AboutDavid L. Russell, PE Expertise I`m a Chemical,Civil and Environmental Engineer and have a number of projects in all phases of the environment.
I have worked in the chemical industry and am active in professional societies, and am currently on an industrial wastes committee for the Water Environment Federation, and have taught courses in remediation in the US and abroad.
I have written one book on Remediation of petroleum Contaminated Sites, and have a second book on PRACTICAL WASTEWATER TREATMENT to be published by John Wiley in September, 2006. I've also written over 30 articles on various elements of environmental problems and cleanup. Most Recently, I have addressed a NATO Scientific and Techical Conference on Ecoterrorism, and have worked with the same group on remediation of sites contaminated with Chemical Warfare Agent materials and othe materials as well. . I can answer q`s about Chemical and Environmental Engineering, land development, air pollution, water pollution, soil and water cleanup, combustion, international environmental problems, industrial processes chemical processes. Civil and Environmental and Chemical Engineering. Overall, I have over 35 years of experience in this area. Note: I do not answer homework questions
Experience I love work in the third world and developing areas
because it is challenging and one can get a sense of accomplishment.
Question QUESTION: If heat transfer for cremation of 150-pound human body is by radiation only and such cremation must be done within 10 seconds, what is your estimate of required temperature of heat-emitting body? (This is no homework question. I received my BSChE from Virginia Tech in 1949
ANSWER: First, I don't think that the standard includes only radiation and second I don't believe that it is only a ten second requirement.
My gut reaction about the heat required would be WOW, that's Huge.
Just in terms of the fluid if a human body is about 95% water, and I believe that's an acceptable figure, we are talking about 1300 BTU per pound or so, it may be only 1100 but that's close. So that would require about 150*0.95*1300= 185,250 BTU to evaporate the water. Reducing that figure maybe 20% for the combustibles in the body, that still gives you a figure close to 150,000 BTU (148,200 BTU) . Ten seconds would require 66.7 Million BTU/HR to accomplish that in ten seconds.
Even with Radiation, assuming an efficiency factor of about 20% initially (based upon color) and a final factor of close to unity (again based upon charring) I might use a guess at 0.1 to 0.8 for the transfer of radiant energy (absorbance)I might be tempted to pick a value in the range of 0.4 to 0.5. So the energy source would have to produce between 300,000 and 400,000 BTU in that ten second burst of energy, which would produce 1055 watts per BTU per second, or a total of about 156351000 watts or 156.351 Gigawatts.
Hope that helps. I'm a bit rusty on the use of radiation, but something close to those values might do the trick. Barbeque anyone?
Dave
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QUESTION: Could a mini-nuke, with its emission adjusted to produce 70 per cent radiation energy (in a desired direction) and 30 per cent blast energy, produce those 156 Gigawatts, multiplied by at least 600 for the number of trapped people in the WTC North Tower on September 11, 2001?
ANSWER: The problem is that there are several assumptions in the premisis which make it problematical. First is that I'm not a nuclear engineer and have only the basic knowledge of nuclear physics, so I'm not qualified to answer the question.
The second is that, depending upon the source, you are looking at between 9 and 20 kg of material for a basic nuclear explosion. The energy release would be by Einstein's formula e= mc^2 where the mass and the value of C are in grams-centimeters - ergs. Whatever the units, it's a huge number.
The third problem is that explosions are not necessarily tunable in the way you suggest. A nuclear explosion would have generated x ray radiation which would have killed the people in the surrounding buildings with radiation.
The fourth problem is the temperatures. Nuclear explosions occur at temperatures in the hundreds of thousands of degrees, and there would be extensive evidence of vaporization of steel, concrete, etc. The portion of the building would disappear in a flash not in the slow failure shown on the various videos, and which I remember watching live when it occurred.
Fifth, a nuclear blast is too fast. Rather than the 10 seconds you requested, you would be looking at milli-seconds to seconds and substantial radiation, alpha, beta, and gamma, plus x rays, and that would have also led to substantial source fallout.
Sixth: I have looked at the 9/11 fallout pictures, from the USGS - they are on the web and the spectral analysis shows that the dispersion pattern follows the winds in a rather defined fashion.
So, while it's possible, that this type of event could have been planned, I don't believe that you can look for a nuclear source.
Sorry.
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QUESTION: I've already written it out.
Answer I don't know enough about nuclear energy to know if that is possible.
Assume a 10kg mass of nuclear material of the right type, that 's 10000 grams Energy release is : 10^5 * 30000000^2 ergs = 9*10^18 ergs
or 853035289.11 BTU, or 9* 10^11 Watt seconds.
156*10^6*600= 93,600 gigawatts. as compared to 9*10^11*0.7/10^6 =
630,000 gigawatts, so a 10Kg nuclear device (relatively small) would produce about 6.73 times the energy required for your hypothesis.
Conclusion: Even a very small nuclear device would produce way too much energy. Note that the critical mass for 100% U238 is between 9 and 10 kg.
You might want to check wikipedia under the topic of Atomic Weapons and nuclear critical mass for more information. I've taken this about as far as I can go, and it's not my primary area.
Hope that helps
I don't know how you feel about it, but Ed Ward, in my opinion, needs a job to keep him busy, and he is on the fringe of rationality with conspiracy and environmental disaster theories. He obviously has never seen concrete stressed above it's ultimate limit where it deflagrates explosively. I have seen this. The sheer impact of a floor's steel colapse in the 9/11 disaster could trigger precisely what happened.
BTW, the debris site I mentioned was: http://minerals.cr.usgs.gov/projects/dusts/
and http://pubs.usgs.gov/of/2001/ofr-01-0429/
Look at the second publication first.
With regard to global warming, it ain't happening despite what Al Gore says!
