As for the 'logs' creating her shield, I believe Aeka creates the shield.
The logs being part of that creation.
Just off hand, every time I have seen Aeka create the shield the logs
would appier.
Take a look at 'No need for a Showdown' at the end of the Universe
series.
When Kagato shot the energy at her she attempted to block it with 'her'
force field.

        ~Washu
!-=-Where were you when they handed out the brains?-=-!
---------------
**I know all you people are goin to kill me but, however, how many of you
have seen No Need for Rivals in the Tenchi Universe.  If you remember,
Aeyka made her butt kicking logs appear in defense of an attack that came
from Nagi behind her.  Now, there wasn't any way she <Aeyka> could of been
able to tell that Nagi was going to attack her from behind.  And I agree
with ~Washu, just about every time she creates logs.  

--Snapdragon--
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"I wonder if it is even possible to collect a sample?"
    "Why didn't you grab that thing for me Tenchi?" --Washu
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Ayeka: "You're such a joker. You know Jurai's Royal Family 
          will last forever. We're everlasting."
Ryoko: "What? Jurai's Royal Family is NEVERLASTING?"
Ayeka:  "EVERLASTING!"
Ryoko: "Well, isn't that too bad!"
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