Cold bottoms

Tanaka, T., Guo, L, Deal, C., Tanaka, N., and Whitledge, T. (2004). N deficiency in a weU-oxygenated cold bottom water over the Bering Sea shelf influence of sedimentary denitrification. Cont. Shelf Res. 24, 1271-1283. 

Premixed NFj [Air Products] and BFj [Matheson] (27 mmol of each) are condensed into the cold bottom of the quartz reactor. Fluorine [Air Products] (9 mmol) is added, and the mixture is photolyzed at —196° for 1 hr. After termination of the photolysis, volatile material is pumped out of the reactor (through a scrubber ) during its warm-up to room temperature. The nonvolatile white solid residue (1.0 g) is pure [Np4][BF4]. Instead of the pan-shaped reactor, a simple round quartz bulb can be used with a [NF4][Bp4] yield of about 0.3 g/ hr. 

Use two-side heating by placing the load(s) on piers and firing above and below them. Any load more than 4" (0.1 m) thick should be placed on piers in the furnace so that the loads do not have cold bottoms. The piers should be a minimum of 8" high (0.2 m) so that underfiring can be used to heat the pieces from below (and traditional overfiring to heat from above). If the load pieces must be placed in the... 

Place 0 5 ml. of acetone, 20 ml. of 10% aqueous potassium iodide solution and 8 ml. of 10% aqueous sodium hydroxide solution in a 50 ml. conical flask, and then add 20 ml. of a freshly prepared molar solution of sodium hypochlorite. Well mix the contents of the flask, when the yellow iodoform will begin to separate almost immediately allow the mixture to stand at room temperature for 10 minutes, and then filter at the pump, wash with cold w ater, and drain thoroughly. Yield of Crude material, 1 4 g. Recrystallise the crude iodoform from methylated spirit. For this purpose, place the crude material in a 50 ml. round-bottomed flask fitted with a reflux water-condenser, add a small quantity of methylated spirit, and heat to boiling on a water-bath then add more methylated spirit cautiously down the condenser until all the iodoform has dissolved. Filter the hot solution through a fluted filter-paper directly into a small beaker or conical flask, and then cool in ice-water. The iodoform rapidly crystallises. Filter at the pump, drain thoroughly and dry. 

After the 45 minutes heating, pour the contents of the flask into a large excess of cold water (about 300 ml.), in which the nitrobenzene, being heavier than water, sinks to the bottom. Stir the mixture vigorously in order to wash out as much acid as... 

Place 0 5 ml. of the pyridine in a 200 ml. round- or flat-bottomed flask and add 34 ml. (30 g.) of benzene. Fit the flask with a reflux water-condenser, and then place it in a cold water-bath. If the experiment is conducted in a fume-cupboard, the top of the condenser can be closed with a calcium chloride tube bent downwards (as in Fig. 61, p. 105 or in Fig. 23(A), p. 45, where the outlet-tube A will carry the calcium chloride tube) and the hydrogen bromide subsequently allowed to escape if, however, the experiment is performed in the open laboratory, fit to the top of the condenser (or to the outlet-tube A) a glass delivery-tube which leads through a piece of rubber tubing to an inverted glass funnel, the rim of which dips just below the surface of some water... 

When all the sodium nitrite has been added and diazotisation is complete, transfer the cold solution to a 600 ml. round-bottomed bolt-head flask. Dissolve 35 g. of potassium iodide in 50 ml. of water, and add this solution slowly with shaking to the cold... 

Place in a 25 or 50 ml. round-bottomed flask, 3 g. of finely powdered anhydrous aluminium chloride and 7 5 ml. of dry benzene. Fit the flask with a reflux water-condenser. Place the flask in a cold water-... 

Fit a 50 ml. round-bottomed flask to a reflux water-condenser fitted with a calcium chloride tube. Dissolve 1-05 ml. of dry bromobenzene in 5 ml. of dry ether and add this solution to 0-25 g. of magnesium contained in the round-bottomed flask. Now add a crystal of iodine so that it rests on the magnesium. Warm if necessary to start the reaction if the latter becomes too vigorous immerse the flask in cold... 

Place 35 ml. of water in the separatory funnel and run it into the vigoroiisly stirred reaction mixture at such a rate that rapid refluxing occurs. Follow this by a cold solution of 15-5 ml. of concentrated sulphuric acid in 135 ml. of water. Two practically clear layers will now be present in the flask. Decant as much as possible of the ethereal layer A) into a 500 ml. round-bottomed flask. Transfer the remainder, including the aqueous layer, into a separatory funnel wash the residual solid with two 10 ml. portions of ether and combine these washings with the liquid in the separatory funnel. Separate the ethereal portion and combine it with (A). Distil off the ether through an efficient fraction-... 

In a 1500 ml. round-bottomed flask, carrying a reflux condenser, place 100 g. of pure cydohexanol, 250 ml. of concentrated hydrochloric acid and 80 g. of anhydrous calcium chloride heat the mixture on a boiling water bath for 10 hours with occasional shaking (1). Some hydrogen chloride is evolved, consequently the preparation should be conducted in the fume cupboard. Separate the upper layer from the cold reaction product, wash it successively with saturated salt solution, saturated sodium bicarbonate solution, saturated salt solution, and dry the crude cycZohexyl chloride with excess of anhydrous calcium chloride for at least 24 hours. Distil from a 150 ml. Claisen flask with fractionating side arm, and collect the pure product at 141-5-142-5°. The yield is 90 g. 

Place 92 5 g. (114 5 ml.) of n-butyl alcohol and 8 55 g. of purified red phosphorus (Section 11,50,5) in a 500 ml. round-bottomed flask (attached at C) and 100 g. (32 ml.) of bromine in A. Pass a stream of cold water through the condenser F and through the double surface condenser fitted at D the condenser F prevents the volatilisation of the alcohol from the... 

Mix 50 ml. of formalin, containing about 37 per cent, of formaldehyde, with 40 ml. of concentrated ammonia solution (sp. gr. 0- 88) in a 200 ml. round-bottomed flask. Insert a two-holed cork or rubber stopper carrying a capillary tube drawn out at the lower end (as for vacuum distillation) and reaching almost to the bottom of the flask, and also a short outlet tube connected through a filter flask to a water pump. Evaporate the contents of the flask as far as possible on a water bath under reduced pressure. Add a further 40 ml. of concentrated ammonia solution and repeat the evaporation. Attach a reflux condenser to the flask, add sufficient absolute ethyl alcohol (about 100 ml.) in small portions to dissolve most of the residue, heat under reflux for a few minutes and filter the hot alcoholic extract, preferably through a hot water fuimel (all flames in the vicinity must be extinguished). When cold, filter the hexamine, wash it with a little absolute alcohol, and dry in the air. The yield is 10 g. Treat the filtrate with an equal volume of dry ether and cool in ice. A fiulher 2 g. of hexamine is obtained. 

Into a 250 or 500 ml. round-bottomed flask provided with a reflux condenser place 46 g. (38 ml.) of A.R. formic acid (98/100 per cent.) and 37 g. (46 ml.) of n-butyl alcohol. Reflux for 24 hours. Wash the cold mixture with small volumes of saturated sodium chloride solution, then with saturated sodium bicarbonate solution in the presence of a httle... 

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