Sodium expansions

For the purpose of outlining the results which we have obtained In studying supersonic sodium expansions, the data presented in Figure 2 will be useful. Here we consider calculated RKR potential curves for the X Zg" , A Zy" ", and 8 11 states of Na2 and a rough schematic of two cuts through the Naa potential surface based, in part, on the recent quantum chemical calculations of Martin and Davidson (40). For Na2, the location of the... 

Further detailed studies In this (39) and other laboratories (47) Indicate that It Is possible to Induce Internal excitation In the products of supersonic expansion by Inserting devices Into the oven expansion chamber which restrict the sodium expansion creating a "cloud" In the region directly In front of the oven. 

Sun, Y., Forslund, K G., et al. (2004). "3-D modelling of thermal and sodium expansion in soderberg aluminium reduction cells." Light Metals 2004 587-592. 

The primary, secondary and tertiary (steam-water) circuits each have three loops. Each secondary circuit loop includes two intermediate heat exchangers (enclosed in the reactor vessel), steam generator, sodium expansion tank, main circulating pump and pipes. The once-through steam generator consists of eight sections, each comprising three modules evaporator, superheater and reheater. Every section can be isolated (if necessary) by valves. 

II - steam supply to reheater, 12 - sodium expansion tank, 13 - steam- sodium reaction products dump line. 

FIG. XX-6. Work energy release from sodium expansion. 

In the A1 industry, it is necessary to take into account the thermal expansion of refractories in the bottom part of holding and melting furnaces in the cast house and in anode baking furnaces. The thermal expansion of carbon cathode is relatively small however, it might be sufficient to take it into account. Yet the sodium expansion of cathode blocks is several times higher compared to the values of thermal expansion. In the design of the reduction cells, the value of the thermal expansion of carbon cathode blocks is only the reference data. 

Grade of carbon cathode material Resistivity, pf2 m Sodium expansion, % Wear resistance Strength Comments on transformations during service... 

Figure 3 and Figure 4 showed the electrical resistivity change of TGI and TG2 after aluminum electrolysis, compared with the corresponding values before electrolysis. It is seen that the electrical resistivity after electrolysis increases distinctly for sample TGI, while increases only some extent for TG2. In connection with the results of sodium expansion for both samples [5], it is considered as a result of cryoUte/sodium penetration. During aluminum electrolysis, the cryolite/sodium penetration deteriorates the materials of samples, which induces cubical dilatation and micro-cracks within the samples, so that their electrical resistances increase after electrolysis. Therefore, a better resistance to cryolite/sodium penetration with TG2 than with TGI [5] could lead to a lower resistance with TG2. 

Success in the chlorine industry led to the incorporation of DSA in sodium chlorate [7775-09-9] NaClO, manufacture. The unique stmctural characteristics of the anode allowed for innovative designs in ceU hardware, which in turn contributed to the extensive worldwide expansion of the sodium chlorate industry in the 1980s. 

Sodium Chloride. Sodium chloride, a corrodent of many materials, is the archetype contaminant and has been studied more than other salts. The solubiUty of sodium chloride in superheated steam is shown at the conditions of a typical steam turbine expansion in Figure 14. The solubiUties were measured in the region of higher solubiUty (9). As the steam expands, sodium chloride becomes considerably less soluble. The solubiUty, S, in parts per biUion (ppb) can be represented by equation 3 ... 

Trimethylpyrazole (336) adds dichlorocarbene generated under basic conditions (CHCla-EtONa) to give 10% of 4-dichloromethyl-3,4,5-trimethylisopyrazole (337 Scheme 28) (bromine also transforms (336) into an isopyrazole (312) Section 4.04.2.1.4(v)). Treatment with sodium ethoxide results in ring expansion of (337) into an ethoxymethyl-pyridazine (338) (B-76MI40402). 

H-Benzo[a]carbazole, 4,4a,5,l 1,1 la,l Ib-hexahydro-synthesis, 4, 283 Benzo[b]carbazole, N-acetyl-photochemical rearrangements, 4, 204 Benzo[/]chroman-4-one, 9-hydroxy-2,2-dimethyl-synthesis, 3, 851 Benzochromanones synthesis, 3, 850, 851, 855 Benzochromones synthesis, 3, 821 Benzocinnoline-N-imide ring expansion, 7, 255 Benzocinnolines synthesis, 2, 69, 75 UV, 2, 127 Benzocoumarins synthesis, 3, 810 Benzo[15]crown-5 potassium complex crystal stmcture, 7, 735 sodium complex crystal stmcture, 7, 735 Benzo[ 18]cr own-6 membrane transport and, 7, 756 Benzo[b]cyclohepta[d]furans synthesis, 4, 106 Benzocycloheptathi azoles synthesis, 5, 120... 

When most of the alcohol has distilled, a yellow scum forms on the surface of the red, viscous liquid. The distillation is stopped at this point. When the solution is cooled, the sodium derivative crystallizes with considerable expansion in volume. 

The eoneentration of ozone in O2/O3 mixtures ean be determined by eatalytie deeomposition to O2 in the gas phase and measurement of the expansion in volume. More eonveniently it ean be determined iodometrieally by passing the gas mixture into an alkaline borie-aeid-buffered aqueous solution of KI and determining the I2 so formed by titration with sodium thiosulfate in aeidified solution ... 

Furthermore they claimed that the dichloromethyhndolenine 17 could be converted into the quinohne 18 by hot ethanolic sodium ethoxide. They also reported other similar cases of ring expansion of the dichloromethyl bases, with loss of hydrogen chloride, on further treatment with sodium ethoxide (cf. ref. 67). They considered that chloroform acted like a simple alkyl halide giving jS-alkylation of the... 

Azelastine (107) is an antiallergic/antiasthmatic agent prepared from 4-chlorobenzyl-2 -car-boxyphenylketCHie (105) by condensation with hydrazine to give the phthalazinone (106) followed by reaction of the sodium salt of this last with 2-(2-chloroethyl)-N-methylpyrrolidine (presumably involving nucleophilic ring expansion of the bicyclic quaternary salt putatively formed as a first product) to complete the synthesis [30]. 

The ring expansion of nitronaphthalenes with dimethyl phosphite and sodium methoxide in the presence of strong base to give 2-benzazepines (see Section 3.2.1.4.2.1.) has been adapted successfully to the synthesis of pyridoazepines, e.g. 24, 25, and 26, from 5-, 6-, and 8-nitro-quinoline, respectively43... 

Treatment of isoquinoline tV-oxide (55) with sodium hydride in dimethyl sulfoxide results in ring expansion, albeit in poor yield, to the 3//-3-benzazepine 56, along with a trace of naphthalene (0.8%), and much tar.26... 

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