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Experimental research project proposal by Jeff Warren and conducted by David Haffner

by dhaffnersr | May 24, 2016 08:43 | 31 views | 4 comments | #13140 | 31 views | 4 comments | #13140 24 May 08:43

Read more: stable.publiclab.org/n/13140


This is a collaborative research proposal introduced by Jeff Warren, asking me if I would help in conducting some testing of various light sources on different sample media.

I am presenting the initial test set-up for consideration and community feedback, and certainly welcome all input to possible changes or ideas to make this experiment a success.

Here is the initial draft for the set-up:

  • pure mineral oil
  • pure ethanol
  • pure motor oil (being clear which you have)
  • X drops of crude oil diluted in mineral oil
  • X drops of crude oil diluted in ethanol

"Clear photos of the entire setup and labelled photos of all the samples will be good. We'll also need to document the cuvette materials."

• 4 light types (3 LEDs and 1 laser) in exactly the same positions • mineral oil negative control • one sample of motor oil • a calibration reference

Here are a set of pictures of the light sources:

all_4_light_sources_may23.png

Here is a picture of the sample container tubes:

sample_tube_racks_may10.png

Mineral oil:

mineral_oil.png

Crude oil:

crude_oil_may10.png

Cuvettes:

cuvettes_may23.png

Cuvette holder design:

labsetup4.JPG

Please, we need some feedback on this to make it a success!

Thanks!


4 Comments

Great documentation! Thanks, Dave. May I ask how you're powering the LEDs? Also let me link to the LEDs. You wrote me that you're doing:

  1. UV 365nm 700mW 4vdc high power single color
  2. UV 385nm 550mW 4vdc high power single color
  3. Prolight UV 410nm 350mW high power single color

Number 3 is your own, right? Can you link to a source?

And can you link to the exact oil on http://onta.com?

Thanks! Just want to be thorough.

Also, we may want to post a calibration spectrum before and after each scan, to be sure there's not drift as things are swapped out. I know this is a lot of extra work, but I'd like to try doing a really clean, rigorous test! Thanks!

Is this a question? Click here to post it to the Questions page.

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hey Jeff, yeah the 410nm LED is mine, the power supply is below: 12vdc 120vac 60Hz 750mA, the rest of the circuit is my own LED driver design.

Also I posted the exact page were I got the crude oil sample (sweet Wyoming crude, 4th one down on the list.

http://onta.com/id14.html - 4th one down/sweet Wyoming crude oil/$29.95 (US) 8oz bottle

pwr_supply_led1.png

pwr_supply_led2.png

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Well, it's been a week now since posting this proposal up and no responses except from Warren. Disappointing, so I am going to discuss some observations from pre-testing that I have already done on the 365nm LED and the 385nm LED from Mouser electronics. Number one is, from the picture above you can see the perspective size ratio looking at the penny in relation to the LED, this is a very difficult LED to work with, and its luminous intensity is insufficient to illuminate ANY sample at the appropriate right angle for fluorescence, even adjusting the LED flush with the sample cuvette will not produce the necessary illumination of the sample.

Since I haven't received any feedback on this proposal yet from the "community," I am strongly considering NOT using these two LEDs, and looking for an alternative.

On the point of a "community," this is another interesting point of contention, a very interesting definition of this word is: "an assemblage of interacting populations occupying a given area." Notice the operand word; "interacting," if there is any real interacting, it certainly isn't here in this area of cyber-space. There just seems to be no leadership or real direction, I am a voracious reader, I appreciate and have a real love of learning and with that, entails a high degree of interactive feedback and personal interaction.

I'm just not really finding the same type of enthusiasm at all here, I always continue to post my research here but I'm not really going to expect much in the way of any feedback or interaction, so as far as this experimental proposal is concerned, it will get done whenever Jeff wants, I'm in no rush.

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@Lakehaz I am so very happy that you are finding my work this helpful!

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