Recent content by dand5

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    Question about momentum transfer from fluids to discrete particles

    I have looked at a lot of this research. The problem it poses for me is precisely the fact that in most cases a diffussion equation for the heavy particles is coupled together with the fluid equations, and the diffusion coefficient is said to depend on velocity correlations. To solve this kind...
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    Question about momentum transfer from fluids to discrete particles

    Hi, I am having trouble find information on the following topic, I think mostly in part because I don't know the correct terminology. Basically, I have a number of particles that are falling at their terminal velocities within a gaseous fluid, and turbulent velocity fluctuations in the fluid...
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    Comments on AP article about prehistoric tropical arctic

    http://news.yahoo.com/s/ap/20060601/ap_on_sc/hot_arctic;_ylt=Ap5sztcWGDT3_X9KlVBicqGs0NUE;_ylu=X3oDMTA3MzV0MTdmBHNlYwM3NTM-" I don't know much about geology, but shouldn't this AP science writer have at least asked about the possibility that the location where these preserved tropical...
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    Why it's too late to stop global warming

    You shouldn't forget that there are some pretty potent sinks for co2: 1) oceans 2) soils 3) plants/biosphere - which tend to increase uptake as the concentration increases
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    Statistical analysis that warmer oceans caused the crazy hurricains last year

    Statistically fewer atlantic cyclones mature into tropical storms during pacific El Ninos. http://www.aoml.noaa.gov/hrd/Landsea/elnino/ Theoretically, El Nino episodes increase vertical wind shear and hence turbulence which distort and mix out the latent heat release from developing...
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    Statistical analysis that warmer oceans caused the crazy hurricains last year

    Hi Mk, thanks for the welcome. But I don't think I said that El Nino allowed them to develop into storms, what I said was that the absence of an "El Nino"/other pacific signals did not prevent them from developing into significant storms.
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    Statistical analysis that warmer oceans caused the crazy hurricains last year

    I think the number of cyclones ejecting from the "african train" was about average and that combined with little pacific tampering (no El Nino) allowed most of them to develop into storms. But it should be noted that what was particularly astounding about last hurricane season was the number of...
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    Chemical asorb sun energy?high CO2 in atmosphere

    True, but generally speaking the atmosphere is relatively transparent to incoming solar radiation (which falls mostly in the UV to visible range). Though, some chemicals such as ozone (0_3), certain aerosols, certain hydrocarbons absorb/scatter efficiently over certain bands, most shortwave...
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    Climate Classification of the Southern US

    I have seen several different definitions, which means there is probably no real consensus. But based on the criteria you mentioned, places like Paris, London, Seattle would all have subtropical climates. I've also heard that the location has to lie between 20 and 40 N/S and/or that it has to...
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    Climate Classification of the Southern US

    I have been wondering about climate classifications. Based on average annual temperature and precip, a large chunk of the southeast/southcentral United States is lumped into the Humid Subtropical climate zone. But that seems misleading to people with agriculture or gardening interests, since...
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    When lightning happens. Does energy bleed off into space?

    Since rain storms that Tornadoes are caused by sharp gradients in the wind field (i.e wind shear) that are then transformed into vertical vorticity by tilting. Shear profiles along with bouyancy profiles are ideal for tornado formation over the United States, but not in Asia, Europe, Africa or...
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    Question about how two fundamental constants are measured

    Ok, I understand it now. Thanks. Just out of curiosity, why was 1/299792458 chosen? Did it best match the existing second? What, I meant by this was that the permittivity was used in Maxwell's equations before the advent of relativity, i.e. before it was known that the speed of light is...
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    Question about how two fundamental constants are measured

    Ok, I understand how the permiability is defined now. But I thought that the permitivitty of free space existed before the speed of light was defined. Also, I always thought the reason c could be "defined" was because the permiability and the permitivitty appeared in the Maxwell's equations out...
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    Question about how two fundamental constants are measured

    How is the permittivity of free space, \epsilon_0, and the magnetic permeability in vacuum, \mu_o, measured? Thanks
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    Ok, so it is 80 degrees F in Texas

    Yeah, it was insane. Seems like the death toll is pretty high now, which is bad. On the other hand mid 40's here and no snow in mid January, just the way I like it.
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