Medal Winners: Air Traffic Control Tapes

On 6 Feb 2006 11:40:13 -0800, wrote:


Roger wrote:
On Sun, 05 Feb 2006 17:50:04 GMT, Richard Lamb
wrote:

Might we go a bit farther?

The reason I ask is that I've seen people take big lungfuls of Helium,
which (obviously) doesn't produce the same effect.

A really big lung full can make you light headed in a hurry, but
beyond that?


Can someone explain why N is such a disaster but He doesn't?

"I think" it has to do with the partial pressure of He compared to N,
but I really don't know.

Partial Pressure of a gas is what the pressure would be if all the
other gasses were removed without changing the volume.

Equal volumes of gas at the same temperature and pressure have
equal numbers of molecules (Avogadro's law). So no, that isn't
the explanation.

I thought Avogadro's Law (number the same?) was a gram molecular
weight of any element will have the same number of molecules as the
gram molecular weight for any other element. As I recall it's
6 X 10^28


There are warnings about inhaling He, but
I've not heard of any reactions like those of N2.

The warnings I have heard regard hydrocarbon contaminants
like compressor oils, putting the huffer at risk for chemical
pneumonia.

Still, He is used
as an N2 replacement in diving air at times to reduce the likely hood
of getting the bends on deep dives.


One presumes contaminants like compressor oils are filtered out
when the Helium is intended for that purpose, something one might
not bother to do for balloons.

I don't think in today's world compressor oils would be a problem with
He.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger wrote:
On 6 Feb 2006 11:40:13 -0800, wrote:


Roger wrote:
On Sun, 05 Feb 2006 17:50:04 GMT, Richard Lamb
wrote:

Might we go a bit farther?

The reason I ask is that I've seen people take big lungfuls of Helium,
which (obviously) doesn't produce the same effect.

A really big lung full can make you light headed in a hurry, but
beyond that?


Can someone explain why N is such a disaster but He doesn't?

"I think" it has to do with the partial pressure of He compared to N,
but I really don't know.

Partial Pressure of a gas is what the pressure would be if all the
other gasses were removed without changing the volume.

Equal volumes of gas at the same temperature and pressure have
equal numbers of molecules (Avogadro's law). So no, that isn't
the explanation.

I thought Avogadro's Law (number the same?) was a gram molecular
weight of any element will have the same number of molecules as the
gram molecular weight for any other element. As I recall it's
6 X 10^28


Perhaps he has more than one law named for him.

In essence, Avogadro's number is the conversion factor between
gram molecular weight of an and the number of molecules
in a sample of that element with a mass numerically equal in grams
to its gram molecular weight. Which, as stated in the law you quote,
is the same for all elements, or for that matter any substance which
consists of but a single molecule.

6.022 E23, as I recall.

Avogadro's law, Boyle's law and Charles' law may be combined to
produce the ideal gas law.

--

FF

On 7 Feb 2006 10:08:43 -0800, wrote:


Roger wrote:
On 6 Feb 2006 11:40:13 -0800, wrote:


Roger wrote:
On Sun, 05 Feb 2006 17:50:04 GMT, Richard Lamb
wrote:

Might we go a bit farther?

The reason I ask is that I've seen people take big lungfuls of Helium,
which (obviously) doesn't produce the same effect.

A really big lung full can make you light headed in a hurry, but
beyond that?


Can someone explain why N is such a disaster but He doesn't?

"I think" it has to do with the partial pressure of He compared to N,
but I really don't know.

Partial Pressure of a gas is what the pressure would be if all the
other gasses were removed without changing the volume.

Equal volumes of gas at the same temperature and pressure have
equal numbers of molecules (Avogadro's law). So no, that isn't
the explanation.

I thought Avogadro's Law (number the same?) was a gram molecular
weight of any element will have the same number of molecules as the
gram molecular weight for any other element. As I recall it's
6 X 10^28


Perhaps he has more than one law named for him.

