Funnel-shaped test

Figure 2.10. Schematic of the apparatus used in funnel-shaped testing. The foam volume, Uf, is calculated from the equations shown, where Af and Aq are the areas of the normal cross-sections at heights of hf and ho, respectively hf is the foam height and r is the radius of the base of the truncated cone. The steady-state volume is determined at a set gas flow and the slope of the foam volume versus gas flow curve gives the kinetic foam stability (lifetime of gas in the foam) measurement...

The most convincing evidence of the effectiveness of some lures was obtained at the Berkel, a little border river between Germany and Holland. Here we mainly used the method with artificial entrances, in which funnel-shaped traps were placed (Figure 2). In the slope of the bank 24 holes were dug in which pipes with traps were placed. Three different lures were tested in sixfold against an equal number of controls. In addition, 4 floating traps, baited with apples, and the same lures were tested. Five drops of lure were applied to corks placed on sticks above the funnel traps and similar corks were used on the rafts. 

A simple crude assessment of flow behavior can be achieved on-site using so-called flow cups - funnel-shaped vessels with specified orifices in their bases. The measurement variable is the efflux time, that is the time taken for a known volume of dispersion to exit the cup through the orifice. It is important to be aware of the fact that a variety of cups are in use and that each type of cup produces a different efflux time. The most common types are the ISO cups (complying with ISO 2431) and the Ford cups used in the ASTM D 1200 test procedure. 

Introduce 10 g of the lobelia in No. 60 powder and 10 g of ignited sand into a pear-shaped separator provided with a plug of cotton wool in the tube below the stopcock. Add 75 ml of a mixture of 4 volumes of ether and 1 volume of 95 per cent ethanol. Shake and set aside for fifteen minutes, add 5 ml of dilute ammonia solution and shake in a mechanical shaker for one hour or by hand for one minute at ten-minute intervals during one hour. Allow the liquid to percolate into another separating funnel. When the liquid ceases to flow, pack the drug firmly by means of a button-ended glass rod. Continue the percolation, first with 25 ml of the ether-95 per cent ethanol mixture and then with ether, until the alkaloid is completely extracted, as shown by testing in the usual manner. 

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