Elongation, determination

It has long been known that the ductility of electroless copper can be increased by annealing at relatively low temperatures, and that the hydrogen content of the deposit decreases upon annealing. The existence of a close correlation between the two annealing effects has been demonstrated [141]. Fig. 24 shows an example of the variation of the ductility (% elongation determined by a mechanical bulge tester)... 

Standard deviation spring constant is defined here as S =F/(Al/lo), where F total force and Al/l is elongation determined on specimens zonule-lens-zonule, after the excision of the ciliary muscles. 

Whereas all of the above theories [54—68] refer in one way or another to the thermally activated breakage of one kind of molecular bonds as primary fracture event, the Bueche-Halpin theory for the tensile strength of gum elastomers [69] employs the idea that the viscoelastic straining of rubber filaments together with the degree of their ultimate elongation determine the kinetics of crack propagation in an elastomeric solid. 

Creep tests are ideally suited for the measurement of long-term polymer properties in aggressive environments. Both the time to failure and the ultimate elongation in such creep tests tend to be reduced. Another test to determine plastic behavior in a corrosive atmosphere is a prestressed creep test in which the specimens are prestressed at different loads, which are lower than the creep load, before the final creep test (11). 

The more quickly and completely a fiber recovers from an imposed strain, the more nearly perfectly elastic it is. The ratio of the instantaneous elastic deformation to the total deformation may be used as a criterion of elasticity (62). The integrated divergences from a theoretical graph of perfect elasticity versus elongation is also used as a criterion for determination of the elasticity index. 

Standard Test Methods for Steel Tire Cord. ASTM standard D2969-92 includes test methods for steel cords that are specifically designed for use in the reinforcement of pneumatic tires. It describes test methods determining steel cord constmction, break strength, elongation at break. 

As an aside, when a large liquid droplet is broken up by shear stress, it tends initially to elongate into a dumbbell shape, which determines the particle size of the two large droplets formed. Then, the neck in the center between the ends of the dumbbell may explode or shatter. This would give a debris of particle sizes which can be quite different than the two major particles produced. 

Tensile strength and elongation at break has been determined by an Instron mechanical analyzer, and the results are as shown in Fig. 10, 11, and 12. 

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