Metalation acceleration

C. The corrosion of the metal considered may be markedly increased by the contact metal. (Acceleration is likely to occur only when the metal becomes wet hy moisture containing an electrolyte, e.g, salt, acid, combustion products. In ships, acceleration may be expected to occur under in-board conditions, since salinity and condensation are frequently present. Under less severe conditions the acceleration may be slight or negligible.)... 

Salts and complexes of transition metals accelerate hydrocarbon oxidation due to the catalytic decomposition of hydroperoxides to free radicals (see Chapter 10). 

Brisance, Determination by Method of Metal Acceleration by Explosives. Kury et al (Ref 7) developed an accurate hydrodynamic test to measure relative metal accelerating... 

Table 3, p 5 of Ref 7, entitled "Relative Metal Accelerating Ability", presents relative energy delivered to metal in geometries characterized by head-on detonations (A) and in geometries characterized by sideways detonations (B)... 

Ibid, UCRL-7797 (1964) (Description of sphere test) 6) M.L. Wilkins, "The Use of One- and Two-Dimensional Hydrodynamic Machine Calculations in High-Explosive Research", 4thONRSympDeton (1965), pp 519-26 7) J.M. Kury et al, "Metal Acceleration by... 

Cylinder Test for Determination of Metal Acceleration of Explosives of Kury et al is briefly described in this Vol under "Bri-sance, Determination by Method of Acceleration by Explosives ... 

W.H. Anderson noted under "Comments on the paper of J.W. Kury et al, Metal Acceleration by Chemical Explosives ... 

J.W. Kury et al in the paper "Metal Acceleration by Chemical Explosives (Ref 15) stated on p 7 that Wilkins, in his earlier paper (Addnl Ref Oi), was able to describe p-v-E (pressure-sp vol -energy) data obtd when a sphere of explosive expanded an Al shell, by the expression ... 

The relative ability of these ex pis to deliver energy to metal has been confirmed in actual full-scale metal acceleration experiments... 

Brisance, determination by method of metal acceleration by expl 4 D150... 

Sphere Test. A metal acceleration test for measuring the relative performance of expls (Ref 1). Kury et al found the cylinder test to be more versatile (Ref 2)... 

Comparisons were made relative to safety performance and cost with other expl materials. It was concluded that the most favorable features of Teledet are its good safety characteristics, good chemical and thermal stability (for a slurry expl), easy emplacement, and the ability to propagate in small diameters. The features that detract are the metal acceleration capacity which is about 75% that of TNT, the separation of ingredients in low-viscosity Teledet, and the higher cost, relative to other slurry expls Re/s I) C.D. Forrest, Thin Layer Propagating Slurry Explosive , USP 3912560 (1975)... 

The Jones-Wilkins-Lee equation of state has been used to describe accurately the pressure-volume-energy behavior of the detonation products of expls in applications of metal acceleration. The parameters for TNT are available in comparison with other common expls (Ref 141)... 

The metal-accelerated hydrolysis of amino acid esters or amides comprises one of the best investigated types of metal-mediated reaction (Fig. 3-7). One of the reasons for this is the involvement of chelating ligands, which allows chemical characterisation of intermediates and products in favourable cases, and allows detailed mechanistic studies to be made. The reactions have obvious biological relevance and may provide good working models for the role of metals in metalloproteins. 

The potential difference developed between aluminium and stainless steel is about the same as that developed between aluminium and copper. The cathodic reaction is easier on copper oxide than that on the highly protective passive oxide of stainless steels. Then, it is not the difference of potential between anode and cathode which counts, but the facility and rate of every reaction. A bare metal is generally a much better cathode than one covered with an oxide. Aluminium is more active than zinc in the electrochemical series. Practically, zinc protects aluminium which becomes covered with an oxide film.20 All more noble metals accelerate corrosion similarly, except when a surface film (e.g., on lead) acts as a barrier to diffusion of oxygen or when the metal is a poor catalyst for reduction of oxygen. 

The pure metal dissolves very slowly in acids and in alkalis the presence of impurities or contact with platinum or copper, produced by the addition of a few drops of the solutions of the salts of these metals, accelerates the reaction. This explains the solubility of commercial zinc. The latter dissolves readily in dilute hydrochloric acid and in dilute sulphuric acid with the evolution of hydrogen ... 

During the decomposition of Ni-Co mixed oxalates the production of nickel metal accelerates reaction, because the nickel constituent reacts about 60 K lower than cobalt oxalate (Sections 16.4.2. and 16.4.4. above). The significance of the relative yields of metal and oxide in the decompositions of the mixed oxalates Co-Ni Co-Mg and Ni-Mg has been discussed [99],... 

In detonation wave applications, the model has successfully calculated embedded gauge, laser interferometric metal acceleration, failure diameter, corner turning, converging, diverging, and overdriven experiments [57,61-63,67]. Figure 9 shows the measured and... 

Traces of transition metals accelerate also auto-oxidation reactions and the decomposition of LOOH to LOO, LO, and cytotoxic aldehydes [139]. Agents that complex these transition metals decrease their biological effects dramatically [36],... 

Complexes of transition metals accelerate the oxidation of phenols in polar solvents [234], Formation of phenoxy radicals was established by the ESR technique [235—241], Molecular products are produced as a result of the reactions of ArO. The initial steps suggested are... 

One possible explanation for the observed selectivity might be that the interaction of the substrate PCP with the surface of the metal accelerator occurred predominantly via the n-electron system of the aromatic ring so that all the Cl substituents were accessible to the catalyst. The ortho - para directing character of the hydroxyl substituent did not seem to explain the relatively high level of selectivity that was associated with the observed sequential dechlorination process. As an alternative explanation, the removal of bull chlorine substituents from the ring would provide relief of steric strain. The initial loss of Cl from the C-2 or C-6 position (ortho to the hydroxyl and a chlorine substituent) decreased steric strain and repulsion more than the loss of a... 

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