In essence, Avogadro's number is the conversion factor between
gram molecular weight of an and the number of molecules
in a sample of that element with a mass numerically equal in grams
to its gram molecular weight. Which, as stated in the law you quote,
is the same for all elements, or for that matter any substance which
consists of but a single molecule.

6.022 E23, as I recall.

Avogadro's law, Boyle's law and Charles' law may be combined to
produce the ideal gas law.

Back in college we had two chemistry books that had exponents on that
that differed by several digits.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Helium is almost exactly the dilutional asphyxiant that nitrogen is.
It's used in deep-diving artificial atmospheres for two reasons:
Nitrogen is a weak anesthetic gas, producing intoxication at several
atmospheres pressure--(nitrogen narcosis"), and it's soluble enough in
blood and other water-based body fluids to fizz out when the pressure is
released suddenly (the bends, caisson worker's disease). Helium has
neither of these properties.

But breath helium in the absence of oxygen and, just like if you breath
nitrogen in similar circumstances, you will become unconscious, have an
anoxic seizure, and die. It's the same mechanism as used by the suicide
who surrounds himself with non-burning natural gas in an oven. The
people you've seen get away with a breath or two of it on the residual
oxygen in their lungs and blood. They can't get away with it for long,
and there are a few deaths per year in the US from people persisting in
breathing toy-balloon oxygen for voice games. There are also a few
deaths to nitrous oxide breathing for intoxication, also for anoxia.

As others have noted, carbon monoxide is a metabolic poison and causes
problems even in the presence of normally adequate oxygen. Carbon
dioxide in high concentrations is primarily a dilutional asphyxiant but,
again as others have noted, also has metabolic toxic effects.

David


David Kazdan, MD, PhD
Anesthesiologist
Pilot

Roger wrote:
On Sun, 05 Feb 2006 17:50:04 GMT, Richard Lamb
wrote:


Might we go a bit farther?

The reason I ask is that I've seen people take big lungfuls of Helium,
which (obviously) doesn't produce the same effect.


A really big lung full can make you light headed in a hurry, but
beyond that?


Can someone explain why N is such a disaster but He doesn't?


"I think" it has to do with the partial pressure of He compared to N,
but I really don't know. There are warnings about inhaling He, but
I've not heard of any reactions like those of N2. Still, He is used
as an N2 replacement in diving air at times to reduce the likely hood
of getting the bends on deep dives.

There *must* be some one who reads this group who knows.


(Should have paid more attention in chemistry classes!)


I should have gotten better grades!

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com



Richard

"David Kazdan" wrote in message m...
Helium is almost exactly the dilutional asphyxiant that nitrogen is. It's used in deep-diving artificial atmospheres
for two reasons: Nitrogen is a weak anesthetic gas, producing intoxication at several atmospheres pressure--(nitrogen
narcosis"), and it's soluble enough in blood and other water-based body fluids to fizz out when the pressure is
released suddenly (the bends, caisson worker's disease). Helium has neither of these properties.

But breath helium in the absence of oxygen and, just like if you breath nitrogen in similar circumstances, you will
become unconscious, have an anoxic seizure, and die. It's the same mechanism as used by the suicide who surrounds
himself with non-burning natural gas in an oven. The people you've seen get away with a breath or two of it on the
residual oxygen in their lungs and blood. They can't get away with it for long, and there are a few deaths per year
in the US from people persisting in breathing toy-balloon oxygen for voice games. There are also a few deaths to
nitrous oxide breathing for intoxication, also for anoxia.

As others have noted, carbon monoxide is a metabolic poison and causes problems even in the presence of normally
adequate oxygen. Carbon dioxide in high concentrations is primarily a dilutional asphyxiant but, again as others have
noted, also has metabolic toxic effects.

David


David Kazdan, MD, PhD
Anesthesiologist
Pilot


Excellent post, David, thank you.

"David Kazdan" wrote in message
m...

