It was one of America's darkest hours -- a terrorist attack struck on American soil, killing 2,974 people. It was a tragedy felt worldwide, as 90 countries were represented among those who died.
The most devastating part of the attack in terms of damage was not the impact of the airplanes themselves, but the fires they caused. The fires burned in the middle stories of the buildings at temperatures of around 500C (932F). They weakened the steel supports, which eventually collapsed, taking the rest of the building with them, killing many in the top floors. Part of the mystery was how this occurred -- steel's melting point is much higher.
Dr Sergei Dudarev, principal scientist at the United Kingdom Atomic Energy Authority (UKAEA) explains, "Steels melt at about 1,150C (2,102F), but lose strength at much lower temperatures. [The steel] becomes very soft. It is not melting but the effect is the same."
This deadly mystery was not first observed in the 9/11 attacks. It was widely known among the scientific community before them that steel became pliable at lower temperatures. This was unfortunate as steel's normal strength would lend itself nicely to many ultra-hot applications, such as lining the wall of a fusion reactor. The phenomena went largely unexplained and unexplored until after 9/11 when the topic was brought into sharp focus.
Now, Dr. Dudarev and his fellow scientist have experienced a breakthrough developing new insight into how steel weakens at higher temperatures. What they discovered was that tiny irregularities in the steel's structure disrupt the internal magnetic fields. When the metal is cool it is hard, but when it is heated the irregularities damage the magnetic fields which hold the atoms rigid, allowing them to slide past each other.
The phenomenon is similar to that exploited since the days of ancient Rome to work iron. While not able to reach temperatures high enough to melt the iron, sometimes, blacksmiths discovered if they heated it to a relatively hot temperature, the metal became pliable, able to be shaped into weapons. While this was good for the Romans, it was not so good for modern applications which demand heat resistance, such as architecture and fusion power.
Architects have previously tried to protect buildings from this phenomenon by placing insulating panels around the support beams. However, as the 9/11 attacks showed, these panels can be easily ripped off by a disaster. This is precisely what is thought to have happened -- the collision with the airliners ripped off the insulation, exposing the steel to the fire. Ultimately this elasticity doomed the structure.
Trying to make something good come of such a negative event, Dr. Dudarev and the UKAEA first worked out the mechanism for this weakness. Now they are working on developing steel that lacks the irregularities and thus is able to operate at blistering temperatures. Such Iron Man-like steel would be a crucial step towards achieving clean cheap power for mankind through nuclear fusion. The group is working on the ITER reactor, the international community's largest experimental fusion reactor yet.
The 500 MW ITER reactor must be lined with ultra-robust materials. By mixing steel with other elements, Dr. Dudarev is confident he and his team can develop exotic steels to fit the bill. He is confident that the problem is not a difficult one, and just comes down to experimentation. He states, "We need to look at the magnetic properties of steel, [and] vary their chemical composition in a systematic way in order to get rid of this behavior."
quote: Not half-brained schemes to try and push solar and wind where they're not feasible and practical. Which is large scale power generation.
quote: 20 grand. Granted that's not chump change but after 5-6 years you get that money back with the money saved from monthly electric bills.
quote: Not necessarily. If you live within your means, try 10-15. If you buy what you really cannot afford, then 30-50 is about right.
quote: this real world data flies in the face of the much touted cheaper cost per kwh associated with Nuclear Power generation. Palo Verde, which is owned and operated by APS, actually has higher rates than SRP, the other leading power provider
quote: . They're only able to reach that goal by selling most of their excess to the European grid...then buying back conventional power.
quote: "had no connection with commercial power generation"
quote: Green energy sources could also be considered a military goal. How many times have we gone to war to secure our sources of oil???
quote: ...and one that DOES NOT work 24/7.
quote: Did you not read?
quote: I'm not sure if you're being intentionally obtuse or not,
quote: , not without energy storage technology we do not yet possess.
