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US Cells beginning loading phase - Update #2 SEM Pics now in Ignite Gallery

Written by Ryan Hunt on .

The US team has begun the loading phase in Cell A.  We just loaded 3 Bar of H2 into the cell and turned the power on to 30 Watts.  It will stay that way for a day or so while the initial absorption happens.  Then we'll refresh the H2 and cycle it 6 hours on, 1 hour off.  We are excited to see if our wire can achieve a similar (or better) resistance change compared to Mathieu's.  The race is on and it's down to the wires!

 

UPDATE 21-06-13 - More troubles than I can shake a stick at

The US cell's loading has been plagued by several minor difficulties that make the data less than attractive to look at.  First, we hadn't turned up the power on the active wire far enough to get a clean baseline resistance reading. Then the temperature with the hydrogen in the cell only barely got into the loading range.  Then when went to turn it up, we found we had to adjust our max power limit (a hardware circuit we had installed after the last time we toasted a wire).  When we adjusted that, we bumped a ground wire on the power meter, causing the reading to go wile and the power output on the NiCr wire to go to max.  In that process, our output port controlling the Celani wire power was toasted, and we had to move that to a different output pin, reconfigure the software, and reload.  After that, over lunch we had a power blink, which reset the power outputs.  Then we found that the second tier software power limit was getting in the way of achieving full power on NiCr wire and had to reset that.  Finally, we thought we had it all going and then one of the instrumentation boards started blinking out every so often and dragging the other one down with it.  When they reset, the power outputs reset also, and the cell cools down.  We are still troubleshooting that one. -- Update-- That was found to be a power wire issue caused by the data acquisition boards being powered from different sources.  Paul and Malachi found it by watching the power chip on the board heating from 40C to 150C before it blinked out.  Turns out it has been wired poorly for 8 months and has worked ok till now.  Pretty resilient boards.

That is all pretty crazy for a system that has basically been up and operating for a couple months as we troubleshot the ambient environment and performed the calibrations.

While the data is not the cleanest, we are definitely seeing a drop in resistance from roughly 16.2 to 15.1, or so.  Not as big a change as Mathieu saw.  

The next step is to begin the cycling (35W, 3 bar H2, 6 hours on, 1 hour off) for most of the weekend.  Since Mathieu has other obligations for the weekend, we should be caught up on Monday and ready to move forward nearly simultaneously.

Here are some pictures from today:

A photo of the wires in the cell.  The Celani wire is looking very light and coppery colored. The NiCr wire is looking almost blue-grey.

Below:  Wes has the interns helping set up to measure something on the powder reactors while Paul and Wes troubleshoot the latest instrumentation mystery.

B

 

Below:  Paul and Malachi watch for an intermittent problem with the thermal camera.  

 

UPDATE #2 SEM Pics now in Ignite Gallery

After some much-needed (and time-consuming) maintenance, our SEM was available for a closer look at what we're testing on in the US1.3 experiment. How timely!

Head over to the Celani V1.3 production gallery to get a glance. 

There're also pictures of the metamorphology produced by adding acetone to the CTC Celani wire in the gallery of all things related to the hydrocarbon anomaly we've been experiencing. 

 

Notice how poor our resolution is? I did a LOT of doctoring to amp-up the contrast and clarity of the resulting images. We are in desperately short supply of an experienced SEM technician since we lost ours to a walkabout in Australia Wink. It seems nano-fine tuning of a 20-year-old JEOL SEM is more of an art than the technical manual lets on. If you or someone you know could be of any help in working with an SEM, drop us a line! We're exceedingly good at utilizing remote instruction and could really use the remaining 295,000X resolution this machine is capable of. It's quite dated but that's no excuse for the limits we're experiencing. 

 

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0 #22 Ecco 2013-06-26 15:21
The T_Amb sensor didn't seem to show such pattern, however.
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0 #21 Ryan Hunt 2013-06-26 15:20
@ecco - I believe that would be real room ambient cycling causing that signature. The CTC ambient is in the open air in the same room and would be a good source to refer to. Our air conditioning has not proved effective enough.
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0 #20 Ecco 2013-06-26 15:07
US Cell A

i.imgur.com/WEso0m2.png

US Cell B

i.imgur.com/SluQEAD.png

Whatever it's causing this, it's affecting US Cell A slightly more than US cell B.
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0 #19 Ecco 2013-06-24 21:45
After the 45W step is done (in about 15 minutes as of writing), cool, measure cold active wire resistance, then 50W passive heating? Seeing how the more heat is applied, the more loading rate appears to increase, it would be very tempting to do so.


i.imgur.com/FuRBjXA.png
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0 #18 Ecco 2013-06-24 20:58
If what I've written above is true, it implies that we want really hot hydrogen inside the cell. Therefore, by taking this concept further, ionized hydrogen. Also, we want the ionized H2 to come in contact as much as possible with the active wire.

Does this ring any bell?
It does to me!

