on my way back. You could have fingered some Lumberjack's favourite PU to your hearts content. That will fill the slot and never come off again.
  13. I am ready
  14. Legionella is not the problem, that needs atomised water to get down the windpipe and into the lungs of immune system compromised people. Ghonheria would be a bigger problem after the immaculate and particular folk have had their swingers party.
  15. The worst job I have ever done was cleaning out the spa bath DE filter at the Sheffield YMCA, I have no idea what those young men did in it.
  16. We need a dedicated rant section, similar to Boffin's Corner. Then let our level headed @Pocster be the moderator for it.
  17. That is an inline heater isn't it Yes. Nothing fancy at all. Could be used for inline heating, but at around 2.8 kW, would need a relatively slow flow rate (I could work it out, but can't be bothered). Safety would be my concern. Not sure what you mean. Water will get thinner as it heats, though limescale may make the heating element thicker. I assume you mean Ancient Romans. Maybe this fellow can answer that, ask the right person on here you may get an answer. https://www.youtube.com/watch?v=wmax3ntBS0Q
  18. A Willis heater. Used them all the time for spa baths we made over 30 years ago. Could have a heat exchanger and a Willis in series. A bit about evaporation losses from water surfaces here. https://www.thermexcel.com/english/program/pool.htm Bubble wrap is as good as anything. But make sure no one can get in the pool when it is on.
  19. Try sticking it where the sun don't shine. Always works for me.
  20. I don't, and always manage to get it though his letter box.
  21. Mine has a unique aroma.
  22. The proper term is densimeter. https://www.anton-paar.com/uk-en/products/details/portable-density-meter-dmatm-35-basic/
  23. Water, probably dog's wee. I am passing Bristol in Friday, more than happy to add to the liquid reservoir. More than happy as long as I don't have to pay the congestion charge that is.
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