quote: I've been imaging what we can do with such cheap "super-batteries" since I was a kid in the early 1970s.
quote: Stanford researchers have found a way to use silicon nanowires to reinvent the rechargeable lithium-ion batteries that power laptops, iPods, video cameras, cell phones, and countless other devices. The new technology, developed through research led by Yi Cui, assistant professor of materials science and engineering, produces 10 times the amount of electricity of existing lithium-ion, known as Li-ion, batteries. A laptop that now runs on battery for two hours could operate for 20 hours, a boon to ocean-hopping business travelers. "It's not a small improvement," Cui said. "It's a revolutionary development."The greatly expanded storage capacity could make Li-ion batteries attractive to electric car manufacturers. Cui suggested that they could also be used in homes or offices to store electricity generated by rooftop solar panels.
quote: A good solar panel system for a home is around 20 grand. Granted that's not chump change but after 5-6 years you get that money back with the money saved from monthly electric bills.
quote: Put your logic away please. It's much more fun "green" type people to point to their success stories that aren't price competitive but rely on subsidies, tax exemptions, or outright exclusive contracts to prove how viable they are.
quote: Why should we focus all of our resources on a technology that hasn't even been proven work, outside of science fiction?
quote: Focus on the renewable energy resources (such as hydro, geo, solar and wind) for the short term and invest in fusion for the long term.
quote: It works pretty well in the sun.
quote: I'd rather focus on nuclear now which research into better plant designs can actually help lead to advances in fusion power.
quote: (in conjunction with others of course)
quote: . Research into advanced fission has a far greater cost-benefit ratio.
quote: You've brought up this red herring before. First of all "known stocks" of uranium are orders of magnitude less than actual values.
quote: That article isn't a peer-reviewed research paper, it's an article written for laymen by laymen.
quote: Nature's reporters don't have Ph.D's, don't work in the nuclear industry
quote: nd have long since demonstrated their bias towards wind and solar.
quote: -in the article they actually supported nature-
quote: I think I'll go out and buy a Weekly World News for my news from now on if everything printed is reliable.
quote: That article isn't a peer-reviewed research paper, it's an article written for laymen by laymen. Nature's reporters don't have Ph.D's, don't work in the nuclear industry, and have long since demonstrated their bias towards wind and solar. The lead author of that story, Quirin Schiermeier, is a German with a degree in geography, who is "particularly interested in climate, oceanography, fisheries and the Earth sciences".
quote: His latest story before this was a popular account of how AGW is causing hurricanes to get stronger, despite the fact that every major hurricanologist says otherwise.Even Emmanuel Kerry from MIT, who won an appearance on the cover of Time Magazine for claiming GW was worsening hurricanes, recently changed his mind.
quote: And he carefully didn't report that nearly a dozen competing papers have observed the exact opposite effect, and the person that this very same reporter previously called the "most influential hurricane expert" recently recanted his views on the subject.
quote: Um, correct me if I am wrong, but there has only ever been one instance of a nuclear power plant having this sort of issue, and it was early in the technology (1960s I believe)
quote: It never fails. I'm always stunned by this line of attack on nuclear.
quote: There is a possible impediment to production of nuclear power plants, due to a backlog at Japan Steel Works, the only factory in the world able to manufacture the central part of a nuclear reactor's containment vessel in a single piece, which reduces the risk of a radiation leak. The company can only make four per year of the steel forgings. It will double its capacity in the next two years, but still will not be able to meet current global demand alone.
