J boats

Three mortar boat groups departed on 26 February, and the two that remained reorganized into j-boat units. Thereafter this sort of support gradually decreased until 3 March, by which time all mortar boats had been recalled. During these last days individual LCI(M) s provided direct daylight support to shore battalions designated by the Headquarters Landing Force. 

With a phase angle = 0, 60°,-----symmetrical (C2 J boat forms are obtained... 

The solution- and solid-state structural features and fluxional energetics of the optically pure RhTp " (CO)2 complex allowed to identify both if - and 77 -Tp " coordination modes (Scheme 4). The activation parameters for the interconversion of two j -boat geometries were determined. ... 

At the end of the sweeping out, the tap Ti is first closed, and then the taps T3, T4, Ts and Tj in this order. The tubes R and S are then detached from the beak of the combustion tube, the guard tube V is then detached from them and replaced on the combustion tube beak. The furnace and thermostatic mortar are then switched off and the combustion tube allowed to cool with the tap to the oxygen supply open. The bung J is removed, and the boat withdrawn by means of a piece of rigid copper wire with a small hook in the end that fits into the small hole in the lip at the back of the boat the bung is then replaced and the boat transferred to its block in the desiccator. 

Germanium [7440-56-4] M 72.6, m 937 , 925-975 , b 2700 , d 5.3. Copper contamination on the surface and in the bulk of single crystals of Ge can be removed by immersion in molten alkali cyanide under N2. The Ge was placed in dry cyanide powder in a graphite holder in a quartz or porcelain boat. The boat was then inserted into a heated furnace which, after a suitable time, was left to cool to room temperature. At 750°, a 1mm thickness requires about Imin, whereas 0.5cm needs about half hour. The boat was removed and the samples were taken out with plastic-coated tweezers, carefully rinsed in hot water and dried in air [Wang J Phys Chem 60 45 7956]. 

Lead (II) bromide [10031-22-8] M 367.0, m 373°. Crystallised from water containing a few drops of HBr (25mL of water per gram PbBr2) between 100° and 0°. A neutral solution was evaporated at 110° and the crystals that separated were collected by rapid filtration at 70°, and dried at 105° (to give the monohydrate). To prepare the anhydrous bromide, the hydrate is heated for several hours at 170° and then in a Pt boat at 200° in a stream of HBr and H2. Finally fused [Clayton et al. J Chem Soc, Faraday Trans 1 76 2362 1980]. 

The dihydrate of the tetramer is particularly stable and is, in fact, the bishydroxonium salt of tetrametaphosphimic acid [H30]J[(NH)4P4-06(0H)2] the anion of which has a boat configuration and is linked by short H bonds (246 pm) into a two-dimensional sheet (Fig. 12.29). The related salts M4[NHP02)4].- H20 show considerable variation in conformation of the tetrametaphosphimate anion, as do the 8-membered heterocyclic tetraphosphazenes (NPX2)4 (p. 537), e.g. 

Savory, J. G. and Packman, D. F., DSIR Forest Products Bulletin No. 31 entitled Prevention of Decay of Wood in Boats, H.M.S.O (1954)... 

Heat Stability of 2,3,7,8-Tetrachlorodibenzo- -dioxin. A sample boat containing 1-3 mg of 2,3,7,8-tetrachlorodibenzo-p-dioxin was placed in a Sargent Tube Heater (Model J-807) which contained a 1/2 inch i.d. quartz tube. Air was aspirated through the tube at a velocity of 0.02 ft/sec. This velocity gave a residence time of 21 sec. (Residence time was extended by connecting a second heater in series with the first.)... 

Thomeycroft J, Bamaby SW (1895) Torpedo-boat destroyers (including appendix and plate at back of volume). Inst C E 122 51-69... 

A man fishing on a riverbank sees a boat pass by. The man estimates the boat is traveling 20 mph. If his estimate is correct, how many minutes will it be before he sees the boat disappear around a bend in the river j mile away ... 

J. Connan, A. Nissenbaum, Conifer tar on the keel and hull planking of the Ma agan Mikhael ship (Israel, 5th century BC) identification and comparison with natural products and artefacts employed in boat construction, Journal of Archaeological Science, 30, 709 719 (2003). 

The energy barrier between the chair and boat form of cyclohexane is about 35 k J/mole and this is not large enough to prevent their rapid interconversion at room temperature. This is why it is not possible to isolate each conformation. 

The potential barrier that separates the chair and boat forms from one another is 42 k J/mole while the energy difference between the two conformations is 21-25 k J/mole. 

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