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#21
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Old film refridged 8 years
William Graham spake thus:
"Alan Browne" wrote in message oups.com... AAvK wrote: Hello all, pertinent to the recent thread "expired film" in rec.photo.equipment.35mm I have several rolls of 120/220 I shot in '97 - '99, I have kept it all refridged in a lead lined travel film bag since then, and only recently put it in the freezer! Need to know, how should it be developed? Pushed or pulled? Special or concentrated chemicals? What damage has been done? The lead bag will do nothing against alpha particles that fly through lead as if empty space. So some fogging of the film may occur. If a "low-ish" speed film (50/100) then possibly not so bad. I don't think so....Usually alpha particles are stopped by a piece of paper.....See this excerpt from Wikepedia.... The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha particles have energies of between 3 and 7 MeV. [...] And of course we can believe it if it says so on Wikipedia. (Until some zit-faced teenager comes along and edits it ...) -- Just as McDonald's is where you go when you're hungry but don't really care about the quality of your food, Wikipedia is where you go when you're curious but don't really care about the quality of your knowledge. - Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm) |
#22
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Old film refridged 8 years
David Nebenzahl wrote:
William Graham spake thus: I don't think so....Usually alpha particles are stopped by a piece of paper.....See this excerpt from Wikepedia.... The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha particles have energies of between 3 and 7 MeV. [...] And of course we can believe it if it says so on Wikipedia. (Until some zit-faced teenager comes along and edits it ...) Seems to me that if you believe what William posted was inaccurate it would be easy to find references that would contradict what he posted. But then you don't really believe there is anything wrong with what he posted do you? Scott |
#23
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Old film refridged 8 years
Scott W spake thus:
David Nebenzahl wrote: William Graham spake thus: I don't think so....Usually alpha particles are stopped by a piece of paper.....See this excerpt from Wikepedia.... The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha particles have energies of between 3 and 7 MeV. [...] And of course we can believe it if it says so on Wikipedia. (Until some zit-faced teenager comes along and edits it ...) Seems to me that if you believe what William posted was inaccurate it would be easy to find references that would contradict what he posted. But then you don't really believe there is anything wrong with what he posted do you? So, by your logic, if one Wikipedia article is accurate, that means all articles there are accurate--did I get that right? -- Just as McDonald's is where you go when you're hungry but don't really care about the quality of your food, Wikipedia is where you go when you're curious but don't really care about the quality of your knowledge. - Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm) |
#24
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Old film refridged 8 years
In article m,
David Nebenzahl wrote: The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha particles have energies of between 3 and 7 MeV. [...] And of course we can believe it if it says so on Wikipedia. (Until some zit-faced teenager comes along and edits it ...) From the US Environmental Protection Agency (presumable no zit-faced teenager edited the EPA's website ... we hope) http://www.epa.gov/radiation/understand/alpha.htm "An alpha particle is identical to a helium nucleus having two protons and two neutrons. It is a relatively heavy, high-energy particle, with a positive charge of +2 from its two protons. Alpha particles have a velocity in air of approximately one-twentieth the speed of light, depending upon the individual particle's energy. "When the ratio of neutrons to protons in the nucleus is too low, certain atoms restore the balance by emitting alpha particles. For example: Polonium-210 has 126 neutrons and 84 protons, a ratio of 1.50 to 1. Following radioactive decay by the emission of an alpha particle, the ratio becomes 124 neutrons to 82 protons, or 1.51 to 1. Alpha emitting atoms tend to be very large atoms (that is, they have high atomic numbers). With some exceptions, naturally occurring alpha emitters have atomic numbers of at least 82 (the element lead)." Alpha emitters include plutonium-236, uranium-238,*radium-226, *radon-222, and polonium-210. [paraphrased] "The health effects of alpha particles depend heavily upon how exposure takes place. External exposure (external to the body) is of far less concern than internal exposure, because alpha particles lack the energy to penetrate the outer dead layer of skin. "However, if alpha emitters have been inhaled, ingested (swallowed), or absorbed into the blood stream, sensitive living tissue can be exposed to alpha radiation. The resulting biological damage increases the risk of cancer; in particular, alpha radiation is known to cause lung cancer in humans when alpha emitters are inhaled." Beta particles: http://www.epa.gov/radiation/understand/beta.htm "Beta particles are subatomic particles ejected from the nucleus of some radioactive atoms. They are equivalent to electrons. The difference is that beta particles originate in the nucleus and electrons originate outside the nucleus.