BTW: US Cell A with 44W of heating power is currently behaving as I previously written. 45W will improve loading further.
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0 #17 Ecco 2013-06-24 18:49
Another explanation could be that when you increased power to 45W, the active wire immediately received irradiated heat from the passive wire, which caused an immediate increase of its resistance as a result, maybe improving hydrogen loading marginally.
Then, as time passed, hydrogen started getting heated too, which improved absorption in the active wire noticeably.

If this makes sense to you, perhaps it would be useful to heat the hydrogen atmosphere more efficiently rather than the wire itself, for example by keeping the gas actively moving around inside the cell. Things could get really interesting.

Just a hunch.
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0 #16 Ryan Hunt 2013-06-24 18:15
@ Ecco - in previous temperature stepping we have seen that there are optimal temperatures for causing the resistance drop. When we went too high, the resistance increased.
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0 #15 Ryan Hunt 2013-06-24 17:55
@ Ed - it sure seems to be improving the slope. We are upping the power by 1 watt every 45 minutes up to 45 W to see where it likes to decrease resistance best. My hypothesis is that our wire might need higher temps to achieve the large resistance drop that Mathieu saw on his.
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0 #14 Edwin Pell 2013-06-24 17:44
It will be very interesting to see if the 10 degree increase in temp improves the loading rate. I especially want to see the power off resistance. It seems each time the temp is increases it activates more of the impurities and increases the resistance which is fine and expected, but it makes it hard to see what effect the loading is having. The off state should tell us.
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0 #13 Robert Greenyer 2013-06-23 13:23
@Sanjeev

Yes the gas leak is quite obvious.

@Edwin

Good question, but it does point to the importance of having multiple experiments.

@Maxwell61

The passing of Sergio Focardi saddens us greatly, his contribution will never be forgotten and hopefully we can all here play a role in realising the potential of the technology he helped advance.
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0 #12 Edwin Pell 2013-06-22 20:35
Why is the U.S. cell loading total different than the E.U. cell?
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+7 #11 Maxwell61 2013-06-22 11:40
OT: Segio Focardi died this morning, on a terminal illness. R.I.P.
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0 #10 Ecco 2013-06-21 17:31
Something strange definitely happened:


i.imgur.com/UNymp2s.png

Was a global offset applied or did temperatures and pressure actually suddently increase for some reason?
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0 #9 Ecco 2013-06-21 17:18
@Ryan Hunt

Please review US Cell A data from 14:20 UTC to about 15:00 UTC. Even if the wires didn't see almost 1 kW of total input power as indicated by the data, some sort of actual power spike might have actually happened, seeing how temperature and pressure readings behaved after that. I doubt that was only due to an instrumental artifact.
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0 #8 Ryan Hunt 2013-06-21 17:10
When the power meter loses a ground reference, all bets are off on the power reading. On the CuNi wire, the amps and volts went negative, which mathematically worked out to a positive power, but was not possible with the DC power supply. The NiCr wire probably did increase in power as the power control algorithm saw low numbers and cranked it up. Both the DC power supplies are hardware power limited, now (after burning out the last wire from a control glitch like this) to between 35 and 40 W, so there is highly unlikely that the wires saw more than they can handle.
Aren't experiments fun?
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0 #7 Ecco 2013-06-21 16:53
If it was just an instrumentation artifact, how did that also cause a natural-looking increase in cell temperatures and gas pressure?

BTW: currently active wire power is again below 250 mW ... 63 mW which is probably causing irregular looking resistance readings.
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0 #6 Ryan Hunt 2013-06-21 16:51
That was when the ground wire on the sensor was coming disconnected when we moved the power supply unit a little bit. That was just an instrumentation artifact and not an actual power spike, luckily.
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0 #5 Ecco 2013-06-21 16:41
I see that a powerful short input power spike at 14:25 UTC on both the active and the passive wires increased US Cell A temperatures significantly.

Shortly before that, active wire resistance started increasing weirdly, together with temperatures and pressure and seemingly without external input.

Is the active wire ok? What happened?
Did both wires short circuit?
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0 #4 Ecco 2013-06-20 22:56
The way active wire resistance on US Cell A is decreasing surely is strange. Maybe there are contaminants in the cell?
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0 #3 Ecco 2013-06-20 22:13
It looks like 250mW applied to the active wire not only improved resistance readings but also started to get things moving. See how T_Mica temperature immediately started increasing. It would have been interesting to check out if that would have been enough to trigger the "Celani wire" loading effect.

Currently it does seem the cell is producing more heat than what the additional 2W to the initial 30W input of the heater wire would suggest. This could be a transitory chemical effect though.

> The power out measurement is NOT to be believed because we are in H2 instead of a vacuum where the calibrations were done.

Wouldn't a lower pressure increasee output power since less heat is being convected to the glass tube where the thermocouple used for calculations is located? Or does the opposite happen under vacuum?
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