Ammonium nitrate modifier

Polymer-based rocket propellants are generally referred to as composite propellants, and often identified by the elastomer used, eg, urethane propellants or carboxy- (CTPB) or hydroxy- (HTPB) terrninated polybutadiene propellants. The cross-linked polymers act as a viscoelastic matrix to provide mechanical strength, and as a fuel to react with the oxidizers present. Ammonium perchlorate and ammonium nitrate are the most common oxidizers used nitramines such as HMX or RDX may be added to react with the fuels and increase the impulse produced. Many other substances may be added including metallic fuels, plasticizers, stabilizers, catalysts, ballistic modifiers, and bonding agents. Typical components are Hsted in Table 1. 

Unloaded silica does not recover HPA from aqueous solution. The surface of silica gel modified with quarternary ammonium salts (QAS) gets anion-exchange properties. The aim of the work is the elaboration of solid-phase reagents on the base of ion associate of HPA with QAS immobilized onto silica surface for the determination of phosphoms and organic reductants. Heterocyclic (safranine and lucigenine) and aliphatic (trinonyloctadecyl ammonium iodide and tetradecyl ammonium nitrate) compounds have been examined as QAS. 

Reduced molibdophosphoric HPA was found to be well recovered by silica modified with tetradecyl ammonium nitrate. It was assumed as a basis of phosphoms determination in the range of 0.5-5 pmole using solid-phase spectrometry. 

Two techniques for sorption-spectroscopic determination of ascorbic acid have been proposed. The first one is the recovery by silica modified with tetradecyl ammonium nitrate of blue form of molibdophosphoric HPA in the presence of vitamin C. And the second one is the interaction between the ascorbic acid in solution and immobilized on silica ion associate of molibdophosphoric acid with lucigenine. The detection limits of vitamin C are 0.07 and 2.6 mg respectively. The techniques were successfully applied to the determination of ascorbic acid in fmit juices. 

Halliday et al. [396] have described a simple rapid graphite furnace method for the determination of lead in amounts down to 1 xg/l in polluted seawater. The filtered seawater is diluted with an equal volume of deionised water, ammonium nitrate added as a matrix modifier, and aliquots of the solution injected into a tantalum-coated graphite tube in an HGA-2200 furnace atomiser. The method eliminates the interference normally attributable to the ions commonly present in seawater. The results obtained on samples from the Firth of Forth (Scotland, UK) were in good agreement with values determined by anodic stripping voltammetry. 

Montgomery and Peterson [675] showed that ammonium nitrate used as a matrix modifier in seawater analysis to eliminate the interference of sodium chloride degrades the pyrolytic coating on graphite-furnace tubes. The initially enhanced sensitivities for copper, manganese, and iron are maintained for up to 15 atomisations. There is then a rapid decline to a constant lower sensitivity. The characteristics depend strongly on the particular lot of furnace tubes. To... 

Grafting and networking may modify the mechanical, chemical, and functional properties of polymers and enhance their utilization for some purposes, such as for water treatment (Kumar and Verma, 2007 Mishra et al., 2003). Psyllium derivatives were prepared by grafting acrylonitrile onto psyllium molecules using a ceric ammonium nitrate and nitric acid system (Mishra et al., 2003). The resulted grafted psyllium samples were not soluble in commonly used solvents or their combinations. In 2007, methacrylic acid derivatives of psyllium were prepared using ammonium persulfate as initiator and cross-linked using N,N-methylenebisacryla-mide as the crosslinker (Kumar and Verma, 2007). The modified psyllium... 

Engel and coworkers [57] have reported the manufacturing process of phase stabilized ammonium nitrate (PSAN) by inducing metal complexes into AN lattices and by using surfactants to modify its properties. Kim [58] has prepared PSAN by precipitation with KN03 from a solution of their salts by the addition of acetone. Kempa et al. [59] have incorporated diammine copper (II) in the AN lattice to improve the phase-transition behavior. Krishnamurthy [60] has reported modification of phase IV—III transition by co-crystallization of AN with KF and KN03. On the other hand, Mishra [61] has reported KF as an effective phase stabilizer for... 

This led to the manufacture of Anzen-Bakuyaku ammonium nitrate safety explosives on the lines of European compositions, but later modified to suit the damp climate of Japan (Yamamoto [85]). The production of the following new explosives began in 1913 ... 

