Re: [Phys-l] Volts/inch in water!?

[Brian Whatcott <betwys1@sbcglobal.net>]

For a given electric gradient, there is some bulk or  surface 
resistivity that maximizes the
the energy transfer. To maximize the heating effect, one could imagine 
only a surface resistivity
effect on an insulating sub-strate as being involved.
(Suppose that thermal and electrical conductivity track) 
What is that critical resistivity value, and what is the energy transferred?

Brian W

Bernard Cleyet wrote:
> My eco. (inter alia) friend wrote to one of our senators.  Herre's her reply (excerpted)
>
>
> Thank you for writing to express your concern about the potential impact that the Asian carp may have on the Great Lakes ecosystem and to share your support for efforts to limit the spread of this invasive species. I appreciate the time you took to write, and I welcome the opportunity to respond. 
>  
>
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>  The electric barrier was completed this year, but the optimal operational voltage is still being determined. At one volt per inch, the barrier may not be strong enough to deter all sizes of Asian carp, but the maximum four volts per inch could cause fires on passing barges.
>
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>
> fires?
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> ----------------
>
> Again, thank you for writing.  If you have any further questions or comments, please contact my office in Washington, D.C. at (202) 224-3841. Best regards.
>
>
>
> Sincerely yours,
>  Dianne Feinstein
>          United States Senator
>
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> -------------------------
>
> bc thinks even one V.  per inch will require much energy.
>
> A bit of googling:
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> Safety Issues Remain
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> The permanent Illinois River electrical barrier system, built in 2006 but not yet placed into operation, has been undergoing a series of safety tests. The barrier can operate at four volts per inch, but the Coast Guard fears using it at full strength would pose a safety risk to anyone who might fall overboard near the barrier and for cargo ships transporting flammable liquids and gases.
>
> EPA says the barrier “poses no threat to people,” but the Coast Guard wants more testing.
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> Coast Guard Captain Bruce Jones expressed concerns about the barrier in a December 15 email to the Milwaukee Journal Sentinel. “I remain very concerned about the potential for personal injury or death to any person who may be immersed in the water ... as well as the potential for sparking between vessels, particularly those carrying highly volatile cargoes such as gasoline,” wrote Jones.
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> Jones added, “I am satisfied that the many safety measures implemented to date reduce these risks to acceptable levels at currents of one volt per inch.”
>
> Coast Guard OKs Operation of Asian Carp Electric Fence - by Alyssa Carducci - Environment & Climate News
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