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Comment Serial RS-232 port (Score 4, Interesting) 620

I use RS-232 (essentialy a 50 years old technology) regularly to read data from lock-ins, picoammeters, and various other instruments. It works well enough, I don't need extra fast reading (the measurement itself is the slowest part). It's not always a smooth ride, but overall it's pretty reliable and straightforward.

Comment Re: Why bother with installed capacity? (Score 2) 259

The right keyword here is "capacity factor". There is a decent article about it on wikipedia. Solar power tends to have around 15%, nuclear around 80%, generally - but it varies from country to country. Basically it is a portion of time the plant is able to run at peak rated power; and since for solar the peak can be attained only around noon and without any clouds, it is so low, compared to other types of powerplants.

Comment Fonts in Chrome are too light (Score 1) 240

The basic problem I have with Chrome is font rendering. The fonts are (still) too light, and have much worse readability than those in Firefox. Seems to me they don't respect cleartype settings at all. This is all tested on vanilla Windows installation, so hardly a problem on my part.

Also, especially on wide-screen displays, the omnibar is overly long and its' space is just wasted. More buttons should/could be (optionally) on the toolbar instead. I am especially missing a "bookmarks" button, that would display available bookmarks as a menu. I know about bookmarks bar, but that eats up precious vertical space. And "(three bars) -> Bookmarks" is just inconvenient (one precise mouse movement - and wait/or click - away).

On the other hand (previously an Opera user) I do like the possibility of Duplication of tabs in Chrome. Most probably there is an extension for Firefox doing the same thing, but I consider it such useful option, that it should be in by default.

Comment Reminds me of calculating factorial with .bat file (Score 1) 486

Reminds me of one really strange course on college. The lecturer calculated factorial, up to ten - using DOS 6.22 .bat file. Actually, he provided three "solutions".
One solution was to write ten "if" cases, and just echo the corresponding number, hardcoded.
I can't remember the second solution.
The third was the real "beast". It was based on recursion. "factor.bat" called itself. The batch created one byte file in the beginning. And this file was joined n-times within each iteration. All this to facilitate multiplication, which was not directly achievable in a batch file. In the end, there was "dir /b fact.txt" and probably an echo with "look at the size, this is the result".
I kid you not. It was something like: for $1==1, fact.bat created a file "fact.txt", with one byte (using echo x > fact.txt) then the file was joined n-times - with type fact.txt >> xfact.txt after fact.txt was added n times to xfact, xfact would be renamed to fact.txt
Of course, in this case, disk access was really slower than pascal version, that run in memory... :)

Comment How to get 99% of ketchup out of the bottle (Score 2) 172

Suppose you have almost empty bottle of ketchup. The following procedure works

1) close the bottle, turn it upside down with one hand
2) tap the bottle (2 or 3 times) to the other hand, while holding it upside down, to move the ketchup from the bottom to the (inside) walls of the bottle
3) Stand the bottle on its cap
4) let it stand for ~20 minutes
5) most of the ketchup will slowly slide to the bottom, leaving the sides almost clean - try it to see it
6) carefully open the cap while still upside down, empty the ketchup on a plate
7) enjoy the ketchup

This procedure leaves only ~1% - at most - in the bottle. Could not believe how well the ketchup slide down. All it needs is a bit of time - really 20 minutes or so, it is not instantaneous.

Comment Capacity factor (Score 1) 356

My guess is, they are comparing peak output, i.e. peak MWs of different power sources. Which is incorrect. There are huge differencies in so called capacity factor, which is basically how much percent of a year the power plant is able to operate at 100% rated (peak) power output. For nuclear power plant, the capacity factor is around 75%, for coal fired power plant it is around 50%. For solar, it is (alas) only 10%, mainly due to simple fact, that peak power is produced only around noon and when the sky is clear. I am actually quite supportive of solar power, but let's just compare apples to apples; for solar plant, you need 5x more peak power to match a coal fired plant (and there is still the - basically unsolved - problem of energy storage for solar cells).

Comment Re:Solar constant is 1kW/m^2. No way around that. (Score 1) 65

No, there is not. You are mixing the number of particles and the energy they have. You can get more free electrons than incident photons - this is really what the Quantum efficiency is about, QE = [number of electrons]/[number of incident photons]. But those "more electrons" would be at a lower energy level, which translates to lower open circuit voltage of the cell. The overall energy of the pair of electrons would still be lower than the energy of the photon that kicked them to the conduction band, i.e. the efficiency would still be (way) below 100%. Sorry pal, energy conservation holds.

Comment Solar constant is 1kW/m^2. No way around that. (Score 4, Interesting) 65

Given the solar constant, i.e. the fact that there is at most 1kW per square meter of solar irradiation, there is no way this kind of planes could be used to air transport as we know it. To make the plane more powerful, way too much wing area would be needed, which would in turn reduce the speed etc. So, unfortunatelly, planes powered directly with photovoltaic panels will always be very limited in the weight they can carry. There are still applications for such kind of planes, though. (the 1kW/m^2 corresponds to a clear sky, the plane perpendicular to the impinging fotons, near the equator around noon, so the sun rays go almost perpendicularly through the atmosphere AM1.0 spectrum - simply the most favorable conditions). Photovoltaics (on a large area) powering the synthesization of hydrocarbons for conventional airplanes, renewably from air CO2 and water - that's completely different story. But it is not what this project is about.

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