A modified type of AN-FO explosive has been suggested in the U.S.A., made by mixing ammonium nitrate with nitromethane (ca. 5%)which is itself explosive. They have a higher rate of detonation than AN-FO (e.g. 3900 m/sec). However, they have not been widely used because of their higher price. 

NTO is being developed in many areas these include i) a substitute for ammonium perchlorate or ammonium nitrate in solid rocket propellants, since it does not liberate undesirable products such as HC1 and has quite a high burn rate compared to ammonium perchlorate and ammonium nitrate, ii) used as a burning rate modifier for composite propellants, iii) replacing RDX and HMX in composite solid propel-... 

We have investigated the humification of straw, as an example, under constant conditions of humidity and temperature in a climatic chamber (4,18) and separated different fractions according to a modified method of Waksman s proximate analysis. The amount of nitrogen present in these processes is the factor limiting the rate of decomposition. Therefore we added nitrogen in form of ammonium nitrate in a quantity of 1% of straw dry weight to a nutrient solution in one experiment while the nutrient solution had no nitrogen in a parallel experiment. Table I shows the calculated data. 

The first explosives to be listed as permissible by the U. S. Bureau of Mines were certain Monobels and Carbonites, and Monobels are still among the most important of American per-missibles. Monobels contain about 10% nitroglycerin, about 10% carbonaceous material, wood pulp, flour, sawdust, etc., by the physical properties of which the characteristics of the explosive are somewhat modified, and about 80% ammonium nitrate of which, however, a portion, say 10%, may be substituted by a volatile salt such as sodium chloride. 

Seramin (Ammonium Nitrate Dynamite). Soon after the invention of the Swedish expl Ammoni-akkrut (qv in this section), Bjoerkmann patented (June 1867) a blasting expl consisting of AN 72.5, NG 18, sawdust or charcoal 8.7, and benz or creosote 0.8%. Seranin, like the modified Ammoniakkrut contg NG, was more powerful than the Guhrdynamite invented earlier by A. Nobel... 

In the reversed phase system, buffers are used most often as the mobile phases with small amount of organic modifiers. The use of buffers as the mobile phases has increased the efficiency of the resolution. Ammonium nitrate, triethylammonium acetate (TEAA), and sodium citrate buffers have been used very successfully. A variety of organic modifiers have been used to alter selectivity [2,5,22], Acetonitrile, methanol, ethanol, 2-propanol, and THF have shown good selectivities for various analytes. In the reversed-phase mode, the amount of organic modifiers is typically low, usually of the order of 10-20%. The typical starting composition of the mobile phase is an organic modifier-buffer... 

Gold in titanosilicate TS-1 has been prepared by DP, but the low site density is a key problem with this support for instance, at a pH of 9-10, only 1-3% of the gold in the solution was deposited.163 In order to improve the yield of deposition and avoid the huge loss of gold in solution, TS-1 support was modified by ammonium nitrate to increase fourfold... 

Modifiers are, however, used in a rather indiscriminate way in many laboratories. If used carelessly they can contaminate the sample solution with the element that is being determined and they can actually add to the background interference which one intends to reduce. By carefully optimizing the ashing and atomization temperatures for specific food matrices, as described above, the use of matrix modifiers can be reduced to the cases when they are really necessary. An additional benefit of matrix modification is that the sample and standard matrix are made very similar, this often making the standard addition method unnecessary. How this is carried out is described in detail in most instrument manuals and in specific textbooks. Commonly used modifiers are ammonium nitrate, ammonium phosphate, Mg nitrate, Pd nitrate, and ascorbic acid. 

Cellulose, Microcrystalline, 95 Cellulose, Modified, (SI) 14 Cellulose, Powdered, 96 Centrifuge, Defined, 4 Ceric Ammonium Nitrate TS, 851 Ceric Sulfate, 0.01 N, 856 Ceric Sulfate, 0.1 N, 856 Chamomile Oil, English Type, 98, 578 Chamomile Oil, German Type, 98, 578 Chamomile Oil, Hungarian Type, 98 Changes in Format to the Food Chemicals Codex, Fourth Edition, xv Chemical Formulas and Atomic Weights, 3... 

Chemical Stability, See Stability Chemical Test (or Purity is conducted by Nitrometer Method, originated by Lange but modified by duPont Co. Detailed description of the test is given in Vol 1 of Encycl, under "AMMONIUM NITRATE, Gasometric Method ,... 

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