quote: A number of other designs for nuclear power generation, the Generation IV reactors, are the subject of active research and may be used for practical power generation in the future. A number of the advanced nuclear reactor designs could also make critical fission reactors much cleaner, much safer and/or much less of a risk to the proliferation of nuclear weapons. It should be noted that such Generation IV reactors are not necessarily fuelled by uranium but by thorium, a more abundant fertile material that decays into U233 after being exposed to neutrons. Such reactors use about 1/300 the amount of fuel to power them. The Liquid Fluoride Reactor is one such example of this. For the future, design changes are being pursued to lessen the risks of fission reactors; in particular, passively safe plants (such as the ESBWR) are available to be built and inherently safe designs are being pursued . Fusion reactors, which may be viable in the future , have no risk of explosive radiation-releasing accidents, and even smaller risks than the already extremely small risks associated with nuclear fission. Whilst fusion power reactors will produce a very small amount of reasonably short lived, intermediate-level radioactive waste at decommissioning time, as a result of neutron activation of the reactor vessel, they will not produce any high-level, long-lived materials comparable to those produced in a fission reactor. Even this small radioactive waste aspect can be mitigated through the use of low-activation steel alloys for the tokamak vessel.
quote: I don't mean to give the impression by any means that i'm a nuclear physicist, but my current understanding of fusion generators lead me to believe that fusion plants will be significantly different than fission plants.
quote: Is it worth half a billion dollars to save the lives of a few fish, fish that aren't endangered, won't go extinct, and, if not killed by the plant, will likely be caught and killed by fisherman anyway? I won't say...
quote: Not half-brained schemes to try and push solar and wind where they're not feasible and practical
quote: Who are you to say we didn't want it?
quote: When it started the majority of America was for it.
quote: But the problem is many Americans don't have the stomach for war
quote: And you are who to say we did ?
quote: Another 'uncle' who slaughtered whole swaths of his population with nary a second thought.
quote: Irrelevant argument now over if we should or should not have
quote: I suggest psychological therapy.
quote: The rest of us live in the present day, and I think most American's realize that the best thing for America in the long run is effecting the best possible outcome in Iraq, regardless of how we got there
quote: Further, you're manipulating Petraeus position.
quote: The way you said it, made it sound as if he were some kind of surrender monkey or believes America can't get a positive outcome out of this. Far from it!
quote: and labour camps--such s those run by Stalin, were different things
quote: Why is this living in the past--the concerns are all too real in the present---costs are being incurred every day both in terms of actual dollar costs and lives losts
quote: I didn't--I merely quoted the headline--which if you click on the link, you will see
quote: Stalin engaged in plenty of mass murder as well. When people needed to get dead, labor camps were just way too slow for Uncle Joe.
quote: Careful before you call me autistic;
quote: concept of "sunk cost.
quote: you got a teddy bear and beat it up.
quote: He said he did not know that he would ever use the word "victory": "This is not the sort of struggle where you take a hill, plant the flag and go home to a victory parade... it's not war with a simple slogan."
quote: The Holodomor (Ukrainian: ?????????) is the famine that took place in Soviet Ukraine during the 1932-1933 agricultural season when the devastating famines also took place in several other regions of the USSR. The Holodomor ravaged the rural population of the Ukrainian SSR, and is considered one of the greatest national catastrophes to affect the Ukrainian nation in modern history. Estimates for the total number of casualties within Soviet Ukraine range between 2.2 million (demographers' estimate)  and 3-3.5 million (historians' estimate). 4.5 to 5 million in the Encyclopedia Britannica , and much higher figures - up to 20 million - in political debates  The reasons of the famine are the subject of intense scholarly and political debate. Some historians claim the famine was purposely engineered by the Soviet authorities as an attack on Ukrainian nationalism, while others view it as an unintended consequence of the economic problems associated with radical economic changes implemented during the period of Soviet industrialization. It is sometimes argued that natural causes may have been the primary reason for the disaster. T here is no international consensus among scholars or politicians on whether the Soviet policies that caused the famine fall under the legal definition of genocide . However, as of March 2008, the parliament of Ukraine and the governments of several other countries have recognized the actions causing Holodomor as an act of genocide.
quote: Are you seriously citing Wikipedia as a definitive source on a political hot-button topic like this?
