Hello Anna

Dubnisheva, Anna wrote:
> 18 sec exposure @15mW/cm-2;

This is a quite high energy. Have a look at this page:
http://www.geocities.com/guerinlj/
There they say that you should avoid applying more than 200mJ/cm2
in one go else you will get a skin.
And with 270 mJ (18 sec * 15mW) you are above this level.
Maybe you can introduce some breaks into your exposure?

cu
Michi

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Michael Riss
Parc Científic de B., Lab. Nanobio
Universitat Politècnica de Catalunya
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