Month: October 2009

Anodizing aluminium

anodizing

We thought all those aluminium bits the cnc-mill spits out needed to look all nice and pretty. So a test with some DIY-anodizing today. Following one of the many guides out on the interwebs (here and here) we mixed ourselves some 20 % sulphuric acid, inserted an aluminium plate which works as the cathode, and suspended the part to be anodized from an aluminum wire.

before

This was tested on these rings which hold the finder-scope on my telescope.

after

After about 30 min of anodizing with the current around 2 A the part was rinsed in water and then put into hot water containing black color used for coloring clothes. The part was then boiled in this solution for another 20 min. The guides tell me the oxide layer formed in anodizing is first very porous and will absorb the color, and while boiling the pores close leaving a less brittle oxide-layer and sealing the color within.

This wasn't too scary and the initial results look promising. More to follow later probably...

Fluorescent DNA

Some very early testing of fluorescence imaging in our optical tweezers instrument. A 10 kb long piece of DNA (ca 3 um long when stretched) is held between two optically trapped microspheres. The DNA is coated with a fluorescent dye (SYBR-gold) which is exited by a 488 nm blue laser and the fluorescence signal is collected with a CCD camera looking through a narrow-band filter centered on the emission spectrum of SYBR-gold.

At around 1:10 in the video there's a double-tether (two DNA-molecules between the beads). We don't want that but there is not much that we can do about it, except discard the data. At the very end there's an image of QDots on the coverglass surface.

Links - October 15, 2009

9k jog

I haven't completely forgot to exercise, but the lack of daylight and cold temperatures make it, at least mentally, a bit harder to get out there and run.

9k_2009oct14

Garmin 405cx aboard an IOM

race1-2

The 405cx gps-watch is small and light enough to just tape to the aft-deck of an IOM. Today's event in Tampere had 12 races but I missed a few due to electrical problems. Races 1 and 2 above, and races 7-12 below. It's funny how google-maps and google-earth show permanent winter and ice in Tampere 🙂

race7-12

The raw-data (tampere_gpsdata.zip) is available in TCX format as well as Google-earth KML format from the garmin connect website.

Anyone have any software or matlab code to extract the instantaneous speed from this data and plot it? Might be useful for further CFD investigations or VPP-programs. Mostly light and shifting no1 rig the whole day. It will be interesting to compare with no2 and no3 rig in a real breeze.

Are there even smaller and lighter GPS-dataloggers? How long before we can have a GPS on every boat and watch playback of the race afterwards at home?

Links - October 1, 2009