ROHS++

written. Not

Yup, I have them all, including the whole RadLab series.

hardback.

They're all good stuff. I liked Dorothy's book (she was Russel's widow) because it wasn't very technical but paints a vivid picture of California between the wars.

John

Then tell me why does the US buy the really advanced stuff from here? A few weeks ago I saw a demonstration of a device based on radar technology to scan people for conceiled weapons. The whole process is passive, i.e. no radiation is emitted in order to get the image. Dutch invention ofcourse...

The half that is fed-up with the 'Bushit' :-)

"based on radar technology"?? Sounds like marketing hype to me. Probably an IR scanner.

And tell me what is this "really advanced stuff" we buy from the Netherlands?

...Jim Thompson

Definitely not. Just look (the text is in Dutch):

Like I said: Radar systems

Yeah, even though the 1/R**4 distance dependence makes this a little less impressive--1/(0.8**4) = 2.44 times (3.8 dB) less sensitivity.

Cheers,

Phil Hobbs

BTW the radar proximity fuze for artillery shells was pretty impressive too--vacuum tubes that survive being fired from a cannon!

Well, yes.

Maybe the noise reference was to using klystrons as receive amps. That would have helped the t/r burnout problem, but I think their nf's were a lot worse then a point-contact diode mixer.

See Baldwin's book, The Deadly Fuze, for lots of neat tales. There were hundreds of millions of those high-G tubes built, and I'd like to acquire a few, but I've never seen them anywhere. I do have a few prox fuze schematics, usually 3 tubes: reflex oscillator, audio amp, thyratron.

John

Hello Jim,

Grolsch, Kanis&Gunninck coffee, Douwe-Egberts coffee, Beerenburger, etc.

No pun intended here but this is all really good stuff :-)

HOWL!

-- "Electricity is of two kinds, positive and negative. The difference is, I presume, that one comes a little more expensive, but is more durable; the other is a cheaper thing, but the moths get into it." (Stephen Leacock)

Acetylsalicylic acid, aspirin, does not occur in nature.

"Greek physician Hippocrates prescribed the bark and leaves of the willow tree (rich in a substance called salicin) to relieve pain and fever."

John

In message , dated Mon, 31 Jul 2006, John Larkin writes

Well, maybe it does somewhere; there's no law against it. But indeed it was developed because salicylic acid is very unpleasant to take. The body strips off the acetyl group.

There are probably more than 10000 natural substances with useful therapeutic effects. Of course, not all are yet known to Western science; hoodia is an example that became widely known only recently. Some that were once known have probably been forgotten entirely.

Or have become extinct

"Silphium (also known as silphion or laser) was a plant of the genus Ferula. Generally considered to be an extinct "giant fennel" (although some claim that the plant is really Ferula tingitana), it once formed the crux of trade from the ancient city of Cyrene for its use as a rich seasoning and as a medicine.[1] It was so critical to the Cyrenian economy that most of their coins bore a picture of the plant (illustration, right).

The valuable product was the resin (laser, laserpicium, or lasarpicium) of the plant. It was harvested in a manner similar to asafoetida, a plant with similar enough qualities to silphium that Romans, including the geographer Strabo, used the same word to describe both.[2]

Aside from its uses in Greco-Roman cooking (as in recipes by Apicius), many medical uses were ascribed to the plant. It was said that it could be used to treat cough, sore throat, fever, indigestion, aches and pains, warts, and all kinds of maladies. Chiefly among its medical uses, according to Pliny the Elder, was its role as a herbal contraceptive.[3] Given that many species in the parsley family have estrogenic properties, and some (such as Wild carrot) have been found to work as an abortifacient, it is quite possible that the plant was pharmacologically active in the prevention or termination of pregnancy. Legend said that it was a gift from the god Apollo. It was used widely by most ancient Mediterranean cultures; the Romans considered it "worth its weight in denarii."

Dirk

Ah, the historical origin of "Not tonight dear, I have a headache."

John

The page won't load for me (3aug06 'bout 2020 hours). Just the same you seem to be local to me (Rancho Cordoba).

Do you think you are in sci.electronics.basics, or do you disrespect us so much as to to feel a need to explain something as easy as that?

He doesn't know where he is, and he doesn't care, either. That is why I have 13 different user names kill filed for him. :(

The press release gives 3mm as the wavelength of the radiation being monitiored - a frequency of 100GHz. The infra-red spectrum is normally taken as extending from 0.5 micron to around 100 micron.

Check out the Dutch contribution to the Joint Strike Fighter. The only specific contribution I could find was from Stork Aerospace (used to be part of Fokker) - Stork Aerospace bijvoorbeeld zal de deuren en de bekabeling leveren - who are contributing the doors and the cable harness.

Philips, Urenco and Fokker Elmo are the other major contributors. See

which includes what lloks like a complete list of the Dutch firms involved.

In message , dated Fri, 4 Aug 2006, Bill Sloman writes

These scanners are described as 'Terahertz technology'; but 1 THz is 0.3 mm wavelength. Obviously, there is no natural boundary between radio waves and the Terahertz band and that and the IR band; they are just arbitrary boundaries.