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Externet

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Everything posted by Externet

  1. Hello all. Am on first steps to make a solar thermal water pump for drip irrigation purposes. Assume 60% efficiency of solar thermal irradiation (600W/m2. Assume average daylight temperature 25C. Assume average night temperature 15C. Or, make those parameters real, entered in the formula. Area of sun exposure as parameter, say =1 m2 (Tank lid) Capacity of reservoir as parameter, say = 1 m3 Volume of air, =Va. Volume of water =Vw. For a desired pumping height, what would be the flow in 24 hours ? [Plus whatever am missing] In the hermetic reservoir, the solar heat expands the air pushing the water up during the day, and suctioning water below from cooled air contraction during the night to refill the reservoir. How to arrive to such a formula, how is it done ? Ordered the parts to build the contraption. Should get in 2weeks.
  2. My vote is to not continue changing the time. And see no problem by trying a year or two.
  3. Applying the lessons from bats... What would have determined the 90 degree disposition of the parabolas signals and the 180 degrees one respect to the other, instead of straight at the ends of the 'ears tube' ?
  4. If has to be a 'clickable link' it is : https://www.world-nuclear-news.org/Articles/Nuclear-battery-Chinese-firm-aiming-for-mass-mark
  5. There is news speculating about it Another ---> https://learn.sparkfun.com/tutorials/nuclear-battery-assembly-guide/all
  6. I do not need nor even look at the screen when am talking on the phone. Other than to initiate or end the call.
  7. Hi. Are different tree species graft-compatible if one of these classifications coincide ? Or has to be an specific one ? Or more than one ? Or that is not it ? Example: Can Apricots and peaches be cross grafted because both share a bunch of clades and more ? If they coincide in only one of the clades; are they compatible ? How is it known ?
  8. At the nursery, the trees they sell are labeled as 'fruiting' , 'flowering' , 'shading' What are the 'flowering' ones biological purpose ? Are these somehow manipulated trees; or their flowers have no stamen, stigma, no reproduction purpose ? Those do not bear fruit. (Like the ornamental cherry blossoms) How does it work ?
  9. Yes I do have identifiers. Passport, driving license and many others in USA and from other countries. Only two cards related to vaccines.
  10. Hello all. Vaccines administered to infants, if have no records or have been lost by parents could be an inconvenient. Is there a simple test to confirm if someone as infant received a vaccine ? From what I know, when we reach adulthood we do not have a card telling what, when, where. Memories from parents may not be reliable either. Is administering to adults vaccines meant for kids a risk ? A record card would have to be mandatory to keep with youngsters documents for life. Is there such global proposal/initiative placing copies at several locations ? Particularly you. Do you know now as adult, what vaccines you received since birth; do you have a record card of such ? How important would be to fix this void ?
  11. Never seen done with hard cheese nor modern flavors. It is a humble invent of natives using only basic ingredients available to them. Perhaps melting such cheese could work ? Some use grated mozzarella instead... Needs to be soft to behave as dough when mixed with the flour !. Not brasilian but colombian style (pandebono) ; here is someone using UK ingredients : ---> https://www.glutenfreealchemist.com/pandebonos-south-american-cheese-bread/ Try the simple very basic recipe I posted first. Then go fancy.
  12. Hi exchemist. My simplest way without claiming being best, that you may alter/improve your way later : Get a plain "cream cheese" equivalent to U.S. 'Philadelphia' brand. 4 ounces (half pack here) WARM !, ~ 25-30 0C not from the refrigerator ! 1 cup of yuca starch. Half a teaspoon maximum of salt. One teaspoon of baking powder. 2 tablespoons of water. Mix to very uniform and make 8 balls to 340 0F for 22 minutes. Come back with results. Bread result should have an elastic cheese core. Goes well served with yogurt
  13. Thanks. Yes, aware of its poisonous nature as the potatoes and yams are. Been consuming it for decades as zillion people in the world. Do not understand the "layer by layer" above. It is a root, finely chopped when making the flour. What layers are there to separate ? The peel is discarded.
  14. Often I bake cheese bread, yuca bread... many names for the same. Not yucca ! Also known as cassava, mandioca, tapioca... When the flour is manufactured, what is added or substracted for it to become/make starch instead ? Am convinced is the same stuff with mythic beliefs. How is it ?
