Winchester mechanism

Critical Phenomena in Dusty Plasma Kinetics Nucleation of Nanoparticles, Winchester Mechanism, and Growth of First Generation of Negative Ion Clusters... 

After initial SiH formation, the main pathway of cluster growth is the chain of ion-molecular processes, called the Winchester mechanism (Section2.2.6), and is based on the thermodynamic advantage of the ion-cluster growth (2-64) (Aj" ... 

The Winchester mechanism (10-7)-(10-ll) of methane conversion into lydrogenwith growth of the carbon cluster (Section 2.2.6) can be interpreted as a chain reaction with multiple uses of a positive ion. Decrease of the ionization potentials in the seqnence Cn 2n+ makes chain propagation (10-9) exothermic (Winchester mechanism) and fast becanse the ion-molecular reactions have no significant activation barriers. Additional information regarding the kinetics of ion-molecttlar reactions in methane and its derivatives can be found, in particular, in Hamlet and Moss (1969) Davis and Libby (1966) Sheridan, Greer, and Libby (1972) Olah and Schlosberg (1968) Adams and Babcock (2001) and Harioka and Kebarle (1976, 1977). 

The rheology of lubricated polytetrafluoroethylene compositions was studied by Lewis and Winchester. The mechanism appeared to be a combination of permanent and elastic deformations in the region just before the orifice of the die in the extruder. As a result of permanent deformation, the polymer particles are partially transformed into long fibers. The relative amounts of permanent and recoverable deformation were related to the rate and temperature of extrusion and the geometry of the extruder. Plastic deformation is favored by extruding at temperatures above the 19 and 30° transitions (Snelling and Lontz). 

---