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Andrew David Thaler
Works at Benthic Mercenary
Attends Nicholas School of the Environment
Lived in Baltimore, MD
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Andrew David Thaler

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Proposed changes to the fishery management plan may dramatically alter the way dogfish are fished.
Earlier this week some new rules were proposed for spiny dogfish management on the east coast.  The changes affect three key parts of the fishery management plan for spiny dogfish: quota set aside ...
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Andrew David Thaler

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Fresh update from the OpenCTD!
 

Andrew had a very productive weekend out with team OpenROV and got some help software hacking and planning for the next phase. The source code is now up on github, fork and tweek at your leisure - https://github.com/SouthernFriedScientist/OpenCTD

One of the suggestions for potting/housing was to use a vertical otterbox with a single passthrough for wires out to the probes - like this http://www.amazon.com/OtterBox-9000-Dry-Box-Series/dp/B003CP07OY/ref=sr_1_12?ie=UTF8&qid=1396921008&sr=8-12&keywords=otterbox+8000 - and potted boards on the outside. This combines the reliability of epoxy-sealed components, with the accessibility of an openable case. Epoxy won't bond perfectly to otterbox plastic, but we can take a page from the deep world (where ground quartz is fitted loosely into a conical bore through the sub's sphere and held in via pressure) and create a countersunk hole for the wires to pass through filled with hysol, which is just flexible enough to form a tighter seal as pressure increases. We envision multiple housing options depending on need, with this being for shallower, long-term deployments. +kersey sturdivant  is working on a much more robust deep-submergence housing.

The pressure gauge has been sourced at $27 for a 30 bar module. At the moment, and depending on the final cost of the conductivity circuit and probe, we're looking at a sub-$100 device.

+Russell Neches continues his herculean effort to complete the conductivity circuit. If you see him, definitely offer him a beer. 

+Andrew David Thaler met with a rep from USGS who is interested in helping with field trials when we're ready.
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Finally, an update on the OpenCTD!
 
Hello Casters! We've got some fresh news on the OpenCTD. This Thursday +Russell Neches and I spent the day hacking probes and working on circuits. Below are the three probes we're working on. 

On the left is the three-ganged temperature probe. Rather than relying on a single thermistor to get measure temperature, we're going to pair three together and get the average. One advantage of the dallas thermistor is that you can run as many probes as you want through a single data port. We did some speed tests on these little thermistors, and though they're officially rated to 30 second, I've found that, in water they reach equilibrium in less than 5 seconds, and are even faster for small differences. In a head to head with a commercial Hanna Instruments temperature probe, the thermistors were about twice as fast at reach equilibrium. We can expect about 0.1C accuracy from this set up. 

In the middle is the depth/temperature/IMU unit graciously provided by our friends at +OpenROV. The final version will use only the pressure sensor, integrated onto the OpenCTD PCB, but, for prototyping and coding, we decided not to reinvent the wheel, since OpenROV already has a nice little hardware/software package developed. 

As of now, Andrew's goals for the next week is to integrate these two probes software together and get them talking to an SD card reader and LCD display. The software is slim enough that we have almost half the arduino's storage capacity left over for the real beast, conductivity.

+Russell Neches has put in a valiant effort constructing the conductivity circuit, which, in its current form needs to draw a whopping 24 volts to drive the oscillator. We have faith that a few more days of elbow grease will get us over the hump. On the right, is the dummy conductivity probe for testing the circuit. It's two steel electrodes, so not great for seawater but serviceable for troubleshooting. The final design will have gold electrodes printed directly onto the PCB. 

So what's next for us? After we complete and test the conductivity circuit, we'll be designing a custom PCB that will contain the arduino and all three probes. The massive power demand of the conductivity probe means there will be plenty of ballast in the CTD to get it to sink. We're also exploring housing and potting options - we want to make the device as waterproof as possible while still giving you easy access to your data. 

And, because of the size and shape of the depth probe, Andrew thinks the final package will resemble nothing as much as a copepod. 
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Hi Ryan, we're sourcing the next model up (good to 30bar rather than 14) for $18.
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Andrew David Thaler

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So good. Well done +Craig McClain 
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Hey Google Plus-ers, are you following +Southern Fried Science? Lots of great content coming out, exclusively on our + page! 
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One of my heroes. Tyrone Hayes, fighting the chemical industry for more than a decade:
 
Tyrone Hayes, fighting the chemical industry for more than a decade:

"2001, seven years after joining the biology faculty of the University of California, Berkeley, Tyrone Hayes stopped talking about his research with people he didn’t trust. He instructed the students in his lab, where he was raising three thousand frogs, to hang up the phone if they heard a click, a signal that a third party might be on the line. Other scientists seemed to remember events differently, he noticed, so he started carrying an audio recorder to meetings. “The secret to a happy, successful life of paranoia,” he liked to say, “is to keep careful track of your persecutors.”"
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Have them in circles
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Andrew David Thaler

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The first round of temp/depth sensors for OpenCTD are curing in epoxy. +Russell Neches +kersey sturdivant
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Live from the bottom of Lake Tahoe!
 