But breath helium in the absence of oxygen and, just like if you breath
nitrogen in similar circumstances, you will become unconscious, have an
anoxic seizure, and die. It's the same mechanism as used by the suicide
who surrounds himself with non-burning natural gas in an oven.

FWIW...

That's real hard to do nowdays.

Back when sticking your head in the oven was a popular movie cliche, the gas
distributed in most big cities was producer gas - a byproduct of of the
process used to make coke out of coal - essentially partial combustion with
inadequate air. The heating value of producer gas was primarily due to the
carbon monoxide content (it also contained a lot of N2 and CO2 as you would
expect). The CO is what made sticking your head in the oven work so well.
However, since the 1950's and the development of the cross country
pipelines, producer gas has been replace with natural gas (primarily methane
with a little mercaptan added to make it smell) which is just not the same
thing. Also, the oven burners are designed to mix air with the natural gas
so it's hard to adequately displace the oxygen in the air to commit suicide
by simply sticking your head in the open door.

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

"David Kazdan" wrote in message
m...

. . . But breath helium in the absence of oxygen and, just like if you
breath nitrogen in similar circumstances, you will become unconscious,
have an anoxic seizure, and die. . . The people you've seen get away with
a breath
or two of it on the residual oxygen in their lungs and blood.

Excellent post and, as far as I know, your facts are correct.

But - I find it odd that person of your stated qualifications does not seem
to know the difference between "breath" and "breathe". ?????

Rich "One can be a typo. Two makes it an error. Three would be enemy
action." S.

Ouch, that's pretty bad. Sorry. No question about it, error. I rather
pride myself on not needing to use a spell checker, too. Ouch, ouch,
ouch. Need lidocaine.

David

Rich S. wrote:
"David Kazdan" wrote in message
m...

. . . But breath helium in the absence of oxygen and, just like if you
breath nitrogen in similar circumstances, you will become unconscious,
have an anoxic seizure, and die. . . The people you've seen get away with
a breath
or two of it on the residual oxygen in their lungs and blood.


Excellent post and, as far as I know, your facts are correct.

But - I find it odd that person of your stated qualifications does not seem
to know the difference between "breath" and "breathe". ?????

Rich "One can be a typo. Two makes it an error. Three would be enemy
action." S.

"David Kazdan" wrote in message
t...
Ouch, that's pretty bad. Sorry. No question about it, error. I rather
pride myself on not needing to use a spell checker, too. Ouch, ouch,
ouch. Need lidocaine.

I think I've got a thirty year old vial of it around hear someplace. . .

Rich S.

Hi David,

David Kazdan wrote:
Helium is almost exactly the dilutional asphyxiant that nitrogen is.
It's used in deep-diving artificial atmospheres for two reasons:
Nitrogen is a weak anesthetic gas, producing intoxication at several
atmospheres pressure--(nitrogen narcosis"), and it's soluble enough in
blood and other water-based body fluids to fizz out when the pressure is
released suddenly (the bends, caisson worker's disease). "Helium has
neither of these properties."

snip

David


David Kazdan, MD, PhD
Anesthesiologist
Pilot

I hesitate to enter this discussion since you are obviously well
qualified, however, that is often how learning occurs and I still
have a lot to learn.

I agree with all of your excellent post with one minor exception.
Helium _is_ absorbed into the bloodstream under high enough partial
pressure and does release bubbles when the pressure is released
too quickly. Heliox (Helium + O2) and Trimix (Helium + N + O2) are
common gasses used in the technical diving community, and they both
require decompression stops on the way back to the surface. Technical
divers use these mixes for dives from 130' (~5 atmospheres) to as much
as 1000' (~31 atmospheres). The O2 content of the mixes is reduced to
avoid oxygen toxicity effects at high PPO2. I also would point out
that helium at high PP--although not narcotic like Nitrogen--does
produce some strange physiological effects including a "buzz" similar
to having had a lot of caffein.

Don Woodbridge P.E.
Engineer
Technical Diver
Pilot