Friday, 9 September 2011

08:42 – Well, the copy finally finished at 10:00 p.m. last night, after 13 hours of writing 300,000+ files totaling about 1,300 GB. I’ll probably do the same thing again to a second new 2 TB Barracuda drive and then pull both of the old 1.5 TB drives. Of course, that leaves me with a system drive that’s older than either of those drives. Barracuda drives are extremely reliable, but these guys are well past retirement age in dog years.

Jerry Coyne just posted an interesting article about science versus religion, Adam and Eve: theologians squirm and sputter. The whole of Christianity is based on the Adam and Eve myth and original sin. Without that, Christianity has no basis whatsoever. And yet science tells us, indisputably, that Adam and Eve never existed. It is amusing to watch accommodationists try to reconcile religious myth with the cold, hard light of science.

We’ll be using a lot of dropper bottles for the biology kits, so I ordered a couple hundred dozen from one of my wholesalers in 15 mL and 30 mL capacities. These bottles are Chinese-made, and they’re fine except for one thing. They arrive with the dropper tips and caps installed, which means that Barbara and I have to disassemble them all before filling and labeling them, and then turn around and reinstall the dropper tips and caps. Doing that for a few bottles is no big deal. Doing it for thousands involves some work.

We’ll also need 30 mL wide-mouth bottles, which none of my current wholesalers offer. So I contacted a bottle supplier about the wide-mouth bottles and decided as long as I was at it to see what they had to offer in the way of dropper bottles. Their bottles are US-made, which is good, and they come in bulk with the dropper tips and caps in separate plastic bags. The problem is, bottles, even Chinese bottles, aren’t cheap, and the US-made ones cost 30% to 40% more than the Chinese-made ones. Still, I was willing to consider paying more for the US-made bottles. Until the samples arrived.

The problem is the dropper tips. The Chinese bottles have dropper tips whose bodies are long plugs that friction-fit the mouth of the bottle. Seating a dropper tip is a simple matter of pressing the tip into the mouth of the bottle until it seats. The dropper tips on the US bottles have much shorter bodies, and snap into place. The problem is that it requires close attention to make sure the tip has actually seated and snapped into place. This would slow down processing significantly, so I decided to stick with the Chinese bottles.

Speaking of processing bottles, I looked into automated methods and concluded that our current manual method is actually better unless and until we reach the point where we need to produce hundreds of kits per month. Working together, Barbara and I can fill, insert dropper tips, cap, and label the bottles at a rate of about 150 bottles per hour. (I fill and insert the dropper tips; Barbara caps and labels.) The only part of that that can be automated at anything approaching a reasonable price is the filling operation, but that still requires individual attention to each bottle as it’s filled, and actually saves almost no time.

10:36 – Barbara saw an article in the paper this morning about using copper sulfate to kill the mildew that’s appeared on some of her shrubs. I buy copper(II) sulfate by the kilogram, so she asked if I could make her up some right here in the sink. Of course, I agreed. The problem is, what concentration?

Apparently, the concentration needed varies. One site mentioned ranges from 2 to 6 pounds per 100 gallons, which translates to something like 909 to 2727 grams per 379 liters, or about 2.4 to 7.2 grams per liter. Or, as I think of it, about 0.01 to 0.03 molar. Since I keep liters of 1.0 M copper(II) sulfate solution in inventory–the stuff takes forever to dissolve–I’ll just compromise on 0.02 M and dilute one part of the stock solution to 49 parts water.

I did wonder whether the high solubility of copper(II) sulfate would be a problem. If Barbara sprays on 0.02 M copper(II) sulfate, it’ll stick around only until the next good rain dissolves it and rinses it off the plants. That’s apparently why people use Bordeaux or Burgundy mixtures, which are solutions of copper(II) sulfate mixed with either calcium hydroxide (lime) or sodium carbonate (washing soda or soda ash) to form insoluble precipitates of either copper hydroxide or copper carbonate. Apparently these are more persistent because they don’t dissolve in rainwater, but I do wonder whether they’d clog up Barbara’s sprayer. What the insoluble copper salts really are is time-release treatments, because even “insoluble” compounds are very slightly soluble in water. So, apparently copper(II) ions kill fungi even in nanomolar or even picomolar concentrations. I think we’ll start with just 0.02 M copper(II) sulfate solution and see if that makes the fungi gag, clutch their tiny little chests, and drop off the plants.