* "Beta particles have an electrical charge of -1. Beta particles have a mass of 549 millionths of one atomic mass unit, or AMU, which is about 1/2000 of the mass of a proton or neutron. The speed of individual beta particles depends on how much energy they have, and varies over a wide range. It is their excess energy, in the form of speed, that causes harm to living cells. When transferred, this energy can break chemical bonds and form ions." Gamma Rays / X-Rays (the ones that fog film): http://www.epa.gov/radiation/understand/gamma.htm "Gamma radiation is very high-energy ionizing radiation. Gamma photons have about 10,000 times as much energy as the photons in the visible range of the electromagnetic spectrum. Gamma photons have no mass and no electrical charge--they are pure electromagnetic energy. "Because of their high energy, gamma photons travel at the speed of light and can cover hundreds to thousands of meters in air before spending their energy. They can pass through many kinds of materials, including human tissue. Very dense materials, such as lead, are commonly used as shielding to slow or stop gamma photons. "Their wave lengths are so short that they must be measured in nanometers, billionths of a meter. They range from 3/100ths to 3/1,000ths of a nanometer." Remember, just because it's in Wikipedia doesn't mean it isn't true. -- jon fabian looked good on paper f a b i a n "at" p a n i x "dot" c o m |
#25
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Old film refridged 8 years
j fabian spake thus:
In article m, David Nebenzahl wrote: The point is, EB had (and still has, I presume) *no* articles on Pokemon, or characters on /House/, or any of the thousands of other articles (known in wiki-speak as "-cruft") which EB would not consider "encyclopedic" in the first place. Sorry: http://www.britannica.com/ebc/article-9384328 "anime" "Style of animation popular in Japanese films. Anim films are meant primarily for the Japanese market and, as such, employ many cultural references unique to Japan. For example, the large eyes of anim characters are commonly perceived in Japan as multifaceted ³windows to the soul. Much of the genre is aimed at the children's market, but anim films are sometimes marked by adult themes and subject matter. Modern anim began in 1956 and found lasting success in 1961 with the establishment of Mushi Productions by Osamu Tezuka, a leading figure in modern manga (Japanese comics). Such anim as Akira (1988), Princess Mononoke (1997), and the Pokmon series of films have attained international popularity." Well whadda ya know -- Pokemon in the Encyclopedia Britannica. I guess they aren't such elitists as some people hope they are... Well, that's good to know. But what they definitely *don't* have is articles on each and every Pokemon character, as Wikipedia does. -- Just as McDonald's is where you go when you're hungry but don't really care about the quality of your food, Wikipedia is where you go when you're curious but don't really care about the quality of your knowledge. - Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm) |
#26
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Old film refridged 8 years
"David Nebenzahl" wrote in message s.com... William Graham spake thus: "Alan Browne" wrote in message oups.com... AAvK wrote: Hello all, pertinent to the recent thread "expired film" in rec.photo.equipment.35mm I have several rolls of 120/220 I shot in '97 - '99, I have kept it all refridged in a lead lined travel film bag since then, and only recently put it in the freezer! Need to know, how should it be developed? Pushed or pulled? Special or concentrated chemicals? What damage has been done? The lead bag will do nothing against alpha particles that fly through lead as if empty space. So some fogging of the film may occur. If a "low-ish" speed film (50/100) then possibly not so bad. I don't think so....Usually alpha particles are stopped by a piece of paper.....See this excerpt from Wikepedia.... The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha particles have energies of between 3 and 7 MeV. [...] And of course we can believe it if it says so on Wikipedia. (Until some zit-faced teenager comes along and edits it ...) Well, if you doubt it, google is full of links to other sources of information about alpha particles....I was a radiation worker for Stanford University for 28 years, and I can tell you that wikipedia is right on the money about this one........ |
#27
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Old film refridged 8 years
