Jump to content


Senior Members
  • Posts

  • Joined

  • Last visited

1 Follower

About Externet

Profile Information

  • Location
    Mideast U.S.
  • Interests
    Old Cadillacs, scuba electronics.
  • College Major/Degree
    Electronics engineer, audio recording engineer.
  • Favorite Area of Science
  • Biography
    Plain old fart tells it all.
  • Occupation
    Retired from electronics and shrimp farming.


  • Molecule

Recent Profile Visitors

30547 profile views

Externet's Achievements


Primate (9/13)



  1. Thanks. After the photovoltaic layer under the sun, there is not much useable energy to collect the whole 1 KW/m2 Solar panels give me winter electric heating by accumulating all year radiation. The panel aluminium frames are almost 5cm void under the cells. Closing the lower frame void I can make their heated air chamber to circulate into a dwelling to yield more heat. How else to wring the 1 KW/m2 leftovers ?
  2. Hi. Solar radiation in all its flavors of infrared, visible light, ultraviolets and all the rest whatever they be hitting a roof for a standard figure of 1KW/m2 What device could collect the most solar energy of all kinds installed on a roof ? Photovoltaics can collect about 18% into direct current.
  3. The wings pictures above do not have winglets for reducing vortexes.
  4. This is not a video, but the link to it shows - screen capture - Better image found :
  5. Hi. From memory, the belly red; the wingtip white strobe and the top red of fuselage beacons flashed sequentially; not simultaneous. The questioned wingtop row of dots may be coincidental with one of them flashing. The dots appeared like tiny 10mm diametre / 3mm high bumps when seen with the ambient light after aircraft stopped, but their diffused light was like 5cm diametre as seen on image. There is a possibility of being reflective adhesive tape dots. My vision is not superb, but was not a dream.
  6. Thanks. Nothing to do with leading/trailing edges nor extends. On top of wings. Flashing during all clear night time trip. Seems Embraer RJ 145. Commenting with a passenger on the right side window, we asked the flight attendant who guessed whatever to answer. From the strong curiosity, found an almost decent image of the lights location, at daylight. Center upper of image below. Ahead of ailerons. Unable to magnify. The nearest is a group of three, then farther another nine, as in post 1 L ooooooooo ooo ==================================== ooo ooooooooo R Same details, in video, not flashing ---> https://www.youtube.com/watch?v=OfV9DnYPyo8&ab
  7. Hi. On a recent flight, perhaps on an Embraer aircraft, noticed diffused flashing red lights on top of wings that I never saw before. Anyone knows ? Took a video but does not show the detail, I was unable to ask the pilot at exit. They are near the 'ends' of wings tops, a centered row of 12, aiming upwards ? Seem as diffuse as if the wing was translucent and lit from the inside. Just curious. L wingtip ooooooooo ooo =================== Main fuselage =================== ooo ooooooooo wingtip R Found a image on the web to better explain the location of those lights on top of wings.
  8. Greetings What makes the shaving products work ? Its application on skin, some action on the facial hair, lubrication? something to do with the sharpness of blades, slipperyness, edges grabbing onto hair, some displacement or not of hair piling on blades ? Seems an optimal thing developed trough years; trying soap, just water, dry, others, is not as successful. Can you explain ?
  9. Hi. I know peanuts about this; that is why am here. Is there test strips that show if it is ethanol, or methanol, or some other compounds when distilling alcohols ? What sorts of identifications/concentrations are test strips made for ? pH and nothing else ? What about salinity ? Glucose ? ...?
  10. Plants, as convert non-living minerals to living and edible sources.
  11. Regards. It is claimed as possible, people does it or so they say, applying a magic powder/compound this-or-that-and-that-too, on such moon phase 'after a rain' to a cut twig, roots develop and then is planted on soil. Nice. OK. I want to do that to a 10cm diametre branch 6 metres long cut off from a very mature 15m tall productive healthy mulberry tree. What is to consider for success ? Or needs the expertise of only an experienced expert with green thumbs ? Is it not science where you do one thing and the result comes as expected ? Yes, I want a tree producing fruit in my backyard much sooner than waiting 5-10 years. The secret, please ?
  12. Greetings. Half a dozen in my house, and other places I maintain with several more also of the not-vintage types. Have replaced them, cleaned them, repaired capacitors, switches, wiring in them but never saw an obvious lubricating points above or below them nor seen owners manuals guidance to oil them. Do they need some dismantling in order to lubricate or there is a clever access to the proper point; or simply is a chinese discard-and-buy-new as if few drops of oil and little effort is too much to ask ?
  13. It is a mathematics question. Am after figures to compare from integrating exposures at sun azimuths, elevations and incidence angles. Or that is a wrong way to find out ? My roof has 4.8KW generation capability, it is slanted for south exposure. In summer, noticed generation does not start until ~9+am; and even the sun is bright 3 hours before sunset, there is no generation then either. Guessing, a total of 3 hours by sunrise + 3 hours at sunset are not productive mostly because sun azimuths on tilted panels. Typical production is 20 to 30 KWh daily. If deserves to relocate post to 'applied mathematics' or 'calculus' please move. [Image taken from south, near noon]
  14. Greetings. This is not simple for me to put into words; please ask what I may be missing to expose properly. For a northern hemisphere latitude chosen as 450 as an average for America, Asia and Europe locations with solar panels. If the solar panels are placed horizontal, as soon as the sun is above horizon, the panels are exposed to direct sun rays. At a very low angle but every day of the year and for more than 12 hours in summer but at a 'lossy' incident angle. There will be a 'bell' curve of exposure peaking at celestial noon, producing a photovoltaic generation of X KWyear. If the solar panels are tilted 450 for optimal exposure, at sunrise above the horizon illuminates the back of the panels producing zero energy until the sun azimuth reaches east and until falls at west to again illuminate the back of the panels until sunset. Am I right in this ? The noon peak is more productive, yields Y KWyear. In winter, the sun hits the panels as soon as above horizon at a more efficient incident angle. The consensus is to install them tilted but am curious about how much detrimental to generation (Y-X) is installing them horizontal. Integration calculus should yield the result but am not capable of performing the operations. Could you ? In other words: how much better is a tilted installation ? Horizontal --> poor angle, more exposure hours in summer. Tilted --> better angle, less exposure hours in summer. Comes from two things... If the photovoltaic generation is for providing heating in winter or cooling in summer. If angling is conveniently justified or not for an existing roof risking windload.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.