Initiation stages

Melroy O R, Toney M F, Borges G L, Samant M G, Kortright J B, Ross P N and Blum L 1989 An In situ grazing incidence x-ray scattering study of the initial stages of electrochemical growth of lead on silver(111) J. Electroanal. Chem. 258 403-14... 

Batina N, Will T and Kolb D M 1992 Study of the initial stages of copper deposition by in situ STM Faraday Discuss. 94 93-106... 

McFeely F R, Morar J F, Shinn N D, Landgren G and Himpsel F J 1984 Synchrotron photoemission investigation of the initial stages of fluorine attack on Si surfaces relative abundance of fluorosilyl species Phys. Rev. B 30 764-70... 

It is rather slow at moderate temperatures sind the hydrobromic acid formed in the initial stages of the resLCtion inhibits its further progress. By carrying out the reaction at 60-70 or above in the presence of a large excess of water, the inhibition observed at lower temper, atuies does not occur. 

The chemistry of furfuryl alcohol polymerization has received much attention over the years. Several recent reviews have been written (5,6,54). Based on the accumulated data, furfuryl alcohol has to be considered a bifimctional monomer in the initial stage and its "normal" reactions give linear chains or oligomers containing essentially two repeating units (15,16) with (16) predominating. 

The SHAKE method for bond constraints reduces the number of degrees of freedom during the initial stages of simulations it is good for minimizing solvent bath overhead. 

Conventional filtration theory has been challenged a two-phase theory has been appHed to filtration and used to explain the deviations from paraboHc behavior in the initial stages of the filtration process (10). This new theory incorporates the medium as an integral part of the process and shows that the interaction of the cake particles with the medium controls filterabiHty. It defines a cake-septum permeabiHty which then appears in the slope of the conventional plots instead of the cake resistance. This theory, which merely represents a new way of interpreting test data rather than a new method of siting or scaling filters, is not yet accepted by the engineering community. 

Thus, for a successful fluorination process involving elemental fluorine, the number of coUisions must be drasticaUy reduced in the initial stages the rate of fluorination must be slow enough to aUow relaxation processes to occur and a heat sink must be provided to remove the reaction heat. Most direct fluorination reactions with organic compounds are performed at or near room temperature unless reaction rates are so fast that excessive fragmentation, charring, or decomposition occurs and a much lower temperature is desirable. 

Liquid crystalline behavior occurs in the exocuticle of certain classes of beetles. The bright iridescent colors that are reflected from the surface of Scarabaeid beetles originates from a petrified chiral nematic stmctural arrangement of chitin crystaUites in the exocuticle (38). It is suggested that this chiral nematic texture forms spontaneously in a mobile, Hquid crystal phase that is present during the initial stages of the exocuticle growth cycle. 

The partial-oxidation process differs only in the initial stages before the water gas shift converter. Because it is a noncatalyzed process, desulfurization can be carried out further downstream. The proportions of a mixture of heavy oil or coal, etc, O2, and steam, at very high temperature, are so adjusted that the exit gases contain a substantial proportion of H2 and carbon monoxide. 

The thiophthalimide (CTP) and sulfenamide classes of retarders differ from the organic acid types by thek abiUty to retard scorch (onset of vulcanization) without significantly affecting cure rate or performance properties. Much has been pubUshed on the mechanism of CTP retardation. It functions particularly well with sulfenamide-accelerated diene polymers, typically those used in the the industry. During the initial stages of vulcanization, sulfenamides decompose to form mercaptobenzothiazole (MBT) and an amine. The MBT formed reacts with additional sulfenamide to complete the vulcanization process. If the MBT initially formed is removed as soon as it forms, vulcanization does not occur. It is the role of CTP to remove MBT as it forms. The retardation effect is linear with CTP concentration and allows for excellent control of scorch behavior. 

The manufacture of silver nitrate for the preparation of photographic emulsions requires silver of very high purity. At the Eastman Kodak Company, the principal U.S. producer of silver nitrate, 99.95% pure silver bars are dissolved in 67% nitric acid in three tanks coimected in parallel. Excess nitric acid is removed from the resulting solution, which contains 60—65% silver nitrate, and the solution is filtered. This solution is evaporated until its silver nitrate concentration is 84%. It is then cooled to prepare the first crop of crystals. The mother Hquor is purified by the addition of silver oxide and returned to the initial stages of the process. The cmde silver nitrate is centrifuged and recrystallized from hot, demineralized water. Equipment used in this process is made of ANSI 310 stainless steel (16). 

In the initial stage of carbonization, it is critical to control the off-gases that evolve from the fiber as it is heated. Excessive heating rates result in void formation, stmctural dismption, and lower carbon fiber properties. 

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