"David Nebenzahl" wrote in message s.com... Scott W spake thus: David Nebenzahl wrote: William Graham spake thus: I don't think so....Usually alpha particles are stopped by a piece of paper.....See this excerpt from Wikepedia.... The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha particles have energies of between 3 and 7 MeV. [...] And of course we can believe it if it says so on Wikipedia. (Until some zit-faced teenager comes along and edits it ...) Seems to me that if you believe what William posted was inaccurate it would be easy to find references that would contradict what he posted. But then you don't really believe there is anything wrong with what he posted do you? So, by your logic, if one Wikipedia article is accurate, that means all articles there are accurate--did I get that right? I know of no source that carries a 100% guarantee of accuracy, but I haven't found any errors in Wikipedia to date. (after reading perhaps 2 or 3 dozen of their entries) The nice thing about them is that if I know something that they don't about any particular subject, I can add my two cents to the mix. That's very hard to do with the Britannica.....:^) Sure, some teenage troll can input erroneous information, but it's usually easy to tell when something like that happens, and it usually doesn't last very long. There's nothing like current information from someone who was (or is) actually there, or who is on the inside of the event and knows the latest. I wrote to the editors of the Britannica once and asked them to publish their books in a loose leaf format, so they could send out errata sheets that could replace the older, out of date pages. This was not my original idea. I worked as a field engineer for IBM at the time, and we had something called, "Customer Engineering Memoranda", or "CEM's" where they did just that. As newer information on the repair/upkeep of a machine was developed, they would send out a replacement page to all the engineers in the field, and we would tear out the old page, and insert the newer version....That way, our books were always up-to-date with the latest information. I wanted the encyclopedia to do this, but they liked the idea of selling a complete set of new books to their customers every 10 years or so better, so they didn't adapt my idea. Now, with the internet, this idea is unnecessary....Continuous updating is taking place all the time. Your point, however, is well taken. Bad information can get into the system. However, as can be done with any troll, you have the opportunity to monitor and correct it. |
#28
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Old film refridged 8 years
William Graham spake thus:
Well, if you doubt it, google is full of links to other sources of information about alpha particles....I was a radiation worker for Stanford University for 28 years, and I can tell you that wikipedia is right on the money about this one........ Ah, so you're a SLACker, eh? -- Just as McDonald's is where you go when you're hungry but don't really care about the quality of your food, Wikipedia is where you go when you're curious but don't really care about the quality of your knowledge. - Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm) |
#29
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Old film refridged 8 years
"David Nebenzahl" wrote in message s.com... William Graham spake thus: Well, if you doubt it, google is full of links to other sources of information about alpha particles....I was a radiation worker for Stanford University for 28 years, and I can tell you that wikipedia is right on the money about this one........ Ah, so you're a SLACker, eh? I was.....I retired in August of 1996. Most of our radiation was gamma radiation while the machine was on, although secondary emissions of alpha and beta rays would be given off from objects inside the beam housing for a while after the beams were turned off....The first people in were the crew that checked out and roped off the "hot spots" so the others could avoid them. |
#30
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Old film refridged 8 years
"David Nebenzahl" wrote in message
s.com... j fabian spake thus: In article m, David Nebenzahl wrote: The point is, EB had (and still has, I presume) *no* articles on Pokemon, or characters on /House/, or any of the thousands of other articles (known in wiki-speak as "-cruft") which EB would not consider "encyclopedic" in the first place. Sorry: http://www.britannica.com/ebc/article-9384328 "anime" "Style of animation popular in Japanese films. Anim films are meant primarily for the Japanese market and, as such, employ many cultural references unique to Japan. For example, the large eyes of anim characters are commonly perceived in Japan as multifaceted ³windows to the soul. Much of the genre is aimed at the children's market, but anim films are sometimes marked by adult themes and subject matter. Modern anim began in 1956 and found lasting success in 1961 with the establishment of Mushi Productions by Osamu Tezuka, a leading figure in modern manga (Japanese comics). Such anim as Akira (1988), Princess Mononoke (1997), and the Pokmon series of films have attained international popularity." Well whadda ya know -- Pokemon in the Encyclopedia Britannica. I guess they aren't such elitists as some people hope they are... Well, that's good to know. But what they definitely *don't* have is articles on each and every Pokemon character, as Wikipedia does. Again, that's not a valid point in support of an argument against the relative worth of wikipedia. Sounds more like a pet peeve, to me. It's not like you have to thumb past the pokemon section to get to whatever you're looking for, is it? Further, I've found the listing and analysis of literary characters on there of interest in pursuit of my other big hobby--reading. Finally, when doing a search for information, wikipedia is a good place to start, but even with encyclopedias, only a school kid would stop there and say, I have the definitive info now. |
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