Recent content by DarioC

I have a tray of ice cubes in my freezer that have been there for months and some of the cubes are as much as 75% reduced in size. The temperature is about minus 20 degrees C.

Perhaps this doesn't belong here but I have found myself amazed at this: I have a carbon steel small paring knife and when I have washed it I can smell the fairly strong odor of "rusted" iron coming from it. I can imagine iron oxide molecules evaporating off the metal surface. I find that...

Yes that is one. Thanks for the photo.

On the triangles, I think somehow you have misunderstood which "triangles" I meant. The ones I am talking about are very small long strips that are located on the leading edge of the inboard part of the wing. Their purpose is to disturb the airflow at high angles of attack and cause the inboard...

I think this is the video I mentioned. Pulsed smoke flow in wind tunnel. Check at about 47 seconds.

Fog37, In reply I think you might want to look at what happens at the leading edge of the wing. I am getting close to the limits of my understanding here. The air running into the leading edge curve is flung/forced upwards which compacts the air above the wing, at the same time making a lower...

I don't understand fog37's initial statement that the air flowing over the top of the wing causes a downward pressure on the top of the wing. None the less:There was (is) an excellent video online of wind tunnel airflow over an airfoil with the flow shown by pulsed smoke. It really changed my...

Negative results yesterday on the minimum gap UV experiment. I have had an interesting experience with very light soot in a computer tripping ground fault outlets so I am considering that combination and similar situations. A question for he OP: Did the controller fail, or is it still functional?

Ah yes, but the circuit is in an enclosed "box", that will be a problem I think. Meanwhile, I found some LEDs in a parts drawer that are rated almost identically to the ratings of the spy pens. That is 405 nm and 5 mW, so I'm going to set up an experiment with AC line voltage and multiple...

Good investigating OmCheeto, and calculating. I see the unit is an enclosed box, so much for just checking behind the panel. I'm just now thinking about how we could get the manufacturer to donate a unit or supply some detailed design information.

As others have suggested, have a experienced electrical person carefully pull the wall plate and first and foremost check for exactly where the arc took place. That will be your best clue as to what happened. If there was sparking there should be some visible marks. The physical...

Picked my curiosity so I compared images and this appears to be a spy pen? If so it is likely, from articles I have just read, to not be UV, but rather the upper end of the visible spectrum at 410 nm. Typically about 5mW LED. Moot point probably, high energy visible anyway. I'm interested in...

Roger on the dimmer. Read it but didn't register/early morning with headache. I will suggest that there may be something a little more complex under those control arms with perhaps marginal contact or sensitive material/clearances that the UV could affect.

I don't see any comment that the "switches" on the right side are variable controls and not off-on switches.

Thanks, point well taken. Have to break out the books and/or look around online for how to calculate/understand that particular aspect of the subject. Oh, I did error in not saying that I am specifically interested in learning about the pattern when it is a single photon or particle at at a...