  15. The battery is too weak for the motors demand. The motors are too weak for the motion demand. The motors are too demanding for the battery capability. The connecting wiring is not soldered presenting resistance to electricity flow. The gearing does not match the needed torque. The motors that are not energized are presenting braking effect to the others. One or more of the above. Check if the car rolls smooth by hand when not energized. Try energizing only one wheeled motor instead and come back with observations.
  16. There is a few ways to turn ultrasonics into sonics for the use of 'normal' test equipment. If not in the market, would need to be built to suit needs. Not a too difficult task. One is a frequency divider, ---> https://www.incbtech.com/index.php/articles/79-bionics-and-medicine/466-ultrasonic-sound-converter-hearing-the-unheard-bm013 Another is a frequency mixer with the vintage NE602 integrated circuit (heterodyning) or other down-mixing chips. ---> https://www.n5dux.com/ham/files/pdf/Single-Chip Frequency Converter.pdf ---> https://www.bats.org.uk/about-bats/bat-detectors-1/heterodyne Microcontrollers can do the translation to audible plus visually in a few ways. The microphone would have to be good, really good with known specifications. Perhaps piezoelectric from echosounder/sonar equipment if for underwater. Whale listeners have their specialized gadgets. ---> https://www.wildlifeacoustics.com/ And as an application: ---> https://apps.apple.com/gb/app/echo-meter-touch-bat-detector/id693958125 A parabolic microphone would help all the above if fitted with a proper sensor : ---> https://search.brave.com/images?q=parabolic microphone
  17. Good day. Is there any found causal or relation between the fall of Rome by the middle of first century and the legalization and rise of christianity ? The prosper peaceful 'pax romana' era that had abundant reported wealth in many roman citizens... Where did that people obtained/earned their wealth ? What business were they involved in those times ? There were also the not wealthy population; but what activities not tied to government made the rich rich ? Yes, can be moved to somewhere else as deserved. Into politics, history, lounge...
  18. Thanks. Appears now like the different density restrictions are a clue... The top outlet side is free to air; the other side below has a wet spongy presenting a much denser on-water restriction. While vibrating, suction works by the partial vacuum on a denser media (water) and no vacuum on the expulsion side into air, forming a flow valve. Am I guessing near right ? When the diaphragm pushes down, has difficulty 'pumping' whatever is in its pores into dense water. When the diaphragm bows up, encounters no resistance in expelling. That differential creates the flow ? Yes, poor wording as always. What am unsure in reasoning if expulsion of droplets happens when diaphragm bows down or when bows up, or during the transit upwards or downwards...
  19. The PZT is of annular shape about 5mm id and 12mm od;, its center void has attached the stainless disc which found to have microperforations and emits/sprays the mist on its top; contacts the water at its bottom. The misting image shows the PZM on top of a wet sponge instead of floating on water. Overview of the little white buoy ---> https://www.youtube.com/watch?v=PlRgi6Mn6CQ
  20. Hi all. Bought several tiny nebulizers to humidify a germinating room. Testing one for two weeks, ceased to produce the fog. Do not know how to revive. By cleaning sort of worked at half production for an hour. Read about and found : ---> https://www.electroschematics.com/mist-maker/ But the surprising specification says "5um" "740 holes" So I projected a laser to the stainless piezodisc and yes, shined trough the supposed-to-be holes in metal (5 micrometres per above) invisible to eyes or magnifying lens. Confirming it is a microperforated disc. Never saw a piezoelement perforated. How is the principle of operation of such nebulizer ? I have other piezo nebulizers with solid discs.
  21. Thanks. Surface mounting would take the U straps/brackets, then. No 'pretty box' as in US at right image. One in a hundred -or more- US dwellings has masonry walls. New masonry/european construction foresees piping in walls to use the one at left, and a drain hole. Found no 'boxes' for additions on masonry.
  22. Hi. In USA, houses made with paper and sticks use flimsy recessed box to connect clotheswasher hoses. How is it done 'surface-mount' on stone/block/brick walls ? Looking for such and cannot find in US
  23. Radio waves propagate same as light from the sun does without a medium. Low or high frequency mean nothing. Waves in water are a mechanical disturbance, not electromagnetic.
  24. Thank you. That implies the flower stigma 'analyzes' if the pollen arrived by an insect is foreign in order to accept it * for fertilization; and check if there is 'a time-or-maturity window' left to decide if taking the self-pollen is a last minute resource. *Of course, ignoring/rejecting other family/genus - which means another analysis of the pollen is not from a rose instead. So much to learn !
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