Operation Solid Shield

For realistic field training, the army conducted such training as Operation Solid Shield 87 to test how the U.S. troops perform on a chemically con-... 

These can be converted to their sodium salts by precipitation below 30° with aqueous 25% NaOH. The salt is then decomposed by addition of solid (powder ) carbon dioxide and extract with low-boiling petroleum ether. The solvent should be removed under reduced pressure below 20°. The manipulation should be adequately shielded at all times to guard against EXPLOSIONS for the safety of the operator. 

C. 1,2,3-Benzothiadiazole 1,1-dioxide. Caution 1,2,3-Benzo-thiadiazole 1,1-dioxide in the solid slate can explode spontaneously, particularly on being warmed, jolted, or scratched. For most purposes it need not be isolated, but can be used in solutions, which are relatively safe. Any operations involving the solid material should be done very carefully, using good shielding. 

During this first distillation, nitrogen oxides are evolved in appreciable amounts. It is suggested this operation be done behind a shield in a well-ventilated area. A trap cooled with a mixture of solid carbon dioxide and acetone or with liquid air should be inserted between the column and the vacuum pump. Pumps used in this distillation did not appear to suffer corrosion damage. A dry oil was used and changed after each distillation. 

The TB MO calculation on the 15N chemical shift of polypyrrole in the solid state allows useful information to be extracted from the observed spectra, namely that the two peaks obtained are correctly assigned to the quinoid and aromatic structures.(l 1,38) ( The quinoid structure is closely to the electric conductivity.) A decrease in the band gap leads to a downfleld shift. These results on conducting polymers demonstrate that the chemical shift behavior provides information about the band gap which, in turn, is a measure of the electric conductivity. It can be said that TB MO calculations offer useful perspectives in interpreting the results of NMR nuclear shieldings in polymers, both in terms of the structure in the solid state and in understanding the effect of intermolecular interactions on nuclear shieldings. The latter are shown to operate through the electronic structures of the polymers considered. 

The stable LC oscillator contained in the WTW Dipolmeter mentioned in Exp. 29 can be used if that equipment is available. The oscillator circuit shown in Fig. 29-2 is probably not sufficiently stable it lacks an amplifier stage to isolate the oscillator stage from the output load. A very stable solid-state LC oscillator for operation at about 1.5 to 2 MHz, constructed inexpensively from a published circuit diagram, has been found to be satisfactory. This should be built in a metal box (which will serve as an electrical shield), with two BNC connectors—one for connecting with the cell and one for the output connection... 

Line broadening in solid-state NMR arises from spin interactions which can be described in first order by coupling tensors of rank two (cf. Section 3.1) [Hael, Mehl, Schl], The spin interactions are either linear or bilinear in the spin operator. Linear interactions are the Zeeman interaction, the chemical shielding, and the interaction with the rf field. Bilinear interactions are the J coupling, the dipole-dipole coupling, and the quadrupolar interaction. In isotropic materials like powders, glasses, and undrawn polymers, wide lines are observed as a result of an isotropic orientational distribution of coupling tensors. 

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