Our third dive in Lake Tahoe, while live streaming via Google Hangout. 

Planning to dive at 11am PST. 
This Hangout On Air is hosted by David Lang. The live video broadcast will begin soon.
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Tahoe Test Dive Part III
Sun, April 6, 1:36 PM
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Andrew David Thaler

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Update on the OpenCTD
 
It's been a long time and we owe everyone an update.

I know it’s been a while since our last update, but fear not, your generous support is not forgotten and the project continues. A few updates:

1. New Team Member: I’m pleased to introduce you to Russell Neches. Russell is a graduate student in microbial ecology at UC Davis, physicist-turned-microbiologist, and hardware hacker extraordinaire. He has joined the OpenCTD team to help us develop the next iteration of the instrument. You can find out more about his interests and experience in this Nature interview: http://www.nature.com/naturejobs/science/articles/10.1038/nj7469-131a

2. Status of the Mark II Prototype: Our initial goal for the OpenCTD was to design something that could be built cheaply using primarily off-the-shelf components. We wanted to minimize the use of specialized or custom made parts and focus on something that was truly do-it-yourself. We wanted interested and enthusiastic makers to be able to take our instructions and build a functional CTD primarily with parts from Radio Shack and their local hardware store. 

After nearly 6 months of prototyping, it is clear that that vision was naive. The initial proof-of-concept never reached the level of precision or accuracy necessary to be used in the field and subsequent development revealed that the technical aspects of reaching those levels would put construction well beyond the reach of our targeted user base and raise the cost significantly above our $200 target. 

Fortunately, my move to San Francisco has placed me among some of the most innovative instrumentation developers in the country. Which leads us to the next piece of news:

3. Developing an integrated platform: We are now in the process of developing a PCB (printed circuit board) that will encompass all the functionality of the CTD. The conductivity probe (which, in the final model will use gold electrodes) will be integrated into the board, so that it will be consistent and uniform across all units. For temperature and depth, we have a 30-bar board mounted sensor that incorporates both measurements into one tiny package - http://www.meas-spec.com/product/t_product.aspx?id=8685 and are exploring options for additional sensors. We’re in the process of designing and printing the circuit board and should have an initial update soon. 

I know this may be disappointing to those who wanted to build your own, but after exhausting all possible angles, this is clearly the best option. Extreme DIY-ers can still develop their own PCB’s or prototyping board. The good news is that this may significantly reduce the cost (our first pressure sensor was $80, the new one comes in at $40, and printing circuit boards in bulk is inexpensive). 

All designs, including that of the PCB will be open-source. There will still be quite a bit of DIY assembling on the user end, including housing and waterproofing the device, but as of now, I am not sure exactly how this will impact the donor reward of a copy of the instruction manual, as the manual itself is now secondary to the circuit board. Depending on cost, I’m considering sending a PCB to donors who would have received a copy of the instruction manual in addition to whatever documentation is needed to construct the CTD. Please let me know if you think that is fair.

All the best and we look forward to an exciting year for the OpenCTD project.

~Andrew, Kersey, and Russell
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Just making sure my ISP is stable enough to hand 1.5 hours+ of video uptime without interruption. So here's some bunnies.
This Hangout On Air is hosted by Andrew David Thaler. The live video broadcast will begin soon.
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Bunny Cam II
Mon, March 24, 1:13 PM
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Dear Bunnies, you are being held hostage by the artificial confines of a carpet. The barrier is in your MINDS. 
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Have them in circles
5,219 people
Work
Occupation
Benthic Mercenary (Freeland Marine Biologist)
Employment
  • Benthic Mercenary
    Freelance Marine Biologist, present
    Doing my part to promote ocean education through teaching and research.
  • Duke University Marine Lab
    Graduate Student, 2007 - 2012
  • Duke University Marine Lab
    Post-Doctoral Fellow, 2012 - 2013
Places
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Previously
Baltimore, MD - Durham, NC - Beaufort, NC - Eleuthera, Bahamas
Story
Tagline
Deep-sea ecology, population genetics, conservation
Introduction
I'm a deep-sea ecologist and the founder and Senior Editor of Southern Fried Science. Ask me about the ocean's deepest ecosystems.
Education
  • Nicholas School of the Environment
    Marine Science and Conservation, 2007 - present
  • Duke University
    Biology, 2003 - 2007
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