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Date: | Wed, 2 Dec 2009 15:54:50 -0500 |
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I appreciate the relplies. Several things struck me as -- I'm looking for the word -- odd?
After years of reading studies and listening to presentations and having been involved in a few experiments myself, and seen how messy data can still make be made into nice looking charts, I've grown somewhat sceptical.
> c.- to high temperature and too low RH% for any treatment.
That is interesting. I only use OA in the late fall, so have not been aware of these limitations. Please comment more.
>e.- too low "natural drop" on control colonies for hives with no treatment after one year.
I could not make sense of the dropped mites I added up and the conclusions reached.
If I understood the area of open brood correctly, I have to wonder what sort of hives these were.
>f.- it is not stated the date when coumaphos was applied.
Or the results.
I like to see the raw data, and am suspicious when the conclusions are given without sufficient background to verify their plausibility.
> They seem to have lost 0.2 of a percent somewhere, careless of them.
Not too reassuring.
> One thing no-one seems to have taken into account is the rather nit-picking fact that the 75g of oxalic acid will increase the volume of 1kg sugar plus 1l water beyond the 1670 ml cited. I don't know what that volume increase will be, but if it is around half of the weight of oxalic acid then 1670 ml becomes 1707.5. So, 75g in 1 kg plus 1 litre (or liter if you prefer) would now not be 4.5% but 4.4%, and after a correction for the water in the oxalic acid this becomes not 3.2% but 3.14%. Nitpicking, just as I said, but the Greeks were still wrong.
Yes. Details like this make a person wonder: where was the supervisor and the peer review?
> This business about subtracting the water of crystalisation is confusing. The convention for concentrations as far as I am aware is normally just to cite what you dissolved in what solvent. In other words: 4.5% (weight/volume) of oxalic acid dihydrate in 50% sugar syrup (not '3.2%' of anhydrous oxalic acid, because you never used that).
Yes. I think the more recent recomendations are moving that way. In fact, I see no reason to state the intended concentration on instruction sheets or labels. People have enough trouble measuring grams and litres. In fact, I suspect that is where any reports of kills comes from.
I wonder if the Greeks measured as accurately as the calculated? +/- ???
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