Hi all,
I have posted on memsnet before regarding some problems that i have
been facing when I use Rhodamine 6g..

My experiment deals with micromixing. I use a microchannel, with
herringbone patterned structures on one wall to enchance mixing. To
characterize mixing, I have 3 inlets for this channel and perform 4
experiments, which can be listed as follows
1) D-ND-D
2) D-D-ND
3) D-ND-ND
4)ND-D-ND

where ND = no dye (ethanol) and D( rhodamine 6g with a concentration
of 2g/L in ethanol). I have used Xenon bulb with a green filter and
532nm Nd:Yag laser as illuminating medium

for experiment 1, when i take an image (using nikon eclipse inverted
microscope) at the entrance region, i get a square wave kinda profile.
Where there is dye, i get say X counts and where is no dye, I get Y
counts. This Y counts is basically the noise and should go to zero
when I subtract the background image from the raw image.

Now as the three liquid streams mix and go to the end of the channel.
I take one more image. Here is expect the intensity profile to be
uniform and of a intensity value less than X at the left and right end
of the image as some of the dye has diffused into the center stream
where there was no dye to begin with. however, in my case, the
intensity of the center stream goes up, but the intensity and the left
and the right end of the image remain X counts. I am not sure as to
why this is happening. I use a Flowmaster camera from LaVision with
DaVis 6. Can anyone explain why this is happening?

Thanks a bunch in advance..
Vishwa