quote: # Ammende, Ewald, "Human life in Russia, (Cleveland: J.T. Zubal, 1984), Reprint, Originally published: London, England: Allen & Unwin, 1936. # «The Black Deeds of the Kremlin: a white book», S.O. Pidhainy, Editor-In-Chief, (Toronto: Ukrainian Association of Victims of Russian-Communist Terror, 1953), (Vol. 1 Book of testimonies. Vol. 2. The Great Famine in Ukraine in 1932—1933). # Conquest, Robert, «The Harvest of Sorrow: Soviet Collectivization and the Terror — Famine», (Edmonton: The University of Alberta Press in Association with the Canadian Institute of Ukrainian Studies, 1986). # Davies, R.W., «The Socialist offensive: the collectivization of Soviet agriculture, 1929—1930», (London: Macmillan, 1980). # «Der ukrainische Hunger-Holocaust: Stalins verschwiegener Volkermond 1932/33 an 7 Millionen ukrainischen Bauern im Spiegel geheimgehaltener Akten des deutschen Auswartigen Amtes», (Sonnebuhl: H. Wild, 1988), By Dmytro Zlepko. [eine Dokumentation, herausgegeben und eingeleitet von Dmytro Zlepko]. # Dolot, Miron, «Execution by Hunger: The Hidden Holocaust, a survivor's account of the Famine of 1932—1933 in Ukraine», (New York City: W.W. Norton & Company Inc., 1985).
quote: Mortality in GULAG camps in 1934-40 was 4-6 times higher than average in Russia. The estimated total number of those who died in imprisonment in 1930-1953 is 1.76 million, about half of which occurred between 1941-1943 following the German invasion .
quote: The 500 MW ITER reactor must be lined with ultra-robust materials.
quote: Second, metal will bend long before 50% of the strength is gone from the metal (1,100 degrees is 50% of melting point). So, with enough weight metal will bend easily at 600 or 700 degrees (ask any black smith).
quote: The internal strength of the building depends on all steel beams being in there correct placement.
quote: In the history of sky scraper fires, we have had only two builds match these two situations and I'm sure I'm missing some key points. Guess what, in 100% of the cases all the builds collapsed onto themselves. The two buildings: tower one and tower two.
quote: I will plan on moving to a more economically and scientifically friendly country
quote: In all of the steel structured buildings fires in the past, this scenario has never come up before where steel melts/weakens way below the melting temperature point that is stated in the article and buildings collapse.
quote: COMPLETE IDOIT
quote: Materials for fusion power plants provide one of the major structural materials challenges of the next 20 years. So far, relatively little demand has been made on the properties of the materials used for JET and other prototype reactors, since they had only to contain an operating plasma for very short times, to prove concepts and predictions of plasma physics. In the next stage of development of fusion reactors (ITER) and particularly in fusion power plants, materials issues will be crucial to success. The first wall will operate at temperatures up to 600ºC and will need to withstand stresses up to 300 MPa, and will accumulate over its lifetime radiation damage from fast neutrons amounting to ~100 dpa. It is essential that any material used here maintains adequate strength and toughness, while suffering minimal dimensional change through swelling and creep.
quote: and will accumulate over its lifetime radiation damage from fast neutrons amounting to ~100 dpa. It is essential that any material used here maintains adequate strength and toughness, while suffering minimal dimensional change through swelling and creep.
quote: Right, and we have steel alloys that can easily survive temperatures like that, even at 300 MPa. The real issue is a bit lower in your excerpt
quote: Anyone else disturbed that all these cool scientific goodies are all coming out of Europe?
quote: The cost is high now but if every home built needed solar panels mass production would occur and prices would fall drastically.
quote: Of course the power companies would lose money and they have lobbyists...
quote: Ive seen at least two stories here on Daily Tech concerning improvements in solar panels including new materials that can be used.
quote: The energy company does not own the solar panel on your roof and you as a consumer are not as dependent on their product.
quote: The energy company does not own the solar panel on your roof and you as a consumer are not as dependent on their product.